Ionospheric Connection Explorer

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Ionospheric Connection Explorer
ICON and Airglow - Daytime View.jpg
Artist's concept of ICON
Mission typeEarth observation
OperatorUC Berkeley SSL / NASA
Websiteicon.ssl.berkeley.edu
Mission durationPlanned: 2 years
Spacecraft properties
BusLEOStar-2[1]
ManufacturerUC Berkeley / Northrop Grumman
Launch mass287 kg (633 lb)[2]
DimensionsHeight: 193 cm x 106 cm diameter[3]
solar panel: 254 cm x 84 cm
Power780 watts[2]
Start of mission
Launch datePlanned: December 2018 or January 2019[4][5]
RocketPegasus XL[6]
Launch siteStargazer
Cape Canaveral Skid Strip[4]
ContractorNorthrop Grumman[4]
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee575 km (357 mi)[2]
Inclination27°
Period97 minutes
EpochPlanned[1]
← TESS

The Ionospheric Connection Explorer (ICON)[7] is a planned satellite designed to investigate changes in the Earth's ionosphere. ICON will study the interaction between Earth's weather systems and space weather driven by the Sun, and how this interaction drives turbulence in the upper atmosphere. It is hoped that a better understanding of this dynamic will mitigate its effects on communications, GPS signals, and technology in general.[7][8] It is part of NASA's Explorers program and will be operated by UC Berkeley's Space Sciences Laboratory.[9]

On 12 April 2013, NASA announced that ICON, along with Global-scale Observations of the Limb and Disk (GOLD), had been selected for development[10] with the cost capped at US$200 million, excluding launch costs.[6] The principal investigator of ICON is Thomas Immel at the University of California, Berkeley.[10][11]

ICON was originally scheduled to launch in December 2017 and has been repeatedly delayed because of problems with its Pegasus XL rocket. Also, it was due to launch on 26 October 2018 but the launch was rescheduled to 7 November 2018, and postponed again just 28 minutes before launch.[5]

Overview[edit]

ICON's observational geometry, showing both in-situ and remote sensing of the ionosphere-thermosphere system.

Once launched, ICON will perform a two-year mission to observe conditions in both the thermosphere and ionosphere.[10] ICON will be equipped with four instruments: a Michelson interferometer, built by the United States Naval Research Laboratory, will measure the winds and temperatures in the thermosphere; an ion drift meter, built by UT Dallas, will measure the motion of charged particles in the ionosphere; and two ultraviolet imagers built at UC Berkeley will observe the airglow layers in the upper atmosphere in order to determine both ionospheric and thermospheric density and composition.

Many low-Earth orbiting satellites, including the International Space Station, fly through the ionosphere and can be affected by its changing electric and magnetic fields. The ionosphere also acts as a conduit for many communications signals, such as radio waves and the signals that make GPS systems work. The ionosphere is where space weather manifests, creating unpredicted conditions such as electric currents that can cause electrical charging of satellites, changing density that can affect satellite orbits, and shifting magnetic fields that can induce current in power systems, causing strain, disrupt communications and navigation or even blackouts.[3] Improved understanding of this environment can help predict such events and improve satellite design.[3]

Launch planning[edit]

ICON was originally scheduled to launch in December 2017 and has been repeatedly delayed because of problems with its Pegasus XL rocket. Most recently, it was due to launch on 26 October 2018 but the launch was postponed indefinitely at that time.[5] In 2017, ICON was going to be launched from Kwajalein Atoll in the Pacific.[12][13] When that was launch was scrubbed, it was possible it to ferry the launch vehicle using the air-launch aircraft Stargazer back the United States where a new launch site was chosen, Cape Canaveral in Florida.[14] The October 2018 launch was to be from Cape Canaveral, Florida before issues were detected with some new components.[15] Whereas the delay in 2017 had to due concerns over the rocket-aircraft separation system;the launch system has a good track record launching small science payloads for NASA, and just had a successful launched in December 2016.[16] The launch system has placed more than 80 satellites in low orbit since its first in 1990.[17]

Launch windows:[18]

  • 2017, Kwajalein Atoll, Pacific Ocean
  • June 2018, Kwajalein Atoll
  • October 2018, Cape Canaveral, FL

Northrop Grumman's Pegasus XL rocket is carried aloft by the Stargazer aircraft to approximately 40,000 feet over the open ocean, where it is released and free-falls five seconds before igniting its first-stage rocket motor.[3] The aircraft can also ferry the launch vehicle to different sites.[19]

Science payload[edit]

ICON carries four scientific instruments designed to image even the faintest plasma or airglow to build up a picture of the ionosphere's density, composition and structure. The complete instrument payload has a mass of 130 kg (290 lb) and are listed below: [20][21]

  • Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI)
  • Ion Velocity Meter (IVM) is an ion drift meter
  • Extreme Ultra-Violet (EUV), an imager
  • Far Ultra-Violet (FUV), an imager

MIGHTI was developed at the United States Naval Research Laboratory, IVM at the University of Texas, and EUV and FUV were developed at the University of California.[22] MIGHTI measures wind speed and temperature between 90 to 300 km in altitude.[23] The velocity measurements are gathered by observing the doppler shift in the red and green lines of atomic oxygen.[24] This is done with the Doppler Asymmetric Spatial Heterodyne (DASH) which uses échelle gratings.[25] The temperature measurements are done by photometeric observations with a CCD.[26] MIGHTI is designed to detect wind speeds as low as 10 mph even though the spacecraft would be traveling at over 14,000 mph (to stay in orbit).[27]

