Solar radiation research. Launched at 1029 local time. Reached 20 km.

A deliberate thrust misalignment of 1 inch was programed into the escape combination. Lift-off was effected cleanly, and a slow pitch started during the burning of the escape rocket motor. The tower separated as scheduled and the drogue and main parachutes deployed as planned. The test was fully successful. References: 483 .

Tests were in progress at Langley in which an aluminium honeycomb structure was used partially to absorb the spacecraft impact load. Robert R. Gilruth, Project Mercury Director, had stated his belief of this requirement on January 16, 1959. References: 483 .

First production model of McDonnell-built Mercury capsule was delivered to NASA. References: 17 .

President John F. Kennedy, in his regular press conference, stated that "no one is more tired than I am" of seeing the United States second to Russia in space. "They secured large boosters which have led to their being first in Sputnik, and led to their first putting their man in space. We are, I hope, going to be able to carry out our efforts, with due regard to the problem of the life of the men involved, this year. But we are behind . . . the news will be worse before it is better, and it will be some time before we catch up. . . ." References: 16 .

Suborbital. References: 5 .

First manned spaceflight, one orbit of the earth. 11 April 1961 was a 'reserve' day in the launch plan, but it was not needed. All the Chief Designers and Military Space chiefs were at the cosmodrome. Gagarin spent that day in meetings with the prominent personalities.

Three press releases were prepared, one for success, two for failures. It was only known ten minutes after burnout, 25 minutes after launch, if a stable orbit had been achieved.

The payload included life-support equipment and radio and television to relay information on the condition of the pilot. The flight was automated; Gagarin's controls were locked to prevent him from taking control of the ship. A key was available in a sealed envelope in case it became necessary to take control in an emergency. After retrofire, the service module remained attached to the Sharik reentry sphere by a wire bundle. The joined craft went through wild gyrations at the beginning of reentry, before the wires burned through. The Sharik, as it was designed to do, then naturally reached aerodynamic equilibrium with the reentry shield positioned correctly.

Gagarin ejected after reentry and descended under his own parachute, as was planned. However for many years the Soviet Union denied this, because the flight would not have been recognized for various FAI world records unless the pilot had accompanied his craft to a landing. Recovered April 12, 1961 8:05 GMT. Landed Southwest of Engels Smelovka, Saratov. References: 1 , 2 , 5 , 6 , 32 , 33 , 60 , 175 , 445 .

First Soviet public announcement of manned lunar goals. References: 72 .

Suborbital. References: 5 , 126 .

ASAT interceptor control and propulsion test. Elaboration of systems providing for the extensive manouevring of space apparatuses. References: 1 , 2 , 5 , 6 , 272 .

High resolution photo reconnaissance satellite; returned film capsule References: 1 , 2 , 6 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

High resolution photo reconnaissance mission. References: 279 .

Uncertain if Molniya-1T model was Molniya-1 or Molniya-1T. Operation of the long-range telephone and telegraph radiocommunications system in the USSR; transmission of television programmes to stations in the Orbita network. References: 1 , 2 , 5 , 6 .

Military navigation satellite. References: 1 , 2 , 5 , 6 .

Replaced Cosmos 1109. Covered Oko constellation plane 9 - 240 degree longitude of ascending node. References: 1 , 2 , 5 , 6 , 100 .

First flight of Space Transportation System (aka Space Shuttle).. Payloads: Development Flight Instrumentation and Aerodynamic Coefficient Identification Package. Additional Details: STS-1. References: 1 , 2 , 5 , 6 , 7 , 33 .

Replaced Cosmos 1371. References: 1 , 2 , 5 , 6 .

It was clear that the planned processing flow could not be followed and still make the spring 1986 launch date. The decision was taken on Cosmonautics Day to ship the flight model to Baikonur and conduct the systems testing and integration there.

Released by STS 51D 4/13/85; failed to orbit and subsequently repaired by STS 51-I on 8/31/85; 178 deg E; leased by U.S. government. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Released by STS 51D 4/13/85; 107.5 deg W. Telecommunications. Operating entity TELESAT Canada. Longitude 107.5 W. Transmit power 11.2 W on each frequency. Frequencies 11730, 11743, 11791, 11804, 11852, 11865, 11913, 11926, 11974, 11987, 12035, 12048, 12096, 12109, 12157, 121 70 MHz. References: 1 , 2 , 5 , 6 .

Manned seven crew. Payloads: Telesat (Canada communications satellite)-I with Payload Assist Module (PAM)-D deployment, Syncom IV-3 communications satellite deploy-ment with its unique stage (unique stage failed to ignite), Continuous Flow Electrophoresis (CFES), Phase Partitioning Experiment (PPE), student experiments, two getaway specials (GAS) Informal science studies (Toys in Space). Additional Details: STS-51-D. References: 1 , 2 , 5 , 6 , 7 , 33 .

It managed to dock to Mir on the third attempt after the crew removed a trash bag from the docking collar in a space walk. The FGB tug, its work done, then backed away from the station. But the manoeuvres had cut into its already-reduced propellant supply. Unable to deorbit itself to a controlled burn-up in the atmosphere, the FGB was instead commanded to boost itself into a storage orbit 40 km above Mir.

Communications satellite is for the European Telecommunications Satellite Organization. The vehicle entered a 153 km x 385 km x 27.4 deg parking orbit nine minutes after launch. The second Centaur stage burn delivered the satellite to a 166 km x 46,076 km x 19.7 deg super-synchronous transfer orbit. The satellite was stationed at 7 deg E and carried 24 Ku-band transponders with a wide beam covering Europe, North Africa and Asia, and a spot beam for digital TV to Turkey.