Grunsfeld Credit - www.spacefacts.de

Personal: Male, Married, Two children. Born in Chicago, Illinois, USA. PhD

Astronaut Career

Astronaut Group: NASA Group 14 - 1992. Active Entered space service: 31 March 1992. Number of Flights: 4.00. Total Time: 45.73 days. Number of EVAs: 5.00. Total EVA Time: 1.56 days.

NAME: John M. Grunsfeld (Ph.D.)

NASA Astronaut

PERSONAL DATA:

Born October 10, 1958, in Chicago, Illinois. Married to the former Carol E. Schiff. They have one child. He enjoys mountaineering, flying, sailing, bicycling, music. His parents, Ernest and Sally Grunsfeld, reside in Highland Park, Illinois. Her parents, David and Ruth Schiff, reside in Highland Park, Illinois.

EDUCATION:

Graduated from Highland Park High School, Highland Park, Illinois, in 1976; received a bachelor of science degree in physics from the Massachusetts Institute of Technology in 1980; a master of science degree and a doctor of philosophy degree in physics from the University of Chicago in 1984 and 1988, respectively.

ORGANIZATIONS:

American Astronomical Society.

SPECIAL HONORS:

W.D. Grainger Fellow in Experimental Physics, 1988-89. NASA Graduate Student Research Fellow, 1985-87. NASA Space Flight Medals (1995, 1997).

EXPERIENCE:

Dr. Grunsfeld's academic positions include that of Visiting Scientist, University of Tokyo/Institute of Space and Astronautical Science (1980-81); Graduate Research Assistant, University of Chicago (1981-85); NASA Graduate Student Fellow, University of Chicago (1985-87); W.D. Grainger Postdoctoral Fellow in Experimental Physics, University of Chicago (1988-89); and Senior Research Fellow, California Institute of Technology (1989-92). Dr. Grunsfeld's research has covered x-ray and gamma-ray astronomy, high energy cosmic ray studies, and development of new detectors and instrumentation. Dr. Grunsfeld studies binary pulsars and energetic x-ray and gamma-ray sources using the NASA Compton Gamma Ray Observatory, x-ray astronomy satellites, radio telescopes, and optical telescopes.

NASA EXPERIENCE:

Dr. Grunsfeld was selected by NASA in March 1992, and reported to the Johnson Space Center in August 1992. He completed one year of training and is qualified for selection as a mission specialist on Space Shuttle flight crews. Dr. Grunsfeld was initially detailed to the Astronaut Office Mission Development Branch. Following his first flight, Dr. Grunsfeld led a team of engineers and computer programmers tasked with defining and producing the crew displays for command and control of the International Space Station (ISS). As part of this activity he directed an effort combining the resources of the Mission Control Center (MCC) Display Team and the Space Station Training Facility. The result was the creation of the Common Display Development Facility (CDDF), responsible for the onboard and MCC displays for the ISS, using object-oriented programming techniques. A veteran of two space flights (STS-67 in 1995 and STS-81 in 1997), Dr. Grunsfeld has logged over 644 hours in space

The STS-67 Astro-2 mission, March 2-18,1995, was the second flight of the Astro observatory, a unique complement of three telescopes. During this record-setting 16-day mission, the crew conducted observations around the clock to study the far ultraviolet spectra of faint astronomical objects and the polarization of ultraviolet light coming from hot stars and distant galaxies. Mission duration was 399 hours and 9 minutes.

STS-81 (January 12-22, 1997) was a ten-day mission, the fifth to dock with Russia's Space Station Mir, and the second to exchange U.S. astronauts. The mission also carried the Spacehab double module providing additional middeck locker space for secondary experiments. In five days of docked operations more than three tons of food, water, experiment equipment and samples were moved back and forth between the two spacecraft. Following 160 orbits of the Earth the STS-81 mission concluded with a landing on Kennedy Space Center's Runway 33 ending a 3.9 million mile journey. Mission duration was 244 hours, 56 minutes.

• 2 March 1995 Flight: STS-67. Flight Up: STS-67. Flight Back: STS-67. Flight Time: 16.63 days.

• 12 January 1997 Flight: STS-81. Flight Up: STS-81. Flight Back: STS-81. Flight Time: 10.21 days.

• 20 December 1999 Flight: STS-103. Flight Up: STS-103. Flight Back: STS-103. Flight Time: 7.97 days.

• 1 March 2002 Flight: STS-109. Flight Up: STS-109. Flight Back: STS-109. Flight Time: 10.92 days.

5 December 1992 - NASA Astronaut Training Group 14 selected.. The group was selected to provide pilot, engineer, and scientist astronauts for space shuttle flights.. Qualifications: Pilots: Bachelor's degree in engineering, biological science, physical science or mathematics. Advanced degree desirable. At least 1,000 flight-hours of pilot-in-command time. Flight test experience desirable. Excellent health. Vision minimum 20/50 uncorrected, correctable to 20/20 vision; maximum sitting blood pressure 140/90. Height between 163 and 193 cm.

Mission Specialists: Bachelor's degree in engineering, biological science, physical science or mathematics and minimum three years of related experience or an advanced degree. Vision minimum 20/150 uncorrected, correctable to 20/20. Maximum sitting blood pressure of 140/90. Height between 150 and 193 cm.. Four pilots and 15 mission specialists, nine civilians and ten military. Chosen from 2054 applicants, 87 of which screened in December 1991/January 1992. Five additional international astronauts.

Under clear and starry skies at the Kennedy Space Center, Discovery lifted off on time at 6:50 p.m. Central time, lighting up the Central Florida coastline, to send Commander Curt Brown, Pilot Scott Kelly, and Mission Specialists Steve Smith, Jean-Francois Clervoy, John Grunsfeld, Mike Foale and Claude Nicollier on a two-day chase to catch up to and retrieve the 12 and a half ton telescope. Hubble was sailing over Eastern Africa at the time of launch.

Eight and a half minutes after the third and final shuttle launch of the year, Discovery was in orbit as its crew members began to configure shuttle systems for the planned 8-day mission. One rendezvous burn of the reaction control system jets is planned before the crew goes to sleep early Monday to fine tune Discovery's path to catch up to Hubble.

Technically, Hubble has been in hibernation since the loss of a fourth gyroscope on November 13 designed to enable the telescope to point precisely at distant astronomical targets for scientific observations. Hubble is in what is known as "safe mode", a state of dormancy in which the telescope aims itself constantly at the sun to provide electrical power to its systems. Hubble is scheduled to be captured by Discovery's robot arm around 6:40 p.m. Central time Tuesday.

Once the crew retrieves Hubble, it will be parked at the rear of Discovery's cargo bay so that two teams of space-walking astronauts can perform repairs and upgrades to its systems during three nights of space walks. The most vital of the space walks will occur on Wednesday night, when Smith and Grunsfeld replace all six of Hubble's gyroscopes and install devices to improve voltage regulation to the telescope's systems. Only three space walks are planned because the mission was shortened. Smith and Grunsfeld will conduct the first and third space walks, while the second will be conducted by Foale and Nicollier.

If all goes as planned, Hubble will be released back into orbit on Christmas Day around 5 p.m. Central time, with landing planned on Dec. 27 at 4:24 p.m.. Central time at the Kennedy Space Center.

The astronauts are scheduled to begin an eight-hour sleep period at 1:50 a.m. Central time Monday and will be awakened at 9:50 a.m. Central time to begin their first full day in orbit.

Discovery is orbiting the Earth at an altitude of about 300 nautical miles, completing one orbit of the Earth every 90 minutes.

