What are the causes of the explosion of Crew Dragon last April during a static firing? The teams responsible for the investigation have just released their first report: the most likely cause of the accident is attributable to leakage of nitrogen peroxide.
Chance of the calendar, while Starhopper, the prototype of Starship, caught fire on its launch pad on Tuesday, July 16, SpaceX released, the day before, the results of the investigation into the explosion of his vehicle Crew Dragon on 20 last April.
A static test that goes wrong
This spacecraft intended for crew travel to the International Space Station(ISS) has been on stand-by since then, and the results of the investigation have been slow. The first tests with the twelve Draco thrusters had gone perfectly, but an anomaly came to interrupt the good series of SpaceX during the test of the eight thrusters SuperDraco intended for the safety of the crews since their role is to eject the capsule in an emergency if a problem occurs with the launcher.
We now know a little more about this anomaly. The joint investigation by NASA officials with the help of observers from the Federal Aviation Administration (FAA) and the National Transportation Safety Board (NTSB) found that the anomaly had occurred approximately 100 times. milliseconds before the ignition of the thrusters, during the pressurization phase of the propulsion systems of the machine.
After analyzing the evidence, these experts concluded that a component leaked, allowing nitrogen peroxide (NTO) to enter the high-pressure helium tubes. This event had the effect of damaging the check valves, which was enough to cause the explosion.
An unexpected reaction
In its statement, SpaceX mentions the fact that such a " reaction between titanium and pressure NTO was not expected " because of its significant use " for many decades and on many spacecraft around the world ". Elon Musk's company believes, however, that many lessons have been learned from this accident, as well as the extensive data from the survey: " The lessons learned from the test - and our other test campaigns - will improve the safety and reliability of SpaceX flight vehicles ".
To avoid this kind of accident in the future, SpaceX has already announced to eliminate the check valves in favor of rupture disks which allow to completely seal the tubes and let the oxidant flow out only after an opening linked to high pressure.
The first manned flight of Crew Dragon is not expected until 2020.
0 Comments