“A-train (satellite constellation)”的意思、由来-开放百科全书

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A-train (satellite constellation)

释义

Satellites
Active Past Failed
References
External links

The A-train (from Afternoon Train) is a satellite constellation of five Earth observation satellites of varied nationality in sun-synchronous orbit at an altitude of {{convert|705|km|mi|abbr=on}} above the Earth.^[1]

The orbit, at an inclination of 98.14°, crosses the equator each day at around 1:30 pm solar time, giving the constellation its name (the "A" stands for "afternoon"^[2]) and crosses the equator again on the night side of the Earth, at around 1:30 am.

They are spaced a few minutes apart from each other so their collective observations may be used to build high-definition three-dimensional images of the Earth's atmosphere and surface.

Satellites

Active

The train, {{as of|2019|01|lc=on}},^[3]^[4] consists of four active satellites:

OCO-2, lead spacecraft in formation, replaces the failed OCO and was launched for NASA on July 2, 2014.
GCOM-W1 "SHIZUKU", follows OCO-2 by 11 minutes, launched by JAXA on May 18, 2012.
Aqua, runs 4 minutes behind GCOM-W1, launched for NASA on May 4, 2002.
Aura, a multi-national satellite, lags Aqua by 15 minutes, crossing the equator 8 minutes behind due to different orbital track to allow for synergy with Aqua, launched for NASA on July 15, 2004.

Past

PARASOL, launched by CNES on December 18, 2004 and moved to another (lower) orbit on December 2, 2009.^[5]
CloudSat, launched with CALIPSO on April 28, 2006 and moved to another (lower) orbit on February 22, 2018.^[4]
CALIPSO, launched on April 28, 2006, is a joint effort of CNES and NASA. It follows CloudSat by no more than 8.5 seconds. CALIPSO was moved to CloudSat's new orbit in September 2018.^[6]

Failed

OCO,^[7] destroyed by a launch vehicle failure on February 24, 2009,^[8] and was replaced by OCO-2.
Glory,^[9] failed during launch on a Taurus XL rocket on March 4, 2011, and would have flown between CALIPSO and Aura.

References

1. ^«A-train Symposium October 2007: Constellation keeps its promises», CNESMAG, January 2008
2. ^NASA, Introducing the A-Train, 10.26.10 (accessed April 30 2012)
3. ^{{cite web|url=http://atrain.nasa.gov/index.php|title=Individual A-Train Missions|last=|first=|date=June 5, 2012|website=|archive-url=|archive-date=|dead-url=|accessdate=2013-11-15}}
4. ^¹{{Cite news|url=https://www.nasa.gov/feature/jpl/cloudsat-exits-the-a-train|title=CloudSat Exits the "A-Train"|last=Greicius|first=Tony|date=2018-02-23|work=NASA|access-date=2018-04-01|language=en}}
5. ^CNES News on Calipso
6. ^[https://www.nasa.gov/feature/langley/sister-satellites-briefly-separated-working-together-again Sister Satellites, Briefly Separated, Working Together Again]
7. ^OCO homepage
8. ^Media Briefing Scheduled To Discuss Orbiting Carbon Observatory Mission
9. ^Glory homepage {{webarchive|url=https://web.archive.org/web/20080916170224/http://glory.gsfc.nasa.gov/ |date=2008-09-16 }}

External links

NASA A-Train Portal
NASA satellite program impacted
NASA Program Page
Orbital Sciences Program Page
{{cite journal |journal=Physics Today |title=Touring the atmosphere aboard the A-Train |first1=T.S. |last1=L'Ecuyer |first2=J.H. |last2=Jiang |year=2010 |pages=36–41 |volume=63 |issue=7 |url=http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_63/iss_7/36_1.shtml |doi=10.1063/1.3463626 |bibcode=2010PhT....63g..36L |deadurl=yes |archiveurl=https://archive.is/20130224065020/http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_63/iss_7/36_1.shtml |archivedate=2013-02-24 |df= }}

1 : Earth observation satellites

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