Stretched Rohini Satellite Series Explained

Stretched Rohini Satellite Series
Manufacturer:ISRO
Country:India
Applications:Gamma ray astronomy
Orbits:Low Earth
Lifetime:2 years
Derivedfrom:Rohini
Status:Retired
Built:4
Launched:4
Retired:1
Lost:3
First:SROSS-A/SROSS-1
24 March 1987
Last:SROSS-C2
4 May 1994
Autoconvert:off
Mass:106kg-150kgkg (234lb-330lbkg)
Power:~100 watts
Batteries:Ni-Cd
Equipment:Gamma-Ray Burst
Retarded Potential Analyser

The Stretched Rohini Satellite Series (SROSS) are a series of satellites developed by the Indian Space Research Organisation as follow ons to the Rohini Satellites[1] for conducting astrophysics, Earth Remote Sensing, and upper atmospheric monitoring experiments as well as for new and novel application-oriented missions.[2] These satellites were the payload of the developmental flights of the Augmented Satellite Launch Vehicle.[1]

Satellites in series

SROSS A and SROSS B

The first two satellites in the series did not make it into orbit due to launch vehicle failure. SROSS-A carried two retro-reflectors for laser tracking.[1] SROSS-B carried two instruments; a West German Monocular Electro Optical Stereo Scanner (MEOSS) and ISRO's 20-3000keV Gamma-ray Burst Experiment (GRB).[1]

SROSS C

The third, SROSS 3 (also known as SROSS C), attained a lower-than-planned orbit on 20 May 1992. The GRB monitored celestial gamma ray bursts in the energy range 20–3000 keV. SROSS C and C2 carried a gamma-ray burst (GRB) experiment and a Retarded Potential Analyzer (RPA) experiment. The GRB experiment operated from 25 May 1992 until reentry on 14 July 1992. The instrument consisted of a main and a redundant CsI(Na) scintillator operating in the energy range 20–3000 keV. The crystals were 76 mm (main) and 37 mm (redundant) in diameter. Each had a thickness of 12.5 mm. A 'burst mode' was triggered by the 100–1024 keV count rate exceeding a preset limit during a 256 or 1024 ms time integration. In this mode, 65 s of temporal and 2 s of spectral data prior to the trigger are stored, as well as the subsequent 16 s of spectral data and 204 s of temporal data. The low resolution data consists of two energy channels (20–100 keV and 100–1024 keV) from 65 s before the trigger to 204 s after the trigger in 256 ms integrations. The 20–1024 keV rates are also recorded with a 2 ms resolution for 1 s prior to 1 s after trigger and a 16 ms resolution for 1s prior to 8 s after the trigger. Energy spectra are conducted with a 124 channel PHA. Four pre-trigger spectra and 32 post-trigger spectra are recorded for every burst with a 512 ms integration time.[3] The RPA measured temperature, density and characteristics of electrons in the Earth's ionosphere.[1] The GRB experiment computer system used the RCA CDP1802 microprocessor.[4]

SROSS C2

See main article: article and SROSS-C2. SROSS-C2 was launched on 4 May 1994. The gamma ray burst experiments on board SROSS-C2 are an improved version of the GRB payload flown successfully on the SROSS-C satellite. The improvements include enhancements of the on-board memory and a better measurement of the background spectra after a burst event. These improvements led to the discovery of twelve candidate events detected up to 15 February 1995, out of a total of 993 triggers.[3] The SROSS-C2 spacecraft is one of the satellites included in the Interplanetary Network[5] The SROSS C2 satellite also used an RCA CDP1802 microprocessor for the GRB experiment.[6]

See also

Notes and References

  1. Web site: SROSS A, B, C, C2 Quicklook . 2009-07-19 . dead . https://web.archive.org/web/20090411021025/http://msl.jpl.nasa.gov/QuickLooks/srossQL.html . 2009-04-11 .
  2. Web site: SROSS. https://web.archive.org/web/20161228041748/http://astronautix.com/s/sross.html. dead. December 28, 2016.
  3. Web site: Stretched Rohini Satellite Series 3 & C2.
  4. Web site: Cosmic gamma ray bursts - Recent developments and observations from SROSS satellites. 10 Nov 1995. Current Science Research Journal.
  5. Web site: IPN3 Home Page.
  6. Recent gamma-ray burst observations from the SROSS-C2 satellite. 7 Aug 1995. Astronomy and Astrophysics. 1997A&A...322..778K. Kasturirangan . K. . Padmini . V. N. . Prasad . N. L. . Rao . U. R. . Seetha . S. . 322 . 778 .