On May 19th, a near-flawless Starliner’s second orbital flight test (OFT-2) took place on a United Launch Alliance (ULA) Atlas V rocket. Despite being a failure in the first go, this second run was a massive success as Boeing and NASA were then finally able to send Starliner to the International Space Station (ISS) and prepare for proximity operations.
Starliner completed the first hour without running into a catastrophic problem which was a massive improvement over the company’s last two orbital flight test attempts. Notably, Starliner’s second OFT and third OFT attempt was mainly greeted with success.
After reaching the orbit, the spacecraft began raising and ‘phasing’ its orbit to rendezvous with the ISS and completed all the burns and navigation required without significant issues. Fortunately, after multiple intentional test maneuvers and about an hour of unplanned troubleshooting, it began its final approach and successfully docked with the ISS – joining a SpaceX Crew Dragon – at 8:28 pm EDT on May 20th (00:28 UTC May 21st).
This successful docking made it the fourth, fifth, or sixth US spacecraft to reach the ISS, joining the Space Shuttle, three primary variants of SpaceX’s Dragon, and Orbital ATK’s Cygnus cargo vehicle. This event also marks the first time both NASA Commercial Crew Program vehicles have been simultaneously docked at the space station, which is a reassuring sign of a future with redundant access after years of Boeing delays forced SpaceX to become NASA’s sole source of astronaut transportation temporarily.
Starliner must still safely depart the ISS, lower its orbit, reenter Earth’s atmosphere, and safely touch down for recovery and reuse despite this initial success. Although it has completed all these tasks during OFT1, it is still a critical future aspect. On top of it all, Starliner’s performance during OFT2 has been far from perfect, and it had to face multiple issues, including four of the spacecraft’s several dozen thrusters having failed by the time it was docked.
Despite these troubles, Boeing could recover all but one before reentry, and this indicates that both missions have demonstrated the solid redundancy of Starliner’s propulsion systems. But still, NASA will undoubtedly demand that Boeing determine probable root causes and qualify fixes before greenlighting Starliner’s first Crewed Flight Test (CFT).
If all goes well, by the end of 2023, NASA will have two fully-redundant astronaut transport spacecraft available and operational.