CRS-25 heads to ISS

July 14 at 8:44 pm E.T. from LC-39A at the Kennedy Space Center

Initially scheduled to launch over a month ago, CRS-25 has finally left Earth after being delayed to due high levels of hydrazine vapor were detected in part of Dragon’s propulsion system during fueling operations. This hydrazine is used by the Dragon’s Draco thrusters and is highly corrosive to components not designed to interact with the fuel. Due to the severity of this issue NASA, and SpaceX took a cautious approach with the situation, pushing the launch back three times over several weeks. In a statement released June 28, NASA cited that teams were repairing and replacing any components that could have the potential to have been degraded by the vapor and would also replace the vehicles main parachute in order to give the potentially affected chute a more thorough inspection.

CRS-25 once docked will have delivered 5,800lbs of science and supplies to the space station. This includes nearly forty ongoing research investigations, fresh apples, oranges, tomatoes, and other fresh foods, and cargo which will be useful to the astronauts onboard. If we are going by weight, then the science equipment accounts for roughly one half of the mission’s total cargo. One of the biggest experiments, not just in size but project scope is EMIT or Earth Surface Mineral Dust Source Investigation. About the size of a regular kitchen oven, it will be flown inside the trunk of Dragon and added to the ISS as an external payload to be used in measuring the mineral composition of dust in the planet’s driest regions. EMIT will focus on how dust in arid landscapes is carried on winds across the globe, adding to the planet’s overall climate system.