MIAMI ( – For the next-to-last time ever, space shuttle astronauts floated out of the International Space Station and closed the hatch behind them as they prepare to come home this week.

Shuttle Endeavour will be undocking from the space station late Sunday night and will then take the next two days to return home. Once the shuttle returns, it will be retired to a museum in California after just 25 missions.

“We’re looking forward to getting home,” Shuttle commander Mark Kelly said, “and we’re going to leave these guys to some peace and quiet and not disturb their space station any more.”

“It was really great seeing you guys,” said station resident Ronald Garan, Jr. “We were just in awe of your finely oiled machine.”

Endeavour delivered a $2 billion cosmic ray detector that will remain on board the space station for the next 10 years. The detector will search for antimatter and dark matter which scientists hope will shed light on the beginning of the universe.

Once Endeavour lands, only one shuttle flight remains for the 30-year-old shuttle program. Shuttle Atlantis will blast off from Cape Canaveral on July 8 with a load of space supplies to end the shuttle fleet’s work.

Endeavour is set to land at the Kennedy Space Center at 2:35 a.m. Wednesday.

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