• Bay 1-2: External airlock/ODS
• Bay 7-8: ORU Carrier (Spacelab pallet). Carried Hubble replacement spares arranged as follows: COPE protective enclosure with three RSU gyros, a new solid state recorder, and an S-band transmitter; LOPE enclosure with an HST-486 computer and voltage improvement kit; ASIPE enclosure with a spare HST-486 and spare RSU; FSIPE enclosure with a replacement FGS-2 fine guidance sensor; and NPE enclosure with New Outer Blanket Layer insulation.
• Bay 11: Flight Servicing System (FSS). Contained the BAPS (Berthing and Positioning System) used to dock with the aft end of the Hubble Space Telescope.
• Bay 8: APC carrier with foot restraint
• Bay 12: APC carrier with HST foot retstraint

Today will be a day of preparation for the crew, gearing up for the rendezvous and capture of HST planned for Tuesday and the three maintenance spacewalks that will follow later in the week. At about 1 p.m., European Space Agency astronaut Jean-Francois Clervoy will power up Discovery's robotic arm to check its operation. Clervoy will survey Discovery's cargo bay using television cameras on the arm, checking the condition of the equipment planned for installation on the telescope and the cradle that will hold HST during the spacewalks. While Clervoy operates the arm, Payload Commander Steve Smith and Mission Specialist John Grunsfeld will power up the payload bay HST support equipment. Later, around 6 p.m., Commander Curt Brown and Pilot Scott Kelly will check out the laptop computers, navigation aids and flight controls in Discovery's cockpit that will be used for tomorrow's encounter with HST.

Meanwhile, on Discovery's middeck, Grunsfeld, along with European astronaut Claude Nicollier, will begin a check of the four spacesuits onboard. Early in the afternoon, about 1 p.m., the crew will lower the cabin pressure aboard Discovery as part of the spacewalk preparations. This reduces the amount of time the spacewalkers must breathe oxygen as part of a standard protocol to purge nitrogen from the body prior to beginning a spacewalk.

At 8:35 p.m. CST, Brown, Smith, Clervoy and Mike Foale will take a break from their work to talk with CBS news and other television networks about their mission.

As some of their final activities today, the crew will fire Discovery's large orbital maneuvering system engines at 10:32 p.m. to slow the rate at which the Shuttle is closing on HST. A second, smaller engine firing will follow at 11:27 p.m. to further fine tune the Shuttle's approach toward Hubble. Capture of the telescope remains scheduled for 6:41 p.m. Tuesday.

Discovery is in excellent condition, orbiting Earth every 95 minutes, 27 seconds. The high point of Discovery's orbit is 363 statute miles and the low point is 298 statute miles.

Controllers at Goddard Space Flight Center had placed the space telescope in an attitude with its closed aperture pointed toward Earth. Commander Curt Brown guided Discovery through an approach from below and fly-around. Then, Mission Specialist Jean-Francois Clervoy reached out with the shuttle's robotic arm to grip a grapple fixture on Hubble. The grapple was made at 6:34 p.m. Central time, one day, 23 hours and 44 minutes after Discovery's launch from the Kennedy Space Center in Florida.

Clervoy used the arm to rotate the space telescope and bring its base into the cargo bay. Hubble, gleaming silver in its Mylar insulation flanked by golden-colored solar arrays, was firmly attached to the Flight Support System in Discovery's cargo by a little after 7:30 p.m. Hubble is as tall as a four-story building. With a maximum diameter of 14 feet, it is about the size of a railroad tank car.

The Flight Support System is a U-shaped device with a circular platform between the U's arms now supporting the space telescope. The system provides power from Discovery to the telescope and can rotate and tilt it to facilitate access to its various compartments by space-walking astronauts. An initial, carefully choreographed survey using a camera at the end of the robotic arm was made. Camera surveys of Hubble's condition will continue during the crew's sleep period, scheduled to begin about 12:50 a.m. Wednesday.

The first of three planned space walks to repair and upgrade Hubble equipment is scheduled to begin at 1:40 p.m. Wednesday, though astronauts may get an early start. If they can get ahead of schedule, they may be able to perform some tasks that had been scheduled for the cancelled fourth spacewalk.

On Wednesday, Mission Specialist and Payload Commander Steve Smith and Mission Specialist John Grunsfeld will first replace the telescope's three Rate Sensor Units. Each contains two gyroscopes. The second major task is installation of six Voltage/Temperature Improvement Kits between Hubble's solar panels and its six 10-year-old batteries. The cell telephone-sized kits are designed to prevent any overheating or overcharging of those batteries.

Discovery's systems continue to function well as the astronauts wind up final preparations for Wednesday's space walks and prepare for sleep. The spacecraft was in an orbit with a high point of 380 statute miles and a low point of 355 miles.

Astronauts Steve Smith and John Grunsfeld are scheduled to begin the first of three planned maintenance spacewalks today at about 1:40 p.m. The crew was awakened this morning to the song "Hucklebuck" performed by Beau Jocque and the Zydeco Hi-Rollers, a tune that the spacewalkers heard many times while training hundreds of hours for the mission in the 6.5-million gallon water tank at the Johnson Space Center in Houston.

Although not scheduled to begin until 1:40 p.m., Smith and Grunsfeld could begin the planned six-hour spacewalk earlier if they complete preparations ahead of schedule. Once outside Discovery's cabin, the first task they will perform will be to replace the telescope's three Rate Sensor Units, each of which contains two gyroscopes. Of the six gyroscopes currently installed in Hubble, four have failed. At least three operable gyroscopes are needed to point the telescope with the accuracy required to track its astronomical targets.

After the rate sensor units have been installed, the two spacewalkers will then open valves on the telescope's Near Infrared Camera and Multi-Object Spectrometer to purge nitrogen coolant from that instrument in preparation for its servicing on the next Shuttle maintenance mission. Next, they will install six Voltage/Temperature Improvement Kits for the Hubble's batteries that will increase the batteries' efficiency and reduce a potential for them to overcharge and overheat. If those tasks are completed and the spacewalkers have extra time, they may perform some additional small jobs such as installing handrail covers and inspecting brackets.

While Smith and Grunsfeld are outside, inside the cabin European astronaut Jean-Francois Clervoy will control Discovery's robotic arm, maneuvering the spacewalkers into position to work on the telescope. Discovery's other spacewalking team, astronaut Mike Foale and European astronaut Claude Nicollier, also will assist from inside the cabin. Foale and Nicollier are scheduled to perform the mission's second spacewalk tomorrow. Smith and Grunsfeld are planned to again venture outside on Friday for the flight's third and final spacewalk.

Discovery remains in near-perfect condition with no mechanical problems of concern to flight controllers, as has been the case since its launch on Sunday. It is orbiting at an altitude of 380 by 365 statute miles.

Working deliberately, Smith and Grunsfeld replaced three Rate Sensor Units, each containing two gyroscopes. Four of Hubble's gyroscopes had failed, making the telescope unable to point itself precisely enough to do science since Nov. 13. At least three operable gyroscopes are needed to point the telescope with the accuracy required to track its astronomical targets.

The spacewalkers also installed Voltage/Temperature Improvement Kits on wiring from Hubble's solar arrays to each of its six batteries. The kits are designed to improve control of the charging of the space telescope's 10-year-old batteries.

With Hubble latched upright in the payload bay, Smith and Grunsfeld completed all major tasks scheduled for the first of three spacewalks on three consecutive days. A few minor objectives, including applying lubricant to the door of one of the telescope's bays and taking close-up photos of the Voltage/Temperature Improvement Kits, were left undone. Flight and telescope controllers decided to cancel the photography job and schedule the 10-minute lubrication job for Thursday's space walk. The duration of the spacewalk was second only to the 8 hour, 29 minute space walk from Endeavour on STS-49 in May 1992.

A few minor problems helped account for the length of the space walk. One of the old gyroscope-containing Rate Sensor Units was a tight fit in the box designed to protect it on its return to Earth, though eventually it was placed inside and the lid closed. Another involved opening valves and removing caps on the Near Infrared Camera and Multi-Object Spectrometer, in preparation for restoring it to operation during the next Hubble Servicing mission. That task too eventually was completed.

All in all flight and telescope controllers were delighted with the accomplishments of the day.

Major tasks on Thursday's space walk by Michael Foale and Claude Nicollier include replacement of Hubble's outmoded DF-224 computer with a more modern unit 20 times faster and with six times the memory. They also will replace one of Hubble's three fine guidance sensors, used to precisely point the telescope and gather scientific data. The astronauts also may perform "get-ahead tasks," some first scheduled for a fourth space walk. That space walk was cancelled because of delays in Discovery's launch. Discovery remains in excellent condition, in an orbit with a high point of 380 statute miles and a low point of 369 miles.

