Solar Maximum Mission

The Solar Maximum Mission satellite (or SolarMax) was designed to investigate Solar phenomena, particularly solar flares. It was launched on February 14, 1980. The SMM was the first satellite based on the Multimission Modular Spacecraft bus manufactured by Fairchild Industries, a platform which was later used for Landsats 4 and 5[1] as well as the Upper Atmosphere Research Satellite.

After an attitude control failure in Nov 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 spacecraft re-entered the atmosphere and burned up over the Indian Ocean.[2]

Solar Maximum Mission
Solar Maximum Mission.
Mission typeSolar physics
COSPAR ID1980-014A
SATCAT no.11703
Mission duration9 years
Spacecraft properties
BusMultimission Modular Spacecraft
ManufacturerFairchild Industries
Launch mass2,315.0 kilograms (5,103.7 lb)
Dimensions~4 by 2.3 metres (13.1 by 7.5 ft)
Start of mission
Launch dateFebruary 14, 1980, 15:57:00 UTC
RocketDelta 3910
Launch siteCape Canaveral LC-17A
End of mission
Decay dateDecember 2, 1989
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee508.0 kilometers (315.7 mi)
Apogee512.0 kilometers (318.1 mi)
Inclination28.5 degrees
Period94.80 minutes
Mean motion15.19
Capturing the Solar Maximum Mission satellite
Astronaut George Nelson attempts to capture the Solar Maximum Mission satellite during STS-41-C


Experiments on board the Solar Maximum Mission
Name Target Principal Investigator
Coronagraph/Polarimeter: 446.5–658.3 nm, 1.5- 6 radii fov, 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's atmosphere Tandberg-Hanssen, Einar A., NASA Marshall 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, J University College, London, Leonard, Gabriel, Alan-Henri, Rutherford Appleton Laboratory
Hard X-ray Imaging Spectrometer: fov 6.4 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

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's attitude control system failed, causing it to rely on its magnetorquers in 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, unmanned satellite to be repaired in space, SMM was notable in that its useful life compared with similar spacecraft was significantly increased by the direct intervention of a manned space mission. During STS-41-C in April 1984, the Space Shuttle Challenger rendezvoused with the SMM, astronauts James van Hoften and George Nelson attempted to use the Manned Maneuvering Unit to 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 Trunion 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 by 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 the Shuttle's robotic arm. This proved to be a much better plan. The satellite had been fitted with one of the arm's grapple fixtures so 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 1985 IMAX movie The Dream Is Alive.


A coronal transient as seen by the SMM on May 5, 1980

Significantly, the SMM's ACRIM instrument package showed that contrary to expectations, the Sun is actually brighter during the sunspot cycle maximum (when the greatest number of dark 'sunspots' appear). This is because sunspots are surrounded by bright features called faculae, 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.[5]

The SMM discovered ten sungrazing comets between 1987 and 1989.[6]

End of mission

SMM's orbit slowly decayed due to atmospheric drag taking it down into denser regions.

The March 1989 geomagnetic storm was reported to have led to SMM dropping half a kilometre at the start of the storm and 3 miles over the whole period.[7]

SMM lost attitude control on November 17, 1989, and re-entry and burn-up occurred on 2 December 1989 over the Indian Ocean.[2]

See also


  1. ^ Suzuki, Masaharu (11 February 1999). "TOPEX/Poseidon – Description of Mission". University of Texas. Retrieved 9 July 2013. 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.
  3. ^ "STS-41-C Press Kit" (PDF). NASA. Retrieved 9 July 2013. 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.
  4. ^ a b "STS-41-C Press Kit" (PDF). NASA. Retrieved 9 July 2013. 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.
  5. ^ Strong KT; Saba JLR; Haisch BM; Schmelz JT, eds. (1999). The many faces of the sun : a summary of the results from NASA's Solar Maximum Mission. New York: Springer. Bibcode:1999mfs..conf.....S.
  6. ^ "JPL comet catalogue".
  7. ^ "Effects of the March 1989 Solar Activity", by Allen, Frank, Sauer, Reiff, in Eos, November 14, 1989 p. 1488

External links


The Active Cavity Radiometer Irradiance Monitor Satellite, or ACRIMSAT is a defunct satellite and instrument that was one of the 21 observational components of NASA's Earth Observing System program. The instrument followed upon the ACRIM1 and ACRIM2 instruments that were also launched on multi-instrument satellite platforms. ACRIMSAT was launched on 20 December 1999 from Vandenberg Air Force Base as the secondary payload on the Taurus rocket that launched KOMPSAT. It was placed into a high inclination, 700 km. sun-synchronous orbit from which the ACRIM3 instrument monitored total solar irradiance (TSI). Contact with the satellite was lost on 14 December 2013.

