Astronauts will not fly on the first flight of NASA's deep space rocket, the Space Launch System, NASA announced Friday.
NASA has been researching for the past two months if the agency could put crew on the first flight of SLS, known as Exploration Mission-1 or EM-1, at the request of the Trump administration.
SLS is currently being assembled and is tentatively schedule for its EM-1 launch in 2019 from NASA's Kennedy Space Center. The rocket will launch the Orion spacecraft on a lunar orbit mission to test the launch system.
"NASA appreciates the energy, creativity, and depth of engineering and program analysis that was brought to the decision, but ultimately, the decision was made not to fly crew on the first flight after weighing the data and assessing all implications," writes acting NASA administrator Robert M. Lightfoot.
The agency made the decision after evaluating the cost, risk and technical needs, Lightfoot said.
The changes to EM-1 in ordered to accommodate crew on the Orion spacecraft would have cost between $600-$900 million, William H. Gerstenmaier, NASA associate administrator for human exploration and operations, said.
The program designed to bring humans to Mars has already experienced multiple delays.
Production delays were also a factor in the Em-1 decision, Lightfoot said.
A February tornado damaged the Michoud Assembly Facility in New Orleans where the rocket's core stage is being assembled. The rear dome of a liquid oxygen tank for the core stage was also damaged in a incident at the facility on May 3, according to NASA. That damage is still being assessed.
The U.S. Government Accountability Office warned last month that a delay was likely for the first SLS flight, with or without crew. The current exploration effort will cost nearly $24 billion by the end of fiscal 2018, the GAO reported.
The next opportunity for a crewed flight would be EM-2 in 2021.
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