Hermann Oberth writes to Goddard for a copy of his 1920 monograph, 'A Method of Reaching Extreme Altitudes'. Goddard, concerned with German interest in space flight, sends him a courtesy copy with some apprehension. The following year Oberth reciprocates by sending Goddard a copy of 'Die Rakete zur Weltraumfahrt', including an acknowledgement of Goddard's work in an Addendum ('...Goddard's work was received just as this was going to press....my theoretical approach is supplemented by his practical work....'). Goddard is convinced that Oberth has borrowed his ideas and refers to him as '..that German Oberth...'. References: 377 .

Upper-air pressures and temperatures; earth photography research. Engine cut-out after 55 seconds. Launched at 0914 local time. Reached 80.5 km.

The Air Force disclosed that a $41 million guided missile production facility would be built at Sorrento, California, for the Atlas launch vehicle. Convair was announced as the prime contractor. References: 483 .

Sunfollower spectrograph. Launched at 0704 local time. Reached 204 km.

The first Rocketdyne H-1 engine for the Saturn arrived at the Army Ballistic Missile Agency (ABMA ). The H-1 engine was installed in the ABMA test stand on May 7, first test-fired on May 21, and fired for 80 seconds on May 29. The first long-duration firing - 151.03 seconds - was on June 2. References: 16 .

STG members presented the proposed advanced manned spacecraft program to the Lewis Research Center staff. Work at the Center applicable to the program included: analysis and preliminary development of the onboard propulsion system, trajectory analysis, and development of small rockets for midcourse and attitude control propulsion. References: 16 .

Also known as TOSZ - Heavy Orbital Station of the Earth, this was Korolev�s first 1961 project for a large N1-launched military space station.

The nation's first silo launch of a Titan I at Vandenberg AFB. References: 88 .

At El Centro, Calif., Northrop Ventura conducted the first of a series of qualification tests for the Apollo earth landing system (ELS). The test article, CM boilerplate 3, was dropped from a specially modified Air Force C-133. The test was entirely successful. The ELS's three main parachutes reduced the spacecraft's rate of descent to about 9.1 meters (30 feet) per second at impact, within acceptable limits. References: 16 .

Maximum Speed - 732 kph. Maximum Altitude - 13720 m. Flight Time - 245 sec. References: 49 , 97 .

Police and military units arrest as many as 12,000; most are later released. Pentagon Papers published

MPTA-098 proof load test setup, Lockheed test site, Palmdale References: 15 .

Completed repair of Salyut 7 propulsion system fuel lines. References: 66 .

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

US civilian geostationary weather satellite in the Geostationary Operational Environmental Satellite series. It was the first GOES launch on the Atlas II launch vehicle (the Atlas I having been phased out). Built by SS/Loral, based on the FS-1300 bus. It was equipped with one solar panel array and a counter-boom with a solar sail. The satellite carried well as an imaging radiometer and an X-ray detector to monitor solar activity. Stationed at 106 deg W.

Advanced imaging reconnaissance satellite. Relays digital imagery to earth via geostationary comsats. The last such satellite, Cosmos 2359, reentered in July 1999 after one year in orbit. The Soyuz-U launcher placed it in a 183 x 277 km x 64.8 deg initial orbit; it raised altitude to 240 x 300 km about 24 hr after launch.