Three decades after the space shuttle Challenger exploded during liftoff from the Kennedy Space Center in Florida, the next generation of space technology is building on changes made after the accident.
NASA's Space Shuttle was the first largely reusable spacecraft, designed to make flying into space cheap, simple and safe.
Each shuttle was designed to complete more than 100 missions and used reusable booster rockets to lift it into space.
But 73 seconds after the space shuttle Challenger launched on January 28, 1986, a seal on one of its rocket engines failed, resulting in an explosion that destroyed the craft, killing all seven crew.
|Spectators at the Kennedy Space Center in Cape Canaveral, Florida, witnessed the explosion of the space shuttle Challenger [AP]
|The doomed Challenger space shuttle (from left, front row) astronauts Mike Smith, Dick Scobee, Ron McNair and (from left, rear row) Ellison Onizuka, school teacher Christa McAuliffe, Greg Jarvis, and Judith Resnik [NASA]
Changes were made to later missions, and despite the deaths of another seven crew members when space shuttle Columbia broke up on re-entry in 2003, the rest of the shuttle fleet continued flying until being retired in 2011.
"We shouldn't forget about the legacy of these 14 brave astronauts that gave their lives for the exploration for mankind," Eric Stallmer, president of the Commercial Spaceflight Federation told Al Jazeera.
"But you've got to think about the other 135 missions that were a success, the work they did with the Hubble telescope and the interplanetary missions and probes that were sent off from the space shuttle, as well as building and developing the international space station."
Achievements and costs
Over 30 years (1981-2011) the space shuttle clocked up 135 flights and carried a combined total of 1,593 tonnes of cargo into space.
NASA's five shuttles orbited the Earth 20,830 times.
But it was the growing cost of the programme that led to its demise: running costs of $4bn a year, and total programme costs of $209bn over 30 years.
"It was very expensive but it was a good test bed for the technology," Stallmer said.
The shuttle disasters exposed a number of design shortcomings and problems with how the programme was being operated.
It also helped to seed a commercial space transportation industry that is now developing both passenger and cargo supply spaceships.
"The shuttle was a government programme and now the government is really depending on the commercial sector to bring a lot of these reusable technologies into the mainstream," Stallmer added.
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With the demise of the shuttle, NASA has increasingly looked to private companies for cheaper ways to deliver cargo and crew into space, among them SpaceX, which has been trying - not always successfully - to land its Falcon 9 booster rockets back on Earth.
The company says reusable rockets will reduce launch costs from tens of millions of dollars to only a few million, opening up space to many more companies and countries.
Earlier this week another US company, Blue Origin, made history by sending the same reusable rocket into space and landing it back on Earth for a second time.
"If you can get the cost and access to space down, it's going to open tremendous opportunities for what we can do in space," Stallmer said.
"I think we are only scratching the surface on the possibilities that can happen and the commerce that could happen in space."
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The shuttle disasters have also resulted in a rethink of the way passengers are carried into orbit.
Challenger's six astronauts and a high-school teacher had no chance of escaping owing to a spacecraft design decision that is not being repeated on the passenger spaceships now under development.
These will launch on top of rockets, not alongside them, and have separate systems to fly crews to safety if a booster falters.
"Spaceflight is like any other big engineering system," Mike Leinbach, a former NASA shuttle launch director, said.
"You get smart by successes. You get smart by failures. I just hope that the new entrants into the market learn from the mistakes of the past."
With additional reporting from Al Jazeera's Science and Technology Editor Tarek Bazley
Source: Al Jazeera and agencies