SOLRAD 9
 Solrad 9. | |
| Mission type | Solarscience |
|---|---|
| Operator | NASA |
| COSPAR ID | 1968-017A[1] |
| SATCATno. | 3141 |
| Mission duration | 22 years, 8 months and 10 days (final) |
| Spacecraft properties | |
| Manufacturer | Naval Research Laboratory |
| Launch mass | 198 kilograms (437 lb) |
| Start of mission | |
| Launch date | 5 March 1968, 18:28UTC[2][3] |
| Rocket | Scout B-1S160C |
| Launch site | Wallops LA-3A[3] |
| End of mission | |
| Last contact | March 1974 |
| Decay date | 16 November 1990[4] |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Eccentricity | 0.01372 |
| Perigee altitude | 448 kilometers (278 mi) |
| Apogee altitude | 638 kilometers (396 mi) |
| Inclination | 59.4° |
| Period | 95.5 minutes |
| Epoch | 5 March 1968[1] |
| Instruments | |
| 14Photometers(UVandX-ray) | |
Solrad 9,also knownExplorer 37andExplorer SE-B,was one of the SOLRAD (Solar Radiation) program that began in 1960 to provide continuous coverage of solar radiation with a set of standard photometers.
Launch and operations[edit]
Was launched on March 5, 1968 fromWallops Flight Facility,Virginia,United States,withScoutlaunch vehicle.[5]
Solrad 9 was a spin stabilized satellite oriented with its spin axisperpendicularto the sun-satellite line so that the 14 solarX-rayandUVphotometerspointing radially outward from itsequatorial beltviewed the sun with each revolution. Data were simultaneously transmitted viaFM/AMtelemetryand recorded in a core memory that read out its contents on command. Individual scientists and institutions were invited to receive and use the data transmitted on the 136 MHz telemetry band on the standard IRIG channels three through eight.[1][6]
In the time that elapsed between the termination ofSolrad 8operations in August 1967 and the orbiting of Solrad 9, solar activity data were obtained using photometers in satellitesOSO-4andOGO-4.
Solrad 9 was particularly important among the Solrad series satellites because thanks to the collected data were useful to predict the behavior of the sun during the period of the first crewed missions of theApollo Program,starting from the first,Apollo 7,it is therefore useful to draw up a mission program to ensure, from this point of view, the safety ofastronauts.[6]It recorded important data on one of the strongestsolar stormsthat occurred betweenApollo 9andApollo 10and which would have produced potentially hazardous (to even fatal) effects to astronauts had then been in space (if the spacecraft were outside the Earth's protectivemagnetosphere) at the time.[7]
As of July 1971, it was decided to use theSolrad 10memory data, put into orbit on the 8th of the same month, and so continued until June 1973, when theSolrad 10data storage device had a bad operation andNASAbegan to read data from the memory of Solrad 9. The satellite remained active until February 25, 1974, when the gas reserves useful to maintain control of the facility were over. Once the stability was lost, in fact, the satellite became useless and therefore was turned off.
UnlikeSolrad 8,its predecessor, Solrad 9 did not remain in orbit and returned to theatmosphere,disintegrating on November 16, 1990.[1]
References[edit]
- ^abcd"Solrad 9".NSSDCA.NASA Goddard Space Flight Center.Retrieved17 June2018.
This article incorporates text from this source, which is in thepublic domain.
- ^"Solar Observing satellites".Colorado State University.Retrieved17 June2018.
- ^abMcDowell, Jonathan."Launch Log".Joanthan's Space Page.Retrieved17 June2018.
- ^"Explorer 37 (SE-B)".n2yo.Retrieved17 June2018.
- ^Vítek, Antonín (7 December 2004)."1968-017A - Explorer 37".Space 40(in Czech).Retrieved17 June2018.
- ^ab"United States Space Science Program: Report to COSPAR".National Academies, 1969, p. 27.National Research Council. Space Science Board,COSPAR.1969.Retrieved17 June2018.
- ^Lockwood, Mike; M. Hapgood (2007)."The Rough Guide to the Moon and Mars"(PDF).Astron. Geophys.48(6): 11–17.Bibcode:2007A&G....48f..11L.doi:10.1111/j.1468-4004.2007.48611.x.
