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

NASA officials say the International Space Station’s logistics chain was designed to absorb a launch failure like the mishap that destroyed an Orbital Sciences Corp. cargo craft in October, but pressure is on SpaceX to deliver supplies on time this year.

SpaceX is preparing for liftoff Tuesday of its first mission for the U.S. Space Force, a launch from Cape Canaveral that will deploy a new GPS navigation satellite using a redesigned profile to allow the Falcon 9 rocket’s first stage booster to reserve enough propellant for landing on SpaceX’s drone ship in the Atlantic Ocean.

The payload onboard hasn’t been officially confirmed by a customer or the spacecraft manufacturer. Liftoff from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station happened Monday, Dec. 16, at 7:51 p.m. EST (0051 UTC).