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.
Other research experiments on their way to the space station include a biopoylmer concrete investigation to study the building material’s formation in microgravity using resources comparable to lunar regolith, or Martian dust. Another known as the immunosenescense investigation will study the effects of aging on cells’ ability to repair tissues in the body and if reversing those affects are possible in astronauts post space flight. If all that wasn’t enough, Dragon will also deliver five CubeSats, or small satellites with varying focuses of study into orbit along the course of its mission.
aptly named CRS-25 or Commercial Resupply Services mission 25, since this is the twenty-fifth cargo mission that SpaceX has launched for NASA. The Dragon space craft will remain docked at the ISS for thirty-three days before returning home with nearly as much cargo as it with up with. Dragon has the unique ability to be reused and will not burn up upon reentry to Earth’s atmosphere, unlike some other cargo spacecrafts. This means it can return home with research samples, and equipment. When Dragon returns this time, it will do so containing samples and equipment from about fifty research investigations along with waste and other circulated station lifecycle supplies. This includes one spacesuit worn by European Space Agency astronaut Matthias Maurer. The suit experienced a water leak during an EVA (extravehicular activity) or spacewalk rather that took place on March 23 of this year.
CRS-25 also marks the first time a Dragon 2 spacecraft will have supported three missions. Beginning with CRS-21 and later with CRS-23, this mission marks its third trip to the International Space Station. Currently there are two Cargo Dragon 2s in operation. A second was introduced on the CRS-22 mission, and soon a third will be introduced to the Dragon fleet. As their contract extends through CRS-35 at this point SpaceX is confident that three Cargo Dragons are enough to handle the workload, even if there are multiple more contract extension.
Flying today’s mission was Falcon 9 B1067, a regular of their launching fleet. Starting with the company back in June 0f 2021 on the CRS-22 mission, landing on the drone ship Of Course I Still Love You, the only time she ever landed anywhere besides A Shortfall of Gravitas. Of its five missions flown to date, two have been CRS missions, and two have ferrying astronauts to the ISS. The odd mission out is when it carried a Turkish satellite to orbit back in December of last year.