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STEREO

"STEREO satellite" redirects here. For the musical ensemble, see Stereo Satellite.
This article is about the NASA spacecraft. For other uses of "Stereo", see Stereo (disambiguation).

STEREO (Solar Terrestrial Relations Observatory) is a solar observation mission. Two nearly identical spacecraft were launched in 2006 into orbits around the Sun that cause them to respectively pull farther ahead of and fall gradually behind the Earth. This enabled stereoscopic imaging of the Sun and solar phenomena, such as coronal mass ejections.

STEREO
Illustration of a STEREO spacecraft during solar array deployment
Mission typeSolar observation
OperatorNASA
COSPAR IDSTEREO-A:2006-047A
STEREO-B:2006-047B
SATCAT no.STEREO-A: 29510
STEREO-B: 29511
Websitehttp://stereo.gsfc.nasa.gov/
http://stereo.jhuapl.edu/
Mission duration
  • Planned: 2 years
  • STEREO-A elapsed: 15 years, 8 days
  • STEREO-B final: 9 years, 10 months, 27 days
Spacecraft properties
ManufacturerJohns Hopkins University Applied Physics Laboratory
Launch mass619 kg (1,364 lb)
Dry mass547 kg (1,206 lb)
Dimensions1.14 × 2.03 × 6.47 m
3.75 × 6.67 × 21.24 ft
Power475 W
Start of mission
Launch dateOctober 26, 2006, 00:52 (2006-10-26UTC00:52) UTC
RocketDelta II 7925-10L
Launch siteCape Canaveral SLC-17B
ContractorUnited Launch Alliance
End of mission
Last contactSTEREO-B: September 23, 2016
Orbital parameters
Reference systemHeliocentric
PeriodSTEREO-A: 346 days
STEREO-B: 388 days
Instruments
SECCHISun Earth Connection Coronal and Heliospheric Investigation
IMPACTIn-situ Measurements of Particles and CME Transients
PLASTICPlasma and Suprathermal Ion Composition
S/WAVESSTEREO/WAVES
Hinode
MMS

Contact with STEREO-B was lost in 2014 after entering an uncontrolled spin preventing its solar panels from generating enough power, but STEREO-A is still operational.

Contents

This introductory video demonstrates STEREO's locations and shows a simultaneous image of the entire Sun.
Animation of STEREO's trajectory
Around the Sun
Relative to the Sun and the Earth
STEREO-A

STEREO-B Earth

Sun

The two STEREO spacecraft were launched at 00:52 UTC on October 26, 2006, from Launch Pad 17B at the Cape Canaveral Air Force Station in Florida on a Delta II 7925-10L launcher into highly elliptical geocentric orbits. The apogee reached the Moon's orbit. On December 15, 2006, on the fifth orbit, the pair swung by the Moon for a gravity assist. Because the two spacecraft were in slightly different orbits, the "ahead" (A) spacecraft was ejected to a heliocentric orbit inside Earth's orbit, while the "behind" (B) spacecraft remained temporarily in a high Earth orbit. The B spacecraft encountered the Moon again on the same orbital revolution on January 21, 2007, being ejected from Earth orbit in the opposite direction from spacecraft A. Spacecraft B entered a heliocentric orbit outside the Earth's orbit. Spacecraft A took 347 days to complete one revolution of the Sun and Spacecraft B took 387 days. The A spacecraft/Sun/Earth angle will increase at 21.650° per year. The B spacecraft/Sun/Earth angle will change −21.999° per year. Given that the length of Earth's orbit is around 940 million kilometres, both craft have an average speed, in a rotating geocentric frame of reference in which the Sun is always in the same direction, of about 1.8 km/s, but the speed varies considerably depending on how close they are to their respective aphelion or perihelion (as well as on the position of Earth). Their current locations are shown here.

Over time, the STEREO spacecraft continued to separate from each other at a combined rate of approximately 44° per year. There were no final positions for the spacecraft. They achieved 90° separation on January 24, 2009, a condition known as quadrature. This was of interest because the mass ejections seen from the side on the limb by one spacecraft can potentially be observed by the in situ particle experiments of the other spacecraft. As they passed through Earth's Lagrangian points L4 and L5, in late 2009, they searched for Lagrangian (trojan) asteroids. On February 6, 2011, the two spacecraft were exactly 180° apart from each other, allowing the entire Sun to be seen at once for the first time.

