Deep Space Climate Observatory

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Deep Space Climate Observatory
DSCOVR rendering (transparent bg).png
Artist's rendering of DSCOVR
Names Triana
Mission type Solar observation
Operator NASA / NOAA
COSPAR ID 2015-007A
SATCAT № 40390
Website http://www.nesdis.noaa.gov/DSCOVR/
Mission duration Planned: 5 years[1]
Elapsed: 2 months and 14 days
Spacecraft properties
Launch mass 570 kg (1,257 lb)[2]
Dimensions Undeployed: 1.4 × 1.8 m (54 × 72 in)[2]
Power 600W
Start of mission
Launch date 11 February 2015, 23:03:02 (2015-02-11UTC23:03:02Z) UTC
Rocket Falcon 9 v1.1
Launch site Cape Canaveral SLC-40
Contractor SpaceX
Orbital parameters
Reference system Heliocentric
Regime L1 point[1]
Instruments
DSCOVR Logo (transparent bg).png

Deep Space Climate Observatory (DSCOVR) (formerly known as Triana, unofficially known as GoreSat[3]) is a NOAA Earth observation and space weather satellite launched by SpaceX on a Falcon 9 launch vehicle on 11 February 2015 from Cape Canaveral.[4]

It was originally developed as a NASA satellite proposed in 1998 by then-Vice President Al Gore for the purpose of Earth observation. It is intended to be positioned at the Sun-Earth L1 Lagrangian point, 1,500,000 km (930,000 mi) from Earth, to monitor variable solar wind condition, provide early warning of approaching coronal mass ejections and observe phenomena on Earth including changes in ozone, aerosols, dust and volcanic ash, cloud height, vegetation cover and climate. At this location it will have a continuous view of the Sun and the sunlit side of the Earth. The satellite is planned to orbit the Sun-Earth L1 point in a six-month period, with a spacecraft-Earth-Sun angle varying from 4 to 15 degrees.[5] It will take full-Earth pictures about every two hours and be able to process them faster than other Earth observation satellites.[6]

DSCOVR has an expected arrival at L1 around the beginning of June 2015.[7]

History[edit]

Deep Space Climate Observatory

Originally known as Triana, named after Rodrigo de Triana, the first of Columbus's crew to sight land in the Americas, the satellite's original purpose was to provide a near-continuous view of the entire Earth and make that live image available via the Internet. Gore hoped not only to advance science with these images, but also to raise awareness of the Earth itself, updating the influential Blue Marble photograph taken by Apollo 17.[8] In addition to an imaging camera, a radiometer would take the first direct measurements of how much sunlight is reflected and emitted from the whole Earth (albedo). This data could constitute a barometer for the process of global warming. The scientific goals expanded to measure the amount of solar energy reaching Earth, cloud patterns, weather systems, monitor the health of Earth's vegetation, and track the amount of UV light reaching the surface through the ozone layer.

In 1999, NASA's Inspector General reported that "the basic concept of the Triana mission was not peer reviewed", and "Triana's added science may not represent the best expenditure of NASA's limited science funding."[9] The Bush Administration put the project on hold shortly after George W. Bush's inauguration.[10] Congress asked the National Academy of Sciences whether the project was worthwhile.[when?] The resulting report stated that the mission was "strong and scientifically vital."[11]

Falcon 9 second stage carrying DSCOVR, with Earth in background

Triana was removed from its original launch opportunity on STS-107 (the ill-fated Columbia mission in 2003). The $100 million satellite remained in storage for the duration of the Bush administration. In November 2008 the satellite was removed from storage and began recertification for a possible launch on board a Delta II or a Falcon 9.[12][13] Al Gore used part of his book Our Choice (2009) as an attempt to revive debate on the DSCOVR payload. The book mentions legislative efforts by Senators Barbara Mikulski and Bill Nelson to get the satellite launched.[14] NASA renamed the satellite Deep Space Climate Observatory (DSCOVR), in an attempt to regain support for the project. In February 2011, the Obama administration attempted to secure funding to re-purpose the DSCOVR spacecraft as a solar observatory to replace the aging Advanced Composition Explorer (ACE) spacecraft.[15]

In September 2013 NASA cleared DSCOVR to proceed to the implementation phase targeting an early 2015 launch,[16] which had been announced in December 2012 as launching on a SpaceX Falcon 9 rocket.[17] NASA Goddard Space Flight Center is providing management and systems engineering to the mission.

