Discovery has touched down for the final time. With two more shuttle missions left these iconic machines will soon be confined to museums
The space shuttle Discovery has completed its final flight, successfully docking with the International Space Station (ISS) for the last time.
Discovery, on its 39th mission, delivered a new module and components to the ISS including Robonaut 2, the first humanoid robot in space.
The crew went on two space walks to fit the new module, Leonardo, and perform maintenance on the ISS.
The space shuttle, Space Transportation System (STS) to give it is proper name, arrived on 26 February and departed on 6 March. This was Discovery’s 13th rendezvous with the space station.
Discovery has had a considerable career. The fourth shuttle to be built, it has travelled further, completed more orbits, and flown more flights than any of its sister craft.
Discovery delivered the Hubble Telescope into orbit, flew the final flight to the Mir space station and flew the first flights following both the Challenger and Columbia disasters.
After Discovery the space shuttle programme has two more scheduled launches before the programme ends after 30 years of service.
The shuttle Endeavour is confirmed to launch in April and has begun its slow journey from its assembly building to the launch pad. There will be a swansong later this year with STS-135 in June: the launch of Shuttle Atlantis.
The first launch, on 12 April 1981, coincided with the 20 year anniversary off Yuri Gagarin’s first excursion into orbit.
The 1981 flight of the shuttle Columbia was the culmination of 12 years of planning and development. The brains of NASA began working on it just two months after Neil Armstrong’s momentous moon landing of 1969.
Fifty years on from Gagarin’s pioneering flight and thirty from Columbia’s maiden voyage, this craft will pass into aeronautical history. It will signal the beginning of the end for one of the most iconic machines.
Robonaut2, the first humanoid robot in space, has been delivered by the ISS
Though they appear a gulf apart, the space shuttle and the ubiquitous white van have something in common. They are both built to move a lot of stuff quickly from A to B.
The requirements made on the shuttle on each mission are extraordinary. In building and running the fleet NASA has advanced the field of aerospatial engineering considerably.
The space shuttle travels at over 27,000mph, can transport more than 28,800kg of cargo and orbits at altitudes of up to 625km above sea level.
On re-entry the shuttle has to force its way through Earth’s atmosphere. The friction from this heats the surface of the craft up to 1600°C (3,000°F).
The craft’s aluminium frame would melt at 175°C (350°F); the Orbiter Thermal Protection System (OTPS) protects the shuttle from the searing heat.
The OTPS not only stops the shuttle from melting as it enters the atmosphere, it also protects the shuttle from the temperature variations of space; the thermometer rises from -130°C to 90°C (200°F to +200°F) and back again during each 90 minute orbit.
The shuttle has become an increasingly expensive programme. Endeavour, the youngest of the fleet, cost around $1.7bn to build. Each mission costs roughly $450m a go.
That it is re-useable has inflated its running costs. Its re-usability was intended to cut the price of space flight by reducing the need to fabricate a whole rocket, all to be lost in bits in space.
However the incredible strain of the round trip of each shuttle mission takes its toll on the shuttle. This means engineers must replace and retune so many components after each mission. It has been something of a drain on NASA’s purse.
Each of the five shuttles made were built to have a lifespan of 100 missions. In total the fleet has flow 132 missions, just over a quarter of what they are designed for.
Images: Courtesy of NASA/Mike Kerley
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