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 . Space History News - People and events in development of space travel Space History News - People and events in development of space travel Space History News - People and events in development of space travel  

Space History for April 6

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647 B.C.
The earliest solar eclipse recorded by the ancient Greeks occurred.

Died, Niels H. Abel, Norwegian mathematician (infinite series)

J Chacornac discovered asteroid #25 Phocaea.

J Chacornac discovered asteroid #34 Circe.

Prosper Henry discovered asteroid #186 Celuta.

Born, Andre L. Danjon, French astronomer (Danjon Scale, color brightness of the Moon during a Lunar eclipse due to Earth's atmospheric conditions)

Born, Anthony H. G. Fokker, Dutch aircraft designer

J Palisa discovered asteroid #309 Fraternitas.

Born, Donald Wills Douglas Sr., US aircraft pioneer,_Sr.

Born, Harold E. "Doc" Edgerton, foremost high-speed photographer (invented stroboscopic photography)

P Gotz discovered asteroid #563 Suleika.

J H Metcalf discovered asteroid #755 Quintilla.

The American Radio Relay League (an organization for hams - amateur radio operators) was founded.

S Belyavskij discovered asteroid #857 Glasenappia.

B Jekhovsky discovered asteroid #977 Philippa.

Four US Army Air Corps planes left Seattle on what would become the first successful around-the-world flight when two of them returned 175 days later, on September 28.

Born, James D. Watson, American molecular biologist (DNA structure, Nobel 1962 with Crick and Wilkins "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material")

Born, Barbara M. Koschara, mother of Fred Koschara, founder of the L5 Development Group

Polytetrafluoroethylene resin (Teflon) was discovered by Roy J. Plunkett at EI Du Pont de Nemours & Company.

K Reinmuth discovered asteroid #2249 Yamamoto.

USSR's Sputnik 3 re-entered the atmosphere.

Sputnik 3, launched on 5 May 1958, was an automatic scientific laboratory spacecraft, conically shaped and 3.57 m long. The twelve scientific instruments provided data on pressure and composition of the upper atmosphere, concentration of charged particles, photons in cosmic rays, heavy nuclei in cosmic rays, magnetic and electrostatic fields, and meteoric particles. The Earth's outer radiation belts were detected during the flight. The spacecraft remained in orbit until 6 April 1960.

1962 17:16:00 GMT
USSR launched Cosmos 2, the second satellite in the Soviet Earth Satellite series, which employed radio methods to study the structure of the ionosphere.

Died, Otto Lyudvigovich Struve, Russian-American astronomer, one of the most distinguished and prolific astronomers of the mid-20th century (over 900 journal articles and books)

1965 23:45:00 GMT
Intelsat 1 ("Early Bird") was launched, the first commercial geosynchronous communication satellite.

T Smirnova discovered asteroid #1804 Chebotarev.

1967 03:21:00 GMT
NASA launched ATS 2, but the satellite failed to reach its intended orbit. However, useful (although limited) data were returned from the orbit it did achieve.

ATS 2 (Applications Technology Satellite) was a medium altitude, gravity gradient stabilized spacecraft designed to (1) test new concepts in spacecraft design, propulsion, and stabilization, (2) take high quality cloudcover pictures, (3) provide in situ measurements of the aerospace environment, and (4) test improved communication systems. The cylindrically shaped spacecraft was 56 inches (142 cm) in diameter and 72 inches (183 cm) long. Its structure consisted primarily of a corrugated thrust tube with honeycombed bulkheads secured to each end. Equipment components and payload were externally mounted on the outer surface of the thrust tube as well as on a structure that slid into the interior of the thrust tube. Electric power was provided by two solar arrays mounted on either end of the spacecraft's outer shell and by two rechargeable nickel-cadmium batteries. Extending radially outward from the side of the spacecraft were four 92.5 foot (28.2 m) adjustable gravity gradient booms. The spacecraft telemetry system consisted of four 2.1 W transmitters (two at 136.47 MHz and two at 137.35 MHz), and a microwave communications experiment.

