By Irene Klotz
Cape Canaveral, Florida
It took more than a decade for Europe to finally join the International Space Station partnership with a laboratory in orbit, but in just one month it has shed its "rookie" status and is awaiting the return of the first science results from the Columbus module.
The experimental specimens and data gathered in the new laboratory will come back with French astronaut Leopold Eyharts when he lands with shuttle Endeavour.
The orbiter is due back at the Kennedy Space Center in Florida at 2305 GMT on Wednesday following a successful 16-day mission to the orbiting platform.
Eyharts, who previously flew on Russia's Mir space station, arrived at the outpost aboard shuttle Atlantis on 9 February. It was the flight that also delivered Columbus to the station.
"It's hard for me to believe that it's already finished," Eyharts said before leaving the station on Monday. "It has been a great flight."
During his seven weeks aboard the station, Eyharts commissioned Columbus and ran the first set of experiments.
These included the so-called Waico study which has probed the effect gravity has on the root growth of tiny Arabidopsis plants. Eyharts initiated the tests in Columbus' Biolab facility and is now bringing the seedlings back to Earth for further analysis.
Scientists, led from Leibniz Universitat Hannover, Germany, hope the investigations could aid future plant breeding, for food crops on Earth and on long-duration space missions.
Eyharts' one regret is that he will not be in orbit to oversee Europe's second station contribution: the arrival of the "Jules Verne" cargo ship.
The freighter, also known as the Automated Transfer Vehicle (ATV), has been loitering in orbit since its launch on 9 March, awaiting Endeavour's departure before beginning two days of rendezvous demonstrations.
If all goes well, the ship will dock on Thursday 3 April.
The Waico study has examined root growth in plants
"The mission as a whole was very intense and very active," Eyharts said during inflight interviews. "Of course, I would have liked to stay longer on the station."
Eyharts' mission was shorter than originally planned because of a technical problem with the shuttle that bumped Columbus' launch from December to February.
That didn't leave much time before Eyharts' replacement - Nasa astronaut Garrett Reisman - arrived with the shuttle Endeavour crew on 12 March.
"It's up to you Garrett; it's your turn," Eyharts said before climbing into the shuttle for the ride home. "C'est la vie."
Eyharts said Tuesday he felt he had enough time in orbit to accomplish his goals.
"I am very happy that Columbus was able to be commissioned and that the experiments are being run.
"It was very tiring," he added. "So I am happy to come back."
Europe's next astronaut to serve on the station will be Belgian Frank de Winne, who is scheduled for launch in May 2009.
De Winne, who trained as Eyharts' backup, will be a member of the station's first six-member crew.
Currently, only three astronauts can live on the station at a time.
Nasa has 10 more construction and resupply missions to the space station planned before the end of 2010 when its shuttle fleet is due to be retired.
The next flight will be in May to ferry the main section of Japan's huge Kibo complex to orbit. The US space agency also plans a final servicing mission to the Hubble Space Telescope later this year.