Even as the angle increases, the addition of an Earth-based view, e.g., from the Solar Dynamics Observatory, still provided full-Sun observations for several years. In 2015, contact was lost for several months when the STEREO spacecraft passed behind the Sun. They then started to approach Earth again, with closest approach sometime in 2023. They will not be recaptured into Earth orbit.

Loss of contact with STEREO-B

On October 1, 2014, contact was lost with STEREO-B during a planned reset to test the craft's automation, in anticipation of the aforementioned solar "conjunction" period. The team originally thought that the spacecraft had begun to spin, decreasing the amount of power that could be generated by the solar panels. Later analysis of the received telemetry concluded that the spacecraft was in an uncontrolled spin of about 3° per second; this was too rapid to be immediately corrected using its reaction wheels, which would become oversaturated.

NASA used its Deep Space Network, first weekly and later monthly, to try to re-establish communications.

After a silence of 22 months, contact was regained at 22:27 UTC on August 21, 2016, when the Deep Space Network established a lock on STEREO-B for 2.4 hours.

Engineers planned to work and develop software to fix the spacecraft, but once its computer was powered up, there would only have been about 2 minutes to upload the fix before STEREO-B entered failure mode again. Further, while the spacecraft was power-positive at the time of contact, its orientation would drift, and power levels fall. Two-way communication was achieved, and commands to begin recovering the spacecraft were sent through the rest of August and September.

Six attempts at communication between September 27 and October 9, 2016, failed, and a carrier wave was not detected after September 23. Engineers determined that during an attempt to despin the spacecraft, a frozen thruster fuel valve probably led to the spin increasing rather than decreasing. As STEREO-B moved along its orbit, it was hoped that its solar panels may again generate enough power to charge the battery.

Four years after the initial loss of contact, NASA terminated periodic recovery operations effective October 17, 2018.

The principal benefit of the mission was stereoscopic images of the Sun. In other words, because the satellites are at different points along the Earth's orbit, but distant from the Earth, they can photograph parts of the Sun that are not visible from the Earth. This permits NASA scientists to directly monitor the far side of the Sun, instead of inferring the activity on the far side from data that can be gleaned from Earth's view of the Sun. The STEREO satellites principally monitor the far side for coronal mass ejections — massive bursts of solar wind, solar plasma, and magnetic fields that are sometimes ejected into space.

Since the radiation from coronal mass ejections, or CMEs, can disrupt Earth's communications, airlines, power grids, and satellites, more accurate forecasting of CMEs has the potential to provide greater warning to operators of these services. Before STEREO, the detection of the sunspots that are associated with CMEs on the far side of the Sun was only possible using helioseismology, which only provides low-resolution maps of the activity on the far side of the Sun. Since the Sun rotates every 25 days, detail on the far side was invisible to Earth for days at a time before STEREO. The period that the Sun's far side was previously invisible was a principal reason for the STEREO mission.

STEREO program scientist Madhulika Guhathakurta expected "great advances" in theoretical solar physics and space weather forecasting with the advent of constant 360° views of the Sun. STEREO's observations are incorporated into forecasts of solar activity for airlines, power companies, satellite operators, and others.

STEREO has also been used to discover 122 eclipsing binaries and study hundreds more variable stars. STEREO can look at the same star for up to 20 days.

On July 23, 2012, STEREO-A was in the path of the solar storm of 2012, which was similar in strength to the Carrington Event. Its instrumentation was able to collect and relay a significant amount of data about the event. STEREO-A was not harmed by the solar storm.