The primary goal of today's spacewalk, to be conducted by Mike Foale and European Space Agency astronaut Claude Nicollier, is to install a new computer to replace the one currently in use by Hubble. The new computer is 20 times faster and has six times the memory of the outdated unit being replaced. Nicollier and Foale also will change out one of Hubble's three Fine Guidance Sensors that are used to precisely point the telescope as it conducts scientific observations. The unit being installed today is a refurbished unit that was removed and returned to Earth by the STS-82 crew during its servicing of the telescope in February 1997. If time permits, the space walkers also may perform some optional "get ahead" tasks. Foale has conducted two previous spacewalks, during the STS-63 mission in February 1995 and again in September 1997 as he and Mir Space Station Commander Anatoly Solovyev conducted a six-hour survey of the Mir. This is Nicollier's first spacewalk.

Today's spacewalk is scheduled to begin at 1:50 p.m., but could begin earlier if the crew members complete their preparations ahead of schedule. During the spacewalk, Foale can be recognized by the broken red stripes on the legs of his EVA suit, and Nicollier by the diagonally broken red stripes on his suit.

Discovery's astronauts also supported a functional test of the voltage temperature improvement kits - referred to as VIKs - installed by Steve Smith and John Grunsfeld during their spacewalk yesterday. To ensure the checkout is complete prior to the start of today's scheduled EVA, the astronauts began the work shortly after crew wake-up. During the 90-minute long checkout, investigators will monitor the performance of the voltage kits as the telescope's batteries are charged.

This morning's wake-up music honored the two space-walking astronauts, Nicollier and Foale. Traditional Swiss music was played for Nicollier and the song "Only When I Sleep" by The Corrs was played for Foale.

Discovery remains in excellent condition, in an orbit with a high point of 380 statute miles and a low point of 369 miles.

Flight controllers said all major activities of the space walk, the second of three on consecutive days of Discovery's space telescope repair and improvement mission, had been accomplished. Controllers reported that power was reaching both of the new pieces of equipment.

"The brains of Hubble have been replaced," said Mission Specialist John Grunsfeld, who worked Thursday in Discovery's cabin with the space-walking crew members outside. About 30 minutes later Hubble began thinking with those new brains. At an evening mission status briefing, John Campbell, Hubble Space Telescope program manager, said the functional checkout of the new computer showed it was functioning well. Checkout of the Fine Guidance Sensor, is continuing.

The length of Thursday's space walk made it the third longest in history, behind only the 8-hour, 15-minute effort on Wednesday by Payload Commander Steve Smith and Grunsfeld and an 8-hour, 29-minute space walk by three Endeavor astronauts on STS-49 on its Intelsat rescue mission in May 1992.

Replacement of one of Hubble's two S-band transmitters is a highlight of Friday's space walk by Smith and Grunsfeld. The transmitter to be replaced had failed. The second transmitter was able to carry the load alone, so no science was lost. The transmitters are considered very reliable, and unlike most of the equipment aboard Hubble, they were not designed to be changed out in orbit. Special tools were developed to enable astronauts to do the job more easily. Installation of a Solid State Recorder to replace a less reliable and less capable 10-year-old recorder is the second major item on the schedule.

Also on the timeline of the space walk, scheduled to begin at 1:50 p.m. CST, is installation of new insulation on equipment bay doors. The spacewalk could, like its two predecessors on STS-103, begin earlier if the crew completes preparations early. Flight controllers are anxious to end this third space walk at 8 p.m. as scheduled.

Discovery remains is in excellent condition, in an orbit with a high point of 380 statute miles and a low point of 364 miles.

Astronauts Steve Smith and John Grunsfeld on Friday installed a transmitter that sends scientific data from Hubble to the ground. The transmitter replaced one that failed in 1998. A second transmitter had successfully carried the load without any disruption to Hubble scientific operations. Since the transmitters are considered very reliable, they were not designed to be replaced in orbit and special tools were developed to make the job easier.

Smith and Grunsfeld also installed a solid state digital recorder, replacing an older mechanical reel-to-reel recorder version. The digital Solid State Recorder provides more than 10 times the storage capacity of the old unit. They also applied new insulation on two equipment bay doors.

Both the transmitter and the recorder checked out normally on early tests by telescope controllers.

Two previous space walks on Wednesday and Thursday had completed the highest priority tasks of the mission. Those tasks included installation of six new gyroscopes and six Voltage/Temperature Improvement Kits, giving Hubble a new computer 20 times faster and with six times the memory of the old computer, and replacement of one of Hubble's three Fine Guidance Sensors.

Friday's space walk lasted 8 hours and 8 minutes, ending at 9:25 p.m., making it the fourth longest in history. Part of the reason for the length of the space walk was difficulty in hooking Grunsfeld's suit up to orbiter power after he had returned to Discovery's airlock. Friday's space walk brings the total time of STS-103 extravehicular activity to 24 hours, 33 minutes. This mission's three space walks bring the total amount of time spent servicing Hubble to 93 hours, 13 minutes. Space Shuttle Program space walks now total 317 hours, 3 minutes. And Steve Smith now is the astronaut with the second longest combined space walk time, with 35 hours, 33 minutes behind only Jerry Ross, with 44 hours, 11 minutes.

Discovery is in an orbit with a high point of 380 miles and a low point of 363 miles. All of the orbiter's systems continued to function normally.

Today's planned 7 ½ hour-long space walk will see Smith and Grunsfeld install a transmitter that relays Hubble's scientific data from the telescope to the ground and an upgraded digital recorder replacing an older mechanical version.

The transmitter to be installed today replaces one that failed in 1998. Since that time, the second on-board transmitter has successfully carried the load without any disruption to Hubble operations. The transmitters are considered very reliable, and unlike most of the equipment aboard Hubble, were not designed to be changed out in orbit. Special tools were developed to enable astronauts to do the job more easily.

The digital Solid State Recorder being installed on the telescope will replace an older mechanical model and provide more than 10 times the storage capacity. Smith and Grunsfeld also will apply some new insulation on equipment bay doors to minimize any degradation of the telescope's protective thermal coverings.

The space walk currently is scheduled to being at 1:20 p.m. Central Time and is expected to last about 7 ½ hours.

Mission Control awakened the crew at 8:50 a.m. today to the sounds of Steppenwolf's "Magic Carpet Ride" played for Smith and the children's song "Skinnamarink" by Kimbo for Grunsfeld. Discovery remains in excellent condition, in an orbit with a high point of 380 statute miles and a low point of 364 miles.

"Merry Christmas to all of you down there," replied Brown. "And Hubble will be home for Christmas 'cause today we're going to set her free."

Discovery's astronauts will be doing the gift-giving this afternoon as they return the Hubble Space Telescope to orbit, allowing it to continue its astronomical observations. About 1:45 p.m. CST, European Space Agency astronaut Jean-Francois Clervoy will use Discovery's robot arm to firmly grasp the telescope. After a series of commands to disconnect from external power and confirm Hubble is ready for release, Clervoy will gently lift it out of the support structure in Discovery's payload bay where it has rested since he first plucked it from orbit on December 21. The telescope's aperture door will be commanded open and at 4:50 p.m., Clervoy will release the upgraded telescope.

Hubble's capabilities were enhanced over the course of three spacewalks, lasting a combined total of 24 hours, 33 minutes. Spacewalking astronauts Steve Smith, John Grunsfeld, Mike Foale and Claude Nicollier installed six new gyroscopes, six Voltage/Temperature Improvement Kits, a new more efficient computer, and a refurbished Fine Guidance Sensor. Functional checks and tests of the hardware indicate that the new equipment is working properly and will further enhance the Hubble's scientific capabilities.

This afternoon, the spacewalking team, including arm operator Clervoy, will take a break from their duties to discuss the progress of the mission so far in a series of interviews with CNN, the Associated Press and the Fox News Network. That interview is scheduled for 7:12 p.m. today.

Discovery is in an orbit with a high point of 380 miles and a low point of 363 miles with all systems on board performing well.

European Space Agency Astronaut Jean-Francois Clervoy used the shuttle's robot arm to gently release the telescope at 5:03 p.m. CST, then placed the arm into an upright salute as Commander Curt Brown fired Discovery's steering jets to begin separating from the telescope.

The telescope's re-deployment took place at an altitude of 370 statute miles as the two spacecraft flew over the South Pacific's Coral Sea northeast of Australia, its aperture door opened to the heavens before the release.

