During an eventful journey, Atlantis was the first shuttle to dock with the ISS; fittingly, it was also the last. It was also the final spaceship to visit the other iconic symbol of success in space: the Hubble Space Telescope. No space shuttle will ever fly again; the shuttle is history.

Was it a spa cecraft? It was launched like one. Was it an aircraft? It landed much like a conventional glider on a runway. Was it a space passenger bus? It was certainly promised to be, but the cost worked out way too high and the US Government finally baulked at paying the price. Was it a cargo truck? The space shuttle’s enormous load carrying capacity was vital in building and replenishing the International Space Station (ISS) which might otherwise have taken decades to complete.

On July 8, almost a million people thronged the beaches around the Kennedy Space Center in Florida for a final glimpse of the majestic Atlantis as it raced skyward. This was the 135th and last mission of a shuttle—the pioneering craft that has defined the US space programme for 30 years. Only four astronauts were on board, since no shuttle was available to mount a rescue mission if Atlantis sustained damage—the stricken crew would have to be recovered aboard the smaller Russian Soyuz capsule. In the event, Atlantis landed safely on July 21, 42 years almost to the day after human beings first set foot on the moon. During an illustrious career, Atlantis was the first shuttle to dock with the ISS; fittingly, it was also the last. It was also the final spaceship to visit the other iconic symbol of success in space: the Hubble Space Telescope. No space shuttle will ever fly again; the shuttle is history.

History in the Making

Officially known as the Space Transportation System (STS), the shuttle programme was launched in 1972. The US space programme’s manned flights had begun with the Mercury programme, followed by Gemini and Apollo. They were all singleuse spaceships. The space shuttle was revolutionary because it was the first reusable spacecraft in history. Only six shuttles were built. STS-1 was launched on April 12, 1981 (twentieth anniversary of the first human spaceflight) with two crew members aboard Columbia. Enterprise never flew in space, Challenger exploded soon after lift-off in 1986, and Columbia disintegrated during its return to earth in 2003. Atlantis, Discovery and Endeavour are now in peaceful retirement.

The space shuttle was the most complex flying machine ever built. The stubby-winged device was mounted on a huge external fuel tank containing cryogenically stored liquid hydrogen and oxygen, strapped to two solid rocket boosters, which collectively became known as “the stack”. In launch configuration, the entire assembly contained more than 3,500 subsystems and 2.5 million parts. Fully fuelled, it had the explosive potential of a small nuclear device. Launched vertically like a rocket and gliding back to earth like an aircraft, shuttles proved their worth in carrying astronauts, cargo, heavy machinery, satellites, even the Hubble Space Telescope. That versatility, however, meant higher construction and operating costs, because a crewed vehicle needs complex life-support systems, escape methods and high safety that an unmanned rocket can do without.

Through three decades of its operational history, 355 individuals (306 men and 49 women) flew 852 times on 135 shuttle missions. The astronauts were from 16 countries. They conducted more than 2,000 experiments in the fields of earth, biological and materials sciences and astronomy. Shuttles have docked with two space stations—nine missions flew to the Russian Mir station and 37 flights were to the ISS. Shuttles were responsible for the orbiting and repair of Hubble, just one of the 180 satellites and other spacecraft they successfully launched. Shuttles were critical in the construction and replenishment of the ISS, more than 12 years and 37 shuttle trips in the making. Construction of the space station began in 1998, and is planned for completion in 2012. It should remain operational till 2020.

Complex and Costly

In the early 1970s, the National Aeronautics and Space Administration (NASA) projected a rate of 48 shuttle flights per year, at a cost per launch of around $15 million ( Rs. 67.5 crore). In the event the programme averaged five launches per year. NASA claims that a single launch eventually worked out to about $450 million ( Rs. 2,025 crore). But if the costs of development and operation over the duration of the programme are factored in, the total tab has been estimated at $208 billion ( Rs. 9,36,000 crore) in 2010 dollars. For the tally of 135 missions, this works out to around $1.5 billion ( Rs. 6,750 crore) per flight and perhaps $250 million ( Rs. 1,125 crore) for each person going into space.