Instrument locations on STEREO

Each of the spacecraft carries cameras, particle experiments and radio detectors in four instrument packages:

  • Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) has five cameras: an extreme ultraviolet imager (EUVI) and two white-light coronagraphs (COR1 and COR2). These three telescopes are collectively known as the Sun Centered Instrument Package or SCIP. They image the solar disk and the inner and outer corona. Two additional telescopes, heliospheric imagers (called the HI1 and HI2), image the space between Sun and Earth. The purpose of SECCHI is to study the 3-D evolution of coronal mass ejections through their full journey from the Sun's surface through the corona and interplanetary medium to their impact at Earth. The principal investigator for SECCHI was Russell Howard.
  • In-situ Measurements of Particles and CME Transients (IMPACT), to study energetic particles, the three-dimensional distribution of solar-wind electrons and interplanetary magnetic field. Janet Luhmann was the principal investigator for IMPACT.
  • PLAsma and SupraThermal Ion Composition (PLASTIC), led by Antoinette Galvin, to study the plasma characteristics of protons, alpha particles and heavy ions.
  • STEREO/WAVES (SWAVES) is a radio-burst tracker to study radio disturbances traveling from the Sun to the orbit of Earth. Jean Louis Bougeret was principal investigator for SWAVES, with co-investigator Michael Kaiser.

Each STEREO spacecraft had a dry mass of 547 kg (1,206 lb) and a launch mass of 619 kg (1,364 lb). In their stowed configuration, each had a length, width and height of 2.0 × 1.2 × 1.1 m (6.67 × 4.00 × 3.75 ft). Upon solar-array deployment, its width increased to 6.5 m (21.24 ft). With all of its instrument booms and antennae deployed, its dimensions are 7.5 × 8.7 × 5.9 m (24.5 × 28.6 × 19.2 ft). The solar panels can produce an average of 596 watts of power, and the spacecraft consumes an average of 475 watts.

The STEREO spacecraft are 3-axis-stabilized, and each has a primary and backup miniature inertial measurement unit (MIMU) provided by Honeywell. These measure changes to a spacecraft's attitude, and each MIMU contains three ring laser gyroscopes to detect angular changes. Additional attitude information is provided by the star tracker and the SECCHI Guide Telescope.

STEREO's onboard computer systems are based on the Integrated Electronics Module (IEM), a device that combines core avionics in a single box. Each single-string spacecraft carries two CPUs, one for command and data handling and one for guidance and control. Both are radiation-hardened 25-megahertz IBM RAD6000 processors, based on POWER1 CPUs (predecessor of the PowerPC chip found in older Macintoshes). The computers, slow by current personal computer standards, are typical for the radiation requirements needed on the STEREO mission.

STEREO also carries Actel FPGAs that use triple modular redundancy for radiation hardening. The FPGAs hold the P24 MISC and CPU24 soft microprocessors.

For data storage, each spacecraft carries a solid-state recorder able to store up to 1 gigabyte each. Its main processor collects and stores on the recorder images and other data from STEREO's instruments, which can then be sent back to Earth. The spacecraft have an X-band downlink capacity of between 427 and 750 kbit/s.

  • STEREO probes stacked at Astrotech in Florida
    August 11, 2006

  • Launch of the STEREO probes on a Delta II rocket
    October 26, 2006

  • One of the first images of the Sun taken by STEREO
    December 4, 2006

  • A lunar transit of the Sun captured during calibration of STEREO-B's ultraviolet imaging cameras. The Moon appears much smaller than it does from Earth, because the spacecraft–Moon separation was several times greater than the Earth–Moon distance.
    February 25, 2007

  • The Sun's South Pole. Material can be seen erupting from the Sun in the lower right side of the image.
    March 2007

  • A three-dimensional anaglyph taken by STEREO
    March 2007
    3D red cyan glasses are recommended to view this image correctly.

  • A three-dimensional time-for-space wiggle image taken by STEREO
    March 2007

  • Jupiter as seen by STEREO-A HI1
    November 23, 2008

  • Nearly the entire far side of the Sun
    February 2, 2011

  • Nearly the entire surface of the Sun, taken in extreme ultraviolet at 19.5 nm, with white lines showing solar coordinates (0° is directly towards Earth)
    February 10, 2011

  • A full day of Sun data from the STEREO satellites
    February 13–14, 2011

  • For STEREO's 10th anniversary, Deputy Project Scientist Terry Kucera gives an overview of the mission's top 5 success stories.

