A little while ago, SpaceX’s Dragon 2 spacecraft docked with the International Space Station’s Harmony module completing the first part of its CRS-31 mission. Astronauts Butch Wilmore and his colleague Nick Hague monitored the operation but the cargo spacecraft, which blasted off almost 13 hours earlier, completed the maneuvers automatically without any problem.
The Dragon spacecraft’s approach to the International Space Station follows a procedure that has become routine but remains long and delicate. The Station’s safety is the top priority so every little step of the Dragon gets checked. Only if all goes well in the spacecraft’s position and velocity they proceed with the next step and in case of any problems can be aborted at every step. The Dragon 2 carries out all the maneuvers automatically up to the docking and the procedure can be interrupted until the last moment.
Previous missions already provided positive feedback regarding the possibility of reusing the new version of the Dragon cargo spacecraft. In SpaceX and NASA’s initial plans, each Dragon should be used up to 5 times but the new goal for SpaceX is to use each spacecraft up to 15 times. The newly arrived cargo spacecraft is on its fifth mission, a record that will lead to new assessments of its reusability.
The Dragon 2 spacecraft’s cargo is almost 2,800 kilograms (a bit more than 6,000 pounds) between the pressurized and unpressurized sections. There are about 961 kilograms (about 2,119 pounds) of food and other supplies for the crew of the International Space Station but the majority of the cargo consists of instruments, various hardware, and other materials needed for experiments and scientific research conducted on board the Station.
Among the new instruments carried on the International Space Station is CODEX (COronal Diagnostic EXperiment), which aims to examine the solar wind to add new data to that collected by other missions. The goal is to test theories that try to explain how the solar wind is a million degrees hotter than the surface of the Sun.
Among the biological experiments is ARTEMOSS, in which an Antarctic moss of the species Ceratodon purpureus will be studied in the conditions existing in orbit to study how certain plants can tolerate exposure to radiation and microgravity.
ESA’s Euro Material Ageing double experiment aims to study how certain materials degrade when exposed to space. The aim is to gain insights useful to improve spacecraft designs, including satellites.
Nanolab Astrobeat is an investigation into the use of a type of cold welding to repair damage to the outer hull of a spacecraft from the inside. The results could be very useful for repairing damage caused by micrometeorites and space debris.
Among the nanosatellites on board the Dragon cargo spacecraft is LignoSat, built from magnolia wood using a traditional Japanese technique. It will measure the wood’s reactions to space conditions to test the possibility of building satellites with materials that are completely destroyed upon re-entering the atmosphere without leaving behind dangerous or otherwise polluting debris.
The CRS-31 mission will end in about a month with the return to Earth. The second version of the Dragon cargo spacecraft can stay in space much longer than the first version but for now, NASA hasn’t extended its missions.
