"It's great to be back on earth," said Bowersox, who landed some 440 kilometres (275 miles) off the target in the steppes of Kazakhstan early on Sunday.

"Kazakhstan is such a beautiful place. Today I looked out the window. I went outside and I saw beautiful brown earth, the greenest grass I've ever seen. It was fantastic," he told AFP during the plane flight to Moscow from the Kazakh capital Astana.

"I am a test pilot and test pilots always dream of getting to fly a vehicle for the first time. So today I was able to fulfil a dream," said Bowersox.

US astronauts Bowersox and Donald Pettit and their Russian crewmate Nikolai Budarin had been aboard the International Space Station (ISS) since December.

They were to have left in March but their return to earth was delayed because of the Columbia space shuttle disaster.

US spacecraft Columbia disintegrated during re-entry to the earth's atmosphere on February 1, killing all seven crew members and leading NASA to suspend all shuttle missions, including those to the ISS.

Russian spacecraft now provide the only transportation to the space station.

"We lost our friends but being in space in some ways made it harder and in some ways easier," Bowersox said.

"The space station is wonderful environment. It helped ease the blow to know we were still in space. The extra two months were a gift," he said, adding: "Humans were meant to be in space."

Anxiety was high ahead of the landing on Sunday of the Russian Soyuz spacecraft that brought Bowersox and his colleagues back to earth. It was the first time a US astronaut had been brought back to earth aboard a Russian spacecraft.

The Soyuz is based on technology that dates back more than three decades but has recently been upgraded. The new version was being used for the first time on Sunday.

Russian space officials said the Soyuz had been forced to land using an uncontrolled "ballistic" trajectory rather than the usual manual or automatic descent.

But Bowersox shrugged off fears about the landing, saying it had gone to plan.

"It's a lot scarier than landing on an aircraft carrier. It was great. Everything worked. Soyuz is very reliable. It worked just like it was supposed to. The landing was actually pretty great," he said.

SPACE.WIRE