  1. "NASA Launch Schedule". NASA. September 20, 2006. RetrievedSeptember 20, 2006.
  2. Zell, Holly, ed. (February 6, 2011). "First Ever STEREO Images of the Entire Sun". NASA.
  3. Sarah, Frazier (December 11, 2015). "Saving STEREO-B: The 189-million-mile Road to Recovery". NASA.
  4. "What's New". STEREO Science Center. NASA. October 11, 2016. Archived from the original on October 23, 2016.
  5. Fox, Karen C. (August 22, 2016). "NASA Reestablishes Contact with STEREO Mission". NASA. RetrievedAugust 22, 2016.
  6. Geldzahler, Barry; et al. (2017). A Phased Array of Widely Separated Antennas for Space Communication and Planetary Radar(PDF). Advanced Maui Optical and Space Surveillance Technologies Conference. September 19–22, 2017. Wailea, Maui, Hawaii. pp. 13–14. Bibcode:2017amos.confE..82G.
  7. Mosher, Dave (August 23, 2016). "NASA may have less than 2 minutes to rescue its long-lost spacecraft". Business Insider. RetrievedAugust 24, 2016.
  8. Kucera, Therese A., ed. (October 23, 2018). "STEREO-B Status Update". NASA/STEREO Science Center. RetrievedFebruary 26, 2019.
  9. "Sun bares all for twin space probes". CBC News. February 7, 2011. RetrievedFebruary 8, 2011.
  10. Lemonick, Michael (February 6, 2011). "NASA Images the Entire Sun, Far Side and All". Time. Archived from the original on February 9, 2011. RetrievedFebruary 8, 2011.
  11. Winter, Michael (February 7, 2011). "Sun shines in twin probes' first 360-degree images". USA Today. RetrievedFebruary 8, 2011.
  12. "Stereo satellites move either side of Sun". BBC News. February 6, 2011. RetrievedFebruary 8, 2011.
  13. "STEREO turns its steady gaze on variable stars". Astronomy. Royal Astronomical Society. April 19, 2011. RetrievedApril 19, 2011.
  14. "Near Miss: The Solar Superstorm of July 2012". NASA. July 23, 2014. RetrievedJuly 24, 2014.
  15. "STEREO Spacecraft & Instruments". NASA. March 8, 2006. RetrievedMay 30, 2006.
  16. Howard, R. A.; Moses, J. D.; Socker, D. G.; Dere, K. P.; Cook, J. W. (June 2002). "Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)". Advances in Space Research. 29 (12): 2017–2026. Bibcode:2002AdSpR..29.2017H. doi:10.1016/S0273-1177(02)00147-3.
  17. Luhmann, J. G.; Curtis, D. W.; Lin, R. P.; Larson, D.; Schroeder, P.; et al. (2005). "IMPACT: Science goals and firsts with STEREO". Advances in Space Research. 36 (8): 1534–1543. Bibcode:2005AdSpR..36.1534L. doi:10.1016/j.asr.2005.03.033.
  18. Gurman, Joseph B., ed. (2007). "STEREO Spacecraft". NASA/Goddard Space Flight Center. RetrievedAugust 22, 2016.
  19. "STEREO - Solar TErrestrial RElations Observatory"(PDF). NASA. 2005. NP-2005-8-712-GSFC. RetrievedAugust 22, 2016.
  20. Beisser, Kerri (ed.). "STEREO – Characteristics". Applied Physics Laboratory. RetrievedAugust 22, 2016.
  21. "Honeywell To Provide Miniature Inertial Measurement Units For STEREO Spacecraft". Honeywell International. Archived from the original on November 25, 2005. RetrievedOctober 25, 2006.
  22. Driesman, Andrew; Hynes, Shane; Cancro, George (April 2008). "The STEREO Observatory". Space Science Reviews. 136 (1): 17–44. Bibcode:2008SSRv..136...17D. doi:10.1007/s11214-007-9286-z. S2CID 123239123.
  23. Mewaldt, R. A.; Cohen, C. M. S.; Cook, W. R.; Cummings, A. C.; Davis, A. J.; et al. (April 2008). "The Low-Energy Telescope (LET) and SEP Central Electronics for the STEREO Mission"(PDF). Space Science Reviews. 136 (1): 285–362. Bibcode:2008SSRv..136..285M. CiteSeerX10.1.1.459.4982. doi:10.1007/s11214-007-9288-x. S2CID 21286304.
Wikimedia Commons has media related toSTEREO.

