Boeing Starliner Joins SpaceX’s Crew Dragon at the International Space Station

Boeing’s Starliner crew capsule successfully rendezvoused with, approached and docked with the International Space Station for the first time, marking several important milestones for NASA and its second commercial crew partner.

Starliner’s second orbital flight test (OFT-2) began as expected with a nearly flawless launch on May 19 on a United Launch Alliance (ULA) Atlas V rocket. As thousands of employees and stakeholders held their collective breath, the unmanned prototype safely separated from Atlas V’s Centaur upper stage and propelled the rest of the vehicle into a stable parking orbit on its own. Two and a half years after its first attempt, Boeing and NASA were finally able to send the Starliner on its way to the International Space Station (ISS) and prepare for close proximity operations.

As previously discussed on Teslarati, Starliner making it past the first hour of flight without encountering a catastrophic issue was already a huge milestone for Boeing and a massive improvement over the company’s last two orbital flight test attempts.

“The story of Starliner’s tortured Orbital Flight Test (OFT) campaign began in earnest on December 20, 2019, when an unmanned prototype first attempted to launch to the International Space Station (ISS) atop an Atlas V rocket. United Launch Alliance (ULA). A major software bug that could have been easily detected by even the most basic on-cycle hardware pre-launch testing caused the Starliner to lose control the moment it was separated from the Atlas V. After hundreds of seconds of unplanned power-ups of its many attitude checks. boosters, Boeing eventually regained control, but the Starliner no longer had enough propellant to reach the ISS safely.

Boeing would later detect and fix another unrelated software bug just hours before Starliner’s planned re-entry and recovery that, if undetected, could have caused the spacecraft’s capsule and service sections to collide with each other slightly. after separation.

On July 30, 2021, shortly before another uncrewed Starliner was scheduled to reattempt the first orbital flight test, the launch was aborted. Boeing and NASA later reported that 13 of Starliner’s 24 main oxidizer valves failed to open during a pre-launch test just hours before liftoff. Ultimately, it was concluded that faulty valves supplied by Aerojet Rocketdyne and poor integration by Boeing allowed for water intrusion and extensive corrosion. As a result, the next OFT-2 launch attempt was delayed by almost ten months.”

Teslarati.com – May 19, 2022

Rather than a calamity, Starliner’s second and third OFT attempts were mostly met with success. After reaching orbit, the spacecraft began to rise and ‘phase’ its orbit to rendezvous with the ISS and completed all necessary power-ups and navigation without major problems. Finally, after several intentional test maneuvers and about an hour of unplanned troubleshooting, the Starliner began its final approach and successfully docked with the ISS, joining a SpaceX Crew Dragon, at 8:28 p.m. EDT on May 20 (00:28 UTC on May 21). .

Starliner’s successful docking made it the fourth, fifth, or sixth American spacecraft to reach the ISS, joining the Space Shuttle, three major Dragon variants from SpaceX, and Orbital ATK’s (now Northrop Grumman) Cygnus cargo vehicle. It also marked the first time that both NASA’s Commercial Crew Program vehicles docked simultaneously on the space station, a reassuring sign of a future with redundant access after years of Boeing delays that forced SpaceX to temporarily become the only NASA astronaut transportation source. While SpaceX will likely ultimately need to maintain NASA’s access to the ISS on its own for seven six-month (>3-year) ‘expeditions’, Starliner’s so far successful OFT2 mission significantly improves the odds that the Boeing spacecraft will be completely ready within a year or two.

Nonetheless, Starliner must still safely exit the ISS, lower its orbit, re-enter Earth’s atmosphere, and land safely for recovery and reuse. Starliner has already accomplished all of those tasks during OFT1, but tensions will remain high. Also, Starliner’s performance during OFT2 has been far from perfect. Aside from some minor problems with coolers and radiators, Boeing and NASA revealed that four of the spacecraft’s several dozen thrusters (two larger maneuvering/control thrusters and two smaller attitude control thrusters) had failed. at the time it was attached. During OFT1, as many as 13 boosters failed as a result of minutes of unplanned firings, but Boeing was able to recover all but one before re-entry.

Technically, that means both missions have demonstrated the robust redundancy of Starliner’s propulsion systems, but NASA will undoubtedly require Boeing to determine likely root causes and qualify solutions before greenlighting the first flight test. manned aircraft (CFT) of Starliner. For SpaceX, it took 14 months after Crew Dragon’s near-flawless first uncrewed debut for NASA to agree to proceed with a manned flight test. However, during post-flight testing, the capsule supporting Demo-1 catastrophically exploded, prompting a months-long investigation. The effect of some faulty boosters is decidedly less severe, so Starliner might not have to wait as long for CFT. With any luck, that means NASA will have two fully redundant astronaut transport spacecraft available and operational by the end of 2023, if not sooner.

Boeing Starliner Joins SpaceX’s Crew Dragon at the International Space Station






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