After almost two years of debate, NASA has finally approved SpaceX's plans to charge propellant on its rockets with people on board – a step that some aviation experts considered to be risky. However, approval is dependent on one thing: SpaceX must successfully demonstrate this fuel method at least five times on its new upgraded Falcon 9 rocket, the Block 5, before the process is certified for human space flight.
NASA announced Friday night on this website that it was the priority of the space agency to continue with this. "To make this decision, our teams conducted a comprehensive evaluation of SpaceX ground operations, vehicle launch design, escape systems and operational history," said Kathy Lueders, manager of NASA's Commercial Crew Program in a statement. "Safety for our staff was the engine for this analysis and the team's assessment was that this plan is least risky."
SpaceX has been relying for some time on a tank process that & # 39; load & unload & # 39; is mentioned, with the company pumping propellant into its rocket half an hour before the launch. That is quite close to launch compared to other launch providers, such as the United Launch Alliance, which is fueling its Atlas V rocket one and a half hours before its launch. However, the procedure is ideal for SpaceX. Because the company uses extremely cold propellants and provides the vehicle with fuel just before take-off, the propellant gas reduces too much and boils away. It also increases the performance of the rocket.
However, this means that when SpaceX is going to fly NASA astronauts for the Commercial Crew Program, passengers must board before the propellant is charged. That idea does not suit a few safety experts, especially Lt. General Thomas Stafford, who chairs NASA's ISS advisory committee, oversees the projects of the space agency. The load and go approach would mean that most of the refueling takes place in people who are already on board and that the loading of propellants is a "dangerous operation" that should not occur in people. The commission cited the SpaceX accident in 2016, which occurred when one of the company's Falcon 9 rockets exploded while being loaded with propellant for a test.
Since then, SpaceX has been lobbying that the process is safe, although CEO Elon Musk said it is possible for the company to carry out a different loading procedure. "I think that issue is somewhat exaggerated," he said at a press conference in May. "We could certainly charge the propellants and then the astronauts could go onboard Dragon, which is certainly something we could do." However, in recent months, NASA has penetrated the idea. NASA Aerospace Safety Advisory Panel members, who oversee the safety of various space agency projects, said the procedure was a "viable option" at a meeting in May.
Now SpaceX has to perform its fivefold demonstration of load and go before it can use the process with people. The company has planned several missions before people have to fly the Falcon 9 for the first time in April 2019, so there are still months left to certify the process. However, SpaceX still has to carry out an important update of its rocket before it can start these demonstrations. The company must add upgraded helium tanks to its Falcon 9, called COPVs, before the vehicle is in its final form for launching crew members. Those COPVs are not scheduled to fly until November, when SpaceX launches its first Crew Dragon capsule without people on board.
So somewhere between November and April, SpaceX has to load and go five flights. Thereafter, NASA will find out if there is still a "residual risk" before the crew procedure is certified.