Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

Nine Merlin engines ignited and throttled up to nearly 2 million pounds of thrust Sunday during a brief hold-down firing of SpaceX’s Falcon 9 rocket, sending a plume of smoke out of the flame trench at Kennedy Space Center’s historic launch pad 39A as the company preps for a space station cargo mission next weekend.

The nine Merlin main engines at the base of a recycled Falcon 9 rocket booster ignited Thursday night for several seconds during a pre-flight test-firing on a Cape Canaveral launch pad, clearing a major hurdle ahead of a scheduled May 31 liftoff with a high-power communications satellite for SES.

The Starlink 10-18 mission will be SpaceX’s 75th Falcon 9 launch of 2025. It’s targeting liftoff from pad 40 at Cape Canaveral Space Force Station at 1:55 a.m. EDT (0555 UTC).