SpaceX launched its 23rd International Space Station resupply mission August 29 carrying 2,207 kilograms of experiments, cargo, and crew supplies.
The CRS-23 mission was launched aboard a flight-proven Falcon 9 from Launch Complex 39A at the Kennedy Space Center at 07:14 UTC. The launch had been pushed a day after bad weather precluded a launch on August 28.
Designed to be used on as many as five missions, the upgraded Cargo Dragon spacecraft was introduced with the launch of the CRS-21 mission in late 2020. The new cargo spacecraft, itself a derivative of the Crew Dragon, was introduced to enable shorter processing times between flights.
The Cargo Dragon utilised for the CRS-23 mission was the first to be reflown having previously supported the CRS-21 mission, which splashed down in mid-January following a 35-day visit to the space station.
The CRS-23 Cargo Dragon is expected to dock autonomously with the forward hatch of the station’s Harmony module at 15:00 UTC on August 30. It will deliver 1,046 kilograms of science investigations, 338 kilograms of vehicle hardware, 480 kilograms of crew supplies, 69 kilograms of spacewalk equipment, and 24 kilograms of Russian hardware.
Included in the equipment set to be delivered to the station is the Japanese GITAI S1 Robotic Arm Tech Demo. The experimental robotic arm will initially be installed inside the Bishop Airlock for testing. Later, it will be moved to the exterior of the station to test its performance under the harsh conditions of space.
In addition to the CRS-23 mission being the first to utilise a flight-proven upgraded Cargo Dragon spacecraft, the mission was also notable for being the first to utilise the newest addition to the SpaceX droneship fleet, A Shortfall of Gravitas for a Falcon 9 booster recovery. The booster was also flight-proven having previously supported three other missions included two Crew Dragon flights.
SpaceX returns to flight
Yesterday’s CRS-23 flight was the first SpaceX launch in almost two months, a notable gap following the unstoppable launch cadence the company pursued in the first six months of 2021 that saw it complete 20 launches.
During a prelaunch briefing, the director of Dragon mission management at SpaceX Sarah Walker stated simply, “we launch when our customers need us to launch.” However, according to SpaceX COO Gwynne Shotwell, there is more to it.
Speaking at the 36th annual Space Symposium on August 24, Shotwell stated that the company would not launch another Starlink satellite without key hardware for laser crosslinks between satellites. With 13 of the 20 launches completed in the first half of 2021 dedicated to Starlink, it’s no wonder that the company has not had all that much to launch over the last two months.
However, there is a more worrisome consideration. Speaking at the Space Symposium, Shotwell identified a shortage of Liquid oxygen (LOX) as a challenge moving forward. The shortage has been caused by increased demand from hospitals to deal with the rise of the Covid-19 Delta variant. This may have prompted SpaceX to triage its launch manifest to ensure it can effectively service its most important customers.