Gary Zhou 
For the second time in ten days, a SpaceX Crew Dragon spacecraft has undocked from the International Space Station (ISS) and is on its way back to Earth.
This time around, four professional Crew-3 astronauts from NASA and ESA boarded Crew Dragon and departed the station after almost six months in orbit, handing off command and control of the US segment to Crew-4. After grappling with a 12-day delay, SpaceX successfully launched Crew-4 to the ISS on April 27th and the astronauts arrived at the station later the same day. Crew-4 was only able to launch after a separate crew of exclusively private astronauts known as Axiom-1 finally departed the ISS on April 24th.
Falcon 9 launched Axiom-1 and Crew Dragon on April 8th on what was initially supposed to be a 10-12 day mission in orbit. As a result of extensive weather-related recovery delays, Axiom-1 instead splashed down on April 25th. Those collective delays ultimately gave Crew-3 around two extra weeks in orbit before Crew-4 was able to take over, freeing them up to return to Earth.
NASA astronauts Raja Chari, Tom Marshburn, Kayla Barron, and German ESA astronaut Matthias Maurer began preparing for their departure in earnest about half a day prior on May 4th and boarded Dragon a few hours before undocking. Now verging on routine, Crew Dragon undocked from the ISS without issue at 1:20 am EDT on May 5th, kicking off a roughly 24-hour return to Earth.
Crew-3’s Dragon will perform a final deorbit burn shortly before midnight on May 6th and, if all goes well, the spacecraft’s reusable capsule will splash down off the coast of Florida a bit before 1am EDT. It will be Crew Dragon’s second astronaut reentry and splashdown in ten days after Axiom-1 completed the same process on April 25th.
In just four weeks, SpaceX will have launched Ax-1, docked Ax-1 with the ISS, undocked and recovered Ax-1; launched Crew-4, docked Crew-4 with the ISS; and undocked and recovered Crew-3 – a series of eight major Dragon operations involving three of the company’s fleet of four reusable orbital spacecraft. Given the numerous delays suffered by all three missions as a result of their close proximity, it would be hardly surprising if NASA and SpaceX explicitly try to avoid that level of cadence for future ISS-related Dragon operations.
Nonetheless, SpaceX and NASA are already in the late stages of preparing an uncrewed variant of Dragon 2 for the company’s 25th ISS cargo delivery. CRS-25 is scheduled to launch as early as June 7th and will be SpaceX’s third Dragon launch and third mission to the ISS in less than two months. Later this year, SpaceX Dragons are scheduled to support CRS-26 in September, Axiom-2 as early as Q3 2022, Crew-5 in October, and Polaris Dawn – a free-flyer mission – in Q4 2022.
