San Francisco, Sep 4 : As NASA scrubbed the Artemis 1 uncrewed mission to the Moon once again, Tesla and SpaceX CEO Elon Musk on Sunday came up with a suggestion for the ailing mission that will finally land astronauts on the lunar surface after decades. NASA engineers could not overcome a hydrogen leak in a 'quick disconnect' phase of the Space Launch System (SLS) rocket launch on Saturday. According to Eric Berger of Ars Technica, NASA has a tolerance for a small amount of hydrogen leakage and anything above a 4 per cent concentration of hydrogen near the 'quick disconnect' is considered a flammability hazard. Musk replied to Berger's 'accurate assessment', saying that "Raptor design started out using H2 (hydrogen), but switched to CH4 (hydrogen). Latter is the best combo of high efficiency and ease of operation in my opinion." "Delta-v difference between H2 and CH4 is small for most missions, because the CH4 tank is much smaller & no insulation is needed," Musk explained. The delta-v is the difference of velocity that a rocket engine can impose on a spacecraft as a function of the specific impulse and the variation in the mass of the vehicle itself. According to him, CH4 (methane) is easier to produce on Mars and is "very important" for launch missions. SpaceX is among the first companies to use liquid methane and hydrogen as fuel. Musk also hopes for a self-sustaining city on the Red Planet in 20 years' time, as his space company prepares the Starship mega rocket to take people and cargo to the moon, Mars and beyond. According to the report, The NASA showstopper "was an 8-inch diameter line carrying liquid hydrogen into the rocket. It sprung a persistent leak at the inlet, known as a quick-disconnect, leading on board the vehicle". NASA will next have the launch window from September 19 to October 4. "However, making that window would necessitate fixing the rocket at the pad, and then getting a waiver from the US Space Force, which operates the launch range along the Florida coast," said the report. The space agency has another Artemis I launch opportunity from October 17 to October 31. /IANS