Encyclopedia Astronautica
Chandra



axaf.jpg
AXAF
Credit: NASA
American x-ray astronomy satellite. One launch, 1999.07.23.

The Chandra Advanced X-ray Astrophysics Facility was designed to study the composition and nature of galaxies, stellar objects and interstellar phenomena as well as basic issues in theoretical physics using the most sensitive X-ray telescope ever built.

The Chandra Advanced X-ray Astrophysics Facility was one of the four Great Observatories (along with HST, GRO, and SIRTF). International participants include the UK, Germany, and the Netherlands. Originally consisting of 2 separate spacecraft, the AXAF program was reduced to a single spacecraft in 1993 due to fiscal constraints. Satellite operations would be conducted by MSFC using NASA's Deep Space Network.

The spacecraft: had a light weight composite structure, and was 3-axis stabilized, using a zero momentum biased control system. Solar arrays generated over 2 kW and recharged three 40 AHr nickel hydrogen batteries. Six reaction wheels provided attitude control, with the control system fed by four 2-degree-of-freedom dry tuned rotor gyros. Two 1.8 Gbit solid state recorders could store 18.8 hours of data per recorder. The Integral Propulsion System on Chandra used four TR-308 bipropellant thrusters for orbit changes. The thrusters used N2O4 (nitrogen tetroxide) oxidizer and N2H4 (hydrazine) fuel. They had a thrust of 472 N and a specific impulse of 322.3s; the TR-308 was an upgrade of the TR-306 that was used on three Lockheed Martin Series 5000 satellites. The same fuel tanks also fed Marquardt 89 N monopropellant hydrazine RCS thrusters. In addition to the IPS, the MUPS (Momentum Unloading Propulsion System) used 0.9 N hydrazine thrusters to unload momentum from the gyro systems used to point Chandra.

The X-ray telescope consisted of four pairs of nearly cylindrical mirrors, ranging from 1.4 meters in diameter to 0.68 meters in diameter. These mirrors focused X-ray energy over a 10 m focal length onto two of the four science instruments, the High Resolution Camera (HRC) and the AXAF CCD Imaging Spectrometer (ACIS). Also carried were two non-focal plane instruments, the High-Energy Transmission Grating (HETG), and Low-Energy Transmission Grating (LETG).

AKA: Advanced X-Ray Astrophysics Facility; AXAF.
Height: 12.20 m (40.00 ft).
Span: 18.90 m (62.00 ft).
First Launch: 1999.07.23.
Number: 1 .

More... - Chronology...


Associated Countries
See also
  • Shuttle The manned reusable space system which was designed to slash the cost of space transport and replace all expendable launch vehicles. It did neither, but did keep NASA in the manned space flight business for 30 years. More...

Associated Launch Vehicles
  • Shuttle American winged orbital launch vehicle. The manned reusable space system which was designed to slash the cost of space transport and replace all expendable launch vehicles. It did neither, but did keep NASA in the manned space flight business for 30 years. Redesign of the shuttle with reliability in mind after the Challenger disaster reduced maximum payload to low earth orbit from 27,850 kg to 24,400 kg. More...

Associated Manufacturers and Agencies
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...
  • TRW American manufacturer of rockets, spacecraft, and rocket engines. TRW Corporation, Redondo Beach, CA, USA. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • McDowell, Jonathan, Jonathan's Space Report (Internet Newsletter), Harvard University, Weekly, 1989 to Present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • NASA Report,
  • NASA Report, Chandra First Light Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Supernova 1987 A Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Deep Field Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra M82 Black Hole Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Strange Matter Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Crab Nebula Movie Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra XTE J1550-564 Press Kit , Web Address when accessed: here.
  • NASA Report, Chandra NGC 6240 Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Perseus Cluster Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra RX J1242-11 Press Kit, Web Address when accessed: here.
  • NASA Report, Chandra Galaxy Clusters and Dark Energy Press Kit , Web Address when accessed: here.
  • NASA Report, Chandra Specifications, Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC39B Shuttle, Saturn V, Saturn I launch complex. LC39A and LC39B, part of the Kennedy Space Center, were built on Merritt Island (north/northwest of the Cape) to support the Saturn V/Apollo lunar landing program in 1963-1966. The sites were modified in the last half of the 1970s to support the manned Space Shuttle program. More...

Chandra Chronology


1999 July 23 - . 04:31 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-93.
  • Chandra - . Payload: OV-102. Nation: USA. Agency: NASA Huntsville. Manufacturer: TRW. Class: Astronomy. Type: X-ray astronomy satellite. Spacecraft: Chandra. USAF Sat Cat: 25867 . COSPAR: 1999-040B. Apogee: 128,769 km (80,013 mi). Perigee: 20,046 km (12,455 mi). Inclination: 45.1000 deg. Period: 3,808.60 min. The Chandra Advanced X-ray Astrophysics Facility was one of NASA’s four Great Observatories (along with Hubble Space Telescope, Compton Gamma Ray Observatory, and the SIRTF). Chandra will study the composition and nature of galaxies, stellar objects and interstellar phenomena as well as basic issues in theoretical physics using the most sensitive X-ray telescope ever built. The IUS under-performed and placed Chandra in an orbit about 900 km lower than planned. Therefore Chandra's own IPS propulsion system had to be used to make up the difference. The first such manoeuvre was at 01:11 GMT on July 25 when the IPS engines fired for 5 minutes to raise perigee to 1192 km. Further perigee burns on July 31, August 4, and August 7 raised the orbit to its final 10,000 km x 140.000 km. Additional Details: here....

Home - Browse - Contact
© / Conditions for Use