By 5:30 p.m. CST, controllers at the Space Telescope Operations Control Center in Maryland were reporting that the telescope was in normal operating mode. Controllers will perform two weeks of testing before resuming observations with the telescope.

"The HST is now orbiting freely once again and is in fantastic shape," Hubble Space Telescope Program Manager John Campbell said after the release. "The spacecraft is being guided by its new gyros, under the control of its brand new computer. The Hubble team is very grateful to the Discovery crew, to the launch and flight teams and to all those who made this mission so successful. We especially thank the families of the entire STS-103 team, who made so many personal sacrifices at this holiday season, enabling the Hubble Space Telescope to resume its voyage of discovery."

At 5:39 p.m. CST, Brown executed a second steering jet burn, lowering Discovery's orbit slightly, so that it would begin orbiting faster than the telescope and move away at just under 6 statute miles per orbit. Afterward, each of the seven astronauts on board called down holiday wishes from space in several languages.

"The familiar Christmas story reminds us that for millennia, people of many faiths and cultures have looked to the skies and studied the stars and planets in their search for a deeper understanding of life and for greater wisdom," radioed Brown. "We, the Discovery crew and this mission to the Hubble Space Telescope, are very proud to be part of this ongoing search beyond ourselves. We hope and trust that the lessons the universe has to teach us will speak to the yearning that we know is in human hearts everywhere -- the yearning for peace on Earth, good will among all the human family. As we stand at the threshold of a new millennium, we send you all our greetings."

Over the course of three space walks, Astronauts Steve Smith, John Grunsfeld, Mike Foale and Claude Nicollier installed six new gyroscopes, six Voltage/Temperature Improvement Kits, a new more efficient computer, and a refurbished Fine Guidance Sensor. Functional checks and tests of the hardware indicate that the new equipment is working well.

The space-walking team, including arm operator Clervoy, also took a break from their duties to discuss the progress of the mission so far in a series of interviews with CNN, the Associated Press and the Fox News Network.

The crew is scheduled to go to bed just before midnight Central time and wake up at 7:50 a.m. Sunday to begin a day of preparations for Monday's landing. Discovery is in a 363 by 380 statute mile orbit with all systems on board performing well.

After waving off the first landing opportunity of the day because of a concern with cross winds at the landing site, the crew was given a "go" to perform the deorbit burn which came at 4:48 p.m. CST and caused Discovery to fall out of its 380 statute mile high orbit to start the journey home to the Kennedy Space Center.

With Commander Curt Brown at the controls, Discovery touched down at 6:01 p.m CST on Runway 33 at the three mile long Shuttle Landing Facility runway at KSC to complete a mission spanning almost 3.3 million miles. Pilot Scott Kelly, Flight Engineer Jean-Francois Clervoy and Mission Specialist Michael Foale joined Brown on the flight deck for entry and landing. Mission Specialists Steve Smith, John Grunsfeld and Claude Nicollier were seated down in the middeck. The end of the STS-103 mission marked the 20th consecutive landing at the Florida spaceport and the 13th night landing in the history of the Shuttle program.

Left behind in orbit, the Hubble Space Telescope now features six new gyroscopes, six new voltage/temperature improvement kits, a new onboard computer, a new solid state recorder and new data transmitter, a new fine guidance sensor along with new insulation on parts of the orbiting telescope.

The STS-103 crew will spend the evening in Florida before returning to Houston on Tuesday. The crew is expected to leave Patrick Air Force Base in Cocoa Beach, FL at approximately 1:30 p.m. CST. The crew should land at Ellington Field at about 5 p.m. where the seven astronauts will be greeted by JSC management and center employees. The crew return ceremony will occur at Hangar 990 and is open to the general public.

In the course of five spacewalks, the crew installed new equipment on HST. This was the first flight of Columbia since the launch of Chandra in 1999 following refurbishment. In the first two spacewalks, two new solar arrays were installed, and the two old arrays stowed on the RAC carrier. The RWA-1R reaction wheel assembly on the MULE carrier replaced the faltering RWA-1 in the telescope. The third spacewalk was the most difficult, as HST was entirely powered down while astronauts replaced its power controller unit, not designed for on-orbit replacement. On the fourth spacewalk the astronauts removed the European FOC camera, aboard HST since launch in 1990, and replaced it with the new ACS (Advanced Camera for Surveys). They also installed the CASH wire harness, part of the aft shroud cooling system. On the final spacewalk, the astronauts installed the NCS (NICMOS cooling system) cryocooler in the aft shround and the associated NCS radiator on the telescope's exterior. The NICMOS infrared camera had been idle since its original thermal control system failed. With the removal of FOC, the COSTAR device (which deployed contact lenses for the original instruments) became obsolete, since the newer instruments made the corrections to the incorrect HST mirror internally. Cargo manifest:

• Middeck:4 EMU spacesuits - 480 kg
• Bay 4: RAC (Rigid Array Carrier) - 2393 kg. The RAC carried the two folded SA-III rigid solar arrays which replaced the SA-II roll-up arrays. It calso carried the DBA2 diode box assembly which controlled the arrays, and a wire harness and containers associated with the NICMOS cooling system.
• Bay 7-8: SAC (Second Axial Carrier) - 2517 kg. The SAC was a specially designed pallet that flew on the first two Hubble SM flights, STS-61 and STS-82. On this flight it carried the ACS camera up (and the FOS camera down) as well as the NCS cryocooler, the PCU-R power controller, the CASH wire harness, and the thermal covers used in the PCU replacement.
• Bay 11: FSS (Flight Support System) - 2111 kg. The FSS first flew on STS 41-C (the Solar Max Repair) and was reused for each of the HST SM flights. It carried the BAPS Berthing and Positioning System, which was the docking ring for HST. Stowed on the FSS were a support post for BAPS and a cover for the HST low gain antenna.
• Bay 12: MULE (Multi-Use Lightweight Equipment Carrier) - 1409 kg. The MULE carried the NCS radiator, the NCS electronics support module, and the RWA-1R reaction wheel unit. MULE first flew on STS-48 carrying the UARS satellite, and then on STS-95 carrying the HOST payload which tested out the NCS.
• Sill: RMS arm No 201 - 410 kg

Commander Scott Altman, Pilot Duane Carey, Flight Engineer Nancy Currie and spacewalkers John Grunsfeld, Rick Linnehan, Jim Newman and Mike Massimino blasted off of Launch Pad 39-A at the Kennedy Space Center at 5:22 a.m. Central time as Hubble orbited just west of Sarasota, Florida at an altitude of about 360 miles. Because of its brightness and elevation, the telescope was visible in the pre-dawn sky over the launch site as Columbia began its pursuit.

Less than nine minutes later, the pioneer shuttle was in orbit for the first time since July 1999, following an extensive modification period in which many of its systems were replaced and enhanced.

Columbia began a two-day chase to reach Hubble for its fourth service call, in which the observatory's solar arrays, main power switching unit, and a gyroscopic pointing mechanism will be replaced by newer components. In addition, the spacewalkers will also install a new scientific instrument ten times more powerful than the Hubble's Wide Field Planetary Camera to survey the universe and will attempt to restore an infrared instrument through the installation of a cooling system and an external radiator.

If all goes as planned, Currie will use Columbia's robot arm to grapple Hubble shortly after 3 a.m. CST on Sunday, setting the stage for five consecutive days of servicing spacewalks beginning early Monday morning.

Columbia's crew will spend the next few hours unpacking equipment, setting up computers and conducting the first of periodic engine firings that will occur over the next two days to refine the shuttle's approach to Hubble. The shuttle crew will begin its first sleep period at 12:22 p.m. CST and will be awakened at 8:22 p.m. this evening to begin its first full day in orbit, designed to test the ship's robot arm, spacesuits and rendezvous equipment which will be used over the next few days.

Commander Scott Altman, Pilot Duane Carey, Flight Engineer Nancy Currie and spacewalkers John Grunsfeld, Rick Linnehan, Jim Newman and Mike Massimino are beginning a complex mission to replace and upgrade key systems in the Hubble Space Telescope - a job that requires five back-to-back spacewalks, each more than six and a half hours long.

