On August 29 at 03:14 UTC, a SpaceX Falcon 9 launched the CRS-23 mission towards the International Space Station from LC-39A at the Kennedy Space Center. Cargo Dragon C208 was deployed about twelve minutes after liftoff, beginning its second trip to the ISS. It is the first Cargo Dragon 2 to be reused, with its first flight on CRS-21 back in December 2020.

Onboard Dragon was the usual complement of scientific experiments and technology demonstrations. In total, it brought 2,207 kilograms of cargo up to the station or the equivalent of just over 1,100 two-liter soda bottles.

This was the fourth flight for Booster 1061. It successfully landed on the ASDS A Shortfall Of Gravitas, SpaceX’s newest droneship, marking the 90th landing of a Falcon booster.

One of the technology demonstrations will help astronauts take better care of their eyes. The Retinal Diagnostics device takes an off-the-shelf ophthalmology lens and puts it in a handheld device suitable for use in orbit. It will be used to take pictures of astronaut retinas to monitor the progression of Space-Associated Neuro-Ocular Syndrome. This condition affects astronauts who perform long-duration missions in space and comes from increased fluid in the head due to microgravity. This results in swelling of the optic nerve and flattening of the eye shape. 

The change in an astronaut’s vision is severe enough that they need glasses to see clearly when they return to Earth. With future missions to Mars planned, astronauts need to be able to diagnose themselves instead of needing a trained professional and an office full of equipment. The mobile diagnostic device will also help treat patients in remote or extreme environments on Earth.

In addition to its payloads for the inside and outside of the station, CRS-23 also carries CubeSats to be deployed into orbit. The group of CubeSats called Educational Launch of Nanosatellites (ELaNa) 37 includes CAPsat, a 3U CubeSat designed to test different technologies including thermal management, deployable panels, and a “single-photon avalanche detector”, which is an electrical sensor for detecting very faint signals down to a single photon as the name suggests. The bread-loaf-sized CAPsat will specifically investigate the on-orbit repair of the said sensor by annealing, or heating it up and cooling it down in a controlled manner, using a laser to allow the atoms of the sensor to reorder themselves into an undamaged state.

You can read about the other two CubeSats carried by CRS-23 in our Patreon show notes.

More Information

NASA press release

23rd SpaceX Commercial Resupply Mission Launches Bone, Plant, and Materials Studies to International Space Station (NASA)

CAPSat info page (Gunter’s Space Page)

What’s a SPAD? (SPADlab)

From the Classroom to the Launchpad – University Satellites Prepare for Launch (NASA)

Launch video