STEREO
STEREO Language Watch Edit STEREO satellite redirects here For the musical ensemble see Stereo Satellite This article is about the NASA spacecraft For other uses of Stereo see Stereo disambiguation STEREO Solar Terrestrial Relations Observatory is a solar observation mission 1 Two nearly identical spacecraft were launched in 2006 into orbits around the Sun that cause them to respectively pull farther ahead of and fall gradually behind the Earth This enabled stereoscopic imaging of the Sun and solar phenomena such as coronal mass ejections STEREOIllustration of a STEREO spacecraft during solar array deploymentMission typeSolar observationOperatorNASACOSPAR IDSTEREO A 2006 047A STEREO B 2006 047BSATCAT no STEREO A 29510 STEREO B 29511Websitehttp stereo gsfc nasa gov http stereo jhuapl edu Mission durationPlanned 2 years STEREO A elapsed 15 years 8 days STEREO B final 9 years 10 months 27 daysSpacecraft propertiesManufacturerJohns Hopkins University Applied Physics LaboratoryLaunch mass619 kg 1 364 lb Dry mass547 kg 1 206 lb Dimensions1 14 2 03 6 47 m 3 75 6 67 21 24 ftPower475 WStart of missionLaunch dateOctober 26 2006 00 52 2006 10 26UTC00 52 UTCRocketDelta II 7925 10LLaunch siteCape Canaveral SLC 17BContractorUnited Launch AllianceEnd of missionLast contactSTEREO B September 23 2016Orbital parametersReference systemHeliocentricPeriodSTEREO A 346 days STEREO B 388 daysInstrumentsSECCHISun Earth Connection Coronal and Heliospheric InvestigationIMPACTIn situ Measurements of Particles and CME TransientsPLASTICPlasma and Suprathermal Ion CompositionS WAVESSTEREO WAVESSolar Terrestrial Probes program HinodeMMS Contact with STEREO B was lost in 2014 after entering an uncontrolled spin preventing its solar panels from generating enough power but STEREO A is still operational Contents 1 Mission profile 1 1 Loss of contact with STEREO B 2 Mission benefits 3 Science instrumentation 4 Spacecraft subsystems 5 Gallery 6 See also 7 References 8 External linksMission profile Edit Play media This introductory video demonstrates STEREO s locations and shows a simultaneous image of the entire Sun Animation of STEREO s trajectory Around the Sun Relative to the Sun and the Earth STEREO A STEREO B Earth Sun The two STEREO spacecraft were launched at 00 52 UTC on October 26 2006 from Launch Pad 17B at the Cape Canaveral Air Force Station in Florida on a Delta II 7925 10L launcher into highly elliptical geocentric orbits The apogee reached the Moon s orbit On December 15 2006 on the fifth orbit the pair swung by the Moon for a gravity assist Because the two spacecraft were in slightly different orbits the ahead A spacecraft was ejected to a heliocentric orbit inside Earth s orbit while the behind B spacecraft remained temporarily in a high Earth orbit The B spacecraft encountered the Moon again on the same orbital revolution on January 21 2007 being ejected from Earth orbit in the opposite direction from spacecraft A Spacecraft B entered a heliocentric orbit outside the Earth s orbit Spacecraft A took 347 days to complete one revolution of the Sun and Spacecraft B took 387 days The A spacecraft Sun Earth angle will increase at 21 650 per year The B spacecraft Sun Earth angle will change 21 999 per year Given that the length of Earth s orbit is around 940 million kilometres both craft have an average speed in a rotating geocentric frame of reference in which the Sun is always in the same direction of about 1 8 km s but the speed varies considerably depending on how close they are to their respective aphelion or perihelion as well as on the position of Earth Their current locations are shown here Over time the STEREO spacecraft continued to separate from each other at a combined rate of approximately 44 per year There were no final positions for the spacecraft They achieved 90 separation on January 24 2009 a condition known as quadrature This was of interest because the mass ejections seen from the side on the limb by one spacecraft can potentially be observed by the in situ particle experiments of the other spacecraft As they passed through Earth s Lagrangian points L4 and L5 in late 2009 they searched for Lagrangian trojan asteroids On February 6 2011 the two spacecraft were exactly 180 apart from each other allowing the entire Sun to be seen at once for the first time 2 Even as the angle increases the addition of an Earth based