British-born astronaut Piers Sellers says he is confident Nasa can fix the problems on Discovery.
Dr Piers Sellers is due to fly in September
All shuttles are grounded after pieces of foam were seen falling from Discovery's external fuel tank during lift-off, despite efforts to fix the problem.
Discovery was cleared to land on Monday but poor weather has delayed its return by a day.
Dr Sellers is part of the crew for the next mission to the space station.
"Right now we're booked for September 22 and we're holding that date," he told the BBC.
"But we'll see how things go when we inspect the vehicle when it gets back."
He said Nasa needed to figure out why the gap fillers between the tiles worked their way loose, why foam fell off the fuel tank and why a piece of blanket billowed out under the windshield.
"They do have a few nip-noid details to nail down before we can launch again," he said. "But none of them are real show stoppers as far as I can tell. I think they are all things that can be solved."
Experts are investigating items seen to fall around the orbiter
Dr Sellers is due to join Commander Steve Lindsey and five colleagues on Atlantis for the second test flight to the International Space Station (ISS); a mission known as STS-121.
He carried out three space walks during his trip there in 2002, and said it was an extraordinary experience.
"The strangest thing is to open the hatch in the floor and look out and see the world just moving past you at five miles a second," he said.
"And then just use your fingers to push yourself out through the hatch and just float there, out in the open, with the world below you and black space above you and this huge spacecraft just hovering above you.
"Spacewalking is quite an experience. Belting around the world once every one-and-a-half hours and watching whole continents go by underneath you while you're just floating there, it's an extraordinary feeling."
Dr Sellers became only the third Briton to go into space when he completed an 11-day mission to the International Space Station in October 2002.
As an astronaut with the US space agency, Dr Sellers flies as an American citizen. The UK does not fund human spaceflight.