One of NASA's headlining programs is the Space Launch System, a giant rocket program aimed at eventually delivering astronauts to the moon, Mars, asteroids and the deep space beyond. The space agency signed a long-term deal with Boeing earlier this summer to continue work on the mission.

But a new report by federal auditors at the Government Accountability Office say NASA and its contracting partners are unlikely to meet their goal of a December 2017 test flight. Officials with the federal watchdog agency claim NASA's allotted spending figures aren't realistic, and that the mission likely needs at least another $400 million to reach its initial 2017 launch date on time.

"While the technical challenges associated with those efforts appear manageable, the compressed development schedule in conjunction with the agency's relatively flat funding profile for SLS through 2017 place the program at high risk of missing the planned December 2017 launch date for the EM-1 initial test flight," the report reads.

The report casts into doubt the promise made by Virginia Barnes earlier this month. Boeing's Space Launch System vice president and program manager said: "Our teams have dedicated themselves to ensuring that the SLS -- the largest ever -- will be built safely, affordably and on time."

The GAO says the choice for NASA is simple: either delay the first test launch date or find a way to procure additional funds.