SAC-D - Wikipedia

Argentine Earth science satellite For the Senate Appropriations Committee - Defense, see United States Senate Appropriations Subcommittee on Defense. SAC-D

Artist's impression of SAC-D
Mission type	Technology demonstration Earth observation
Operator	CONAE
COSPAR ID	2011-024A
SATCAT no.	37673
Website	conae.gov.ar
Mission duration	Planned: 5 years Final: 3 years, 11 months, 28 days
Spacecraft properties
Bus	Small Satellite Standard Platform[1]
Manufacturer	INVAP[2]
Launch mass	1,350 kg (2,977 lb)[2]
Dimensions	2.7 × 5.0 m (8.9 × 16.4 ft)[2]
Power	1,362 watts[2]
Start of mission
Launch date	10 June 2011, 14:20:13 (2011-06-10UTC14:20:13) UTC[3]
Rocket	Delta II 7320-10C
Launch site	Vandenberg SLC-2W
Contractor	United Launch Alliance
End of mission
Disposal	Spacecraft failure
Last contact	8 June 2015 (2015-06-09)
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Semi-major axis	7,031.6 km (4,369.2 mi)
Eccentricity	0.000181
Perigee altitude	652.2 km (405.3 mi)
Apogee altitude	654.7 km (406.8 mi)
Inclination	98.0 degrees
Period	97.8 minutes
Epoch	17 December 2015, 15:47:23 UTC[4]
Instruments   Aquarius MWR Microwave Radiometer NIRST New Infrared Sensor Technology HSC High Sensitivity Camera DCS Data Collection System TDP Technological Demonstration Package ROSA Radio Occultation Sounder for Atmosphere ICARE-NG Influence of Space Radiation on Advanced Components-New Generation SODAD Orbital System for an Active Detection of Debris

SAC-D (Spanish: Satélite de Aplicaciones Científicas-D, meaning Satellite for Scientific Applications-D), also known as Aquarius after its primary instrument, is an Argentine Earth science satellite built by INVAP and operated by CONAE.[1] SAC-D was launched from Vandenberg Air Force Base on 10 June 2011, with a planned mission life of five years.[1] Due to a power system failure, the mission was ended on 8 June 2015.[5]

Description[edit]

SAC-D was an international collaboration between the space agencies of Argentina and the United States, CONAE and NASA, with participation from Brazil (INPE), Canada (CSA), France (CNES) and Italy (ASI).[6] It carried five Earth observation instruments (NASA, CONAE, CSA, ASI), two space science instruments (CNES), a data collection instrument (CONAE), and a technology demonstration system (CONAE).[6][7][8]

The spacecraft's main instrument, Aquarius, was built by NASA's Jet Propulsion Laboratory and Goddard Space Flight Center.[6] It collected data from 25 August 2011 to 7 June 2015, exceeding its intended three year primary mission.[1][9] Aquarius' mission was to demonstrate that accurate measurements of salinity could be made from space, and was the first spaceborne instrument to use both passive radiometers and active radar in the L band.[1][6] By measuring ocean salinity, scientists are better able to understand the Earth's water cycle and ocean circulation.[6] Project scientists later derived a method of pulling soil moisture data from Aquarius' radiometer.[1]

Launch[edit]

NASA launched SAC-D from Vandenberg Air Force Base's Space Launch Complex 2W aboard a Delta II 7320-10C on 10 June 2011 at 14:20:13 UTC.[1][10] The launch was delayed from May 2010 because development of the spacecraft was taking longer than expected.[11]

Accomplishments[edit]

The Aquarius instrument's surface salinity measurements contributed to a better understanding of ocean dynamics and advancing climate and ocean models, both from season to season and year to year. The models still are improving El Niño prediction. Aquarius global salinity maps show how freshwater plumes coming from the mouth of large rivers and the precipitation and evaporation over the oceans affect the salinity structure of the ocean.

“The Aquarius sensor collected three years and nine months of valuable data. It was truly a pioneering effort to determine how accurately we could measure ocean salinity from space and for the first time study large and small-scale interactions of the global water cycle.” Aquarius principal investigator Gary Lagerloef of Earth & Space Research, Seattle.

Aquarius provided information into the natural exchange of freshwater between the ocean, atmosphere and sea ice, which influences ocean circulation, weather and climate.

Data from Aquarius showed how extreme floods affect the seas and how low-salinity river plumes affect hurricane intensity. Aquarius data was important to the Salinity Processes in the Upper Ocean Regional Study (SPURS), a year-long international field study of the oceanographic processes that sustain the maximum surface salinities in the central subtropical North Atlantic, and influence global ocean circulation.

The Aquarius instrument successfully achieved its science objectives and completed its primary three-year mission in November 2014.[12]

Failure of spacecraft[edit]

On 7 June 2015 at 12:53:17 UTC, telemetry indicated a failure of the spacecraft's Remote Terminal Unit (RTU), causing loss of onboard power regulation and attitude stabilization. While efforts were made to recover the spacecraft, the mission was declared over on 8 June.[9][12]

Instruments[edit]

Abbreviation	Name	Operator	Purpose[7]
—	Aquarius	NASA	Ocean salinity research
MWR	Microwave Radiometer	CONAE	Radiometry
NIRST	New Infrared Sensor Technology	CONAE CSA	Infrared imagery, determination of sea temperatures
HSC	High Sensitivity Camera	CONAE	Imaging of aurorae, fires, and lights
DCS	Data Collection System	CONAE	Collection of data provided by platforms on Earth. Compatible with Argos system
TDP	Technological Demonstration Package	CONAE	Technology demonstration involving GPS navigation and inertial guidance
ROSA	Radio Occultation Sounder for Atmosphere	ASI	Measurement of temperature and humidity in the atmosphere
ICARE-NG	Influence of Space Radiation on Advanced Components-New Generation	CNES	Part of CARMEN-1 mission; study of cosmic radiation and its effects on electronics
SODAD	Orbital System for an Active Detection of Debris	CNES	Part of CARMEN-1 mission; study of particles and debris in space