Mission managers met Friday evening to review information about the performance of the port side freon cooling system in Columbia's payload bay, which exhibited a degraded flow rate shortly after launch. They gave Columbia's crew a "go" to proceed with normal operations today and expressed confidence the shuttle will be allowed to complete its full mission. However, shuttle managers will meet again at midday Saturday for a further review of the potential cooling system problem and they are expected to reach a final conclusion at that time on proceeding with a Sunday capture of Hubble and the ensuing spacewalks. The degraded cooling system is one of two such systems aboard Columbia. The other system is operating perfectly. Only one of the systems is needed to provide cooling for the shuttle's electronics, but the concerns are whether the degraded cooling system can be used as a backup in the event the fully operational system were to experience unexpected problems. Although the one system is operating at a lower capacity, the problem has had no impact on any of the crew's activities and is not noticeable by the crew. Altman and Carey are getting ready to fire Columbia's reaction control system thrusters to fine-tune its approach to Hubble at 11:10 p.m. CST. Also tonight, the crew will test Columbia's robotic arm, examine the spacesuits on board, check out rendezvous equipment, and prepare the Flight Support System that will hold the telescope while it is berthed in the orbiter's payload bay.

Currie is scheduled to use Columbia's robot arm to grapple Hubble shortly after 3 a.m. CST Sunday, setting the stage for the first spacewalk early Monday morning.

During Hubble's fourth service mission, the crew of Columbia will spend five days replacing the observatory's solar arrays, its main power switching unit, and a gyroscopic pointing mechanism called a Reaction Wheel Assembly. In addition, the spacewalkers will install a new camera called the Advanced Camera for Surveys that can view twice the area of the sky as Hubble's current camera. The spacewalkers will install a cooling system and an external radiator for the Near Infrared Camera and Multi-Object Spectrometer, which requires very cold temperatures to function.

Columbia is in a 356 by 127 statute mile orbit of the Earth, catching up to Hubble about 1,000 miles every orbit.

There are two freon cooling loops that are part of the shuttle's active thermal control system, one on the port and one on the starboard side of the payload bay. Freon loop 1 on the port side is showing a degraded flow rate.

While low, the flow rate is slightly above flight rule limits. Mission managers are currently reviewing the flight data and studying the past performance of the sensors that measure the flow rate of the freon through the loops to build confidence in the performance of the freon loop and its ability to support the STS-109 mission through completion.

After reaching orbit this morning, Commander Scott Altman and Pilot Duane Carey commanded the first in a series of engine firings to position Columbia for its Sunday morning rendezvous with the Hubble Space Telescope. Their crew mates - Mission Specialists John Grunsfeld, Mike Massimino, Nancy Currie, Jim Newman and Rick Linnehan - began readying Columbia for its on-orbit operations by stowing away their launch and entry suits and opening the interior hatch to Columbia's airlock.

This is Columbia's first flight since July 1999, following an extensive modification period in which many of its systems were replaced or enhanced. Columbia was NASA's first shuttle orbiter and flew for the first time in April 1981.

Following an extensive analysis, managers determined that, although operating at a lower capacity, the system in question still provides sufficient cooling for shuttle equipment and Columbia can proceed with the capture and rejuvenation of the Hubble Space Telescope. Today, the STS-109 crew - Commander Scott Altman, Pilot Duane Carey, and Mission Specialists Nancy Currie, Jim Newman, Rick Linnehan, John Grunsfeld and Mike Massimino - prepared for Sunday morning's planned rendezvous and capture of the orbiting observatory.

Altman, Carey and Currie checked out the various tools that will be used during the final phases of tomorrow's rendezvous activities and performed another in a series of burns designed to refine Columbia's approach to the telescope. The two space walking pairs, Grunsfeld and Linnehan, and Massimino and Newman, began a checkout of the spacesuits they will wear over the course of five scheduled space walks and configured the airlock in readiness for the first spacewalk early Monday morning.

Currie, who will operate the shuttle's robotic arm to capture the telescope and maneuver astronauts during the spacewalks, powered up the 50-foot long arm today, finding it in good condition.

The final phases of the rendezvous will begin about 1 a.m. Sunday as Altman closes in on the telescope. Nancy Currie is planned to capture the telescope at 3:14 a.m. Sunday using the robotic arm. At that time, the two spacecraft will be over the Pacific Ocean, just east of Australia.

Columbia's capture of the telescope is planned for 3:13 a.m. Sunday. The shuttle's final approach will begin this evening with the longest rendezvous engine firing in shuttle program history. The three and a half minute firing, to be performed using the shuttle's two large orbital engines just after 10 p.m., will dramatically slow the rate at which Columbia is closing on the telescope, raising the shuttle's orbital low point more than 200 miles.

In the cockpit, shuttle Commander Scott Altman and Pilot Duane Carey will guide Columbia's approach. On the shuttle's lower deck this evening, Mission Specialists John Grunsfeld, Rick Linnehan, Jim Newman and Mike Massimino will check out and prepare the tools they'll use during five upcoming space walks. Mission Specialist Nancy Currie will power up Columbia's robotic arm, moving it to a position poised to capture Hubble.

The final phase of the rendezvous with Hubble will begin at about 1 a.m. Sunday, when Columbia is about nine statute miles behind the observatory. An engine firing at that time will put the shuttle on course to directly intercept the telescope. As the shuttle moves within about a half-mile below Hubble about an hour and a half later, Altman will take over manual control of the approach. Altman will ease Columbia to within 35 feet of the telescope, within reach of the outstretched 50-foot-long robotic arm.

As Columbia flies 350 miles above the Pacific Ocean east of Australia, Currie will latch the arm onto a fixture on Hubble. Currie will then lower the telescope into position to be latched to a special support structure in the shuttle's cargo bay. The cargo bay Flight Support System, as the structure is called, will hold the telescope for the next week, turning and tilting it as needed for the spacewalking work.

At about 7 a.m. Sunday, commands will be sent to begin retracting the telescope's two solar arrays, one at a time over the course of about two hours, in preparation for Monday's first space walk. The first space walk, which Grunsfeld and Linnehan are planned to begin at about 12:30 a.m. Monday, will install a pair of new-generation solar arrays on the telescope.

Within hours of awakening Grunsfeld and Linnehan, with the assistance of crewmates Jim Newman and Mike Massimino, will begin donning their spacesuits. Grunsfeld, performing his third spacewalk, will wear a spacesuit with red stripes. Linnehan, who is conducting his first spacewalk, will be wearing a spacesuit without any stripes. The pair may work ahead of schedule and leave the airlock as much as an hour earlier than planned.

They will begin the spacewalk with about an hour of setup activities in the payload bay to prepare for the total of five spacewalks for this mission. The next scheduled task is to install the new solar array's electrical support components, called a Diode Box Assembly, on the Hubble Space Telescope.

Space shuttle robot arm operator, Nancy Currie, will move the spacewalking duo by providing transportation to and from the worksite at the starboard array of the telescope. Grunsfeld, anchored to the telescope, will prepare the array for removal. Linnehan, on the end of the robotic arm, will then hold onto the array as Currie guides the arm into the payload bay where Linnehan will stow the old array for its return to Earth. Linnehan will then return to the worksite to help install the new solar array.

The third-generation solar arrays are two-thirds the size of the current arrays but will provide 20 percent more power to the telescope. Because of their smaller size, the new arrays will impart less atmospheric drag, slowing the rate at which Hubble's orbit decays.

Columbia Commander Scott Altman and Pilot Duane Carey will document their crewmates' work during the spacewalk with television and still-photo cameras, while also monitoring systems onboard Columbia. Today's spacewalk is scheduled to last 6 1/2 hours.

The crew is to begin its sleep period at 11:52 a.m. CST.

Columbia's chase of the telescope ended with Commander Scott Altman and Pilot Duane Carey manually flying Columbia to within 35 feet of Hubble allowing Mission Specialist Nancy Currie to use the shuttle's robot arm to gently grasp the orbiting observatory.

With the telescope safely in the payload bay, the crew turned its attention to retracting the two large solar arrays that generate power for the telescope. The motors that drive the two arrays had not been used since the panels were originally deployed during the first servicing mission in December 1993. The motors performed flawlessly taking approximately five minutes to retract each of the two arrays. The retractions were scheduled to take place during orbital daytime to allow sunlight to adequately warm the arrays prior to retraction.

