NACA flight 17. Stability and loads investigation. Plane's nosewheel collapsed on landing. Moderate damage.

AF flight 28. Pressure distribution survey. Only cylinders 2 and 4 ignited.

First successful sled-launched Snark airframe.

NASA requested that the Air Force furnish two TF-102B and two T-33 aircraft to be used by the Project Mercury astronauts. One of the requirements in the astronaut training program was to maintain proficiency in high performance aircraft.

Integrated Weapon System Training 1. First Thor IRBM launched by British crew at Vandenberg AFB.

This dramatic failure resulted in a loss of thrust, and the lateral strap-on units separated and flew over the tracking stations and living areas. The core continued on its trajectory.

Decree 'On Important Development of Intercontinental Ballistic and Global Missiles and Carriers-Rockets for Space Objects--work on the N1, R-36, R-36-O, and R-56' was issued.

Central Committee of the Communist Party and Council of Soviet Ministers Decree 'On the Development of the 'Soyuz' Complex for Piloted flight to the Moon--approving the Soyuz program for circumlunar flight' was issued. The Soyuz was to be capable of the following:

• Automatic rendezvous with other spacecraft
• Automatic approach and alignment
• Automatic docking
• Exit of crew into open space for transfer from spacecraft to spacecraft
• Astronavigation
• Maneuvering in orbit (changing of orbital parameters)
• Test of re-entry using body lift to modify the landing point and alleviate G-forces
• Test of the operation of radio equipment and tracking equipment
• Scientific research

NASA's Office of Space Science and Applications (OSSA) and the National Academy of Sciences (NAS) were planning a scientist-astronaut program. The screening-for-selection process could be scheduled for February 1965. - Additional details.

Joseph F. Shea, ASPO Manager, in a letter to North American's Apollo Program Manager, summarized MSC's review of the weight status of the Block I and the design changes projected for Block II CSM's.

The Block II design arose from the need to add docking and crew transfer capability to the CM. Reduction of the CM control weight (from 9,500 to 9,100 kilograms (21,000 to 20,000 pounds)) and deficiencies in several major subsystems added to the scope of the redesign. - Additional details.

MSFC conducted the first clustered firing of the Saturn V's first stage (the S-IC). The booster's five F-1 engines burned for about 6½ seconds and produced 33,360 kilonewtons (7.5 million lbs) thrust.

Eight days later, at its static facility in Santa Susana, California, North American first fired the S-II, intermediate stage of the Saturn V. The event was chronicled as the "second major Saturn V milestone" during April. - Additional details.

Gagarin and the rest of the male cosmonauts, as many as other VVS officers, are opposed to Kamanin's plan for a female Voskhod flight. The first cosmonaut group are also opposed to appointment of Beregovoi and Shatalov to flight crews. Tereshkova has lost 5 kg and looks ill, but all the doctors say she is healthy.

The Soyuz 2 crew trains from 15:00 to 20:00 - they had to wait due to problems with the spacecraft, but then the training went all right. The argument continues on whether to do an automatic or a manual docking. The design bureau wants to use the Igla automatic system; the cosmonauts want to do it manually. They have done 800 dockings in the simulator, so they should know best, in Kamanin's opinion. They want to let the automatic system take the spacecraft up to 50 to 70 m from the target, then use manual maneuvering to proceed to dock. The number two valve on the Soyuz 1 spacecraft's nitrogen tank was inadvertently opened during preparation. It was said not to be serious, but the problems are getting on everyone's nerves.

Soyuz s/n 31 is completed. The crew are given a final look at it in the afternoon. They spend four hours in the powered-down spacecraft. Kamanin notes that Nikolayev and Sevastyanov do not look out after their physical condition even on the ground -- no wonder they were so sick after their flight! Afterwards all three crews go to the sauna together.

The Apollo 16 (AS-511) space vehicle was launched from Pad A, Launch Complex 39, KSC, at 12:54 p.m. EST April 16, with a crew of astronauts John W. Young, Thomas K. Mattingly II, and Charles M. Duke, Jr. After insertion into an earth parking orbit for spacecraft system checks, the spacecraft and the S-IVB stage were placed on a trajectory to the moon at 3:28 p.m. CSM transposition and docking with the LM were achieved, although a number of minor anomalies were noted.

