SROSS-C2 or Stretched Rohini Satellite Series C2 was a satellite developed by the

Indian Space Research Organisation The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman of ...

. It conducted research on

Gamma Ray Burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten millis ...

s in

Low Earth Orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

. It was launched on 4 May 1994 using an

ASLV The Augmented Satellite Launch Vehicle or Advanced Satellite Launch Vehicle, also known as ASLV, was a small-lift launch vehicle five-stage solid-fuel rocket developed by the Indian Space Research Organisation (ISRO) to place 150 kg satellit ...

rocket from

Satish Dhawan Space Centre Satish Dhawan Space Centre - SDSC (formerly Sriharikota Range - SHAR) is a rocket launch centre ( spaceport) operated by Indian Space Research Organisation (ISRO). It is located in Sriharikota, Tirupati district of Andhra Pradesh. Sriharikota ...

. The first two satellites in the SROSS series failed to attain orbit. The third one attained a much lower orbit than planned. SROSS-C2 is thus the first fully successful, and the last satellite in the series.

Design

Magnetic Torquer and Magnetic Bias Control Sensors, Magnetometer, Twin-slit Sun sensor and Temperature sensors helped the satellite to be spin stabilized. This was done using monopropellant,

Hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazin ...

based with six thrusters each capable of delivering 1 Newton force. It has an octagonal structure. Body mounted and deployable solar panels provided 45 watts of power, with NiCd battery of 12-amp hours. S-band and VHF bands were used for communication. The SROSS C2 satellite also used an RCA CDP1802 microprocessor for the GRB experiment.

Science data

Diagram of the SROSS 3 gamma-ray burst detectors

The

gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nucleus, atomic nuclei. It consists of the shortest wavelength electromagnetic wav ...

burst experiments on board the satellite are an improved version of the payload on the SROSS-C satellite. The improvements include increased on-board memory and a better measurement of the background spectra after a burst event. These modifications led to the discovery of twelve candidate events detected up to 15 February 1995, out of a total of 993 triggers. The SROSS-C2 spacecraft is one of the satellites included in the Interplanetary Network. The mission also contained a Retardating Potential Analyser (RPA). It measured temperature, density and characteristics of electrons in the Earth's ionosphere, mainly in situ measurements of F-region ionospheric plasma. The instrument consisted of an electron RPA, ion RPA and a potential probe (PP), designed and developed at the National Physical Laboratory,

New Delhi New Delhi (, , ''Naī Dillī'') is the Capital city, capital of India and a part of the NCT Delhi, National Capital Territory of Delhi (NCT). New Delhi is the seat of all three branches of the government of India, hosting the Rashtrapati B ...

. It simultaneously sampled electron and ion plasma in the altitude range of 420–620 km for more than half a

solar cycle The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfa ...

from minima to maxima of the 23rd solar cycle activity. Measurements were made in a higher orbit for a limited period of two months during the initial phase, while the satellite

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

was at 930 km keeping the

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

same.

References

{{reflist Space research Satellites of India Spacecraft launched in 1994