Within a few weeks, the Indian Space Research Organisation (Isro) will team up with the Indian Air Force to conduct a simple experiment: it will drop a 3.7-tonne capsule from a height of 3.5 km and try to land it softly with parachutes. If successful, Isro will take this capsule in November-end to a height of 120 km on a rocket and eject it from there, to be recovered from the sea after a soft landing. Success in this experiment would be the first step in Isro’s next frontier: human space flight. Isro has made this capsule, called the crew module, in record time with very little money. The total budget sanctioned was just Rs 145 crore to make the crew module, space suits and other technologies necessary for a human flight into space. Isro still has money left for some more work. The development lasted just over a year and a half, once again emphasising the frugal nature of Isro’s engineering. “We wanted to show that we can do this if there is a need,” says Isro Chairman K Radhakrishnan. An actual human flight requires political clearance and heavy investments , a study seven years ago put the cost at Rs 12,400 crore. But Isro is readying itself by developing all necessary technologies. The crew module that is set to fly in November is built to be just like in a final human mission, with only the internal layouts being different. While the helicopter experiment will test the parachutes, an experimental GSLV Mark III flight in November-end will test the re-entry capabilities of the module.
Isro had done a study seven years ago about the requirements of a human flight, but never really pursued it seriously because a good human-rated vehicle was not ready. The reliable Polar Satellite Launch Vehicle (PSLV) could carry only one person, and so was not a candidate for human flight. The Geostationary Launch Vehicle (GSLV) had a few failures, leaving Isro with no tested vehicle for launching humans into space yet. The current contender is the GSLV Mark III, the completely new heavy lifter that Isro is developing. It is still a few years away from first launch, but technology development is proceeding at full pace. One can get a taste of the eventual flight from within a model capsule that is kept at the Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram. Two crew members lie looking up into the roof of the module, watching all the flight data as they move up. The rocket with the passengers would lift off from Sriharikota, move in a nearstraight line towards Australia, where the crew module is pushed into orbit at a height of about 270 km by the cryogenic engine. The module completes seven days in orbit and then descend into the atmosphere to land softly in the sea. This landing and recovery will be tested in end November, but from a height of 120 km. A crew module needs highly sophisticated engineering, as the conditions of descent into the atmosphere are very harsh. The temperatures cross 1,500 degrees centigrade and the forces on the module as it slows down can be 13 times that of gravity; with crew inside feeling a force of four times gravity. The crew module has to withstand these forces and also keep the crew safe. The thermal protection system of the current module is made to be good enough for actual re-entry. The deceleration system of the module is as in the final mission. “With this flight data we would be confident about our aero-thermal predictions,” says S Unnikrishnan Nair, Project Director, Human
A number of companies worked on the development of this project along with Isro. Hindustan Aeronautics Limited (HAL) developed the metallic internal structure, apart from other things. Valeth High Tech Composites in Chennai worked on the thermal protection system. SIDCO near Thiruvananthapuram worked on the vibration fixer and other things. Suresafety India in Baroda developed the space suit. Many of them are regular partners of Isro. None of them make any money on the development, and some have even invested some resources of their own. “It is not business alone,” says Peter Valeth, founder of Valeth High Tech Composites. “We are happy to see some unique products becoming successful.” Valeth now routinely develops special materials for Isro and the defence forces. All of Isro’s rockets use its ablative lining for their nozzles, where temperatures can be very high. It has adapted this work to make silica tiles for the crew module base, which would take the full brunt of the heating while descent through the atmosphere. This is one of the most critical technologies in the module: one space shuttle once lost its crew because of a problem in these tiles. This technology is very useful for the company in the long run, as it is eying exports and planning a manufacturing plant in Thailand.
Suresafety designed a space suit from scratch for this programme. It is this space suit that protects the crew in case of an environmental emergency inside the capsule. The development lasted a year and used a material specially designed for this project. The company claims to have put in Rs 50-60 lakh apart from the money given by Isro, with the hope of making the suit in larger quantities one day. “We are waiting for the moon project and to produce it ourselves,” says managing director Nishith Dand. After the technologies are developed, the actual human flight can be very expensive, and hinges on a political decision. The expense is to create a third launch pad and astronaut training facilities, and to humanrate the launch vehicle. Production assemblies need to be created too. Human rating the launch vehicle is difficult, as it requires at least six continuous flawless flights of the GSLV Mark III. In any case, barring serious failures on the way, Isro could be ready to put humans into space in four to five years.