NACA flight 44. Plane and instrument check. References: 49 , 97 .

The seven Project Mercury astronauts reported for duty. A tentative schedule of Mercury astronaut activities for the first months of training was issued. Actual training began the next day. Within 3 months the astronauts were acquainted with the various facets of the Mercury program. The first training week was as follows: Monday, April 27, check in; April 28, general briefing; April 29, spacecraft configuration and escape methods; April 30, support and restraint; May 1, operational concepts and procedures. These lectures were presented by specialists in the particular field of study. Besides the above, unscheduled activities involved 3 hours flying time and 4 hours of athletics. References: 483 .

Meeting of DOD working group on Project Mercury search and recovery operations was held at Patrick Air Force Base, with major emphasis placed on the first two ballistic Atlas shots, and command relationships. References: 17 , 278 .

Various gamma ray detectors were carried aboard Explorer XI on its orbital flight. These detectors found a directional flux of gamma radiation in space and thereby provided serious evidence against one formulation of the 'steady state' cosmological theory. References: 483 .

Completion of technical review of Dyna-Soar program announced by the Air Force. References: 17 .

State Committee for Defence Technology (GKOT) Decree 'On the Organisation of Military Duty of the R-16U (Unified Variant)--putting the R-16U missile into operation' was issued. References: 474 .

Gamma ray data. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). References: 1 , 2 , 5 , 6 .

KH-4A. Mission failed. Recovery vehicle impacted in Venezuela. References: 1 , 2 , 5 , 6 .

Decree 10 'On approving the work plan to build the p8loted spacecraft 7K-L1 -- approving the plan for for the UR-500K-L1 and terminating the UR-500K-LK-1' was issued. References: 474 .

Worked with Cosmos 144. Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 .

ASPO Manager George M. Low explained to the Apollo Program Director the underlying causes of slips in CSM and LM delivery dates since establishment of contract dates during the fall of 1967. The general excuse, Low said, was that slips were the result of NASA-directed hardware changes. "This excuse is not valid." He recounted how NASA-imposed changes had been under strict control and only essential changes had been approved by the MSC Level II Configuration Control Board (CCB). Additional Details: Delays in Apollo CSM and LM delivery dates. References: 16 .

Suborbital. References: 5 .

First test firing of seven segment solid rocket booster motor for Titan 3M for MOL. The test at Coyote Canyon, California, generated 0.7 million kgf for two minutes. References: 128 .

James C. Fletcher was sworn in as NASA Administrator at a White House ceremony. President Nixon had nominated him for the position on March 1, and the Senate had confirmed the nomination on March 11. George M. Low, NASA Deputy Administrator, had been Acting Administrator since the resignation of Administrator Thomas O. Paine on September 15, 1970. References: 16 .

Released 1 Romb radar calibration subsatellite. Possible partially failed spacecraft bus. References: 1 , 2 , 5 , 6 .

First flight test of Yantar-4K1 satellite. Returned as planned after 30 days. High resolution photo reconnaissance; returned film in two small SpK capsules during the mission and with the main capsule at completion of the mission. References: 1 , 2 , 5 , 6 , 69 .

Unmanned supply vessel for Salyut 6. Delivery of various cargoes to the Salyut-6 orbital station. Docked with Salyut 6 on 29 Apr 1980 08:09:19 GMT. Undocked on 20 May 1980 18:51:00 GMT. Destroyed in reentry on 22 May 1980 00:44:00 GMT. Total free-flight time 3.32 days. Total docked time 21.45 days. References: 1 , 2 , 6 , 275 .

Military cartographic satellite; returned film capsule. References: 1 , 2 , 6 .

Topographic mapping for the Army General Staff. Mission normally would have run 44 days. References: 1 , 2 , 6 , 101 , 102 .

Tracking stations downrange did not pick up the spacecraft. It was later determined that the rocket nose fairing failed to separate four minutes after launch. The extra mass caused the vehicle to reenter over the South Pacific on the first partial orbit. Space Imaging's Ikonos 1 was to have been the first commercial imaging satellite with a high a resolution camera.