Washington, May 7 (IANS): An approach used by SpaceX to make its Falcon 9 rocket more powerful could put the lives of astronauts at risk, NASA's safety experts have warned.

To make the Falcon 9 rocket even more powerful, SpaceX came up with the idea of keeping the propellant at super-cold temperatures to shrink its size, allowing them to pack more of it into the tanks. But the approach comes with a major risk, The Washington Post reported on Saturday citing the experts.

The new approach requires the propellant to be loaded just before takeoff, while astronauts are aboard, but an accident during this manoeuvre, known as "load-and-go," could set off an explosion.

As NASA and SpaceX prepare to launch humans into orbit as early as this year, one watchdog group labelled load-and-go a "potential safety risk," the Post reported.

In a letter, a NASA advisory group warned that the method was "contrary to booster safety criteria that has been in place for over 50 years."

SpaceX suffered a setback in September 2016 when a Falcon 9 rocket blew up while it was being fuelled ahead of an engine test.

As a result of the explosion, a multi-million dollar satellite was lost. Although no one was hurt in the incident, it raised safety concerns in the minds of the people at NASA.

The report quoted NASA's William Gerstenmaier as saying that the agency had not decided whether it would allow SpaceX to load crews before loading the fuel.