Cosmic radiation, pressure, temperature research. Launched at 1614 local time. Reached 87.6 km.

Bell flight 1. Pilot familiarization. Fuel jettison test. Glide flight only. References: 49 , 97 .

Bell flight 2. Planned as powered flight, but completed as glide flight following propellant-system difficulties. References: 49 , 97 .

NACA established "Round Three" Steering Committee to study feasiblity of a hypersonic boost-glide research airplane. "Round Three" was considered as the third major flight research program which started with the X-series of rocket-propelled supersonic research airplanes, and which considered the X-15 research airplane as the second major program. The boost-glide program eventually became known as DynaSoar. References: 17 .

A report entitled, 'Basic Objectives of a Continuing Program of Scientific Research in Outer Space,' was presented by the IGY Committee. The committee was of the opinion that the need for space research would be required far past the close of the IGY in December 1958. References: 483 .

19,861 acres of South Camp Cooke transferred from the Army to the Navy on interim permit basis (actual transfer on 27 May). References: 88 .

NASA Nike-Cajun rocket launched from Wallops Station, carrying 60-pound payload ejecting explosive charges, which fired at intervals from 20- to 80-mile altitude to provide data on density of the atmosphere. References: 18 .

Unfavorable weather conditions caused the Mercury-Atlas 6 (MA-6) manned orbital mission to be postponed. References: 483 .

Experimental commsat; lost contact following orbital injection. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Research and Development ASAT test.

MSC ordered North American to design the SM's reaction control system with the capability for emergency retrograde from earth orbit. References: 16 .

Following Korolev's death, Mishin discovered that growth of the mass of the L3 payload had taken the low earth orbit payload requirement to 95 tonnes, beyond the 75 tonne lifting capability of the N1. To achieve the 95 tonne payload, changes in plans and redesign of the N1 would be necessary. The measures taken were: reduction of the orbital inclination for the initial earth orbit from 65 degrees to 52 degrees; reduce the altitude of the lunar orbit from 300 km to 220 km; increase the propellant mass by supercooling the propellants prior to loading in the lunach vehicle (the kerosene to be at -15 to -20 degrees Centigrade, the liquid oxygen to -191 degrees centigrade); add six engines to the first stage; increase thrust of all the engines on the first, second, and third stages by 2%; add a fourth stabilizer. The result of all of these measures would increase the launch mass to 2800 tonnes and the payload to the required 95 tonnes. References: 21 .

MOL major subcontractors announced by prime contractor Douglas: Republic for the waste management system; Marquardt for 45 kgf and 20 kgf orientation thrusters; IBM for computers; Garrett for ECS; Scientific Data Systems for ground support equipment. References: 128 .

Ministry of General Machine Building (MOM) Decree 'On construction of the N1 payload fairing by the Khrunichev Plant' was issued. References: 474 .

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

In discussing the results of a manned test with MSC Director Robert R. Gilruth, George M. Low mentioned that a single 45-degree motion of the abort handle was required to initiate a launch abort in Apollo. Gilruth voiced concern that an abort could be caused by a single motion. Additional Details: Concern of inadvertent Saturn V abort. References: 16 .

Soft landed on Moon; returned soil samples to Earth. Landed on Moon 21 February 1972 at 19:19:00 GMT, Latitude 3.57 N, Longitude 56.50 E - Mare Fecunditatis. Luna 20 was placed in an intermediate earth parking orbit and from this orbit was sent towards the Moon. It entered lunar orbit on February 18, 1972. On 21 February 1972, Luna 20 soft landed on the Moon in a mountainous area known as the Apollonius highlands, 120 km from where Luna 18 had crashed. While on the lunar surface, the panoramic television system was operated. Lunar samples were obtained by means of an extendable drilling apparatus. The ascent stage of Luna 20 was launched from the lunar surface on 22 February 1972 carrying 30 grams of collected lunar samples in a sealed capsule. It landed in the Soviet Union on 25 February 1972. The lunar samples were recovered the following day. References: 1 , 2 , 5 , 6 , 67 , 274 , 296 .

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

Solar Maximum Mission; solar observatory; repaired 4/9/84 by STS-41C in orbit. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Optical investigations of ionosphere. EXOS-C (OHZORA). Optical study of the stratosphere and middle atmosphere. Study of the specific phenomena of the ionospheric plasma over the southern Atlantic geomagnetic anomaly zone which was discovered by the third scientific satellite 'TAIYO'. Launch vehicle Mu-3S-4, launching organization ISAS (Institute of Space and Astronautical Science). Launch time 0800 GMT. References: 1 , 2 , 5 , 6 .

Launch vehicle test. Mass model of Orlets-2 reconnaissance satellite. References: 1 , 2 , 5 , 6 .

Covered Oko constellation plane 4 - 32 degree longitude of ascending node. References: 1 , 2 , 5 , 6 , 100 .

Second generation Global Positioning System. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). References: 1 , 2 , 5 , 6 .

Released 10 Romb radar calibration subsatellites. References: 1 , 2 , 5 , 6 .

Low-power Atmospheric Compensation Experiment for SDIO. Research and exploration of the upper atmosphere and outer space. The McDonnell Douglas Corporation has provided the following information for its launch of the Losat spacecraft on 14 Feb 1990: LACE spacecraft (Losat-L), launch time 1615:00.626 GMT, ETR L aunch Complex 17. Programmed orbital parameters 95.6 min, apogee 551 km, inc. 43.1 deg. Evaluate laser beam distortion in space. References: 1 , 2 , 5 , 6 .

Relay Mirror Experiment; also known as Losat-R. RME validated stabilization, tracking, and pointing technologies for Strategic Defense Initiative (SDI) missions through a credible demonstration of a space-based relay mirror system. The Wideband Angular Vibration Experiment (WAVE) measured low-level angular vibrations affecting performance of acquisition, tracking, and pointing systems. The experiment demonstrated that a laser beam can be accurately relayed from the earth to an orbiting satellite 450 kilometers away and then back to a 3-meter target on the ground. It achieved relay beam pointing accuracy which was 16 times better than the technical requirement. WAVE demonstrated the capability to discern platform disturbance amplitudes of a few nanoradians at discrete frequencies and is therefore a candidate to fulfill similar requirements for future ATP experiments. References: 1 , 2 , 5 , 6 .

Geosynchronous ballistic missile early warning satellite. Declared purpose: 'Investigation of outer space and of processes occurring in the Earth's atmosphere'. References: 1 , 2 , 5 , 6 , 67 , 107 , 274 .

Hubble Space Telescope Servicing Mission 2 - NICMOS installation. References: 66 .

Six satellites launched by a single carrier rocket. References: 4 , 105 .

Plane 1. Ascending node 43.8 degrees. References: 4 , 276 .

Plane 1. Ascending node 43.9 degrees. References: 4 , 276 .

Plane 1. Ascending node 42.4 degrees. References: 4 , 276 .

Plane 1. Ascending node 43.6 degrees. References: 4 , 276 .