The Augmented Satellite Launch Vehicle (संवर्धित उपग्रह प्रक्षेपण यान) or Advanced Satellite Launch Vehicle, also known as ASLV, was a five-stage solid propellant rocket developed by the Indian Space Research Organisation (ISRO) to place 150 kg satellites into LEO. This project was started by India during the early 1980s to develop technologies needed for a payload to be placed into a geostationary orbit. Its design was based on Satellite Launch Vehicle. ISRO did not have sufficient funds for both the PSLV programme and the ASLV programme at the same time and the ASLV programme was terminated after the initial developmental flights. The payloads of ASLV were Stretched Rohini Satellites.
The ASLV was not a simple variant of the earlier SLV but a more complex vehicle; a five-stage vehicle with the core stage not igniting until the two strap-on first stage boosters burn out. The payload capacity of the ASLV is approximately 150 kg to an orbit of 400 km with a 47-degree inclination.
At liftoff, the ASLV generated 92,780 kgf of thrust. It was a 41,000 kilogram rocket, measuring 23.5 metres in length with a core diameter of one metre.
The ASLV made four launches, of which one was successful, two failed to achieve orbit, and a fourth achieved a lower than planned orbit which decayed quickly. The type made its maiden flight on 24 March 1987, and its final flight on 4 May 1994.
Three successive failures plunged the project into a crisis. ISRO scientist had to confront new technological challenges and one of the important design changes was the addition of the 2 strap on boosters attached to either side of the first stage. Strap on separation, bulbous heat shield, "closed loop" guidance system as opposed to the "open loop" guidance system of the SLV-3 and heat shield management and separation had to be adapted by the scientists. However, all the problems and new technological challenges were overcome with ISRO's customary resolve and zeal, and the important ASLV program crossed an important rubicon.