Dragon arrives at ISS ahead of reboost test

SpaceX's thirty-first Cargo Re-Supply (CRS) mission arrived at the International Space Station on November 5th, at 14:52 pm Universal Coordinated Time. This mission carries 2,762 kilograms of cargo, with 327 kilograms of unpressurized cargo.

Notably, for the first time during a Dragon spacecraft's mission to the space station, Dragon's Draco thrusters will be performing a reboost burn. This burn is expected to last twelve and a half minutes on November 8th to test Dragon's systems and collect data to inform the development of the U.S. Deorbit Vehicle, which SpaceX won the contract for back in July.

If this test is successful, NASA may contract SpaceX to periodically reboost the International Space Station during future Crew or Cargo Dragon missions. Currently, only Northrop Grumman's Cygnus and Roscosmos' Progress vehicles have the capability to reboost the station. To maintain its orbit, the station requires reboost burns a few times each year.

Liftoff of the CRS-31 mission occurred at 02:29 am Universal Coordinated Time, on November 5th, from Launch Complex 39A, in Florida. This launch was also SpaceX's 400th successful Falcon launch overall, including Falcon 9, Falcon Heavy, and Falcon 1.

The booster supporting the CRS-31 mission was B1083, performing its fifth launch and landing. This booster has previously supported the Crew-8, Starlink Group 6-48, Starlink Group 6-56, and Polaris Dawn missions.

The Cargo Dragon V2 spacecraft conducting the resupply mission is believed to be C208, making its fifth trip to the International Space Station. C208 has been actively supporting resupply missions since December 2020, having flown for the CRS-21, CRS-23, CRS-25, and CRS-28 missions.

NASA plans for Cargo Dragon C208 to be docked at the space station for approximately one month before it returns to Earth toward the end of the year. While at the station, C208 will remain docked at the Harmony modules forward-facing docking port.

Notable research experiments onboard

The items from these sections are from NASA and can be found along with more information here.

Measuring Solar Wind 

The CODEX (COronal Diagnostic EXperiment) examines the solar wind, creating a globally comprehensive data to help scientists confirm theories for what heats the solar wind, which is a million degrees hotter than the Sun’s surface, and sends it streaming out at almost a million miles per hour.

Antarctic Moss in Space 

A radiation tolerance experiment, ARTEMOSS, uses a live Antarctic moss, Ceratodon purpureus, to study how some plants better tolerate exposure to radiation and to examine the physical and genetic response of biological systems to the combination of cosmic radiation and microgravity. Little research has been done on how these two factors together affect plant physiology and performance, and results could help identify biological systems suitable for use in bioregenerative life support systems on future missions. 

Exposing Materials to Space 

The Euro Material Ageing investigation from the European Space Agency includes two experiments studying how certain materials age while exposed to space. The first experiment, developed by Centre National d’Etudes Spatiales, includes materials selected from 15 European entities. The second experiment looks at organic samples and their stability or degradation when exposed to ultraviolet radiation not filtered by Earth’s atmosphere. 

Repairing Spacecraft from the Inside

Nanolab Astrobeat investigates using cold welding to repair perforations in the outer shell or hull of a spacecraft from the inside. Less force is needed to fuse metallic materials in space than on Earth, and cold welding could be an effective way to repair spacecraft.

What's going up on Dragon?

• Potable Water Dispenser Filter: The filter unit, installed into the potable water dispenser on the station, will provide the capability to remove iodine from the water before the crew consumes it in food and drink packages. 
• Reducer Cylinder Assembly & Emergency Portable Breathing Apparatus: Together, this hardware provides 15 minutes of oxygen to a crew member in case of an emergency (smoke, fire, alarm). Two are launching to maintain minimum in-orbit spare requirement. 
• Multifiltration Bed: Supporting the water processor assembly, this spare unit will continue the International Space Station program’s effort to replace a degraded fleet of units in orbit that improve water quality through a single bed. 
• Pump Package Assembly: A variable speed pump, reservoir, accumulator assembly used for circulating coolant through the internal active thermal control system loops. This assembly is being flown to maintain the minimum in-orbit spare requirement. 
• Microbial Removal Filter Cartridge Bag Assembly: Used with the microbial removal filter to offload stowed water to water tank, the assembly will operate under suction to pull water through the filter. These assemblies are replacing current systems that are expiring. 
• Advanced Restrictive Exercise Device Cable Arm Rope Assembly: Distributes exercise loads through a series of pulleys. The ropes have a limited life cycle, and it is necessary to replace ropes that have achieved their cycle-life limit. This unit is being launched as an in-orbit spare. 
• International Docking Adapter Planar Reflector Assembly: With an aluminum base and reflective element, visiting vehicles reflect a laser to compute relative range, velocity and attitude to the space station. The current unit is scheduled to be retrieved and replaced during an upcoming spacewalk. 