The first in a pair of new-generation solar arrays will be installed by John Grunsfeld and Rick Linnehan on the first scheduled spacewalk of the mission, which is set to begin about 12:30 a.m. Monday. However, it is possible the spacewalk could begin up to one hour earlier than scheduled.

The crew is scheduled to wake up about 8 p.m. today, and within hours Grunsfeld and Linnehan, with the assistance of crewmates Jim Newman and Mike Massimino, will begin donning their spacesuits. They will begin the spacewalk by setting up some of the tools they will use, before Grunsfeld and Linnehan, working together, remove the old array, stow it in the payload bay and install the new starboard side array. They will also install its associated electrical support components, called a Diode Box Assembly. Mission Control bid the crew goodnight just before noon today concluding a busy and successful day culminating with the capture of the Hubble Space Telescope.

Newman, making his fifth spacewalk, will work closely with crewmate, Mike Massimino, who will be conducting his first spacewalk. Newman will wear a spacesuit marked with horizontal broken red strips for identification and Massimino will have on a spacesuit with diagonally broken red stripes.

This spacewalk mirrors much of the work done by spacewalkers John Grunsfeld and Rick Linnehan who replaced the Hubble Space Telescope's starboard solar array in today's seven-hour spacewalk. The second team of spacewalkers will remove the port-side array, stow it in the payload bay, and install a new-generation array along with its electrical components, or Diode Box Assembly. An additional task for the pair is to replace a Reaction Wheel Assembly (RWA) inside the telescope. Space shuttle robot arm operator Nancy Currie will provide transportation for the spacewalkers to and from the worksite at the port array of the telescope and Bay 6, the location of the RWA.

The RWA to be replaced is one of four onboard the telescope. They are pointing devices that control Hubble's steady view of the cosmos. After the solar array installation, Massimino will ride the end of the robot arm to Bay 6, remove the old RWA, and then carry it to the payload bay where Newman will be waiting with the new component. They will exchange the units and Massimino will take the new RWA back to Bay 6 for installation, while Newman stows the old RWA for the flight home. Setup tasks for future spacewalks of this mission, including removing the thermal cover on Bay 5 and installing foot restraints, will wrap up the spacewalk.

Columbia Commander Scott Altman and Pilot Duane Carey will document their crewmates' work during the spacewalk with television and still-photo cameras, while also monitoring systems onboard Columbia. Today's spacewalk, the second of five for this mission, is scheduled to last almost seven hours.

The crew is to begin its sleep period at 11:52 a.m. CST.

During the space walk, which began at 12:37 a.m. CST, Grunsfeld and Linnehan removed the old starboard solar array from Hubble and installed in its place a new third-generation solar array and its associated Diode Box Assembly. The old solar array was stored in Columbia's payload bay where it will be returned to Earth to allow engineers to determine how it fared during its nine years in space. The new arrays are two-thirds the size of the current arrays but will provide 20 percent more power to the telescope. Because of their smaller size, the new arrays also will impart less atmospheric drag, slowing the rate at which Hubble's orbit decays.

Throughout the space walk, Mission Specialist Nancy Currie used the shuttle's robotic arm to maneuver the two space walkers around Columbia's payload bay and the Hubble telescope. Linnehan was on the arm for most of the space walk, with Grunsfeld taking his place about five hours and fifteen minutes into the space walk.

From the aft flight deck of Columbia, astronauts Mike Massimino and Jim Newman assisted the two spacewalkers throughout their numerous tasks. Newman and Massimino will be performing their first spacewalk of the mission tomorrow morning, replacing Hubble's port solar array and a Reaction Wheel Assembly, one of four devices that help Hubble maintain a steady position as it photographs distant objects.

During the spacewalk, Grunsfeld's EVA suit did not transmit its normal telemetry signal to the ground, though the Flight Surgeon was able to monitor the astronaut's biomedical data. After resetting power to the suit later following the spacewalk, EVA officers in Mission Control were able to receive data normally. It is believed a relay in the suit's communication system needed to be reset.

The crew is to begin its sleep period at 11:52 a.m. CST.

Controllers at the Space Telescope Operations Control Center in Greenbelt, MD, will begin sending commands to power down the telescope's systems around 10:30 p.m. CST. The power is planned to be off until the telescope is brought back to life at 5:30 a.m. CST Wednesday with a newly installed power center.

The shuttle crew was awakened today by the song "Carmen Ohio," performed by the Ohio State University marching band and played for Ohio State alumni Nancy Currie and Rick Linnehan aboard Columbia. Space walkers John Grunsfeld and Linnehan are scheduled to begin their work outside the shuttle about 12:30 a.m. CST Wednesday.

Grunsfeld and Linnehan will replace Hubble's power control unit, or PCU, the central power switching station that distributes electricity to all of the observatory's systems and scientific instruments. Currie will operate the shuttle's robotic arm, moving the space walkers to and from worksites on the telescope. Linnehan will ride the arm first to a position where he will disconnect the telescope's batteries. Meanwhile, Grunsfeld will install blankets to protect components that will not be heated while the power is off.

The pair will work in tandem to replace the PCU. Linnehan will remove 30 of the 36 connectors on the old PCU and then move to the shuttle's payload bay to prepare the new unit for installation. Grunsfeld will then work at the end of the arm to unhook the remaining connectors, ease the old PCU out of the telescope and carry it to the shuttle's payload bay to be stored. There, Linnehan will hand the new unit to Grunsfeld, who will take it to the worksite, install the new box in its bay and reattach the 36 connectors.

Inside Columbia, the flight's other space walking team, Jim Newman and Mike Massimino, will assist. They will act as in-cabin choreographers guiding Grunsfeld and Linnehan through their tasks. Newman and Massimino are scheduled to perform the mission's fourth space walk on Thursday. Columbia Commander Scott Altman and Pilot Duane Carey will operate television and still cameras to document the work.

The crew is to begin its sleep period at 11:52 a.m. CST Wednesday.

Spacewalkers Jim Newman and Mike Massimino spent seven hours 16 minutes installing the new equipment. Massimino, on his first spacewalk and Newman, making his fifth spacewalk, began their work at 12:40 a.m. CST. Newman and Massimino first removed the old port solar array and stowed it in Columbia's payload bay for a return to Earth. They then installed a third-generation solar array and its associated electrical components, the Diode Box Assembly. When the solar array installation was complete, the spacewalkers moved on to the removal and replacement of the RWA. Nancy Currie once again used the shuttle's robotic arm to maneuver the spacewalkers to and from the worksite at the port array of the telescope and the RWA in Bay 6.

Initial validation tests performed by the Space Telescope Operations Control Center in Greenbelt, Md. indicate that the new solar array and reaction wheel assembly are working flawlessly. The new RWA is one of four pointing devices on the telescope that uses its spin to control Hubble's position, providing a steady view of the universe for the telescope's sensitive cameras.

Toward the end of their spacewalk, Newman and Massimino also installed a thermal blanket on Bay 6, door stop extensions on Bay 5, and foot restraints in preparation for tomorrow's spacewalk by John Grunsfeld and Rick Linnehan.

The spacewalkers also tested two bolts on the telescope's aft shroud doors. Those doors protect the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Space Telescope Imaging Spectrograph (STIS.) The two spacewalkers determined that the bottom of the two bolts required replacement and an aft shroud latch replacement kit was used to ensure that both bolts keep the door tightly closed.

During the spacewalk, Columbia Commander Scott Altman and Pilot Duane Carey used television and still-photo cameras to document the work, while monitoring systems onboard Columbia. Grunsfeld and Linnehan, who will be outside Columbia tomorrow for the third spacewalk of the mission, assisted Newman and Massimino from the aft flight deck.

The crew is scheduled to awaken at 7:52 p.m. CST.

Spacewalkers Jim Newman and Mike Massimino are ready to begin the first science instrument upgrade of the servicing mission when they step outside about 2:30 a.m. CST Thursday. The fourth of five spacewalks to rejuvenate Hubble will feature installation of the Advanced Camera for Surveys, which will see far beyond the reach of current instruments. The final original science instrument remaining on the telescope, the Faint Object Camera, will be removed to make room for the advanced system.

