CAPE CANAVERAL, FL — SpaceX successfully launched its Dragon spacecraft to the International Space Station (ISS) on April 21, delivering a cargo manifest prioritizing crew supplies over the usual amount of scientific experiments.
A Falcon 9 rocket lifted off precisely at 4:15 a.m. Eastern Time from Launch Complex 39A at NASA’s Kennedy Space Center. Approximately ten minutes later, the SpX-32 cargo spacecraft was successfully deployed into low Earth orbit. The Dragon is scheduled to autonomously dock with the ISS around 8:20 a.m. Eastern Time on April 22.
The Dragon is transporting a total of 3,021 kilograms of cargo to the orbiting laboratory. Notably, the SpX-32 mission carries a significantly larger quantity of crew provisions – 1,468 kilograms – compared to the 961 kilograms on the SpX-31 mission in November and the 545 kilograms on the SpX-30 mission in March 2024.
NASA had announced in March its intention to increase the crew supplies on SpX-32 due to concerns about potential damage to a Cygnus cargo spacecraft slated for the NG-22 mission in June during pre-launch shipment. Ultimately, NASA and Northrop Grumman canceled the NG-22 mission in late March after confirming damage to the spacecraft’s pressurized cargo module.
This increased focus on crew supplies for SpX-32 has resulted in a reduction in the amount of science being transported. While SpX-30 carried 1,135 kilograms of scientific investigations within its pressurized section and SpX-31 transported 917 kilograms, SpX-32 is only carrying 255 kilograms of science inside the Dragon capsule.
During a prelaunch briefing on April 18, NASA officials could not specify the exact number of science investigations removed from this mission to accommodate the additional supplies. “It is a continuous process as we’re working with our cargo team,” explained Jennifer Buchli, NASA chief scientist for the ISS program.
NASA later clarified to SpaceNews that 14 science investigations were reallocated from SpX-32. “Resupply flight manifests are dynamic leading up to the final close out as NASA continuously looks for efficiencies to maximize cargo space,” the agency stated. “As more space becomes available, more science is added to the manifest.”
Buchli noted that over 30 science payloads are still onboard SpX-32, and the investigations removed from this flight will be scheduled for future cargo missions or potentially the Crew-11 mission launching to the station this summer.
The scientific research heading to the ISS on SpX-32 includes experiments on plant growth, an aerosol monitor for studying the station’s internal atmosphere, and pharmaceutical payloads. Additionally, the spacecraft is delivering 755 kilograms of unpressurized cargo in its trunk: the European Space Agency’s Atomic Clock Ensemble in Space (ACES) experiment, designed to study fundamental aspects of general relativity, and the Space Test Program – Houston 10 suite of experiments.
At the prelaunch briefing, NASA assured that there were no immediate concerns regarding the levels of food and other consumables on the station. “Right now the crew remains well supplied,” stated Zebulon Scoville, deputy manager of the NASA ISS Transportation Integration Office. This buffer accounts for potential delays with the subsequent cargo mission, SpX-33, planned for late this summer.
Looking ahead, the cargo resupply situation for the ISS is expected to improve by the fall. Scoville indicated that the Cygnus NG-23 mission is targeted for launch in mid-September, and the maiden flight of Japan’s HTV-X, an enhanced version of their HTV cargo vehicle, is anticipated later in the fall.
Furthermore, Sierra Space’s Dream Chaser spacecraft may also make its initial voyage to the station before the year concludes, following significant delays. “We’re still trying to assess the exact timing,” Scoville commented, “and the mission objectives that they’re going to be able to accomplish.”
The scheduling of these forthcoming cargo missions will also be contingent on the availability of docking and berthing ports on the ISS. “The traffic pattern is full,” Scoville remarked.