Enlarge / In January, feathers are seen from the refueling engines of SpaceX Cargo Dragon’s Draco spacecraft as they ignite after being decoupled from the International Space Station.
NASA
NASA and SpaceX have delayed the launch of a Cargo Dragon spacecraft for at least a couple of weeks due to a problem during pre-launch loading of hypergolic propellants.
The space agency had planned to launch the spacecraft on June 12, but announced the delay in an email Monday evening to reporters.
“During the propellant loading of the Cargo Dragon spacecraft, high readings of mono-methyl hydrazine vapor were measured in an isolated region of the Draco propellant propulsion system,” the space agency said. “The propellant and oxidizer have been discharged from this region to support further inspections and testing.”
Draco thrusters provide in-orbit maneuvering propulsion for the Dragon spacecraft. NASA said it is working with SpaceX to identify the source of the high readings and take any corrective action. On Tuesday morning, Mission Control in Houston told astronauts aboard the International Space Station that the launch date would be at least until June 28th.
Announcements
This is not a new Dragon vehicle. Designated Dragon “C208”, this vehicle has previously performed two supply missions, both in 2021. It is an improved version of the original Cargo Dragon spacecraft, known as “Cargo Dragon 2”.
NASA will want to study this topic carefully, because the propulsion system in this version of Cargo Dragon shares a lot in common with Crew Dragon, which also uses Draco propellers and the hypergolic propellers themselves. However, there should be plenty of time for this work, as the next release of Crew Dragon, with “Mission Crew 5”, is not scheduled until September.
These Draco thrusters have a significantly smaller thrust than the SuperDraco thrusters used to power the Crew Dragon launch exhaust system. During a test in April 2019, a leak of oxidant just before the ignition of these SuperDraco propellers caused an explosion that destroyed a spacecraft. No one was injured.
Cargo Dragon does not have these SuperDraco thrusters, however, NASA and SpaceX will want to understand all the issues related to the latest leak before launching supplies or people.