view e g from the Solar Dynamics Observatory still provided full Sun observations for several years In 2015 contact was lost for several months when the STEREO spacecraft passed behind the Sun They then started to approach Earth again with closest approach sometime in 2023 They will not be recaptured into Earth orbit 3 Loss of contact with STEREO B Edit On October 1 2014 contact was lost with STEREO B during a planned reset to test the craft s automation in anticipation of the aforementioned solar conjunction period The team originally thought that the spacecraft had begun to spin decreasing the amount of power that could be generated by the solar panels Later analysis of the received telemetry concluded that the spacecraft was in an uncontrolled spin of about 3 per second this was too rapid to be immediately corrected using its reaction wheels which would become oversaturated 4 3 NASA used its Deep Space Network first weekly and later monthly to try to re establish communications 3 After a silence of 22 months contact was regained at 22 27 UTC on August 21 2016 when the Deep Space Network established a lock on STEREO B for 2 4 hours 5 4 6 Engineers planned to work and develop software to fix the spacecraft but once its computer was powered up there would only have been about 2 minutes to upload the fix before STEREO B entered failure mode again 7 Further while the spacecraft was power positive at the time of contact its orientation would drift and power levels fall Two way communication was achieved and commands to begin recovering the spacecraft were sent through the rest of August and September 4 Six attempts at communication between September 27 and October 9 2016 failed and a carrier wave was not detected after September 23 Engineers determined that during an attempt to despin the spacecraft a frozen thruster fuel valve probably led to the spin increasing rather than decreasing 4 As STEREO B moved along its orbit it was hoped that its solar panels may again generate enough power to charge the battery Four years after the initial loss of contact NASA terminated periodic recovery operations effective October 17 2018 8 Mission benefits EditThe principal benefit of the mission was stereoscopic images of the Sun In other words because the satellites are at different points along the Earth s orbit but distant from the Earth they can photograph parts of the Sun that are not visible from the Earth This permits NASA scientists to directly monitor the far side of the Sun instead of inferring the activity on the far side from data that can be gleaned from Earth s view of the Sun The STEREO satellites principally monitor the far side for coronal mass ejections massive bursts of solar wind solar plasma and magnetic fields that are sometimes ejected into space 9 Since the radiation from coronal mass ejections or CMEs can disrupt Earth s communications airlines power grids and satellites more accurate forecasting of CMEs has the potential to provide greater warning to operators of these services 9 Before STEREO the detection of the sunspots that are associated with CMEs on the far side of the Sun was only possible using helioseismology which only provides low resolution maps of the activity on the far side of the Sun Since the Sun rotates every 25 days detail on the far side was invisible to Earth for days at a time before STEREO The period that the Sun s far side was previously invisible was a principal reason for the STEREO mission 10 STEREO program scientist Madhulika Guhathakurta expected great advances in theoretical solar physics and space weather forecasting with the advent of constant 360 views of the Sun 11 STEREO s observations are incorporated into forecasts of solar activity for airlines power companies satellite operators and others 12 STEREO has also been used to discover 122 eclipsing binaries and study hundreds more variable stars 13 STEREO can look at the same star for up to 20 days 13 On July 23 2012 STEREO A was in the path of the solar storm of 2012 which was similar in strength to the Carrington Event 14 Its instrumentation was able to collect and relay a significant amount of data about the event STEREO A was not harmed by the solar storm Science instrumentation Edit Instrument locations on STEREO Each of the spacecraft carries cameras particle experiments and radio detectors in four instrument packages Sun