In the vacuum of space, the slightest risk of leakage must be taken very seriously, even if it is only a precautionary principle.
Clearly, NASA and its partners are having some sealing issues right now. Last March, the agency was confronted with a new liquid leak that occurred in the helmet of an astronaut; it was therefore forced to launch an investigation and suspend all non-essential spacewalks pending the results (see our article). And she is not at the end of her troubles; we learn today that she had to postpone a planned mission with SpaceX. The reason given: a potential fuel leak detected on board a Dragon capsule.
Fortunately, NASA identified the problem immediately; here, no one was caught off guard, unlike the astronauts who were victims of these leaks. When the ground crew began loading fuel, engineers detected monomethylhydrazine (MMH) fumes. It is one of two compounds that react when they come into contact to generate thrust from small Draco thrusters.
A potentially serious incident detected in time
Unlike the huge rocket engines that are used to pull the launch vehicle out of the grip of gravity, these small boosters are designed to operate exclusively in space. They develop low thrust which allows the craft to be maneuvered with precision; it is systems of this type that make it possible, for example, to gently dock with the international space station. Suffice to say that this dysfunction could have had serious consequences without the vigilance of the troops.
NASA and SpaceX have agreed to an investigation. They will try to identify the origin of the leak before they can consider putting a Dragon capsule back into service. This will allow them in particular to determine if it is an isolated case linked to a malfunction that seems to be punctual; otherwise, expect to find the problem on other Dragons in the future. “Once the exact source of these high readings has been identified and its cause determined, NASA and SpaceX will determine and then announce a new launch date.”, explains the agency in a press release.
No (yet) reason to doubt the Dragon
Thankfully, as it stands, there’s no suggestion that this might be a widespread issue. Nothing to do with the old NASA suits which flirt dangerously with obsolescence; so far, the Dragon has demonstrated its exemplary reliability with dozens of launches, almost all of which have been without incident. The list of isolated dysfunction therefore seems to be preferred; but even if it is only a formality, the precautionary principle remains the absolute priority in this context.
Until then, ISS staff will have to be patient before they can unwrap their gift package. Indeed, this Dragon was supposed to deliver a large amount of material to them, including an important scientific instrument, the SURface MLineral Dust Source Investigation. “This tool will identify the composition of mineral dust from arid regions of the Earth and analyze the dust that travels through the atmosphere to study its effect on the planet” as part of a large data collection serving several climate change studies, says NASA.