WASHINGTON — A SpaceX Falcon 9 successfully launched a Dragon cargo spacecraft bound for the International Space Station Dec. 5 on a mission that will also perform a test of the rocket’s upper stage.
The Falcon 9 lifted off from Space Launch Complex 40 at Cape Canaveral, Florida, at 12:29 p.m. Eastern after a one-day delay caused by high upper-level winds. The Dragon spacecraft, flying a mission designated CRS-19 by SpaceX, separated from the upper stage about 10 minutes after liftoff, shortly after the rocket’s first stage landed on a droneship in the Atlantic Ocean.
This Dragon is making its third flight to the ISS, after the CRS-4 mission launched in September 2014 and CRS-11 in June 2017. This is the second time a Dragon spacecraft has been flown three times, and the eighth mission involving a reused Dragon.
CRS-19 is the penultimate mission in SpaceX’s original Commercial Resupply Services contract with NASA. SpaceX will transition to its follow-on CRS contract with the CRS-21 mission in the fall of 2020. Those missions will use a cargo version of the Crew Dragon spacecraft with increased payload volume and the ability to be flown on up to five missions each.
Unlike many recent Dragon cargo launches, where the Falcon 9 first stage makes a landing back at Cape Canaveral, the Falcon 9 for this mission landed on a SpaceX droneship in the Atlantic east of Jacksonville, Florida. Jessica Jensen, director of Dragon mission management at SpaceX, said the droneship landing was because of plans to use the rocket’s second stage for a “thermal demonstration” experiment after deploying the Dragon spacecraft.
“It’s going to be a long six-hour coast that then results in a disposal burn,” she said at a Dec. 3 press conference. “We need extra performance for that demonstration, so basically what we have to do is burn the first stage for a longer period of time so the second stage can have its performance reserved for that demo.” That, in turn, limited the ability of the first stage to return to Cape Canaveral, requiring the droneship landing.
Jensen said that demonstration was for “some of our other customers for longer demonstration missions that we’re going to have to fly in the future.” She didn’t identify those customers, but some national security missions, such as those that place payloads directly into geostationary orbit, do require long coast periods.
The Dragon is carrying 2,617 kilograms of cargo in the form of science experiments, crew supplies and hardware. They include a Japanese hyperspectral imager, a rodent research payload, an experiment studying the behavior of flames in microgavity and a “robot hotel” for storing robotic tools outside the station. It will arrive at the station early Dec. 8.
At the Dec. 3 press conference, Kenny Todd, NASA ISS operations integration manager, demurred when asked if the cargo included any holiday presents for the crew. “There’s always goodies on the flight in general,” he said. “As far as presents and so forth, I’m not sure I want to divulge anything, but I would tell you that Santa’s sleigh is, I think, certified for the vacuum of space.”