Earth Connection Coronal and Heliospheric Investigation SECCHI has five cameras an extreme ultraviolet imager EUVI and two white light coronagraphs COR1 and COR2 These three telescopes are collectively known as the Sun Centered Instrument Package or SCIP They image the solar disk and the inner and outer corona Two additional telescopes heliospheric imagers called the HI1 and HI2 image the space between Sun and Earth The purpose of SECCHI is to study the 3 D evolution of coronal mass ejections through their full journey from the Sun s surface through the corona and interplanetary medium to their impact at Earth 15 16 The principal investigator for SECCHI was Russell Howard In situ Measurements of Particles and CME Transients IMPACT to study energetic particles the three dimensional distribution of solar wind electrons and interplanetary magnetic field 15 17 Janet Luhmann was the principal investigator for IMPACT PLAsma and SupraThermal Ion Composition PLASTIC led by Antoinette Galvin to study the plasma characteristics of protons alpha particles and heavy ions 15 STEREO WAVES SWAVES is a radio burst tracker to study radio disturbances traveling from the Sun to the orbit of Earth 15 Jean Louis Bougeret was principal investigator for SWAVES with co investigator Michael Kaiser Spacecraft subsystems EditEach STEREO spacecraft had a dry mass of 547 kg 1 206 lb and a launch mass of 619 kg 1 364 lb In their stowed configuration each had a length width and height of 2 0 1 2 1 1 m 6 67 4 00 3 75 ft Upon solar array deployment its width increased to 6 5 m 21 24 ft 18 19 With all of its instrument booms and antennae deployed its dimensions are 7 5 8 7 5 9 m 24 5 28 6 19 2 ft 20 The solar panels can produce an average of 596 watts of power and the spacecraft consumes an average of 475 watts 18 19 The STEREO spacecraft are 3 axis stabilized and each has a primary and backup miniature inertial measurement unit MIMU provided by Honeywell 21 These measure changes to a spacecraft s attitude and each MIMU contains three ring laser gyroscopes to detect angular changes Additional attitude information is provided by the star tracker and the SECCHI Guide Telescope 22 STEREO s onboard computer systems are based on the Integrated Electronics Module IEM a device that combines core avionics in a single box Each single string spacecraft carries two CPUs one for command and data handling and one for guidance and control Both are radiation hardened 25 megahertz IBM RAD6000 processors based on POWER1 CPUs predecessor of the PowerPC chip found in older Macintoshes The computers slow by current personal computer standards are typical for the radiation requirements needed on the STEREO mission STEREO also carries Actel FPGAs that use triple modular redundancy for radiation hardening The FPGAs hold the P24 MISC and CPU24 soft microprocessors 23 For data storage each spacecraft carries a solid state recorder able to store up to 1 gigabyte each Its main processor collects and stores on the recorder images and other data from STEREO s instruments which can then be sent back to Earth The spacecraft have an X band downlink capacity of between 427 and 750 kbit s 18 19 Gallery Edit STEREO probes stacked at Astrotech in Florida August 11 2006 Launch of the STEREO probes on a Delta II rocket October 26 2006 One of the first images of the Sun taken by STEREO December 4 2006 Play media A lunar transit of the Sun captured during calibration of STEREO B s ultraviolet imaging cameras The Moon appears much smaller than it does from Earth because the spacecraft Moon separation was several times greater than the Earth Moon distance February 25 2007 The Sun s South Pole Material can be seen erupting from the Sun in the lower right side of the image March 2007 A three dimensional anaglyph taken by STEREO March 2007 3D red cyan glasses are recommended to view this image correctly A three dimensional time for space wiggle image taken by STEREO March 2007 Jupiter as seen by STEREO A HI1 November 23 2008 Nearly the entire far side of the Sun February 2 2011 Nearly the entire surface of the Sun taken in extreme ultraviolet at 19 5 nm with white lines showing solar coordinates 0 is directly towards Earth February 10 2011 Play media A full day of Sun data from the STEREO satellites February 13 14 2011 Play media For STEREO s 10th anniversary Deputy Project Scientist Terry