With storms threatening to delay their return to Earth, the Atlantis astronauts took a break from landing preparations Thursday to update a Senate panel on their triumphant Hubble Space Telescope repairs.
The astronauts checked their ship’s flight systems and monitored the weather at NASA’s spaceport, which was pounded by fierce thunderstorms. More bad weather was expected Friday when Atlantis was due to land.
The rain did not dampen NASA’s jubilation over the astronauts’ impressive Hubble repairs, which garnered kudos from the president and members of a U.S. Senate subcommittee who invited the crew to testify at a hearing from space. Such in-orbit testimony was a first for the Senate, although a space station crew member gave House testimony in 2005.
“When we talk about the Hubble and giving it essentially a new life and a new way of going and seeing the universe, you’ve touched our hearts and you’ve also made history,” said Sen. Barbara Mikulski, D-Md., chairwoman of the science appropriations subcommittee.
Fresh off a call from President Barack Obama the day before, the seven astronauts recounted their most nail-biting moments of the past one and a half weeks.
“You should have seen the action out the back window” during each spacewalk, said pilot Gregory Johnson. “I was on the edge of my seat.”
With their work in space complete, the astronauts aimed for a Friday morning touchdown at Kennedy Space Center — but given the dismal weather reports, they were conserving power in order to remain aloft until Monday if necessary. Mission Control warned that Friday’s weather would be “iffy.” The backup landing site in Southern California could be used Saturday, if Florida keeps getting hit by storms.
“We flew over today, saw it looked kind of nasty at the moment, but saw some clearing behind it — maybe,” commander Scott Altman radioed down. “As long as you think there’s a chance, we’ll be willing to do whatever it takes.”
Atlantis rocketed away on NASA’s last visit to Hubble on May 11. In five back-to-back spacewalks beset by stuck bolts and other problems, the astronauts installed two top-of-the-line science instruments and replaced burned-out electronics in two other science scopes. They also gave the 19-year-old observatory a new computer for sending back science data, freshened up the power and pointing systems, and beefed up the exterior with steel foil sheets.
Chief repairman John Grunsfeld said he felt satisfaction, but no sadness, as he watched Hubble drift away from the shuttle Tuesday after repairs were finished. In a series of TV interviews Thursday afternoon, he recalled turning to Altman and saying, “We got it done.”
“That’s when it all sort of sunk in, that everything worked, we deployed Hubble, it’s at the apex of its scientific capabilities, and we really pulled it all off,” Grunsfeld said.
The refurbished Hubble is expected to perform better than ever over the next five to 10 years and probe even deeper into the universe, as far back in time as 500 million to 600 million years from creation.
Besides watching the weather, NASA had been keeping the shuttle Endeavour ready for liftoff in case a rescue mission were needed. On Thursday morning they canceled the backup plan, which was put in place long ago to minimize the risk the Hubble repair crew was taking. With the astronauts having only enough air to last until Monday, Endeavour could not be launched in time to save them at this point.
The Atlantis crew of six men and one woman had to launch into a 350-mile-high (560-kilometer-high) orbit to get to Hubble and had nowhere to go in the event their ship was damaged seriously by space junk, a bigger problem than usual so high up. The international space station is in a different orbit and unreachable.
NASA considered this last Hubble mission so dangerous that it was canceled in 2004, a year after the Columbia tragedy. It was reinstated in 2006.
On Wednesday, NASA said an extensive survey of Atlantis’ vulnerable wings and nose showed no evidence of worrisome trouble, and managers cleared the shuttle for re-entry.
A hole the size of a dinner plate, in the left wing, brought down Columbia.