During its launch on 6 April 1967, the booster's second stage failed to ignite, resulting in an unplanned elliptical orbit. Stresses caused by this orbit eventually induced spacecraft tumbling. In spite of these conditions, useful data were obtained from some of the experiments, most notably the cosmic ray and particle experiments, and the field detection experiments. The satellite reentered the atmosphere on 2 September 1969.

1973 02:11:00 GMT
NASA launched Pioneer 11 to Jupiter and Saturn.

Pioneer 11, launched 6 April 1973, was the second mission to investigate Jupiter and the outer Solar system, and the first to explore the planet Saturn and its main rings. Pioneer 11, like Pioneer 10, used Jupiter's gravitational field to alter its trajectory radically. It passed close to Saturn and then it followed an escape trajectory from the Solar system.

Pioneer 11 was 2.9 m long and carried a 2.74 m diameter high gain antenna. The spacecraft contained two RTG nuclear electric generators, which generated 144 W at Jupiter, but had decreased to 100 W by the time it got to Saturn. There were three reference sensors: a star (Canopus) sensor, and two Sun sensors. Attitude position could be calculated from the reference direction to the Earth and the Sun, with the known direction to Canopus as a backup. Pioneer 11's star sensor gain and threshold settings were modified, based on experience gained from the settings used on Pioneer 10. Three pairs of rocket thrusters provided spin axis control (maintained at 4.8 rpm) and change of the spacecraft velocity. The thrusters could be either fired steadily or pulsed, by command.

Communications were maintained via the omnidirectional and medium gain antennas, which operated together, connected to one receiver, while the high gain antenna was connected to the other receiver. The receivers could be interchanged by command. Two radio transmitters, coupled to two traveling wave tube (TWT) amplifiers, produced 8 W power each in the S band. Communication uplink (Earth to spacecraft) operated at 2110 MHz, and downlink (spacecraft to Earth) at 2292 MHz. At Jupiter's distance, the round trip communication time was 92 minutes. Data were received at the Deep Space Network (DSN). The spacecraft was temperature controlled to between -23 and +38 deg C (-10 to +100 deg F). An additional experiment, a low sensitivity fluxgate magnetometer, was added to the Pioneer 11 payload.

Instruments studied the interplanetary and planetary magnetic fields; Solar wind properties; cosmic rays; the transition region of the heliosphere; neutral hydrogen abundance; distribution, size, mass, flux, and velocity of dust particles; Jovian aurorae; Jovian radio waves; the atmospheres of the planets and satellites; and the surfaces of Jupiter, Saturn, and some of their satellites. Instruments carried for these experiments were a magnetometer, a plasma analyzer (for the Solar wind), a charged-particle detector, an ionizing detector, non-imaging telescopes with overlapping fields of view to detect sunlight reflected from passing meteoroids, sealed pressurized cells of argon and nitrogen gas for measuring penetration of meteoroids, a UV photometer, an IR radiometer, and an imaging photopolarimeter, which produced photographs and measured the polarization. Further scientific information was obtained from celestial mechanics and occultation phenomena.

Pioneer 11, like Pioneer 10, contains a plaque that has a drawing depicting a man, a woman, and the location of the Sun and Earth in the galaxy.

During its closest approach on 4 December 1974, Pioneer 11 passed within 34,000 km of Jupiter's cloud tops. It passed Saturn on 1 September 1979, at a distance of 21,000 km from Saturn's cloud tops, the first probe launched from Earth to do so. The spacecraft has operated on a backup transmitter since launch. Instrument power sharing began in February 1985 due to declining RTG power output. Science operations and daily telemetry ceased on 30 September 1995 when the RTG power level was insufficient to operate any experiments. As of the end of 1995 the spacecraft was located at 44.7 AU from the Sun at a nearly asymptotic latitude of 17.4 degrees above the Solar equatorial plane and was heading outward at 2.5 AU/year.

Routine tracking and project data processing operations were terminated on 31 March 1997 for budget reasons.

Obtain Pioneer 10/11 position data (heliographic coordinates)

See also the Pioneer Project page at NASA/ARC.

