Solar Maximum Mission
![]() Solar Maximum Mission. | |
Mission type | Solar physics |
---|---|
Operator | NASA |
COSPAR ID | 1980-014A |
SATCATno. | 11703 |
Mission duration | Final: 9 years, 9 months, 17 days |
Spacecraft properties | |
Bus | Multimission Modular Spacecraft |
Manufacturer | Fairchild Industries |
Launch mass | 2,315.0 kilograms (5,103.7 lb) |
Dimensions | 4 by 2.3 metres (13.1 by 7.5 ft) |
Start of mission | |
Launch date | February 14, 1980, 15:57:00 | UTC
Rocket | Delta 3910 |
Launch site | Cape CanaveralLC-17A |
End of mission | |
Decay date | December 2, 1989 |
Orbital parameters | |
Reference system | Geocentric |
Regime | Low Earth |
Eccentricity | 0.00029 |
Perigee altitude | 508.0 kilometers (315.7 mi) |
Apogee altitude | 512.0 kilometers (318.1 mi) |
Inclination | 28.5 degrees |
Period | 94.80 minutes |
Mean motion | 15.19 |
![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/58/Capturing_the_Solar_Maximum_Mission_satellite.jpg/220px-Capturing_the_Solar_Maximum_Mission_satellite.jpg)
TheSolar Maximum Missionsatellite(orSolarMax) was designed to investigateSolarphenomena, particularlysolar flares.It was launched on February 14, 1980. The SMM was the first satellite based on theMultimission Modular Spacecraftbus manufactured by Fairchild Industries, a platform which was later used forLandsats 4and5[1]as well as theUpper Atmosphere Research Satellite.
After anattitude controlfailure in November 1980 it was put in standby mode until April 1984 when it was repaired by a Shuttle mission.
The Solar Maximum Mission ended on December 2, 1989, when the spacecraftre-entered the atmosphereand burned up over the Indian Ocean.[2]
Instruments[edit]
Name | Target | Principal Investigator |
---|---|---|
Coronagraph/Polarimeter: 446.5–658.3 nm, 1.5- 6 sq.solar radiifov,6.4 arcsec res. | Solar corona, prominences, and flares | House, Lewis L.,High Altitude Observatory |
Ultraviolet Spectrometer and polarimeter 175.0–360.0 nm raster imager, 0.004 nm sp.res. | Solar UV,Earth'satmosphere | Tandberg-Hanssen, Einar A.,NASAMarshall Space Flight Center |
Soft X-ray Polychromator: raster imager, crystal spectrom. in parts of 0.14–2.25 nm | Solar flares, active solar regions | Acton, Loren W.,Lockheed Palo Alto,Culhane, JUniversity College, London,Leonard, Gabriel, Alan-Henri,Rutherford Appleton Laboratory |
Hard X-ray Imaging Spectrometer:fov6.4 arcmin, 8 or 32 arcsec res, 3.5–30 keV | Solar active regions and flares | de Jager, Cornelis,University of Utrecht |
Hard X-ray Burst Spectrometer: CsI(Na), 15 energy channels covering 20–260 keV | Solar flares and active regions | Frost, Kenneth J.,NASA Goddard Space Flight Center |
Gamma-ray Spectrometer: NaI(T1),0.01-100 MeV in 476 channels, 16.4 s per spectrum | solar gamma-rays | Chupp, Edward L,University of New Hampshire |
Active Cavity Radiometer Irradiance Monitor: 0.001-1000 micrometer solar flux | solar irradiance | Willson, Richard C,NASA Jet Propulsion Laboratory |
Failure and repair[edit]
The white-light coronagraph/polarimeter (C/P) took coronal images for about six months from March 1980 before suffering an electronics failure in September that prevented operation.[2]
In November 1980, the second of four fuses in SMM'sattitude controlsystem failed, causing it to rely on itsmagnetorquersin order to maintain attitude. In this mode, only three of the seven instruments on board were usable, as the others required the satellite to be accurately pointed at the Sun. The use of the satellite's magnetorquers prevented the satellite from being used in a stable position and caused it to "wobble" around its nominally sun-pointed attitude.[3]SMM was left in standby mode for 3 years.[2]
The first orbiting, uncrewed satellite to be repaired in space, SMM was notable in that its useful life compared with similarspacecraftwas significantly increased by the direct intervention of a crewed space mission. DuringSTS-41-Cin April 1984, theSpace ShuttleChallengerrendezvoused with the SMM, astronautsJames van HoftenandGeorge Nelsonattempted to use theManned Maneuvering Unitto capture the satellite and to bring it into the orbiter's payload bay for repairs and servicing. The plan was to use an astronaut-piloted Maneuvering Unit to grapple the satellite with the Trunnion Pin Attachment Device (TPAD) mounted between the hand controllers of the Maneuvering Unit, null its rotation rates, and allow the Shuttle to bring it into the Shuttle's payload bay for stowage. Three attempts to grapple the satellite using the TPAD failed. The TPAD jaws could not lock onto Solar Max because of an obstructing grommet on the satellite not included in its blueprints.