Kucera gives an overview of the mission s top 5 success stories See also Edit Spaceflight portal Advanced Composition Explorer ACE launched 1997 still operational as of February 2020 update Heliophysics Living With a Star NASA program still ongoing as of February 2020 update Solar Dynamics Observatory SDO launched 2010 Parker Solar Probe launched August 2018 Solar and Heliospheric Observatory SOHO launched 1995 still observational as of February 2020 update Solar Orbiter SolO launched February 2020 TRACE launched 1998 Ulysses spacecraft launched 1990 Wind spacecraft launched 1994 still operational as of February 2020 update Zooniverse Solar StormwatchReferences Edit NASA Launch Schedule NASA September 20 2006 Retrieved September 20 2006 Zell Holly ed February 6 2011 First Ever STEREO Images of the Entire Sun NASA a b c Sarah Frazier December 11 2015 Saving STEREO B The 189 million mile Road to Recovery NASA a b c d What s New STEREO Science Center NASA October 11 2016 Archived from the original on October 23 2016 Fox Karen C August 22 2016 NASA Reestablishes Contact with STEREO Mission NASA Retrieved August 22 2016 Geldzahler Barry et al 2017 A Phased Array of Widely Separated Antennas for Space Communication and Planetary Radar PDF Advanced Maui Optical and Space Surveillance Technologies Conference September 19 22 2017 Wailea Maui Hawaii pp 13 14 Bibcode 2017amos confE 82G Mosher Dave August 23 2016 NASA may have less than 2 minutes to rescue its long lost spacecraft Business Insider Retrieved August 24 2016 Kucera Therese A ed October 23 2018 STEREO B Status Update NASA STEREO Science Center Retrieved February 26 2019 a b Sun bares all for twin space probes CBC News February 7 2011 Retrieved February 8 2011 Lemonick Michael February 6 2011 NASA Images the Entire Sun Far Side and All Time Archived from the original on February 9 2011 Retrieved February 8 2011 Winter Michael February 7 2011 Sun shines in twin probes first 360 degree images USA Today Retrieved February 8 2011 Stereo satellites move either side of Sun BBC News February 6 2011 Retrieved February 8 2011 a b STEREO turns its steady gaze on variable stars Astronomy Royal Astronomical Society April 19 2011 Retrieved April 19 2011 Near Miss The Solar Superstorm of July 2012 NASA July 23 2014 Retrieved July 24 2014 a b c d STEREO Spacecraft amp Instruments NASA March 8 2006 Retrieved May 30 2006 Howard R A Moses J D Socker D G Dere K P Cook J W June 2002 Sun Earth Connection Coronal and Heliospheric Investigation SECCHI Advances in Space Research 29 12 2017 2026 Bibcode 2002AdSpR 29 2017H doi 10 1016 S0273 1177 02 00147 3 Luhmann J G Curtis D W Lin R P Larson D Schroeder P et al 2005 IMPACT Science goals and firsts with STEREO Advances in Space Research 36 8 1534 1543 Bibcode 2005AdSpR 36 1534L doi 10 1016 j asr 2005 03 033 a b c Gurman Joseph B ed 2007 STEREO Spacecraft NASA Goddard Space Flight Center Retrieved August 22 2016 a b c STEREO Solar TErrestrial RElations Observatory PDF NASA 2005 NP 2005 8 712 GSFC Retrieved August 22 2016 Beisser Kerri ed STEREO Characteristics Applied Physics Laboratory Retrieved August 22 2016 Honeywell To Provide Miniature Inertial Measurement Units For STEREO Spacecraft Honeywell International Archived from the original on November 25 2005 Retrieved October 25 2006 Driesman Andrew Hynes Shane Cancro George April 2008 The STEREO Observatory Space Science Reviews 136 1 17 44 Bibcode 2008SSRv 136 17D doi 10 1007 s11214 007 9286 z S2CID 123239123 Mewaldt R A Cohen C M S Cook W R Cummings A C Davis A J et al April 2008 The Low Energy Telescope LET and SEP Central Electronics for the STEREO Mission PDF Space Science Reviews 136 1 285 362 Bibcode 2008SSRv 136 285M CiteSeerX 10 1 1 459 4982 doi 10 1007 s11214 007 9288 x S2CID 21286304 External links EditWikimedia Commons has media related to STEREO STEREO website by Goddard Space Flight Center STEREO website by Applied Physics Laboratory STEREO Science Center by NASA Instrument sites SECCHI website by the Naval Research Laboratory Heliospheric Imager by Rutherford Appleton Laboratory Comets Tail of Comet Encke removed by CME by Science NASA STEREO SECCHI Comets The First 5 Years by the Sungrazer Project Retrieved from https en wikipedia org w index php title STEREO amp oldid 1051070361, wikipedia, wiki, book,

books

, library,

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