Columbia's crew - Commander Scott Altman, Pilot Duane Carey and mission specialists Nancy Currie, John Grunsfeld, Rick Linnehan, Newman and Massimino - was awakened at 9:52 p.m. CST. The original song "Sittin on Top of the World," played for the wakeup, was recorded and dedicated to the STS-109 crew by Les Paul, a music pioneer and space enthusiast.

Currie will operate the shuttle robot arm to provide transportation to and from the telescope worksites during the spacewalk. Newman will be lifted to Hubble's aft shroud doors where he will meet Massimino, remove the Faint Object Camera and temporarily stow it on the aft fixture of the enclosure holding the new instrument in Columbia's cargo bay. Together they will then unlatch the new camera from its carrier in the shuttle payload bay and install it in the aft shroud of the telescope. Once that is completed, they will stow the old camera in the payload bay carrier for return to Earth.

Massimino will then take a turn on the robotic arm, and the duo will install an Electronic Support Module for a new experimental cooling device to be installed on the fifth spacewalk for the telescope's Near-Infrared Camera and Multi-Object Spectrometer. They also will perform a few remaining cleanup tasks from Wednesday's power control unit installation.

Fellow spacewalkers Grunsfeld and Linnehan will be working inside the shuttle to choreograph the excursion as Altman and Carey provide photo and video documentation of the spacewalk.

Functionality tests continue and already have been fully successful on all of Hubble's major systems that were powered down for the third spacewalk. Functional tests of the telescope's scientific instruments will not be completed until after the telescope is released from Columbia and its aperture door is opened, allowing it to again view the heavens.

The crew is to begin its sleep period at 1:52 p.m. CST Thursday.

In addition to eliminating an intermittent problem with the old PCU, the new unit also is capable of handling the extra 20 percent of power output being generated from Hubble's newly installed set of solar panels attached during back-to-back space walks Monday and Tuesday. Controllers at the Space Telescope Operations Control Center in Greenbelt, MD, powered Hubble down at 3:37 a.m. Wednesday for the first time since its launch in 1990.

Mission Specialist Nancy Currie operated the shuttle's robotic arm throughout the space walk, moving Grunsfeld and Linnehan to and from various worksites on the telescope and in Columbia's payload bay. Grunsfeld later told Mission Control that, "Nancy is my hero" for her work today.

Today's space walk started two hours late due to a water leak in Grunsfeld's spacesuit. After swapping the upper portion of his suit the space walk began at 2:28 a.m. Linnehan, working from the shuttle's robotic arm, began by removing 30 of the 36 connectors on the old PCU. He was then maneuvered by Currie to the shuttle's payload bay where he switched places with Grunsfeld in order to prepare the new PCU for installation. At 4:55 a.m. Grunsfeld, now working from the robotic arm, unhooked the remaining six PCU connectors, eased the old PCU out of the telescope and carried it to the shuttle's payload bay for return to Earth. Grunsfeld installed the new unit at 5:53 a.m. The connectors were mated to the new PCU by 7:19 a.m. Shortly thereafter, the new PCU passed its aliveness test at 8:02 a.m. and all functional tests were completed at 12:18 p.m.

Inside Columbia, the flight's other space walking team, Jim Newman and Mike Massimino looked toward the fourth space walk set to begin tomorrow at about 2:30 a.m. CST to replace the last of Hubble's original science instruments - the Faint Object Camera - with the Advanced Camera for Surveys.

The crew is scheduled to awaken at 9:52 p.m. CST Wednesday.

The crew onboard Columbia was awakened at 9:52 p.m. CST by the Mission Impossible: II theme song, performed by Limp Bizkit.

Astronauts John Grunsfeld and Rick Linnehan plan to step out into the shuttle's payload bay about 2:30 a.m. CST Friday. The objective of the 6 1/2 hour spacewalk is to install the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) Cooling System.

NICMOS was installed on the second servicing mission to Hubble in 1997. The camera operated at extremely low temperatures and its solid-nitrogen cooling block was depleted earlier than expected. Engineers hope the new neon gas cooling system will restore the cold temperatures necessary for the camera to operate.

For the installation, Nancy Currie will give Grunsfeld a ride on the shuttle's robotic arm to the aft shroud doors, which he will open. These doors are on the opposite side of the telescope from where spacewalkers Mike Massimino and Jim Newman worked on Thursday.

Grunsfeld will then retrieve the NICMOS Cryogenic Cooler from the shuttle's payload bay and both spacewalkers will install the unit inside the telescope. After switching places on the arm Grunsfeld will close the left aft shroud door and Linnehan will move to the payload bay to remove the NICMOS Cooling System Radiator from its carrier. Together, they will install the radiator on the outside of Hubble. Linnehan will feed wires from the radiator through the bottom of the telescope to Grunsfeld, located inside Hubble, who will make the necessary connections to NICMOS. They will then close both aft shroud doors and perform the final activities of the spacewalk to prepare the shuttle payload bay for landing.

Commander Scott Altman and Pilot Duane Carey will provide photo and video documentation of this last spacewalk from inside the shuttle.

After the spacewalk, Columbia's smallest steering jets will be employed to boost the shuttle and Hubble's orbit. With the payload bay facing the direction of travel, the shuttle's vernier jets will be fired in a series of pulses, lasting about 36 minutes. The reboost will increase the shuttle and Hubble's orbit by about 3.7 statute miles.

The crew is to begin its sleep period at 1:52 p.m. CST Friday.

Columbia's spacewalkers, Jim Newman and Mike Massimino, began the first science instrument upgrade of this servicing mission at 3 a.m. central time. The duo, with Newman on the shuttle's robotic arm, began by removing the last of Hubble's original science instruments, the Faint Object Camera to make room for the ACS. Newman and Massimino first opened Hubble's aft shroud doors, removing the Faint Object Camera and temporarily stowing it at the edge of Columbia's payload bay. After installing the ACS in the Hubble, Newman and Massimino stowed the old camera in the payload bay for its return to Earth.

Then Massimino, on the shuttle's robotic arm, installed the Electronic Support Module in the aft shroud, with Newman's assistance. That module will support a new experimental cooling system to be installed during tomorrow's fifth and final scheduled spacewalk of the mission. That cooling system is designed to bring the telescope's Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) back to life.

Finally, Newman and Massimino completed some remaining cleanup tasks from yesterday's Power Control Unit installation.

During the first half of the spacewalk, mission specialist Nancy Currie operated the shuttle's robotic arm, providing transportation to and from the various worksites on both the Hubble and in Columbia's payload bay - Commander Scott Altman then took over operation of the arm to maneuver Massimino through his tasks.

Fellow spacewalkers John Grunsfeld and Rick Linnehan worked from inside the shuttle to choreograph the spacewalk, as Altman and Pilot Duane Carey continued to provide photo and video documentation of the work.

Initial functional tests on the ACS and the electronics module conducted by the Space Telescope Operations Control Center in Greenbelt, Md. were both good. Functional tests of the telescope's scientific instruments will not be completed, however, until after the telescope is released from Columbia and its aperture door is opened.

The crew is to begin its sleep period at 2:52 p.m. CST.

The crew completed five spacewalks on consecutive days, installing equipment that will give the telescope more energy, a new electronic "heart," and a camera more powerful than ever before. Columbia will release Hubble at about 4 a.m. CST Saturday, firing its engines soon after to separate the vicinity.

Commander Scott Altman, Pilot Duane Carey and mission specialists John Grunsfeld, Nancy Currie, Rick Linnehan, Jim Newman and Mike Massimino aboard Columbia were awakened at 9:52 p.m. CST by "Who Made Who" by AC DC. The song was played for Carey.

Activities in preparation for Hubble's release will begin about 12:52 a.m. CST when Currie grips a fixture on the telescope with Columbia's robotic arm. The latches that have held the telescope to a special support structure in the shuttle's payload bay will be released at about 2:04 a.m. CST. Currie will then lift the telescope above the cargo bay to a position poised for release. Several systems checks will follow as ground controllers at the Space Telescope Operations Center, Greenbelt, Md., prepare the observatory to again fly free before it is finally released by the shuttle.

After separating from the telescope, Columbia's crew will take a break from duties at 7:03 a.m. CST to participate in interviews by the NBC Weekend Today Show, WCCO-TV in Minneapolis, Minn., and CNN.

