WASHINGTON — NASA introduced Aug. 17 that it’s going to enable SpaceX to make use of a fueling method for its industrial crew missions that attracted prior scrutiny, pending a remaining collection of assessments.
In an announcement printed late Aug. 17, the company mentioned that it was permitting SpaceX to maneuver forward with plans to make use of what’s colloquially often known as “load-and-go,” the place the Falcon 9 launch automobile is full of liquid oxygen and kerosene propellants after astronauts board the Crew Dragon spacecraft on high of the rocket.
“To make this resolution, our groups performed an in depth assessment of the SpaceX floor operations, launch automobile design, escape programs and operational historical past,” Kathy Lueders, NASA’s industrial crew program supervisor, mentioned within the assertion. “Security for our personnel was the motive force for this evaluation, and the crew’s evaluation was that this plan presents the least threat.”
SpaceX makes use of load-and-go for its satellite tv for pc and cargo Dragon missions at present, beginning the fueling course of simply 35 minutes earlier than liftoff. The corporate has adopted that method as a result of it makes use of “supercooled” propellants which can be denser, enhancing the automobile’s efficiency.
That method, although, attracted scrutiny after the September 2016 explosion of a Falcon 9 on the pad at Cape Canaveral throughout preparations for a static-fire take a look at previous to the deliberate launch of the Amos-6 spacecraft. That accident, which destroyed the launch automobile and satellite tv for pc, was blamed on the failure of a composite overwrapped strain vessel in an higher stage propellant tank.
Thomas Stafford, the previous astronaut who chairs NASA’s Worldwide Area Station Advisory Committee, criticized plans to use load-and-go for crewed missions shortly after that accident. He famous that it was opposite to previous NASA human spaceflight applications, the place the launch automobile was fueled first.
Stafford had questioned the method previous to the pad explosion. “There’s a unanimous, and powerful, feeling by the committee that scheduling the crew to be on board the Dragon spacecraft previous to loading oxidizer into the rocket is opposite to booster security standards that has been in place for over 50 years, each on this nation and internationally,” he wrote in a December 2015 letter. That letter obtained renewed consideration after the accident, when Stafford mentioned at an October 2016 assembly of the committee that he had but to obtain a response.
NASA famous on the time that it was the Aerospace Security Advisory Panel (ASAP) that was the first advisor for industrial crew security, and Stafford’s committee not pursued the difficulty. ASAP, at a Could 2018 assembly, concluded after reviewing engineering reports by NASA that load-and-go was a “viable” approach for industrial crew missions.
“It seems that, if all the suitable steps are taken and it addresses the potential hazards, the danger of launching crew within the load-and-go configuration could possibly be acceptable,” mentioned Patricia Saunders, chair of the panel, throughout ASAP’s Could 17 assembly.
These feedback got here every week after SpaceX Chief Government Elon Musk mentioned he was not nervous about NASA rejecting SpaceX’s load-and-go method. “I believe that problem has been considerably overblown,” he mentioned, noting that SpaceX might, if wanted, gas the Falcon 9 earlier than boarding astronauts. “However I don’t assume it’s going to be essential, any greater than passengers on an plane want to attend till the plane is filled with gas earlier than boarding.”
NASA famous in its assertion, although, that formal certification of load-and-go is pending “extra verification and demonstration actions.” That may embody 5 “crew loading demonstrations” to check the crew loading procedures. These assessments might be carried out previous to the primary crewed flight of the automobile, an illustration mission carrying two NASA astronauts at present scheduled for April 2019.