SOLRAD 4

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SOLRAD 4
SOLRAD 4 satellite
NamesGRAB 3
SOLar RADiation 4
SR 4
GREB 3
Mission typeSolar X-Rays
OperatorUnited States Naval Research Laboratory (USNRL)
COSPAR ID1962-F02 (SR4GREB)
Mission durationFailed to orbit
Spacecraft properties
Spacecraft typeSOLRAD
ManufacturerNaval Research Laboratory (NRL)
Launch mass25 kg (55 lb)
Dimensions51 cm (20 in)
Start of mission
Launch date24 January 1962, 09:30 GMT
RocketThor-Ablestar
Launch siteCape Canaveral, LC-17B
ContractorDouglas Aircraft Company
End of mission
Decay dateFailed to orbit
Orbital parameters
Reference systemGeocentric orbit (planned)
RegimeLow Earth orbit
Perigee altitude930 km
Apogee altitude930 km
Inclination66.80°
Period103.00 minutes

SOLRAD (SOLar RADiation) 4 was a solar X-rays, ultraviolet, and electronic surveillance satellite. Developed by the United States Navy's United States Naval Research Laboratory (USNRL), it was the fourth in both the SOLRAD and the GRAB (Galactic Radiation and Background) programs.

The satellite was to be orbited along with ionospheric study satellite LOFTI-2, the United States Army's range calibration satellite SECOR, Navy surveillance calibration satellite Surcal, and the University of Iowa's Van Allen radiation belts-studying Injun 2 satellite. This unprecedented five-in-one mission, called "Composite 1" and "Buckshot", ended in failure on 24 January 1962 after its Thor-Ablestar's second stage failed to deliver the payloads to orbit.

Background

The United States Navy's United States Naval Research Laboratory (USNRL) established itself as a player early in the Space Race with the development and management of Project Vanguard (1956–1959),[1] America's first satellite program. After Vanguard, the Navy's next major goal was to use the observational high ground of Earth's orbit to survey Soviet radar locations and frequencies. This first space surveillance project was called "GRAB", later expanded into the more innocuous backronym, Galactic Radiation And Background.[2] As American space launches were not classified until late 1961,[3][4] a cover mission sharing the satellite bus was desired to conceal GRAB's electronic surveillance mission from its intended targets.[2]

The field of solar astronomy provided such cover. Since the invention of the rocket, astronomers had wanted to fly instruments above the atmosphere to get a better look at the

Sounding rockets had shown that solar output was unpredictable and fluctuated rapidly. A long-term, real-time observation platform above the Earth's atmosphere – in other words, a satellite – was required to properly chart the Sun's radiation, determine its effects on the Earth, and correlate it with ground-based observations of the Sun in other wavelengths of light.[5]
: 63 

Thus, the SOLRAD project was conceived to address several NRL goals at once:

SOLRAD 4 had two successful predecessors in SOLRAD 1 and SOLRAD 3, both of which made significant contributions to the understanding of ultraviolet and X-ray astronomy in the previous two years,[5]: 64–68  and which returned an abundance of intelligence on Soviet air defense radar installations.[9]

Spacecraft

Like its predecessors, SOLRAD 4 was roughly spherical, modeled on the Vanguard satellite (which also had been developed by the United States Naval Research Laboratory), and included both the scientific SOLRAD and the electronic surveillance GRAB packages within the same satellite. Mass of 25 kg,[10] the fourth in the SOLRAD series was more heavily instrumented than prior SOLRADS. Instead of one X-ray photometer, like SOLRAD 1 and SOLRAD 2, or two, like SOLRAD 3, it carried four X-ray photometers, allowing it to detect more intense and higher energy X-rays. Three of the photometers were shielded against Van Allen radiation belts (which could spoil results) by magnets, as had been done on earlier missions. The fourth was protected by a beryllium shield. It was hoped that SOLRAD 4 would not only conduct basic research into solar X-ray astronomy, but also determine the hazard hard X-rays posed to astronauts and satellites.[11]