See also[edit]

• 2011 in spaceflight
• Jason-1
• Ocean Surface Topography Mission
• Aquarius (SAC-D instrument)

References[edit]

1. ^ a b c d e f g "SAC-D (Satélite de Aplicaciones Científicas-D)/Aquarius Mission". eoPortal. European Space Agency. Retrieved 18 December 2015.
2. ^ a b c d "Press Kit: Aquarius/SAC-D Launch" (PDF). NASA. June 2011. Retrieved 18 December 2015.
3. ^ Graham, William (10 June 2011). "ULA Delta II launches with the SAC-D spacecraft". NASA Spaceflight. Retrieved 18 December 2015.
4. ^ "Aquarius - Orbit". Heavens Above. 17 December 2015. Retrieved 18 December 2015.
5. ^ Clark, Stephen (17 June 2015). "International ocean research observatory fails in orbit". Spaceflight Now. Retrieved 18 June 2015.
6. ^ a b c d e Graham, William; Bergin, Chris (17 June 2015). "Farewell Aquarius as SAC-D spacecraft concludes its mission". NASA Spaceflight. Retrieved 18 December 2015.
7. ^ a b "Aquarius/SAC-D onboard instruments". CONAE. Retrieved 18 December 2015.
8. ^ Miklus, Nicole; deCharon, Annette (2010). "Aquarius/SAC-D: Sea Surface Salinity from Space" (PDF). NASA/University of Maine. Retrieved 18 December 2015.
9. ^ a b Lagerloef, Gary; Torrusio, Sandra (18 June 2015). "PI Announcement to Science Team and Broader Science Community". University of Maine. Retrieved 18 December 2015.
10. ^ Buis, Alan; Cole, Steve (10 June 2011). "NASA's 'Age of Aquarius' Dawns With California Launch". NASA. Retrieved 10 June 2011.
11. ^ Clark, Stephen (26 December 2009). "Ocean-watching satellite facing delays in Argentina". Spaceflight Now. Retrieved 6 January 2010.
12. ^ a b Brown, Dwayne; Gran, Rani; Buis, Alan (17 June 2015). "International Spacecraft Carrying NASA's Aquarius Instrument Ends Operations". NASA. Retrieved 18 December 2015.

External links[edit]

Wikimedia Commons has media related to SAC-D.

• SAC-D website by CONAE
• SAC-D website by INVAP
• Aquarius website by NASA
• Aquarius website by the University of Maine

v t e Argentina space program
Organisations	Comisión Nacional de Actividades Espaciales (CONAE) CITEDEF
Satellites	Completed ARSAT (1 2) BugSat 1 MuSat Pehuensat SAC (A B C D/Aquarius) SAOCOM (1A) Planned ARSAT-3 SAOCOM (1B 2A 2B) SAC (E/SABIA-Mar 1 F/ALSAT-2)
Launch Fleet	Completed Centauro (Alfa, Beta, Gamma) Proson-M1 Orión (1, 2) Canopus (1, 2) Rigel Castor A Tauro Condor missile Alacrán missile Gradicom Tronador I Planned FAS 1500 ORBIT (I II LSA) T4000 Tronador II
Projects	VS-30 payload project
Launch sites	Historical Base Aérea Teniente Benjamín Matienzo CELPA (El Chamical) CELPA (Mar Chiquita) Las Palmas, Argentina Tartagal, Salta Villa Reynolds Current Centro Espacial Manuel Belgrano (CEMB) Polo Espacial de Punta Indio Future Complejo Argentino de Acceso Al Espacio [es]

v t e ← 2010Orbital launches in 20112012 →
January	Elektro-L No.1 USA-224 Kounotori 2 Progress M-09M (Kedr)
February	Kosmos 2470 USA-225 Johannes Kepler ATV STS-133 (Leonardo) Kosmos 2471
March	Glory, Explorer-1 [Prime], KySat-1, Hermes USA-226 USA-227
April	Soyuz TMA-21 Compass-IGSO3 USA-229 Resourcesat-2, YouthSat, X-Sat Yahsat 1A, New Dawn Progress M-10M
May	Meridian 4 USA-230 STS-134 (AMS-02, ELC-3) Telstar 14R ST-2, GSAT-8 / INSAT-4G
June	Soyuz TMA-02M SAC-D Rasad 1 ChinaSat 10 Progress M-11M Kosmos 2472 USA-231
July	Shijian XI-03 STS-135 (Raffaello, PSSC-2) Tianlian I-02 Globalstar M083, Globalstar M088, Globalstar M091, Globalstar M085, Globalstar M081, Globalstar M089 GSAT-12 SES-3, KazSat-2 USA-232 Spektr-R Compass-IGSO4 Shijian XI-02
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September	GRAIL-A , GRAIL-B Zhongxing-1A Kosmos 2473 Arabsat 5C, SES-2 IGS Optical 4 Atlantic Bird 7 TacSat-4 Tiangong-1 QuetzSat 1
October	Kosmos 2474 / GLONASS-M 742 Intelsat 18 Eutelsat 16A Megha-Tropiques, SRMSAT, VesselSat-1, Jugnu ViaSat-1 Galileo-IOV FM1 , Galileo-IOV FM2 NPP, AubieSat-1, DICE-1, DICE-2, M-Cubed, RAX-2 Progress M-13M Shenzhou 8
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Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ).Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).