This led to an improvised plan which nearly ended the satellite's mission. The improvisation had the astronaut use his hands to grab hold of a solar array and null the rotation with a push from the Maneuvering Unit's thrusters. Instead, this attempt induced higher rates and in multiple axes; the satellite was tumbling out of control and quickly losing battery life. SMM Operations Control Center engineers shut down all non-essential satellite subsystems and with a bit of luck were able to recover the satellite minutes before total failure. The ground support engineers then stabilized the satellite and nulled its rotation rates for capture with theShuttle's robotic arm.This proved to be a much better plan. The satellite had been fitted with one of the arm'sgrapple fixturesso that the robotic arm was able to capture and maneuver it into the shuttle's payload bay for repairs.[4]
During the mission, the SMM's entire attitude control system module and the electronics module for the coronagraph/polarimeter instrument were replaced, and a gas cover was installed over the X-ray polychromator.[4]Their successful work added five more years to the lifespan of the satellite. The mission was depicted in the 1985IMAXmovieThe Dream Is Alive.
Discovery of comets[edit]
10 comets were discovered in images from the SMM.[5]
Designation | Observation date | Discoverer[6] |
---|---|---|
C1987 T2 (SMM-1) | Oct 5,1987 | Dr Orville Chris St. Cyr |
C/1987 U4 (SMM-2) | Oct 17,1987 | O. C. St. Cyr |
1988l (SMM-3) | Jun 27, 1988 | O. C. St. Cyr |
1988m (SMM-4) | Aug 21, 1988 | David Kobe, C. Waugh |
1988n (SMM-5) | Oct 11-12 1988 | O.C. St. Cyr[7] |
1988p (SMM-6) | Nov 18, 1988 | O.C. St. Cyr[8] |
1988q (SMM-7) | Oct 24, 1988 | Andrew L. Stanger[9] |
1989m (SMM-8) | Jun 2, 1989 | O.C. St. Cyr, David L. Kobe[10] |
1989q (SMM-9) | Jul 8,1989 | O.C. St. Cyr[11] |
1989x (SMM-10) | Sep 28,1989 | O.C. St. Cyr[12] |
Findings[edit]
![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Cp22liberationdaytransient.png/220px-Cp22liberationdaytransient.png)
Significantly, the SMM's ACRIM instrument package showed that contrary to expectations, the Sun is actually brighter during thesunspotcycle maximum (when the greatest number of dark 'sunspots' appear). This is because sunspots are surrounded by bright features calledfaculae,which more than cancel the darkening effect of the sunspot.
The major scientific findings from the SMM are presented in several review articles in a monograph.[13]
End of mission[edit]
SMM's orbit slowly decayed due to atmospheric drag taking it down into denser regions.
TheMarch 1989 geomagnetic stormwas reported to have led to SMM dropping half a kilometre at the start of the storm and 5 kilometres over the whole period.[14]
SMM lost attitude control on November 17, 1989, and re-entry and burn-up occurred on December 2, 1989, over the Indian Ocean.[2]
See also[edit]
- Advanced Composition Explorer
- Charles Hyder
- Parker Solar Probe
- Solar and Heliospheric Observatory
- WIND (spacecraft)
References[edit]
- ^Suzuki, Masaharu (11 February 1999)."TOPEX/Poseidon – Description of Mission".University of Texas. Archived fromthe originalon 20 November 2013.Retrieved9 July2013.
The satellite bus was taken from the Multimission Modular Spacecraft (MMS), which has been proven on previous MMS-based missions: the Solar Maximum Mission and Landsat 4 and 5.
- ^abcdSOLAR MAXIMUM MISSION (SMM)
- ^"STS-41-C Press Kit"(PDF).NASA.Retrieved9 July2013.
All four of those instruments require pointing accuracy from the spacecraft and could not function effectively with the spacecraft spinning through space with its longitudinal axis pointed toward the sun, as it has since the attitude control system failure.
- ^ab"STS-41-C Press Kit"(PDF).NASA.Retrieved9 July2013.
Repairs to be made during the mission include replacing the attitude control system module, replacing the main electronics box on the Polarimeter/Polarimeter, and placing a cover over the gas vent of the X-Ray Polychrometer.
- ^"Sungrazing comets observed by the solar maximum mission coronagraph".Archived fromthe originalon 2022-07-02.Retrieved2022-07-02.
- ^My Solwind Comets (by Rainer Kracht)
- ^[url=https://ui.adsabs.harvard.edu/abs/1988IAUC.4668....1S/abstract}}
- ^[https://ui.adsabs.harvard.edu/abs/1988IAUC.4684....1S/abstract}}
- ^[https://ui.adsabs.harvard.edu/abs/1988IAUC.4692....1S/abstract}}
- ^[http:// cbat.eps.harvard.edu/iauc/04700/04793.html}}
- ^[https://ui.adsabs.harvard.edu/abs/1989IAUC.4815....1S/abstract}}
- ^[https://ui.adsabs.harvard.edu/abs/1989IAUC.4884....1S/abstract}}
- ^Strong, Keith T.; Saba, Julia L. R.; Haisch, Bernhard M.; Schmelz, Joan T. (1999). Strong KT; Saba JLR; Haisch BM; Schmelz JT (eds.).The many faces of the sun: a summary of the results from NASA's Solar Maximum Mission.New York: Springer.Bibcode:1999mfs..conf.....S.
- ^"Effects of the March 1989 Solar Activity",by Allen, Frank, Sauer, Reiff, inEos,November 14, 1989 p. 1488
External links[edit]
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