The space shuttle was conceptualised as a reusable launch system and orbital spacecraft. It was certainly an amazing machine. However, its designers had to make a host of compromises to meet the competing demands of various US civilian and defence agencies. Ultimately, the craft emerged fragile, complicated to operate and unsafe. Being large and aerodynamically unstable it needed sophisticated “fly by wire” systems that were still under development during the 1970s. The engineers also faced a huge challenge in building rocket engines sturdy enough to work repeatedly and flawlessly for over 50 missions. Before the shuttle, space rockets were like Diwali firecrackers—good only for a one-off burn. Shuttle maintenance and refurbishment was an expensive and time-consuming affair. Each time a shuttle touched base, it had to be taken apart, inspected, cleaned, many components replaced, and the whole craft reassembled for the next flight. The process took months, sometimes years. And the promised simplicity of a reusable spacecraft was invalidated by the need for a new external fuel tank for each mission. Florida’s famously stormy weather did its bit to ensure that shuttle flights never became a routine, as had been hoped. Consequently, against the target life of 100 missions apiece, no shuttle exceeded 39 launches.

What really hurt, however, was the safety gap. NASA probably underestimated the risks shuttle astronauts faced. On January 28, 1986, Challenger disintegrated 73 seconds after launch due to the failure of the right solid-rocket booster, killing all seven astronauts on board. Columbia burned up on February 1, 2003, during re-entry into the earth’s atmosphere, just 16 minutes from landing. The cause was later traced; it was because of the damage to the carbon-carbon leading edge of the wing during launch. The entire sevenmember crew died. Notably, Columbia’s fatal flight had been delayed 18 times over the course of two years before its actual launch date of January 16, 2003 (despite its designation as the 107th mission, it was actually the 113th mission launched). After each shuttle accident, the remaining craft were grounded for two to three years. It has been calculated that the space shuttle was 138 times riskier than an airliner, based on deaths per million miles travelled.

What Next?

With America’s long-term fiscal outlook looking increasingly bleak, President Barack Obama’s options in space are severely limited. He has shelved plans to build a powerful new spacecraft to return to the moon. Instead NASA’s goal is to put Americans on an asteroid by 2025. To some, aiming to reach a giant rock floating in space doesn’t quite seem an inspiring objective. But beyond that, there’s destination Mars and its moons by the mid-2030s.

It is remarkable that just before Neil Armstrong’s Apollo 11 spacecraft lifted off in July 1969, Vice President Spiro Agnew declared that America’s next goal should be a manned landing on Mars by the end of the century. A presidential committee on post-Apollo strategy even said that the United States could send astronauts to Mars by the mid-1980s for not much more than the $24 billion ( Rs. 1,08,000 crore) cost of the Apollo programme. However, 40 years later, human flights to Mars are still some decades away.

For now, NASA has decided to farm out much of the routine work of ferrying astronauts into low-earth orbit (especially to the ISS) to commercial firms. The first commercial cargo craft could demonstrate its docking capability with the ISS as early as December. And commercial “space taxis” could be ferrying American astronauts there as early as 2015. Although several corporations are in the race, Space Exploration Technologies Inc. (SpaceX) seems to be the frontrunner. According to company sources, its Falcon 9/Dragon combination has a tremendous advantage over others intended to carry astronauts, because SpaceX vehicles were designed from the start to take humans. Besides, they have already flown successfully. Another company, Orbital Sciences Corporation has a contract to ferry supplies to the ISS beginning next year. Till the private firms (with NASA’s financial and technological backing) come up with something concrete, the US will rely on Russia for resupply of the ISS. For the next few years, the only way for the US astronauts to reach the ISS will be to board a Soyuz space capsule at a cost of $51 million ( Rs. 230 crore) per person.

NASA is continuing work on a space vehicle capable of carrying human beings beyond the earth’s orbit. Up to four astronauts may be able to survive for 21 days in this multipurpose crew vehicle (MPCV), a refinement of the abandoned Orion. The MPCV is designed to be 10 times safer than the space shuttle. Beyond that, there’s the new Space Launch System (SLS) which will be based on Apollo and shuttle technology, although not much is known about it yet. And attracted by the $30 million (Rs. 135 crore) Google Lunar X-Prize, 29 privately-funded teams are competing to become the first to successfully launch, land, and move a robot across the surface of the moon. The deadline is December 2015. Is the age of private space enterprise about to dawn?