A resuable cargo craft making its sixth journey to orbit used to be headline news in its own right. During SpaceX’s most recent visit to the ISS, the fact that a capsule could fly six times was almost secondary to what that capsule brought. The Dragon capsule that arrived at the International Space Station during NASA’s CRS-34 mission delivered roughly 6,500 pounds of cargo to the ISS, but that is not the full story. The importance of this particular shipment lies in what it means for space station operations, science, and even NASA’s future use of the outpost through the end of the ISS lifetime, currently projected for around 2030.
The Dragon capsule’s arrival at the Space Station demonstrates something more important than a reusable cargo spacecraft. It is becoming integral to the scientific operations at the station. It should come as little surprise, then, that the payloads on board Dragon include such projects as ODYSSEY, an experiment that will study the results of spaceflight compared to those obtained using microgravity simulators on the ground. There is also Green Bone, an experiment that will study the way bone cell cultures grow on a scaffold made from wood, a concept with relevance to osteoporois research. Another experiment, SPARK, will analyze how red blood cells behave in space, as well as how spaceflight influences splenic function.
Among the scientific payloads are a few less notable items, but ones that remain crucial to life on board the ISS: hardware that will help process water recovered on board the ISS, waste management hardware, various inspection tools, repair material, gas reserve support equipment, and replacement cables. It may seem like mundane cargo, but ISS is unable to conduct many experiments without such deliveries.
The Dragon capsule deserves some recognition not just for delivering all this cargo to orbit, but because cargo Dragon has matured into a reusable cargo delivery system since its inception as the latest upgrade to the Dragon capsule series. Introduced in 2019, the cargo variant replaced an earlier model introduced in 2012, which helped open the door to private logistics services on the ISS. The shift towards reliable cargo delivery to the station under the framework of NASA’s CRS program helped transition a demonstration project into regular services, complete with redundancy, return capabilities, and reusability.
The latter feature is crucial to the capabilities of the Dragon spacecraft because there is not yet any other station-delivering spacecraft capable of returning cargo to Earth in such a manner. Before departing the station for the last time, Dragon CRS-34 will carry numerous items, such as an ocular imaging instrument, filters that purify the air on the ISS, a separator pump from the station’s hygiene system, and the Advanced Plant Habitat for future display at the Smithsonian Institution. All of that means that a relatively routine resupply mission became part of the ongoing scientific effort on board the ISS, where over 4,000 experiments have been carried out in microgravity conditions.