SpaceX Dragon cargo capsule docks to the ISS

SpaceX’s latest cargo mission to the International Space Station (ISS) – CRS-32 – just docked to the orbiting outpost, bringing extra crew supplies, which resulted in the deferral of several science payloads.

The Falcon rocket carrying the Dragon spacecraft lifted off from Launch Complex 39A at the Kennedy Space Center in Florida on April 21 at 0815 UTC, deploying the freighter into orbit almost 10 minutes later. The first stage landed successfully at the Cape Canaveral Space Force Station Landing Zone 1 (LZ-1). The Dragon docked to the station’s Harmony module on April 22 at 1240 UTC.

Damage sustained during the shipment to the Pressurized Cargo Module (PCM) of Northrop Grumman’s Cygnus vehicle caused an indefinite delay to the NG-22 mission and shifted focus to CRS-32, prompting changes to the Dragon’s manifest. A space agency insider told El Reg that supplies aboard the ISS could have become stretched should there have been any problems. The handover period between Crew-9 and Crew-10 was shortened partly to avoid a possible consumables shortfall.

Zebulon Scoville, deputy manager of the Transportation Integration Office for NASA’s ISS Program, told reporters at the prelaunch briefing, “Right now, the crew remains supplied,” and went on to note that the meals flown on this flight will ensure the crew has sufficient supplies to last through the summer even if the next SpaceX cargo mission – CRS-33 – is delayed.

NASA was coy about exactly what had to be pushed onto a later flight during the briefing. Some items might fly with Crew-11, while others will be loaded onto later cargo missions. Though the agency was happy to throw out trivia such as 1,262 tortillas being flown on the mission, it was a little more guarded about the science payloads that had to be shuffled elsewhere.

While rescheduling those payloads will have been painful for some scientists, some key experiments remained. In the trunk section of the vehicle is the European Space Agency’s (ESA’s) Atomic Clock Ensemble in Space (ACES). ACES consists of a pair of ultra-accurate clocks able to “generate a time signal so precise that ACES would lose just one second in 300 million years,” according to ESA. The plan is to use the clocks to examine fundamental physics, such as relativity, and demonstrate time synchronization between Earth and space “with an accuracy far beyond today’s systems.”

The payload is due to be installed by the station’s robotic arm on the External Payload Facility of ESA’s Columbus module on April 25. ®