Pioneer 11 traveling in space, NASA artwork

1984 08:58:00 EST (GMT -5:00:00)
NASA launched STS 41-C (Challenger 5, 11th Shuttle mission) to deploy the Long Duration Exposure Facility (LDEF) satellite. During the flight, the first on-orbit spacecraft repair was completed (Solar Maximum satellite).

STS 41-C was launched into the first direct ascent trajectory for the Space Shuttle on 6 April 1984 after a countdown that proceeded without delays. Using manned maneuvering units, the astronauts replaced the altitude control system and coronagraph/polarimeter electronics box in the Solar Maximum satellite while it remained in orbit on 10 April 1984. The Long Duration Exposure Facility (LDEF) was deployed, carrying 57 experiments and left on orbit with intention of retrieving it during a later mission. Other payloads carried on STS 41-C were: the IMAX camera; Radiation Monitoring Equipment (RME); Cinema 360; and the Shuttle Student Involvement Program (SSIP) experiment.

STS 41-C ended 13 April 1984 when Challenger landed on revolution 108 on Runway 17, Edwards Air Force Base, California. Rollout distance: 8,716 feet. Rollout time: 49 seconds. Launch weight: 254,254 pounds. Landing weight: 196,975 pounds. Orbit altitude: 313 nautical miles. Orbit inclination: 28.5 degrees. Mission duration: six days, 23 hours, 40 minutes, seven seconds. Miles traveled: 2.9 million. The mission was extended one day when astronauts were initially unable to grapple the Solar Maximum Mission spacecraft. The originally planned landing at KSC was scrubbed, and the mission was extended one revolution to facilitate landing at Edwards. The orbiter was returned to Kennedy Space Center 18 April 1984.

The flight crew for STS 41-C was: Robert L. Crippen, Commander; Francis R. Scobee, Pilot; George D. Nelson, Mission Specialist; James D. A. van Hoften, Mission Specialist; Terry J. Hart, Mission Specialist.

1984 09:15:00 EST (GMT -5:00:00)
This date marked the first time 11 people were simultaneously in space, 6 cosmonauts on the USSR Salyut 7 space station, 5 on NASA's Shuttle Challenger.

Died (heart attack), Ronald Ellwin "Ron" Evans, Captain USN, NASA astronaut (Apollo 17)

Ronald E. Evans (10 November 1933 - 6 April 1990) was a NASA astronaut who occupied the Command Module pilot seat of Apollo 17, the last manned Apollo mission to the Moon. He holds the record of more time in Lunar orbit than anyone else in the world, as of 2015.

Captain Evans was one of the 19 astronauts selected by NASA in April 1966. He served as a member of the astronaut support crews for the Apollo 7 and Apollo 11 flights, and as backup Command Module pilot for Apollo 14. Evans was also backup Command Module pilot for the Apollo-Soyuz Test Project (ASTP) mission. He retired from the United States Navy on 30 April 1976, and remained active as a NASA astronaut involved in the development of NASA's Space Shuttle Program. He served as a member of the operations and training group, within the astronaut office, responsible for launch and ascent phases of the Shuttle flight program.

Evans retired from NASA in March 1977 to become a coal industry executive.

Died, Isaac Asimov, Russian-born American science fiction author

Isaac Asimov (2 January 1920 - 6 April 1992) was a Russian-born United States author and biochemist, a highly successful and exceptionally prolific writer best known for his works of science fiction and for his science books for the lay person. He also wrote mysteries (many of which were collected in the Black Widowers books) and fantasy, and has works in every major category of the Dewey Decimal System except Philosophy. He wrote or edited over 500 volumes, and an estimated 90,000 letters or postcards. Asimov was a long-time member of Mensa, albeit reluctantly (he described them as "intellectually combative"). The asteroid 5020 Asimov is named in his honor, as is Honda's humanoid prototype robot ASIMO.

1997 16:04:00 GMT
USSR launched Progress M-34 carrying 2,430 kg of cargo to the Mir space station.

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