Another point of difference between SOLRAD 4 and its predecessors was its four Lyman-alpha detectors.[11] Used for measuring ultraviolet radiation, two such detectors had been included on SOLRAD 1 and SOLRAD 2 to determine the impact of solar ultraviolet on radio reception.[12] None had been measured, and the detectors had been deleted from SOLRAD 3. They were reinstated on SOLRAD 4 not for solar study, but for night-time measurement to see if ambient Lyman-alpha radiation constituted a threat to astronauts and satellites.[11]

Mission

SOLRAD 4 and other satellites on Composite 1

On 24 January 1962 at 09:30 GMT,

Van Allen radiation belts-studying Injun 2 satellite. This unprecedented five-in-one mission, called "Composite 1" and "Buckshot", ended in failure: the Thor first stage performed properly, but the Ablestar second stage developed insufficient velocity to attain orbit. While the exact cause was not immediately known, there were indications that the Ablestar had not separated cleanly from the Thor stage, instead tumbling end over end.[14] The estimated cost of the lost rocket and payload was US$3.5 million.[15]

Legacy

The SOLRAD/GRAB series flew once more (unsuccessfully), finishing with the

Explorer program numbers. The last in this final series of SOLRAD satellites flew in 1976. In all, there were thirteen operational satellites in the SOLRAD series.[2] The GRAB program was declassified in 1998.[9]

See also

References

  1. ISBN 978-1-97353-209-5. Archived from the original on 3 March 2016. Retrieved 21 March 2019. Public Domain This article incorporates text from this source, which is in the public domain
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  2. ^
    ISBN 978-1-85109-519-3
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  3. ISBN 978-1-56098-830-4
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  4. OCLC 1032873498
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  5. ^
    OCLC 860060668. Public Domain This article incorporates text from this source, which is in the public domain
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  6. ^ ""Bonus" Payload Set for Transit 2A Orbit". Aviation Week and Space Technology. McGraw Hill Publishing Company. 20 June 1960. Archived from the original on 9 January 2019. Retrieved 8 January 2019.
  7. ISBN 978-0-309-18120-4. Archived from the original on 7 January 2019. Retrieved 6 January 2019.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  8. ^ Parry, Daniel (2 October 2011). "NRL Center for Space Technology Reaches Century Mark in Orbiting Spacecraft Launches". U.S. Naval Research Laboratory. Archived from the original on 7 January 2019. Retrieved 12 January 2019. Public Domain This article incorporates text from this source, which is in the public domain.
  9. ^ a b LePage, Andrew. "Vintage Micro: The First ELINT Satellites". Drew Ex Machina. Retrieved 18 January 2019.
  10. ^ a b c "History of the Poppy Satellite System" (PDF). NRO. 14 August 2006. Retrieved 15 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  11. ^ a b c "Navy Plans to Launch Quintuple Satellite". Aviation Week and Space Technology. McGraw Hill Publishing Company. 15 January 1962. Retrieved 15 January 2019.
  12. ^ "Transit, Two Small Satellites Work Despite Malfunction". Aviation Week and Space Technology. McGraw Hill Publishing Company. 10 July 1961. Retrieved 8 January 2019.
  13. ^ a b c McDowell, Jonathan. "Launch Log". Jonathon's Space Report. Retrieved 15 January 2021.
  14. ^ "Composite Launch Attempt Fails". Aviation Week and Space Technology. McGraw Hill Publishing Company. 29 January 1962. Retrieved 15 January 2019.
  15. ^ "5-in-1 Rocket Takes Off, Fizzles Out". Salt Lake Tribune. 25 January 1964. Retrieved 15 January 2021.
  16. ^ "Review and Redaction Guide" (PDF). National Reconnaissance Office. 2008. Retrieved 15 January 2021. Public Domain This article incorporates text from this source, which is in the public domain.
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