Falcon booster landing
The Falcon 9 booster on the Dec. 21 launch completed its first flight with a droneship landing that was the 100th successful landing for a Falcon booster. Credit: SpaceX webcast

WASHINGTON — SpaceX launched a cargo Dragon spacecraft to the International Space Station early Dec. 21 and achieved a milestone for booster landings exactly six years after the first successful landing.

The Falcon 9 lifted off from Launch Complex 39A at the Kennedy Space Center at 5:07 a.m. Eastern. Forecasts had projected just a 30% chance of acceptable weather for the launch, and weather conditions were no-go for much of the countdown, becoming acceptable less than 15 minutes before the instantaneous launch window opened.

The Dragon spacecraft, which first flew on the CRS-22 mission in June, is scheduled to dock with the space station at 4:30 a.m. Eastern Dec. 22. The spacecraft is carrying nearly 3,000 kilograms of experiments and other cargo, such as biomedical and materials science investigations. Two Earth science experiments, stowed in the unpressurized trunk of Dragon, will be installed on the station’s exterior.

The Falcon 9 first stage landed on the droneship “Just Read the Instructions” in the Atlantic Ocean. The landing was the 100th successful recovery of a Falcon booster and took place six years to the day after the first successful landing during the launch of a set of Orbcomm satellites.

Such landings have become routine, with all but one of the 31 Falcon 9 boosters launched by SpaceX in 2021 landing successfully. “One hundred is a big milestone,” said Sarah Walker, director of Dragon mission management at SpaceX, during a prelaunch briefing Dec. 20. “We’re excited about that, and we’re also excited to see how few new boosters we have to produce as the years go by and we develop our robust maintenance processes on the fleet.”

This launch was the 31st Falcon 9 mission of the year, a record for the company, but only the second to use a brand-new booster, after the CRS-22 launch in June. The launch is also the final scheduled mission of the year for SpaceX.

The Dragon spacecraft will spend approximately a month docked to the ISS. It will return with about 2,000 kilograms of science experiments and space station equipment.

Seat barter update

At the Dec. 20 briefing, Joel Montalbano, NASA ISS program manager, said preparations were continuing to fly the first Russian cosmonaut on the Crew-5 commercial crew mission, a SpaceX Crew Dragon spacecraft scheduled for launch in the fall of 2022.

A formal agreement between the U.S. and Russia to swap commercial crew seats for Soyuz seats has not been completed but is progressing. “We are pressing forward with the goal of success in the fall of 2022,” he said.

Cosmonauts have already started training for potential Crew Dragon flights at SpaceX’s Hawthorne, California, headquarters. “We have a cosmonaut right now” in training, he said, with that training to continue in late January or February after an upcoming break.

Montalbano did not disclose the names of the cosmonauts who have been training. Dmitry Rogozin, head of Roscosmos, said Dec. 8 that Anna Kikina would go on an American commercial crew mission in the fall of 2022 in exchange for flying a NASA astronaut on a Soyuz.

He added there were few new developments into the investigation on the inadvertent thruster firings by the Russian Nauka modules hours after its docking in July. Those firings briefly knocked the station out of alignment, disrupting operations.

“We’ve gone through and done our investigation on our side and the next step is where we sit down between NASA and Roscosmos and compare notes,” he said, including lessons learned. “The most important thing is that we take the lessons learned from these and apply them to future programs.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...