NASA weighing risk of adding crew to megarocket's 1st flight

NASA is weighing the risk of adding astronauts to the first flight of its new megarocket, designed to eventually send crews to Mars.

The space agency's human exploration chief said Friday that his boss and the Trump administration asked for the feasibility study. The objective is to see what it would take to speed up a manned mission; under the current plan, astronauts wouldn't climb aboard until 2021- at best.

The Space Launch System, known as SLS, will be the most powerful rocket ever built when it flies.

NASA is shooting for an unmanned test flight for late next year. Putting people on board would delay the mission and require extra money. The space agency's William Gerstenmaier said if adding astronauts to the first flight means delaying beyond 2019, it would probably be better to stick with the original plan.

Under that plan, Gerstenmaier said, nearly three years are needed between an unmanned flight test and a crewed mission to make launch platform changes at Kennedy Space Center.

The crew capsule - Orion - already has been flown in space. Containing memorabilia and toys but no people, the capsule was launched into an extremely long orbit of Earth in 2014 by a Delta IV rocket, and splashed down into the Pacific.

NASA normally prefers testing rockets without people, although for the inaugural space shuttle flight in 1981, two pilots were on board. A crew ofjust two also is planned for the 2021 mission.

NASA expects to issue its report in about a month.