One anomaly, an auxiliary propulsion system leak on the S-IVB stage, produced an unpredictable thrust and prevented a final S-IVB targeting maneuver after separation from the CSM. Tracking of the S-IVB ended at 4:04 p.m. EST April 17, when the instrument unit's signal was lost. The stage hit the lunar surface at 4:02 p.m. April 19, 260 kilometers northeast of the target point. The impact was detected by the seismometers left on the moon by the Apollo 12, 14, and 15 missions.

Spacecraft operations were near normal during the coast to the moon. Unexplained light-colored particles from the LM were investigated and identified as shredded thermal paint. Other activities during the translunar coast included a cislunar navigation exercise, ultraviolet photography of the earth and moon, an electrophoresis demonstration, and an investigation of the visual light-flash phenomenon noted on previous flights. Astronaut Duke counted 70 white, instantaneous light flashes that left no after-glow.

Apollo 16 entered a lunar orbit of 314 by 107.7 kilometers at 3:22 p.m. April 19. After separation of LM-11 Orion from CSM 112 Casper, a CSM active rendezvous kept the two vehicles close together while an anomaly discovered on the service propulsion system was evaluated. Tests and analyses showed the redundant system to be still safe and usable if required. The vehicles were again separated and the mission continued on a revised timeline because of the 5 3/4-hour delay.

The lunar module landed with Duke and Young in the moon's Descartes region, about 230 meters northwest of the planned target area at 9:23 p.m. EST April 20. A sleep period was scheduled before EVA.

The first extravehicular activity began at 11:59 a.m. April 21, after the eight-hour rest period. Television coverage of surface activity was delayed until the lunar roving vehicle systems were activated, because the steerable antenna on the lunar module could not be used. The lunar surface experiments packages were deployed, but accidental breaking of the electronics cable rendered the heat flow experiment inoperable. After completing activities at the experiments site, the crew drove the lunar roving vehicle west to Flag Crater, where they performed the planned tasks. The inbound traverse route was just slightly south of the outbound route, and the next stop was Spook Crater. The crew then returned via the experiment station to the lunar module and deployed the solar wind composition experiment. The duration of the extravehicular activity was 7 hours 11 minutes. The distance traveled by the lunar roving vehicle was 4.2 kilometers. The crew collected 20 kilograms of samples.

The second extravehicular traverse, which began at 11:33 a.m. April 22, was south-southeast to a mare-sampling area near the Cinco Craters on Stone Mountain. The crew then drove in a northwesterly direction, making stops near Stubby and Wreck Craters. The last leg of the traverse was north to the experiments station and the lunar module. The second extravehicular activity lasted 7 hours 23 minutes. The distance traveled by the lunar roving vehicle was 11.1 kilometers.

Four stations were deleted from the third extravehicular traverse, which began 30 minutes early at 10:27 a.m. April 23 to allow extra time. The first stop was North Ray Crater, where "House Rock" on the rim of the crater was sampled. The crew then drove southeast to "Shadow Rock." The return route to the LM retraced the outbound route. The third extravehicular activity lasted 5 hours 40 minutes, and the lunar roving vehicle traveled 11.4 kilometers.

Lunar surface activities outside the LM totaled 20 hours 15 minutes for the mission. The total distance traveled in the lunar roving vehicle was 26.7 kilometers. The crew remained on the lunar surface 71 hours 14 minutes and collected 96.6 kilograms of lunar samples.

While the lunar module crew was on the surface, Mattingly, orbiting the moon in the CSM, was obtaining photographs, measuring physical properties of the moon and deep space, and making visual observations. Essentially the same complement of instruments was used to gather data as was used on the Apollo 15 mission, but different areas of the lunar surface were flown over and more comprehensive deep space measurements were made, providing scientific data that could be used to validate findings from Apollo 15 as well as add to the total store of knowledge of the moon and its atmosphere, the solar system, and galactic space.

The LM lifted off from the moon at 8:26 p.m. EST April 23, rendezvoused with the CSM, and docked with it in orbit. Young and Duke transferred to the CSM with samples, film, and equipment, and the LM was jettisoned the next day. LM attitude control was lost at jettison; therefore a deorbit maneuver was not possible and the LM remained in lunar orbit, with an estimated orbital lifetime of about one year.