IVM collects in situ data about ions in the local environment around the spacecraft, whereas EUV and FUV are cameras.[28] EUV is designed to observe height and density of the daytime ionosphere, and detect the glow of oxygen.[29]

The solar panels produce 780 watts,[2] but the instruments' power consumption ranges between 209-265 watts when in science mode.[3]

References[edit]

  1. ^ a b "ICON: Exploring where Earth's Weather meets Space Weather" (PDF). University of California, Berekeley. Retrieved 4 February 2018.
  2. ^ a b c d ICON Factsheet. (PDF) Northrop Grumman. Accessed: 24 October 2018.
  3. ^ a b c d e ICON - Press Kit (PDF) from October 2018. NASA.
  4. ^ a b c Granath, Bob (21 September 2018). "NASA's ICON launch now targeted for Oct. 26 - ICON Mission". NASA Blogs. Retrieved 21 September 2018.
  5. ^ a b c ICON of Delay? NASA, Northrop Grumman Postpone Earth Satellite Mission Yet Again. Meghan Bartels, Space.com. 23 October 2018.
  6. ^ a b Leone, Dan (20 October 2015). "Heliophysics Small Explorer Solicitation Set for First Half of 2016". SpaceNews. Retrieved 21 October 2015.
  7. ^ a b "Ionospheric Connection Explorer". University of California, Berkeley.
  8. ^ "ICON Mission Overview". NASA. 2016-03-31. Retrieved 4 February 2018.
  9. ^ Sanders, Robert (16 April 2013). "UC Berkeley selected to build NASA's next space weather satellite". Berkeley News. Retrieved 19 January 2016.
  10. ^ a b c Harrington, J. D. (5 April 2013). "NASA Selects Explorer Investigations for Formulation". NASA. Retrieved 6 April 2013.
  11. ^ "ICON Project Management". University of California, Berkeley. Retrieved 14 October 2017.
  12. ^ "Northrop Grumman Innovation Systems updates ICON launch status – NASASpaceFlight.com". www.nasaspaceflight.com. Retrieved 2018-10-26.
  13. ^ "Launch of NASA ionospheric probe delayed to examine rocket issue – Spaceflight Now". spaceflightnow.com. Retrieved 2018-10-26.
  14. ^ "Northrop Grumman Innovation Systems updates ICON launch status – NASASpaceFlight.com". www.nasaspaceflight.com. Retrieved 2018-10-26.
  15. ^ "Northrop Grumman Innovation Systems updates ICON launch status – NASASpaceFlight.com". www.nasaspaceflight.com. Retrieved 2018-10-26.
  16. ^ "Launch of NASA ionospheric probe delayed to examine rocket issue – Spaceflight Now". spaceflightnow.com. Retrieved 2018-10-26.
  17. ^ "Pegasus celebrates quarter of a century milestone – NASASpaceFlight.com". www.nasaspaceflight.com. Retrieved 2018-10-26.
  18. ^ [1]
  19. ^ "Northrop Grumman Innovation Systems updates ICON launch status – NASASpaceFlight.com". www.nasaspaceflight.com. Retrieved 2018-10-26.
  20. ^ "Ionospheric Connection Explorer (ICON) Satellite - Aerospace Technology". Aerospace Technology. Retrieved 2018-10-11.
  21. ^ "ICON (Ionospheric Connection Explorer) - Satellite Missions - eoPortal Directory". directory.eoportal.org. Retrieved 2018-10-11.
  22. ^ "Ionospheric Connection Explorer (ICON) Satellite - Aerospace Technology". Aerospace Technology. Retrieved 2018-10-11.
  23. ^ Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay (2017-04-20). "Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration". Space Science Reviews. 212 (1–2): 553–584. doi:10.1007/s11214-017-0358-4. ISSN 0038-6308. PMC 6042234. PMID 30008488.
  24. ^ Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay (2017-04-20). "Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration". Space Science Reviews. 212 (1–2): 553–584. doi:10.1007/s11214-017-0358-4. ISSN 0038-6308. PMC 6042234. PMID 30008488.
  25. ^ Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay (2017-04-20). "Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration". Space Science Reviews. 212 (1–2): 553–584. doi:10.1007/s11214-017-0358-4. ISSN 0038-6308. PMC 6042234. PMID 30008488.
  26. ^ Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay (2017-04-20). "Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration". Space Science Reviews. 212 (1–2): 553–584. doi:10.1007/s11214-017-0358-4. ISSN 0038-6308. PMC 6042234. PMID 30008488.
  27. ^ [2]
  28. ^ "Counting Down to the Ionospheric Connection Explorer (ICON) Launch". SciTechDaily. 2018-10-18. Retrieved 2018-10-26.
  29. ^ "Counting Down to the Ionospheric Connection Explorer (ICON) Launch". SciTechDaily. 2018-10-18. Retrieved 2018-10-26.

External links[edit]

Media related to Ionospheric Connection Explorer at Wikimedia Commons