What's coming back on Dragon later?

• Hydrogen Dome: includes all hydrogen and oxygen electrolysis components within the space station’s oxygen generation assembly. These items are contained in a sub-ambient dome maintained at near vacuum pressure, designed to contain an explosion or fire in the electrolysis cell stack during operation. The dome provides a second barrier to protect against cabin air internal leakage and external leakage into the rack environment and is pressurized with nitrogen gas for launch. The dome is returning for repair and re-flight. 
• Microgravity Experiment Research Locker Incubator Drawer: An aluminum temperature-controlled container designed to maintain conditions for scientific experiments and is returning for refurbishment and re-flight. 
• Catalytic Reactor: The catalytic reactor replacement unit oxidizes volatile organics from the wastewater so they can be removed by the gas separator and ion exchange bed replacement units as part of the station’s water recycling system. This unit failed in orbit and is being returned for analysis and refurbishment. 
• Ethylene Scrubber: This container removes ethylene, a plant-produced gas, from the plant growth chamber and helps keep vegetables fresh. This unit will return for refurbishment and re-flight. 
• Environmental Control System Module: An aluminum box that holds the environmental control system for the plant growth chamber. The environmental control system controls the humidity and other environmental factors within the plant habitat. This module is returning for refurbishment and re-flight. 
• Ion Exchange Bed: The ion exchange bed unit consists of a pair of tubes in series containing ion exchange resins, which remove organic acids from the catalytic reactor effluent, and microbial check valve resin, which injects iodine into the water as a biocide agent. This unit is returning for repair and re-flight.
• Catalytic Oxidizer: Allows the trace containment control system to remove molecular contaminants from in-orbit atmosphere. This item is returning for repair and re-flight. 
• Urine Processor Assembly Pressure Control and Pump Assembly: This multi-tube purge pump enables the removal of non-condensable gas and water vapor from the distillation assembly within the greater urine processing assembly subsystem. This unit is returning to the ground for repair and refurbishment in support of the legacy environmental control and life support system fleet. 
• Potable Water Dispenser Filter: The filter unit, installed into the potable water dispenser on the station, will provide the capability to remove iodine from the water before the crew consumes it in food and drink packages. This unit will return and be refurbished for re-flight. 

What is Cargo Dragon V2?

Cargo Dragon V2 is a partially reusable spacecraft developed by SpaceX. The primary use for Cargo Dragon V2 is to send cargo to and from the International Space Station. Cargo Dragon V2 consists of the capsule and trunk.

The trunk is used to store unpressurized cargo as well as have solar panels mounted on one side, to generate power, and radiators on the other, to dissipate heat generated inside. The trunk is not reused and burns up in the atmosphere after each mission. Unlike Crew Dragon, Cargo Dragon V2's trunk has two fins due to it lacking the ability to escape from Falcon 9 in the event of a launch failure.

The capsule is used to store pressurized cargo, this could include small living creatures that will undergo experiments onboard the International Space Station. The capsule also has a nosecone that will fold out of the way in space to protect the docking hardware and forward-facing thrusters during launch and landing. The forward-facing thrusters are the main propulsion system for performing maneuvers while in flight. Cargo Dragon V2's capsule is the only part of the spacecraft that can survive returning to Earth.

The original Cargo Dragon was developed as part of NASA's Commercial Orbital Transportation Services program to deliver cargo to the International Space Station. Cargo Dragon V1 would provide SpaceX with valuable insights and experience for it to develop Crew Dragon, which led to the introduction of Cargo Dragon V2.

Lead image from Sen's 4K cameras outside of the International Space Station.