An eight-person group called the International Space Station Advisory Committee is reportedly apprehensive about a SpaceX proposal to fuel rockets while astronauts are present. 

SpaceX and Boeing have contracts with NASA to eventually fly astronauts up to the International Space Station, but SpaceX was rocked by a powerful explosion that destroyed one of its unmanned rockets on the launchpad while it was being fueled on Sept. 1.

"This is a hazardous operation," the committee’s chairman and a former astronaut, Thomas Stafford, said on Monday in a conference call, according to Reuters; Stafford also pointed out that “nobody is ever near the pad when they fuel a booster."

SPACEX ROCKET EXPLODES ON PAD DURING UNMANNED TEST

SpaceX thinks the culprit in the explosion might have been the rocket’s helium system. Last week, SpaceX said the investigation has been further narrowed to one of the pressurized helium containers, located in the second-stage oxygen tank.

A NASA spokesperson, Stephanie Schierholz, told FoxNews.com that there is an “ongoing dialogue” between SpaceX and NASA.

“Spacecraft and launch vehicles designed for the Commercial Crew Program must meet NASA's safety and technical requirements before the agency will certify them to fly crew,” NASA said in a statement. “The agency has a rigorous review process, which the program is working through with each commercial crew partner.”

“Consistent with that review process, NASA is continuing its evaluation of the SpaceX concept for fueling the Falcon 9 for commercial crew launches,” the space agency added. “The results of the company's Sept. 1 mishap investigation will be incorporated into NASA's evaluation.”

The ISS Advisory Committee focuses on the International Space Station, while another, the Aerospace Safety Advisory Panel, focuses on commercial crew safety.

The Associated Press contributed to this report.