Spacecraft[edit]

Diagram of DSCOVR

DSCOVR is built on the SMEX-Lite spacecraft bus, and has a launch mass of approximately 570 kg (1,257 lb). The main science instrument sets are the Sun-observing Plasma Magnetometer (PlasMag) and the Earth-observing NIST Advanced Radiometer (NISTAR) and Earth Polychromatic Imaging Camera (EPIC). DSCOVR has two deployable solar arrays, a propulsion module, boom, and antenna.[18]

Instruments[edit]

PlasMag[edit]

The Plasma-Magnetometer (PlasMag) measures solar wind for space weather predictions. It has three instruments:[19]

  • Magnetometer measures magnetic field.
  • Faraday cup measures positively charged particles.
  • Electrostatic analyzer measures electrons.

NISTAR[edit]

National Institute of Standards and Technology Advanced Radiometer (NISTAR) measures irradiance of the sunlit face of the Earth. This data is to be used to study changes in Earth's radiation budget caused by natural and human activities.[20] The radiometer measures in four channels:

  • For total radiation in ultraviolet, visible and infrared in range of 0.2-100 µm.
  • For reflected solar radiation in ultraviolet, visible and near infrared in range of 0.2-4 µm.
  • For reflected solar radition in infrared in range of 0.7-4 µm.
  • For calibration purposes in range of 0.3-1 µm.

EPIC[edit]

The Earth Polychromatic Imaging Camera (EPIC) takes images of the sunlit side of Earth for various Earth sciences purposes, in 10 different channels from ultraviolet to near infrared. Ozone and aerosol levels will be monitored, as well as cloud dynamics, properties of the land and vegetations. [21]

Launch[edit]

Launch attempt history[edit]

Attempt Planned Result Turnaround Reason Decision point Weather go (%) Notes
1 8 Feb 2015, 11:10:00 pm scrubbed --- technical (T02:30:00) >90 range issues: tracking,[22] first stage video transmitter issues noted
2 10 Feb 2015, 11:04:49 pm scrubbed 1 day, 23 hours, 55 minutes weather 80 upper level winds at the launch pad exceeded 100 knots (190 km/h; 120 mph) at 25,000 feet (7,600 m)
3 11 Feb 2015, 11:03:32 pm success 0 days, 23 hours, 59 minutes >90

Post-launch flight test[edit]

Launch of DSCOVR aboard a Falcon 9 rocket on 11 February 2015

The launch provider SpaceX had planned to conduct a test flight where they would attempt to bring the booster rocket back through the atmosphere and land the nearly-empty first stage on a 90-by-50-meter (300 ft × 160 ft) floating landing platform.[23][24] Relative to earlier tests, the booster return on DSCOVR was much more challenging, especially in atmospheric reentry due to the deep space nature of the Earth-Sun L1 launch trajectory for DSCOVR. SpaceX expected deceleration-force loads to be twice as high, and rocket heating to quadruple, over the reentry conditions on Falcon 9 Flight 14.[25] In the event, the drone ship was in ocean surface conditions that made the barge landing infeasible, and so the landing platform attempt was called off and the test made an over-water soft landing, continuing the collection of returnable booster test data on all the earlier phases of the flight test, including the high-speed, high-load atmospheric entry.[26]

See also[edit]

References[edit]

