The father of the Adelaide-born NASA astronaut Andy Thomas is facing an anxious few hours, praying the space shuttle Discovery, with his son aboard on his farewell mission, lands safely.
Adrian Thomas said he had his fingers crossed for Andy's return to the Kennedy Space Centre, set for 6.46 tonight, Sydney time.
"I'm a little bit nervous, as you can imagine, especially because it's his last mission before he retires from the flight pool," Mr Thomas said yesterday.
With hugs, handshakes and the traditional tolling of a farewell bell, the crew of the shuttle Discovery said goodbye to their comrades on international space station on Saturday and fired thrusters to head their beleaguered spacecraft back to Earth.
Under the control of commander Eileen Collins, a mother of two who has said she can hardly wait to get back to ground and have some Mexican food, Discovery flew around the station then moved off to finalise preparations to enter Earth's atmosphere.
If the weather in Florida does not allow a landing at Kennedy Space Centre, Discovery could land at Edwards Air Force Base, in the California desert.
Yesterday, the crew checked out the flight-control system and started tying down loose items in anticipation of the bumpy ride into the atmosphere.
The Thomas family have been reassured by NASA that everything is going to schedule, but Mr Thomas said that considering Discovery's recent insulator problems the main danger was to the insulator tiles as the space shuttle re-enters the atmosphere.
"The shuttle will be travelling at about 17,000 miles an hour [27,000kmh] and that creates heat on the tiles of about 1250 degrees centigrade," he said.
Discovery's external fuel tank lost some foam insulation upon take-off, but unlike the tragic Columbia mission, the shuttle was not damaged by the debris.
It is understood Andy Thomas, 53, plans to visit Australia with his new wife and fellow NASA astronaut Shannon Walker, 39 , after his retirement
"Andy will be in Australia in October if all goes well and we will celebrate their wedding," his father said.
Despite a series of glitches and one big problem that bedevilled the flight - the first since the Columbia tragedy in 2003 - the crew of Discovery appeared almost giddy as they gathered for the farewell ceremony. They swam back and forth in the weightless atmosphere and hung from the ceiling of a laboratory. Commander Collins performed mock pull-ups.
Discovery's visit was a boon for the space station, which had been limping along since the Columbia accident with infrequent visits from Russian supply ships.
Discovery's crew delivered more than 5000 kilograms of food, water and equipment, repaired a faulty gyroscope, replaced a second one and installed a kind of space tool shed to make things more comfortable for the station crew.
AAP, Los Angeles Times