A SpaceX Dragon cargo ship approaches the International Space Station on August 30, 2021. Credit: NASA
SpaceX has postponed this week’s scheduled launch of a Dragon cargo mission to the International Space Station to investigate a possible leak detected during the spacecraft’s feeding into Cape Canaveral.
The Dragon spacecraft was scheduled to be launched Friday morning from NASA’s Kennedy Space Center in Florida. Officials have not set a new target launch date for the SpaceX resupply mission, but a NASA spokesman confirmed that it will not take place on Friday or Saturday.
SpaceX detected “high vapor readings” of monomethyl hydrazine, or MMH, fuel in an “isolated region” of the Dragon spacecraft’s propulsion system during propellant loading ahead of this week’s launch, the spacecraft said. NASA in a statement.
Feeding the Dragon spacecraft is one of the last steps in preparing the capsule for flight, and usually occurs just before SpaceX moves the spacecraft to the launch pad for integration with its Falcon 9 rocket.
The Dragon spacecraft has propellant tanks that contain hydrazine fuel and nitrogen tetroxide oxidizer. The two thrusters ignite in contact with each other, providing a boost to the cargo ship’s Draco thrusters used for in-orbit maneuvers.
Each Dragon spacecraft has 16 Draco thrusters, small rocket engines that generate about 90 pounds of thrust. Draco engines are used for orbit adjustment burns and to control the approach of the spacecraft to the space station, then shoot at the end of the mission for an orbit burn to guide the capsule. new to the atmosphere to go back and splash.
SpaceX’s ground-based processing team, working on the Dragon refurbishment facility at the Cap Canaveral space force station, discharged fuel and oxidizer from the spacecraft area with high steam readings. of hydrazine, NASA said.
Several sources told Spaceflight Now that a hydrazine fuel leak could be to blame, but NASA said the source of the steam has not yet been identified.
“Once the exact source of the high readings is identified and the cause is determined, the joint NASA and SpaceX teams will determine and announce a new target release date,” NASA said in a statement.
The Dragon spacecraft assigned to the next cargo mission is named C208 in SpaceX’s fleet of reusable capsules. The spacecraft has flown to the space station twice before, the last on a 32-day resupply mission last August and September.
Dragon’s next refueling mission, known as CRS-25, will be SpaceX’s 25th cargo flight to the space station under contract with NASA.
The CRS-25 Mission Dragon Capsule will deliver more than 4,500 pounds of food, supplies and experiments to the orbiting research lab.
The spacecraft will also transport an Earth science instrument to the station to monitor the mineral composition of dust particles in desert regions around the world. Developed at NASA’s Jet Propulsion Laboratory, the Earth Surface Mineral Dust Source Investigation, or EMIT, the instrument is already locked inside the pressure-free trunk of the Dragon spacecraft for the trip to the space station.
The EMIT instrument will be removed from the Dragon’s trunk using the space station’s robotic arm, and then mounted on an experiment platform outside the complex. The data collected by the instrument will help scientists learn more about how dust raised in the desert atmosphere affects Earth’s ecosystems and human health.
While the launch of Dragon cargo is on hold, SpaceX is moving forward with plans for another Falcon 9 launch this week with the Egyptian communications satellite Nilesat 301. The Nilesat 301 is scheduled to rise on Wednesday from Cape Cane plantation during a launch window that will open at 17:04 EDT (2104 GMT).
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