NASA's new megarocket will launch without astronauts on its test flight, now delayed until 2019 because of technical challenges, the space agency's top leaders said Friday.
The super-sized Space Launch System rocket is meant to eventually send astronauts to Mars. The first launch had been targeted for next year, but now won't happen until 2019 when NASA will send an unoccupied Orion capsule to the vicinity of the moon for a three-week trial run.
The Space Launch System rocket is still in development.
The second flight will have astronauts on board. It is scheduled for 2021, but will almost certainly be later because of all the delays with the first flight. The test flight can be more dynamic, as NASA calls it, without a crew, and the lessons learned can help advance the next mission when people finally are on board.
It's also cost efficient. It would have cost an extra $600 million to $900 million to outfit the system for astronauts on the initial flight, according to Bill Gerstenmaier, head of NASA's human explorations and operations.
--The Associated Press contributed to this report.