Cape Canaveral Air Force Station Space Launch Complex 17

Cape Canaveral Air Force Station Space Launch Complex 17 (SLC-17), previously designated Launch Complex 17 (LC-17), was a launch site at Cape Canaveral Air Force Station, Florida used for Thor and Delta rocket launches between 1958 and 2011.

It was built in 1956 for use with the PGM-17 Thor missile, the first operational ballistic missile in the arsenal of the United States. More recently the launch complex has been used for vehicles in the Delta rocket family, derived from the Thor missile, to launch probes to the Moon and planets, solar observatories and weather satellites.

SLC-17 features two expendable launch vehicle (ELV) launch pads, 17A and 17B. The pads were operated by the US Air Force's 45th Space Wing and have supported more than 300 Department of Defense, NASA and commercial missile and rocket launches. Following the last military launch, in August 2009, SLC-17A was withdrawn from use, and SLC-17B was transferred to NASA for two remaining launches.

Pad 17A supported its first Thor missile launch on 3 August 1957, and Pad 17B supported its first Thor launch on 25 January 1957. The site was upgraded in the early 1960s to support a variety of more modern ELVs, which were derived from the basic Thor booster. The modern ELVs based on Thor came to be called the Delta family of rockets.

Thirty-five early Delta rocket missions were launched from Complex 17 between the beginning of 1960 and the end of 1965. At that time the complex was operated by the Air Force. The Air Force transferred Complex 17 to NASA in 1965, but the site was returned to the Air Force in 1988 to support the Delta II program.

As Delta II launches continued over the next decade, Pad 17B was modified in 1997 to support a new, more powerful launch vehicle, the Delta III, which made its maiden flight from the complex on 26 August 1998. The launch ended in failure, as did a second launch the next year. After a third launch on 23 August 2000 placed a mass simulator into a lower than planned orbit, the program was abandoned.

Among the major NASA missions launched from the complex were the Explorer and Pioneer space probes, all of the Orbiting Solar Observatories, the Solar Maximum Mission, Biological Satellites (BIOS), the International Cometary Explorer, the TIROS and GOES meteorology satellites, and the Mars Exploration Rovers Spirit and Opportunity.

On 10 September 2011, a Delta II 7920H-10C made the final launch from Space Launch Complex 17, carrying NASA's GRAIL spacecraft. All remaining Delta II launches will be made from Vandenberg Air Force Base in California.

At 7am EDT (1100 GMT) on 12 July 2018, both historic launch towers had been demolished via controlled demolition to make way for Moon Express to build and test its lunar lander.

Coronal loop

Coronal loops form the basic structure of the lower corona and transition region of the Sun. These highly structured loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing a cooler plasma in footpoints. This plasma is cooler because of the magnetic field radially directed which stop the convective process in these regions. Then heat can't be transported toward the surface by convection, and the contrast between the photosphere and this cooler plasma gives the impression of dark spots, or sunspots.

Frank Cepollina

Frank J. "Cepi" Cepollina (born December 6, 1936 in Castro Valley, California is an American engineer and inventor. He was officially inducted to the National Inventors Hall of Fame for his pioneering concept of in-orbit satellite servicing in May 2003. His organizational leadership style has been compared to that of Al Davis of the National Football League's Oakland Raiders.

Helen Mason (physicist)

Helen Elizabeth Mason OBE is a British theoretical physicist at the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. She holds a Personal Readership in Solar Physics.

Helen Mason has been involved in many solar space projects such as Skylab, Yohkoh and the Solar Maximum Mission. She has been working as a co-investigator of the Solar and Heliospheric Observatory project launched in 1995, and more recently on Hinode and the Solar Dynamics Observatory. She is a Fellow of St Edmunds College.

Kenneth John Frost

Kenneth John Frost (October 3, 1934 – August 5, 2013) was a pioneer in the early space program, designing and flying instruments to detect and measure X-rays and gamma-rays in space, primarily from the Sun. He was the first to suggest the use of an active scintillation shield operated in electronic anticoincidence with the primary detector to reduce the background from cosmic ray interactions, an innovation that made sensitive hard X-ray and gamma-ray astronomy possible. He was an American astrophysicist at Goddard Space Flight Center working as a civil servant for the National Aeronautics and Space Administration. During his career, he was the project scientist of the Solar Maximum Mission, principal investigator of six science instruments, the head of the Solar Physics Branch, and the Associate Director of Space Sciences.

