After the United States beat the Soviet Union in putting the first men on the moon in 1969, Washington considered what to do for an encore. Richard Nixon, then U.S. president, rejected calls for an even more costly human venture to Mars. "With the entire future and the entire universe before us, we should not try to do everything at once," Mr. Nixon said in March 1970, pointing to pressing priorities on Earth. He eventually chose a practical option, the Space Shuttle a re-usable space plane that would take off like a rocket but land on a runway. Officials at the National Aeronautics and Space Administration promised the shuttle would cut the cost of getting people and cargo to and from orbit. It was meant to normalize space flight and make it routine, with launches almost weekly. But Mr. Nixon pledged just $5.5-billion for shuttle development, far short of the $13-billion NASA requested.
Building a reusable space shuttle proved far more difficult than first imagined especially when the job was supposed to be completed for less than half the original estimated cost. One of the most challenging problems scientists had to overcome was protecting the delta-winged orbiter from the enormous heat of friction when it re-entered the Earth's atmosphere at 40 times the speed of sound. The solution involved covering much of the spacecraft with about 24,000 custom-made silica-fibre tiles, which could withstand temperatures of thousands of degrees. Trying to create a Cadillac shuttle on a Corolla budget led to compromises that would ultimately raise operating costs and compromise safety. The shuttles ended up taking longer than expected to prepare for another flight. Once all the development and operational costs are taken into account, the 134 shuttle launches to date have cost $1.4-billion in current dollars per mission.
Two of the five orbiters met tragic ends with the loss of both crews. The Challenger blew up shortly after liftoff on Jan. 28, 1986, and Columbia disintegrated during re-entry into the Earth's atmosphere on Feb 1, 2003. In safety terms, the space shuttle suffered from a major design flaw: the orbiter was strapped to the side of the rockets. Earlier U.S. space capsules sat atop their rockets. If a rocket blew up, the blast was behind the astronauts. With the shuttle, an explosion would surround the spacecraft, minimizing the chances of survival which is what happened to the Challenger. The side-mounted position of the orbiter increased the likelihood it would be hit by foam insulation falling off during liftoff. A piece of insulation hit the edge of Columbia's left wing, damaging the thermal protection system. On its return to Earth, the inside of the wing super-heated and the spacecraft broke apart.
In January 2004, then-U.S. President George W. Bush announced his decision to retire the space shuttles as part of a plan to go back to the moon. They would remain in service only long enough to finish work on the International Space Station. Ending the shuttle program would free up cash so NASA could afford the new lunar venture without a big budget increase. Since then, however, President Barack Obama has axed Mr. Bush's space plans. But Mr. Obama did not grant a reprieve to the shuttles. Instead, he has created financial incentives to encourage industry to build new rockets that will take U.S. astronauts into orbit. It's hoped the private sector will be able to achieve what NASA failed to do make space travel affordable and commonplace. In the meantime, American astronauts will rent seats aboard Russian Soyuz rockets to get to and from the space station.
Many space experts note that the shuttles did not live up to the original billing. But the astronauts who flew on them cherished the experience despite the risks. "It has been a tremendous human invention that has opened the door of space to us," said Canadian astronaut Chris Hadfield. Service missions by shuttle astronauts have kept alive the famed Hubble Space Telescope. (There is Canada's shuttle contribution the robotic Canadarm, which made it possible to capture and release the orbiting satellite.) The shuttles also played an instrumental role in building the $100-billion International Space Station, which showed that diverse nations even former adversaries can work together. Mr. Hadfield calls the shuttle "the great lifter of humanity." Almost 70 per cent of the 523 people who have ventured into space flew on a shuttle. Much of what has been learned in 30 years of operating the shuttles will prove useful in humankind's outward journey into space.