  1. ^ a b "NOAA Satellite and Information Service: Deep Space Climate Observatory (DSCOVR)" (PDF). NOAA. Retrieved 14 March 2015. 
  2. ^ a b "DSCOVR: Deep Space Climate Observatory" (PDF). NOAA. January 2015. Retrieved 14 March 2015. 
  3. ^ Mellow, Craig (August 2014). "Al Gore's Satellite". Air & Space/Smithsonian. Retrieved 12 December 2014. 
  4. ^ Boyle, Alan (10 February 2015). "SpaceX Scrubs Falcon 9's DSCOVR Launch (Again) Due to Winds". NBCNews. Retrieved 15 February 2015. 
  5. ^ "DSCOVR Mission Hosts Two NASA Earth-Observing Instruments". NOAA Satellite and Information Service. US Federal Government. 21 October 2014. Retrieved 9 February 2015. 
  6. ^ Phillips, Ari (4 February 2015). "A Sneak Peek at NASA’s New Satellite That has Been 16 Years in the Making". ThinkProgress. 
  7. ^ "DSCOVR has reached the halfway mark to the L1 position". NOAA. 24 February 2015. Retrieved 2 April 2015. 
  8. ^ Leary, Warren (1 June 1999). "Politics Keeps a Satellite Earthbound". The New York Times. Retrieved 24 July 2009. 
  9. ^ "Assessment of the Triana Mission, G-99-013, Final Report" (PDF). Office of Inspector General. NASA. 10 September 1999. Retrieved 7 February 2009. 
  10. ^ Donahue, Bill (7 April 2011). "Who killed the Deep Space Climate Observatory?". Popular Science. Retrieved 12 December 2014. 
  11. ^ "NASA's Triana Mission Scientific Evaluation Completed". Earth Observatory (NASA). 8 March 2000. Archived from the original on 11 October 2008. Retrieved 3 February 2008. 
  12. ^ Clark, Stephen (2 March 2009). "Mothballed satellite sits in warehouse, waits for new life". Spaceflight ow. Retrieved 2 March 2009. 
  13. ^ "Triana/DSCOVR Spacecraft Successfully Revived from Mothballs". 15 February 2009. Archived from the original on 12 June 2009. Retrieved 7 September 2009. 
  14. ^ Gore, Al (2009). "Chapter 17". Our Choice. Rodale. ISBN 978-1-59486-734-7. 
  15. ^ Clark, Stephen (21 February 2011). "NOAA taps DSCOVR satellite for space weather mission". Spaceflight Now. Archived from the original on 24 February 2011. 
  16. ^ Leslie, John (10 September 2013). "DSCOVR Mission Moves Forward to 2015 Launch". NASA/NOAA. Retrieved 10 September 2013. 
  17. ^ "Spacex awarded two EELV-class missions from the United States Air Force" (Press release). SpaceX. 5 December 2012. Retrieved 12 December 2014. 
  18. ^ "Spacecraft and Instruments". NOAA. Retrieved 10 February 2015. 
  19. ^ "NOAA Satellite and Information Service: Deep Space Climate Observatory (DSCOVR): Plasma-Magnetometer (PlasMag)" (PDF). NOAA. Retrieved 10 February 2015. 
  20. ^ "NOAA Satellite and Information Service: Deep Space Climate Observatory (DSCOVR): National Institute of Standards & Technology Advanced Radiometer (NISTAR)" (PDF). NOAA. Retrieved 10 February 2015. 
  21. ^ "NOAA Satellite and Information Service: Deep Space Climate Observatory (DSCOVR): Enhanced Polychromatic Imaging Camera (EPIC)" (PDF). NOAA. Retrieved 10 February 2015. 
  22. ^ Cresswell, Miriam (8 February 2015). "SpaceX DISCOVR launch scrubbed". Space Alabama. WAAY-TV. Retrieved 2 April 2015. 
  23. ^ Bergin, Chris (17 December 2014). "SpaceX confirms CRS-5 launch slip to January 6". NASA Spaceflight. Retrieved 24 December 2014. 
  24. ^ Graham, William (8 February 2015). "SpaceX Falcon 9 ready for DSCOVR mission". NASA Spaceflight. Retrieved 8 February 2015. 
  25. ^ Musk, Elon (8 February 2015). "Rocket reentry will be much tougher...". Twitter.com. Retrieved 8 February 2015. 
  26. ^ Wall, Mike (11 February 2015). "SpaceX Won't Try Rocket Landing on Drone Ship After Satellite Launch Today". Space.com. Retrieved 20 March 2015. 

External links[edit]

Further reading[edit]