Frost received the John C. Lindsay Memorial Award in 1982 for his role as Project Scientist and one of the prime instigators of the Solar Maximum Mission (SMM). The Lindsay Award is Goddard's highest science award given each year "To recognize the Goddard employee who best exhibits the qualities of broad scientific accomplishments in the area of Space Science." It is named after John Lindsay, the man who hired Frost more than twenty years earlier and who was responsible for starting the series of Orbiting Solar Observatories (OSOs) that produced many of the advances in solar physics and astrophysics in the 1960s and '70s.

List of unmanned NASA missions

Since 1958, NASA has overseen more than 1,000 unmanned missions into Earth orbit or beyond. It has both launched its own missions, and provided funding for private-sector missions. A number of NASA missions, including the Explorers Program, Voyager program, and New Frontiers program, are still ongoing.

Lockheed Martin Solar and Astrophysics Laboratory

The Lockheed Martin Solar and Astrophysics Laboratory (LMSAL) is part of the Lockheed Martin Advanced Technology Center (ATC) that is known primarily for its scientific work in the field of solar physics, astronomy and space weather. The LMSAL team is part of Lockheed Martin Space Systems and has close affiliations with NASA and the solar physics group at Stanford University.

Located in Palo Alto, California, LMSAL is involved in many ground- and space-based missions that study the Sun, with a sharp focus on basic research into understanding and predicting space weather and the behavior of the Sun, including its impacts on Earth and climate.

Michael Weiss (engineer)

Michael L. Weiss is an American engineer who is known for his contributions to on-orbit satellite servicing missions, particular of the Hubble Space Telescope. Weiss most recently served as deputy program director on the Hubble Space Telescope program at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Weiss received his B.S. and M.S. in Aerospace Engineering from the University of Maryland at College Park in 1978 and 1983. He has led the systems engineering for missions including the Solar Maximum Mission, Upper Atmosphere Research Satellite, the Compton Gamma Ray Observatory and Extreme Ultraviolet Explorer as well as the first shuttle based satellite repair, the Solar Maximum Repair Mission in 1984.Weiss was involved in all 5 Hubble Space Telescope servicing missions. He directed systems development during servicing mission 1 and servicing mission 2. He served as deputy program director through servicing mission 4. He also led the Mishap Investigation Board investigating the failure of a balloon launch from Australia carrying a gamma-ray telescope for to the University of California at Berkeley.Weiss is an accomplished diver having accumulated over 200 hours in NASA’s Neutral Buoyancy Laboratory in training Shuttle flight crews on servicing techniques and procedures. Outside NASA, he an open water diver and underwater photographer.Weiss has appeared on NOVA, the Discovery Channel, NPR, and the BBC discussing Hubble and the servicing missions.

MultiMission Modular Spacecraft

MultiMission Modular Spacecraft is a NASA design of modular spacecraft, intended to save cost and ease servicing.MMS were intended to be 'Shuttle compatible', i.e. recoverable/servicable by the Space Shuttle orbiter.It was used for:

Solar Maximum Mission, 1980

Landsat 4, 1982

Landsat 5, 1984

UARS, 1991

EUVE, 1992

TOPEX/Poseidon, 1992


The NASA Standard Spacecraft Computer-1 (NSSC-1) was a computer developed as a standard component for the MultiMission Modular Spacecraft at the Goddard Space Flight Center (GSFC) in 1974. The basic spacecraft was built of standardized components and modules, for cost reduction. The computer had 18 bits of core memory or plated wire memory; up to 64 k. 18 bits was chosen because it gave more accuracy (x4) for data over a 16 bit machine. Floating point was not supported.

Richard Harrison (scientist)

Richard Anthony Harrison MBE FRAS FInstP is the Head of Space Physics Division and Chief Scientist at the Rutherford Appleton Laboratory in the United Kingdom. He is best known for his magnetic twisting theory involving the Coronal heating problem of the Sun's atmosphere.

He was born in Solihull, West Midlands (County) and attended Solihull Sixth Form College and Birmingham University.

Whilst in his late teens, and as a keen acoustic guitarist, he set up a band called Capella. Fellow band members were his brother, Jeremy, and David J Nutting. They performed locally and were influenced by John Denver and The Eagles, amongst others.

Richard Harrison received his B.Sc in 1979 and his Ph.D. in 1983 from the University of Birmingham, United Kingdom. He then became SER (Research Fellow at the Space Research Department, University of Birmingham, and from 1986 Scientific Officer up to grade 7 of the Astrophysics division of the Rutherford Appleton Laboratory. From 1985-1986 he was visiting Scientists at the HAO in Boulder, United States. His main interest has been solar physics research, and he was instigator of the first multi-observatory observation of coronal mass ejections, joint leader at the 81.5 MHz radio array at Cambridge, principal scientists for the first mm observations of the Sun and principal investigator of the Coronal Diagnostic Spectrometer on SOHO. Moreover, he has been associated with several other experiments on the Solar Maximum Mission (SMM) as well as on the solar and Heliospheric Observatory (SOHO). He has been author or co-author of more than 70 articles published in international journals and books.

