Updated 8:50 a.m. Eastern.
WASHINGTON — SpaceX launched a Dragon cargo spacecraft to the International Space Station early May 4 after a one-day delay caused by a droneship problem.
The Falcon 9 lifted off from Space Launch Complex 40 at Cape Canaveral Air Force Station at 2:48 a.m. Eastern, placing the Dragon into orbit nearly 10 minutes later. The rocket’s first stage made a landing on a droneship just offshore.
The launch was previously scheduled for May 3, but scrubbed because of an electrical problem with the droneship. While previous launches of Dragon cargo spacecraft have made use of Landing Zone 1 at Cape Canaveral, this mission shifted to a droneship because of the ongoing investigation into an April 20 Crew Dragon anomaly during testing that took place at the landing site.
“The landing site and the test site were every close. We wanted to basically make sure that we can focus on the evidence and not disturb that,” Hans Koenigsmann, vice president of build and flight reliability at SpaceX, said at a pre-launch briefing May 2. He said the company was “pretty close” to restoring full access to the landing site.
While the investigation into that incident, which destroyed the Crew Dragon spacecraft during a test of its SuperDraco thruster system, continues, NASA proceeded with this cargo Dragon mission after the agency and SpaceX found no evidence of commonality between systems implicated in the incident and those on the cargo Dragon, which does not have SuperDraco thrusters.
“We were able to get our arms around the common areas that we had to look at, that they had to look at,” Kenny Todd, NASA’s space station operations and integration manager, said at the pre-launch briefing. “At the end of the day, we didn’t see any change in our overall measurable risk in going into the mission.”
This cargo Dragon, which first flew to the station on the CRS-12 mission in August 2017, is carrying 2,482 kilograms of cargo on this mission, designated CRS-17. That cargo includes about 1,700 kilograms of science payloads, with the rest devoted to crew supplies and vehicle hardware. The Dragon is scheduled to berth with the ISS May 6.
While the Dragon on this mission has previously flown to the station, the Falcon 9 first stage was new, as was the case with the previous Dragon mission, CRS-16, in December 2018. NASA has previously launched Dragon missions on “flight-proven” Falcon 9 rockets, but Todd said at the pre-launch briefing NASA hasn’t deliberately switched back to using new vehicles instead. “From my perspective there’s nothing’s that changed,” he said. At a briefing after the launch May 4, he noted NASA had a “vested interest” in making sure SpaceX could recover this booster since agency plans to use it on the next two Dragon cargo missions.
Koenigsmann cited the change in perception in the last few years as the use of flight-proven boosters has gone from a novelty to a routine part of SpaceX operations. “It’s interesting how the thinking changed overall,” he said prior to launch. As for this mission, he said, “Every once in a while we need new boosters.”