NASA Prepares To Retire Space Shuttles

The anxiety of waiting for a space shuttle to land will soon be history for NASA. The US space agency will be retiring its fleet of space shuttles in the next two years, leading to a different kind of anxiety altogether how will it ferry its men and machines between earth and the International Space Station till the floating laboratory is completed? NASAs decision to ground the shuttle programme in 2010 came from a growing concern for crew safety and the mounting costs of keeping the shuttles flying. Though the shuttles offer the most flexible option, the accidents to Columbia and Challenger have put the programme under a cloud of doubt. NASA is not planning to extend the service for now though a slim possibility exists.
Meanwhile, the period of five to seven years from 2010 opens up a great deal of opportunity in space commerce, as many countries with space ambitions hope to outsource the ferry service. The possibility of making alot of money by operating a reliable module to fly astronauts to the ISS, a research facility currently being organised in the outer space, is encouraging countries like India and Japan to accelerate their research into the challenging realm of space exploration.
NASA is also encouraging private players to come up with space services, says astronaut Carl E Walz, the agencys director of Advanced Capabilities Division and head of Exploration Systems Mission Directorate. We see this as a chance to strengthen the bond with industriessomething like a venture capital initiative, Walz notes, talking to The New Indian Express at NASA headquarters in Washington. NASA will need an alternative mechanism in place till its Orion Crew Exploration Vehicle is ready for flights, he adds. Orion will borrow its shape from the capsules of the past but will feature the latest technology in computers, electronics, life support, propulsion and heat protection systems. It will be a conventional-looking vehicle. We are saying goodbye to the shuttle concept, says Walz, who has mastered in solid state physics from John Carroll University, Ohio.
Though the shape will remain veteran, the technology will be state-of-the-art. Orion will be similar in shape to the Apollo but significantly larger. The Apollo-style heat shield is the best understood shape for re-entering the earths atmosphere, especially when returning from the moon. We plan to send a man to the moon by 2020 to further the Lunar Network Programme of which India is also a signatory, the 53-year-old Walz says.
Till then, though, NASA admits that the retirement of the shuttles will pose a problem. We plan to address this issue through our international partners who have achieved or are achieving credible manned mission programmes, says Walz, a US Air Force colonel who is a veteran of four space flights, having logged as many as 231 days in space.
NASA has its eye on the Russian Soyuz capsule. There is already considerable cooperation between the two countries, covering large areas, especially the ISS. But the move to associate with Russia the US strongest competitor in space science has NASA think tanks divided. While there is a broad agreement to US-Russia joint flights in order to meet the deadline of the ISS, not many in NASA want the astronauts to fly with cosmonauts while carrying out exclusive assignments.
This leaves NASA in a dilemma as the manned mission programmes of other partners like the European Space Agency and Japan are yet to meet necessary parameters. We are also developing some commercial capability within the US involving private players. We are also looking into the concept of flying 100 per cent robotic missions, says Walz, who joined NASA in 1990.
About Indias manned mission ambitions, Walz says India is one country making steady progress. The Chandrayaan-I is a remarkable achievement and the ISRO needs to be congratulated. But we cannot comment till the manned mission programme is proved. NASA, however, is not against considering a partnership with India. There is a long way to go. We can look at it once the challenges are met. Anyway, we have a blanket pact covering the space interests of both countries with a special focus on future activity, he says.
In India, the possibility of using an ISRO capsule is still a seed of thought. What offers hope is that the Orion is a capsule concept very similar to the Indian manned vehicle.
ISROs crew module has a lot in common with the Orion. While NASA is designing its capsule to carry four people, ISROs concept is to accommodate three, with an option for a fourth traveller. But the salient feature of both capsules is the escape mode that can be activated during any phase of the launch.
A launch abort system atop Orion will be capable of pulling the spacecraft and its crew to safety in the event of an emergency on the launch pad or at any time during the ascent. Ditto with the ISROs capsule. And in both capsules, the decision to abort launch will be at the discretion of the traveller rather than of the ground crew.
While NASA plans to use the new generation Ares V rockets to launch Orion, India is looking at GSLV-Mk-III, a similar class of rocket, to catapult its capsule. But Orion is being designed for even deeper space missions and features capabilities that allow it to dock and undock with other vehicles in various orbits. NASAs plan to send a man to the moon best explains the adaptability of Orion.
The Orion flight will be preceded by the launch of a cargo vehicle that will deliver the earth-departure stage and the lunar module that will carry explorers on the last leg of the journey to the moons surface in a low-earth orbit. Orion will dock with the lunar module and the earth departure stage before propelling its journey to the moon.
Once in lunar orbit the four astronauts will use their lunar landing craft to travel to the moons surface while Orion stays in the lunar orbit. And on completion of the mission, the astronauts will return to the orbiting Orion using a lunar ascent module and will use the service module main engine to break out of lunar gravity and infrared space heater return home. After the re-entry, using a newly developed thermal protection system, parachutes will further slow Orions descent to earth, he says.
On whether the ISS will lose its relevance once the Lunar Network, conceived as a hopping point to reach deeper targets, is set up, Walz says, The two stations have different aims. While the fractional gravity on the moon makes it an ideal stepping stone, research and experiments in the zero-gravity ISS allow us to study various factors. We need to synthesise the risks to the human space programme. There are still gaps in our knowledge, we are trying to fill them. ISS experiments give us a list of ideas for installing counter-measures to such risk factors, he adds. A joint project of the US, Russia, Japan, Canada and space saver storage 11 European countries, the ISS, whose on-orbit construction began in 1998, will be a technology ground for future long-duration space missions.
Walz feels human presence will continue to play a role in spite of the great strides made in robotics and unpiloted expendable launch vehicle programmes. We see a need for both. Robotics has limitations; humans are still the most adaptable frame to any environment. Quality requirements can be updated and damp crawl space evaluated only when a man is flown, feels Walz, who has flown on Atlantis, Columbia, Discovery and Endeavorholds the endurance record of 196 days in space.
manojkdasepmltd.com