It’s often said that the third time is the charm. For Crew 8 commander Matthew Dominick, co-pilot Michael Barratt, Jeanette Epps, and cosmonaut Alexander Grebenkin, the third launch attempt was the one that lifted them off of Pad LC-39A at Kennedy Space Center late Sunday evening.

Twice in previous days, adverse weather had forced mission managers to call off a launch attempt: first, on Friday due to high winds and rough seas beneath the planned ascent corridor. On Saturday, conditions hadn’t improved for a launch attempt, but by late Sunday they were acceptable and the Crew-8 liftoff and journey to the International Space Station was cleared to proceed. The reason for the weather aborts was simple, if a little counterintuitive to the average person: in the case of a launch abort, the crew would have into seas as high as 20 feet in the Atlantic.

Late Countdown Concerns

After a seemingly uneventful countdown that allowed the astronauts and ground crew to get ahead of schedule, late concerns were raised about a crack in the hatch seal of Crew Dragon Endeavour that was discovered after it was sealed. According to SpaceX and NASA commentators, there were concerns that the crack could cause an atmospheric leak during re-entry, which of course would be unacceptable and potentially cause a scrub to facilitate repairs.

With Falcon 9 being loaded with propellants and the countdown clock inexorably ticking down to zero, engineers responsible for this aspect of the spacecraft were consulted, and with ten minutes left in the count, the astronauts were informed by ground control that the crack was too small to pose a threat. Engineers also stated that the crack would seal itself during re-entry heating, was on the “side” of Crew Dragon as it was re-entering, and would not be a problem. The countdown was cleared to continue.

Liftoff at 10:53 PM

A brand-new booster to the Falcon 9 fleet, B1083, fired up at 10:53 PM EST, sending the crew to orbit and ultimately to the International Space Station. Endeavour will dock autonomously to the forward port of the station’s Harmony module about 3 a.m. Tuesday, March 5.

After staging, the return booster put on an incredible display over the Florida coastline, first, as it began its RTLS (Return To Launch Site) maneuvers then later during its re-entry burn — all of which was visible to spectators from near the launch pad at Kennedy Space Center. Some eight and a half minutes after liftoff, Booster B1083 concluded its first mission with a pair of sonic booms after it touched down, followed by the roar of the landing burn.

On to Station

Crew-8 will now catch up with the International Space Station, and autonomous dock is planned for the forward port of the station’s Harmony module about 3 a.m. Tuesday, March 5. After settling in to ISS, Crew-8 will begin a six month assignment on Station to begin a slate of more than 200 science experiments and technology demonstrations that will take place during their mission.