IRS-P3

Names	Indian Remote Sensing satellite-P3
Mission type	Earth observation
Operator	ISRO
COSPAR ID	1996-017A
SATCAT no.	23827
Website	https://www.isro.gov.in/
Mission duration	3 years (planned) 8.5 years (achieved)
Spacecraft properties
Spacecraft	IRS-P3
Bus	IRS-1A
Manufacturer	Indian Space Research Organisation
Launch mass	922 kg (2,033 lb)
Dry mass	838 kg (1,847 lb)
Dimensions	1.56 m x 1.66 m x 1.10 m
Power	873 watts
Start of mission
Launch date	21 March 1996, 04:53 UTC
Rocket	Polar Satellite Launch Vehicle, PSLV-D3
Launch site	Satish Dhawan Space Centre, first launch pad
Contractor	Indian Space Research Organisation
Entered service	June 1996 [1]
End of mission
Deactivated	15 October 2004
Orbital parameters
Reference system	Geocentric orbit
Regime	Sun-synchronous orbit
Perigee altitude	802 km (498 mi)
Apogee altitude	848 km (527 mi)
Inclination	98.69°
Period	101.4 minutes
Instruments
Multispectral Opto-electronic Scanner (MOS) Indian X-ray Astronomy Experiment (IXAE) Wide-Field Sensor (WiFS)
Earth observation satellites series ← IRS-1C IRS-1D →

IRS-P3 was a remote sensing satellite launched by ISRO on board of Polar Satellite Launch Vehicle (PSLV) launch vehicle for remote sensing of Earth's natural resources. It also hosted a scientific instrument, the Indian X-ray Astronomy Experiment (IXAE), for the study of X-ray astronomy. The IRS-P3 satellite contained an X-ray astronomy instrument, a C-band transponder and two remote sensing instruments.^[2]

History

IRS-P3 was one of the satellite in the Indian Remote Sensing Programme of Earth observation satellites, assembled, launched and maintained by Indian Space Research Organisation. There was no data recording device on board of the IRS-P3 and data was transmitted in real-time to the ground stationd in Hyderabad, India and Neustrelitz, Germany.^[2]

Instruments

IRS-P3 carried two remote sensing instruments and one X-ray astronomy experiment:

• Modular opto-electronic scanner (MOS),^[3] which was provided by German Aerospace Center (DLR), in the framework of a cooperative agreement between ISRO and DLR. MOS was designed for ocean remote sensing.^[4]

• Indian X-ray astronomy experiment (IXAE). IXAE was to study the time variability and spectral characteristics of cosmic X-ray sources and for detection of transient X-ray sources. The experiment was developed by ISRO Satellite Centre (URSC) and Tata Institute of Fundamental Research (TIFR). The experiment was intended to study periodic and aperiodic intensity variation in galactic/extragalactic X-ray, spectral characteristics of various sources and properties of newly discovered X-ray transients. IXAE instruments consisted of three identical pointed mode proportional counters (PPCs) operated in the energy range 2-20 keV, FOV of 2° x 2° and effective area of 1200 cm², and an X-ray sky monitor (XSM) operating in the energy range 2-10 keV. The experiment was highly successful and produced more than 30 publications and four PhD thesis.

• Wide-field sensor (WiFS) with additional Short-Wave Infrared band (SWIR). The sensor was designed for vegetation dynamic studies.

Launch

IRS-P3 was launched by the PSLV-D3 launch vehicle on 21 March 1996, at 04:53 UTC, from Satish Dhawan Space Centre, Sriharikota, India. Periodic calibration of Polar Satellite Launch Vehicle tracking radar was located at tracking stations.

Mission

The mission was completed on 15 October 2004 after serving for 8.5 years.^[1] With the consecutive successful launches of the PSLV, it was decided not to plan any more Augmented Satellite Launch Vehicle (ASLV) missions.^[5]