IRS-1E

IRS-1E was an Earth observation mission launched under the National Natural Resources Management System (NNRMS) programme by Indian Space Research Organisation (ISRO). Sometimes written IRS-P1. The objective of the mission was to develop Earth imagery using instruments carried on board. Due to a malfunction of the launch vehicle, the satellite deviated from its path and plunged into the Indian Ocean.

IRS-1E

Names	Indian Remote Sensing satellite-1E Indian Remote Sensing satellite-P1
Mission type	Earth observation
Operator	ISRO
Website	https://www.isro.gov.in/
Mission duration	3 years (planned) Failed to orbit
Spacecraft properties
Spacecraft	IRS-1E (P1)
Bus	IRS-1A
Manufacturer	Indian Space Research Organisation
Launch mass	846 kg (1,865 lb)
Dry mass	766 kg (1,689 lb)
Dimensions	1.56 m x 1.66 m x 1.10 m
Power	415 watts
Start of mission
Launch date	20 September 1993, 05:12 UTC
Rocket	Polar Satellite Launch Vehicle (PSLV-D1)
Launch site	Satish Dhawan Space Centre, First Launch Pad (FLP)
Contractor	Indian Space Research Organisation
Entered service	Failed to orbit
Orbital parameters
Reference system	Geocentric orbit (planned) [1]
Regime	Sun-synchronous orbit
Perigee altitude	817 km (508 mi)
Apogee altitude	817 km (508 mi)
Inclination	98.6°
Period	103.0 minutes
Instruments
Linear Imaging Self-Scanning Sensor-1 (LISS-1) Monocular Electro-Optical Stereo Scanner (MEOSS)
Earth observation satellites series ← IRS-1B IRS-P2 →

History

IRS-1E was a follow-up mission to the satellite IRS-1A, to develop India's capability in the field of remote sensing. The satellite was to take up missions in the area of ground-water exploration, land use, forest and flood mapping.^[2] The letter "E" indicates that the satellite was an engineering model. The letter "P" (IRS-P1) in the Indian Remote Sensing Programme of Earth observation satellite indicates that the satellite was to be launched aboard a Polar Satellite Launch Vehicle (PSLV).^[3] It was launched on 20 September 1993.^[4]

Instruments

IRS-1E carried two instruments:^[1]

• Linear Imaging Self-Scanning Sensor-1 (LISS-1)
• MEOSS (Monocular Electro-Optical Stereo Scanner), built by the German Aerospace Center (DLR), is an experimental sensor with pushbroom Charge-coupled device (CCD) technology. MEOSS is a stereo camera system capable of recording three images simultaneously with a single lens by means of linear scanning (3-line stereo system).^[5]

Launch

IRS-1E mission was a failure, as the last stage of the PSLV-D1 malfunctioned, so failed to launch the satellite into its desired orbit. The PSLV was first launched on 20 September 1993, at 05:12 UTC. The first and second stages performed as expected, but an attitude control problem led to the collision of the second and third stages at separation, and the satellite failed to reach orbit.^[6] After this initial setback, the PSLV successfully completed its second mission in 1994.^[7]

See also

• Spaceflight portal

• Indian Remote Sensing