Richard Harrison served as Editor of the Society’s journal Annales Geophysicae and as General Editor for the COSPAR Information Bulletin as well as member of several committees related to the Royal Society and to ESA, COSPAR or EGS.

Richard Harrison was awarded the NCAR Outstanding Publication Prize and the NASA Group Achievement Award, and he is Fellow of the Royal Astronomical Society, Member of the International Astronomical Union and Corresponding Member of the International Academy of Astronautics.

He was awarded the MBE (Member of the Order of the British Empire) in the 2004 Queen's Birthday Honours List for his services to Solar Research.


SMM may refer to:


Company of Mary, a Roman Catholic missionary religious congregation

St. Mary Magdalene, a church in Toronto, CanadaScience:

Single-molecule magnet

S-Methylmethionine, a derivative of methionine

Soft Magnetic Materials Conference

Solar Maximum Mission or SolarMax, an artificial satellite

Stepwise mutation model of allelic frequenciesTechnology:

Scattering-matrix method, to solve Maxwell's equations

Storage Modification Machine in computing

System Management Mode, of a CPU

Maxwell (microarchitecture) GPU

Super Mario Maker, a side-scrolling platform game and game creation system

Social media marketingOther:

Master of Sacred Music

Semporna Airport, IATA code

Sex Money Murda, a street gang in America

Shanghai Metals Market, China

Single Monthly Mortality, for prepayment of loansmm may refer to:

Musasa language ISO 639-3 code


STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the Space Shuttle Challenger. It launched on February 3, 1984, and landed on February 11 after deploying two communications satellites. It was also notable for including the first untethered spacewalk.

Following STS-9, the flight numbering system for the Space Shuttle program was changed. Thus, the next flight, instead of being designated STS-11, became STS-41-B; the original successor to STS-9, STS-10, was cancelled due to payload delays.


STS-41-C was NASA's 11th Space Shuttle mission, and the fifth mission of Space Shuttle Challenger. The launch, which took place on April 6, 1984, marked the first direct ascent trajectory for a shuttle mission. During the mission, Challenger's crew captured and repaired the malfunctioning Solar Maximum Mission ("Solar Max") satellite, and deployed the Long Duration Exposure Facility (LDEF) experimental apparatus. STS-41-C was extended one day due to problems capturing the Solar Max satellite, and the landing on April 13 took place at Edwards Air Force Base, instead of at Kennedy Space Center as had been planned. The flight was originally numbered STS-13.

Solar Max

Solar Max may refer to:

The solar maximum period of greatest sunspot activity in the 11 year solar cycle of the Sun

The Solar Maximum Mission satellite to investigate solar phenomena

Space Shuttle Challenger

Space Shuttle Challenger (Orbiter Vehicle Designation: OV-099) was the second orbiter of NASA's space shuttle program to be put into service, after Columbia. Challenger was built by Rockwell International's Space Transportation Systems Division, in Downey, California. Its maiden flight, STS-6, began on April 4, 1983. The orbiter was launched and landed nine times before breaking apart 73 seconds into its tenth mission, STS-51-L, on January 28, 1986, resulting in the death of all seven crew members, including a civilian school teacher. It was the first of two shuttles to be destroyed in flight, the other being Columbia, in 2003. The accident led to a two-and-a-half-year grounding of the shuttle fleet; flights resumed in 1988, with STS-26 flown by Discovery. Challenger was replaced by Endeavour, which was built from structural spares ordered by NASA in the construction contracts for Discovery and Atlantis.

Whistler (radio)

A whistler is a very low frequency or VLF electromagnetic (radio) wave generated by lightning. Frequencies of terrestrial whistlers are 1 kHz to 30 kHz, with a maximum amplitude usually at 3 kHz to 5 kHz. Although they are electromagnetic waves, they occur at audio frequencies, and can be converted to audio using a suitable receiver. They are produced by lightning strikes (mostly intracloud and return-path) where the impulse travels along the Earth's magnetic field lines from one hemisphere to the other. They undergo dispersion of several kHz due to the slower velocity of the lower frequencies through the plasma environments of the ionosphere and magnetosphere. Thus they are perceived as a descending tone which can last for a few seconds. The study of whistlers categorizes them into Pure Note, Diffuse, 2-Hop, and Echo Train types.

Voyager 1 and 2 spacecraft detected whistler-like activity in the vicinity of Jupiter, implying the presence of lightning there.

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