The particles and fields subsatellite was launched into lunar orbit and normal system operation was noted. However, the spacecraft orbital shaping maneuver was not performed before ejection and the subsatellite was placed in a non-optimum orbit that resulted in a much shorter lifetime than the planned year. Loss of all subsatellite tracking and telemetry data on the 425th revolution (May 29) indicated that the subsatellite had hit the lunar surface.

The mass spectrometer deployment boom stalled during a retract cycle and was jettisoned before transearth injection. The second plane-change maneuver and some orbital science photography were deleted so that transearth injection could be performed about 24 hours earlier than originally planned.

Activities during the transearth coast phase of the mission included photography for a contamination study for the Skylab program and completion of the visual light-flash-phenomenon investigation that had been partially accomplished during translunar coast. A 1-hour 24-minute transearth extravehicular activity was conducted by command module pilot Mattingly to retrieve the film cassettes from the scientific instrument module cameras, inspect the equipment, and expose a microbial-response experiment to the space environment. Two midcourse corrections were made on the return flight to achieve the desired entry interface conditions.

Released from Apollo 16 into lunar orbit on 24 April 1972 at 21:56:09 GMT into a 96 km x 122 km orbit; fields and particles data; impacted lunar surface 29 May 1972.

High resolution photo reconnaissance satellite; returned film capsule; maneuverable.

Space shuttle main engine 2006, flight engine delivered to NSTL, for acceptance test firing

Photo surveillance; returned film capsule; maneuverable.

RMS 'Ryswatters' installed.

Materials processing tests.

Photo/digital surveillance.

Military navigation satellite. Positioned in plane 5 of constellation. Signals at 150.03 and 400.07 MHz.

Ocean surveillance. Investigation of outer space.

Geosynchronous. Stationed over 78.5E Positioned in geosynchronous orbit at 78 deg E in 1997-1999 As of 3 September 2001 located at 78.53 deg E drifting at 0.008 deg W per day. As of 2007 Mar 10 located at 111.51W drifting at 5.525W degrees per day.

Geosynchronous. Stationed over 110.0E Positioned in geosynchronous orbit at 110 deg E in 1997-1999 As of 4 September 2001 located at 109.56 deg E drifting at 0.018 deg W per day. As of 2007 Mar 10 located at 109.63E drifting at 0.008W degrees per day.

Several US Congressional committees investigated the Clinton administration's policy of exporting space satellite technology to China, asserting it had helped China and other countries to develop and use nuclear missiles. Two US companies were being investegated by the Justice Department as well. Beijing denied that it had gotten any sensitive technology from US.

Haignere launched by hand the Sputnik-99 amateur radio satellite, delivered to Mir by Progress M-41.

From about 1426 UTC to 2106 UTC the astronauts deployed the Airlock Spur, a small ladder from S0 to Quest, as well as installing some floodlights.

Ariane mission V150 placed Lockheed Martin A2100-class satellite NSS 7 satellite into orbit. The satellite was owned by New Skies, an Intelsat spinoff, and carried a C/Ku band telecoms payload. The spacecraft was in a 24200 x 35706 km x 0.7 deg orbit by April 24, on its way to geosynchrnous orbit. As of 2007 Mar 9 located at 22.01W drifting at 0.010W degrees per day.

The satellite was to provide Ka and Ku band communications for Japan's Space Communications Corporation.

The C/NOFS (Communication/Navigation Outage Forecasting System) satellite flew the US Defence Department's Space Test Program P00-3 space weather forecasting mission. The L-1011 launch aircraft staged from Kwajalein atoll to a release point for the Pegasus booster somewhere over the Pacific at 10.5229 N 167.7562 E. The research satellite carring ionospheric instruments, including Aerospace Corporation's CORISS receiver which used GPS signals to determine electron densities in the ionosphere, and the Naval Research Laboratory's CERTO ionospheric radio beacon. The spacecraft was built by General Dynamics C4 Systems (former Spectrum Astro) and was managed by DoD-STP and the Air Force Research Lab. The objective was to provide data that would allow better forecasts of ionospheric scintillation which causes problems with communications and GPS signals. The satellite deployed six 10-meter booms after release from the final booster stage.