PASADENA, July 16: Bolstered by the overwhelming success of the Mars Pathfinder, NASA scientists are rapidly drawing up plans for more relatively cheap planetary exploration missions which can be done without a huge bureaucracy and billion-dollar budgets.

The Mars Pathfinder, which landed on the red planet on July 4, has met all its mission goals and has already carved away at some of the scientific secrets of Martian evolution, NASA researchers say. ``Pathfinder has gone a long way to help us in the future exploration of Mars,'' said the Jet Propulsion Laboratory's Norm Hayden, director of the Mars Exploration Project.

NASA plans to fire off two missions every 26 months, when Earth and Mars are aligned most favourably, leading up to a 2005 flight to return Martian rocks and soil to Earth for analysis.

The Johnson Space Centre, meanwhile, has organised a team to study sending humans to Mars and to outline what technologies will need to be developed for manned missions to the red planet.

NASA administrator Daniel Goldin says he will not endorse a manned mission to Mars until the cost is down to $ 25 billion or less. For comparison, NASA is spending about $ 40 billion to build the international space station.Hayden says the Pathfinder's accomplishments include:

* Proving NASA's concept of building faster, better and cheaper spacecraft for planetary exploration

* Developing an alternative landing system. The Pathfinder landed on Mars directly from interplanetary space, burning 16,000 mph of speed through a heat shield, parachute, thruster rockets and airbags

* Demonstrating how a rover vehicle can be used to supplement science- gathering from a lander.

* Conducting useful science for a fraction of what previous planetary science missions cost.

Mars Pathfinder was developed and flown in three years for about $ 250 million. The Viking missions to Mars would cost about $ 3.6 billion in today's prices.

Copyright © 1997 Indian Express Newspapers (Bombay) Ltd.