The crew will begin a sleep period at 11:52 a.m. CST Saturday.

Astronauts John Grunsfeld and Rick Linnehan began their third spacewalk of the mission at 2:46 a.m. CST. Linnehan was given a ride on the shuttle's robotic arm to the aft shroud doors by Nancy Currie, working from the aft flight deck of Columbia. After the shroud doors were open, Linnehan was moved back to Columbia's payload bay to remove the NICMOS cryocooler from its carrier. Grunsfeld and Linnehan then installed the cryocooler inside the aft shroud and connected cables from its Electronics Support Module. That module was installed yesterday during a spacewalk by Jim Newman and Mike Massimino.

Next, with Grunsfeld on the end of the shuttle's robotic arm, the Cooling System Radiator was retrieved from its carrier in Columbia's payload bat and installed on the outside of Hubble. Linnehan fed wires from the radiator through the bottom of the telescope to Grunsfeld, who made the necessary connections to NICMOS. After ensuring that all the cables were properly connected and stowed, the pair closed both aft shroud doors and performed the final activities of the spacewalk to prepare the shuttle payload bay for landing.

Commander Scott Altman and Pilot Duane Carey provided photo and video documentation of the last spacewalk from inside the shuttle.

Initial tests of the new cooling system by the Space Telescope Operations Control Center in Greenbelt, Md. have all gone very well. NICMOS was originally installed on the second servicing mission to Hubble in 1997. The camera requires extremely low temperatures, but its solid-nitrogen cooling block was depleted earlier than expected. Engineers hope the new neon gas cooling system will restore the cold temperatures necessary for the camera to operate.

About an hour after the spacewalk, at 11:18 a.m., Columbia's smallest steering jets were fired for 36 minutes to boost the shuttle and Hubble's orbit by four statute miles. This reboost places Hubble in the proper orbit for its deployment from Columbia's payload bay early Saturday morning.

The crew began its sleep period at 1:52 p.m. and is scheduled to awaken at 9:52 p.m.

The crewmembers onboard Columbia - Altman, Pilot Duane Carey and Mission Specialists John Grunsfeld, Nancy Currie, Rick Linnehan, Jim Newman and Mike Massimino - will have a rare opportunity to speak with another crew in orbit, the International Space Station Expedition Four crew.

At 2:15 a.m. Sunday the shuttle crew will talk with space station Commander Yury Onufrienko, and Flight Engineers Carl Walz and Dan Bursch. STS-109 is the first space shuttle mission not dedicated to assembly of the space station, since a crew has been living aboard the orbiting laboratory. The station has been continuously inhabited since the first expedition crew arrived in November 2000.

Columbia's crew also will participate in a live question and answer session with reporters at 6:47 a.m. WABC Radio in New York City; KARE-TV of Minneapolis, Minn., and the CBS Radio Network will discuss the Hubble servicing mission with the crew.

Flight Controllers at the Space Telescope Operations Center in Greenbelt, Md., report that all systems on Hubble are operating well after its release from Columbia. The new, more efficient solar arrays and Power Control Unit are performing excellently. The activation of the science instruments is scheduled to begin about 11 p.m. Sunday. Controllers will continue to monitor the newly installed components until everything is brought back on line.

Science observations are expected to resume in the next few weeks from the veteran Space Telescope Imaging Spectrograph and Wide Field Planetary Camera. Any possible moisture accumulated during the maintenance operations will be allowed to evaporate before some instruments will be activated. The newest science instrument, the Advanced Camera for Surveys, will begin peering more deeply into the cosmos in the next few months.

The crew will begin a sleep period at 11:22 a.m. Sunday.

From the flight deck, spacewalker John Grunsfeld expressed the sentiments of the crew - Commander Scott Altman, Pilot Duane Carey and Mission Specialists Nancy Currie, Mike Massimino, Jim Newman and Rick Linnehan - as he said "from the crew of STS-109, we bid Hubble well on its new journey, with its new tools, to explore the universe."

Grunsfeld, Linnehan, Newman and Massimino completed five spacewalks to service and upgrade the telescope on five consecutive days, beginning early Monday morning. The spacewalks set a new record for a single shuttle mission with a total time of 35 hours 55 minutes, surpassing the previous record of 35 hours 26 minutes held by STS-61, the first Hubble servicing mission. The Hubble has now been serviced four times with a total of18 spacewalks, involving 14 different astronauts, for a total spacewalking time of 129 hours 10 minutes.

Over five days, the spacewalkers, assisted by Currie operating the shuttle's robotic arm, installed equipment that gave the telescope more power, a new module to dispense that extra power, and a camera able to see twice as much area, with more speed and clarity. They also installed an experimental cooling system that engineers hope will bring back to life the Near-Infrared Camera and Multi-Object Spectrometer.

At 4:05 a.m., Commander Scott Altman and Pilot Duane Carey fired Columbia's orbital maneuvering system engines to begin separating themselves from Hubble - leaving the telescope to continue it observations of the universe with more capabilities than ever before.

The crew took time this morning to discuss the progress of their mission with the NBC Weekend Today Show, WCCO-TV in Minneapolis, Minn. and CNN. The crew is scheduled to begin their sleep period at 11:52 a.m. CST and to awaken at 8:52 p.m. to begin their 10th day in space.

Landing is scheduled for 3:32 a.m. CST Tuesday at Kennedy Space Center, Fla. The weather forecast for landing calls for generally acceptable conditions with only a slight chance of rain showers developing offshore.

Commander Scott Altman, Pilot Duane Carey, and Mission Specialist Nancy Currie will test Columbia's mechanical maneuvering systems at 12:47 a.m. CST Monday to ensure they will be able to steer the shuttle on the correct path for landing. They also will test the reaction control system jets at 1:47 a.m. for assured maneuverability during re-entry into the Earth's atmosphere. Crewmates Mike Massimino, John Grunsfeld, Rick Linnehan and Jim Newman will help pack away the equipment used throughout the mission.

The crew also will take time to answer questions from middle school students at the Maryland Science Center and the Denver Museum of Nature and Science at 10:12 p.m. The crew news conference with reporters at Kennedy and the Johnson Space Center in Houston is scheduled for 11:57 p.m. Sunday.

The song "Floating" by the Moody Blues awakened the crew at 7:22 p.m. Sunday. The song was dedicated to first-time fliers, pilot "Digger" and spacewalker Massimino.

Tuesday's primary landing opportunity to Kennedy would begin with a deorbit engine firing by Columbia at 2:22 a.m. CST leading to the 3:32 a.m. touchdown. A second landing opportunity also is available for Kennedy on Tuesday, beginning with an engine firing at 4:05 a.m. leading to a touchdown at 5:13 a.m.

Although opportunities do exist for landing at Edwards Air Force Base, Calif., shuttle managers plan to focus Tuesday only on a landing in Florida. Additional landing opportunities are available Wednesday, in both Florida and California.

The crew will begin a sleep period at 11:22 a.m. Monday.

Columbia's main landing gear touched down at 3:32 a.m. CST, completing a mission that covered 3,941,705 statue miles.

Commander Scott Altman, Pilot Duane Carey, and Mission Specialist/Flight Engineer Nancy Currie brought Columbia smoothly back to Earth. They fired the shuttle's orbital maneuvering system engines at 2:23 a.m., while Columbia was over the Indian Ocean, to begin their descent from orbit.

Their ground track took them across the Pacific Ocean and the coast of Baja California, then on an almost due east heading across the southern United States. The plasma trail of the orbiter was visible as it passed over Houston to some flight controllers at Houston's Mission Control Center who took a moment to go outside and watch it move quickly across the northern sky.

Florida weather remained good for the landing, though there had been some concern earlier in the day about formation of ground fog. It did not materialize, and Columbia landed right on time.

Mission Specialists John Grunsfeld, Jim Newman, Rick Linnehan and Mike Massimino completed the five spacewalks, working in teams of two on alternate days. They gave the Hubble new solar arrays, an advanced new camera and installed a cooling system to revive another instrument. They also installed a new power control unit to route electricity from the arrays to batteries and instruments, and a new reaction wheel assembly to help point the telescope.

Tuesday's landing was the 58th for a shuttle at Kennedy Space Center and the 14th night landing there. Five other missions have ended with night landings at Edwards Air Force Base, Calif.