Boeing’s CST-100 Starliner has been cleared to depart the International Space Station, setting the stage for the final act in this important end-to-end demonstration of the system. You can watch all of the action live right here.
Boeing Orbital Flight Test-2 (OFT-2) is rapidly coming to a close. The six-day mission commenced on Friday, May 19 with the launch of an uncrewed Starliner perched atop a ULA Atlas V rocket. The spacecraft managed to reach its proper orbit despite some propulsion glitches, enabling it to dock at the space station on the following day. The docking tests are complete, and it’s now time for Starliner to come home.
The spacecraft is scheduled to disconnect from the Harmony module at 2:36 p.m. (all times eastern) and perform its parachute-assisted landing at approximately 6:49 p.m. NASA will provide full coverage of these return activities starting at 2:00 p.m. The live broadcast will briefly stop once Starliner fully completes its ISS departure but it will resume at 5:45 p.m. to cover the atmospheric re-entry and landing in the western United States. Live webcasts will be made available on NASA TV, Boeing’s website, YouTube, and at the livestream provided below.
The uncrewed Starliner is slated to land near White Sands Space Harbor in New Mexico. Mission operators will check the weather at the landing site approximately one hour prior to ISS undocking and then conduct the “go/no go” poll” 45 minutes prior to undocking. The team will try again on Friday should there be some sort of delay.
Here’s how the final phase of OFT-2 will unfold, according to the mission profile:
When cleared to leave the space station, Starliner undocks, performs a flyaround maneuver, and positions itself for the deorbit burn to slow from orbital velocity in preparation for atmospheric reentry, where it is met with reentry heating of 3,000 degrees Fahrenheit (1,650 degrees Celsius). Starliner will jettison the forward heat shield around 30,000 feet (9 km) above the ground, followed by deployment of a series of parachutes. First, two drogue parachutes continue to slow Starliner, followed by extraction of the three main parachutes. At 3,000 feet [914 meters] from the ground, airbags inflate to further absorb the initial forces of landing, cushioning the crew for a soft, safe return to Earth.
Indeed, unlike SpaceX’s Crew Dragon, which performs a splashdown landing in the ocean, Boeing’s Starliner performs an airbag-cushioned landing in the desert. Crew Dragon has been human-rated since 2020, but OFT-2, should it go well, will move the program further in that direction. Boeing’s CST-100 Starliner, as part of NASA’s Commercial Crew Program, is behind schedule owing to two previous failed test attempts, one in 2019 and one last year.
Expedition 67 crew members Bob Hines and Kjell Lindgren closed the spacecraft’s hatch at 3:00 p.m. on Tuesday. Said Hines during the farewell ceremony: “It’s been an honor to take part in this and be a tiny cog in the wheel that is the Commercial Crew Program and the amazing teams, the operational teams, the design teams, that put this vehicle together.”
Earlier, a camera mounted to Canadarm2 allowed for a close inspection of Starliner’s Thermal Protection System, clearing the spacecraft for re-entry. Hines and Lindgren have spent the past several days running tests and inspections of the vehicle, in addition to removing 500 pounds of incoming cargo and adding 600 pounds of outgoing cargo for the return trip home (including reusable tanks that provide air to ISS crew members).
Upon landing, Boeing’s OFT-2 mission will officially come to an end, but plenty of work remains. Mission planners will pore over the mission data to determine how well the spacecraft performed. As noted, the vehicle experienced propulsion failures during the orbital insertion burn, so that’s already an item of concern. Boeing and NASA are hoping to perform a crewed test of Starliner later this year, but that will depend greatly on the results of this test.