Boeing Starliner

Boeing Starliner. The Boeing CST-100 Starliner is a reusable crew capsule developed by Boeing as part of NASA's Commercial Crew Program. Designed to transport astronauts to and from the International Space Station and other low Earth orbit destinations, it represents a key element in restoring domestic American crew launch capability. The spacecraft completed its first crewed mission, the Boeing Crew Flight Test, in June 2024, docking with the International Space Station for an extended stay.

Development and design

The Starliner was developed under a fixed-price contract awarded by NASA in 2014, competing directly with the SpaceX Dragon 2. Its design emphasizes reusability, with each capsule intended for up to ten missions. The spacecraft consists of a crew module, which is reusable, and a service module, which is expended after each flight. Key design partners include Aerojet Rocketdyne, which supplies the launch abort and orbital maneuvering engines, and United Launch Alliance, which provides the Atlas V and Vulcan Centaur launch vehicles. The capsule's "waste-hygiene compartment" and other interior layouts were informed by extensive astronaut feedback from veterans of the Space Shuttle program.

Operational history

The program's first uncrewed orbital test flight, Boeing Orbital Flight Test (OFT) in December 2019, failed to reach the International Space Station due to a mission-elapsed timer anomaly. A successful repeat, Orbital Flight Test 2 (OFT-2), was completed in May 2022, docking autonomously with the Harmony module. The inaugural crewed mission, Boeing Crew Flight Test (CFT), launched on June 5, 2024, atop an Atlas V rocket from Cape Canaveral Space Force Station. Crewed by NASA astronauts Barry Wilmore and Sunita Williams, it docked with the International Space Station after addressing several helium leaks and thruster issues. The spacecraft is scheduled to begin operational crew rotation missions starting with Starliner-1 in 2025.

Technical specifications

The Starliner stands approximately 5 meters tall with a diameter of 4.5 meters. Its crew module provides 11 cubic meters of pressurized volume and can support up to seven passengers, though NASA missions typically fly four to match the capacity of the Soyuz MS. Propulsion is provided by the service module, which houses four launch abort engines and numerous orbital maneuvering thrusters burning hypergolic propellants. The spacecraft uses a Boeing-designed "pusher" launch abort system integrated into the service module. Thermal protection during re-entry is handled by a Boeing-developed lightweight ablative heat shield, and landing is accomplished via airbags at one of several designated sites in the Western United States, such as White Sands Missile Range.

Mission profile and capabilities

A standard mission begins with launch aboard a United Launch Alliance Atlas V or Vulcan Centaur rocket. Following ascent, the service module provides all orbital insertion, rendezvous, and docking maneuvers, linking autonomously with the International Space Station. The capsule can remain docked for up to 210 days, serving as a lifeboat. For return, it undocks, performs a deorbit burn, jettisons its service module, and re-enters the atmosphere. The crew module descends under parachutes, with airbags deploying just before touchdown for a ground landing. Beyond servicing the ISS, the Starliner is designed for potential missions to future commercial stations like Orbital Reef, being developed by Blue Origin and Sierra Space.

Program challenges and delays

The Starliner program has faced significant technical, financial, and scheduling difficulties. The 2019 OFT mission anomaly led to a lengthy investigation by NASA and an extensive software review. Further delays were caused by issues with the spacecraft's propulsion system, including corroded valves in the service module that postponed the OFT-2 launch by nearly a year. These setbacks resulted in substantial financial losses for Boeing, exceeding $1.5 billion. The 2024 CFT mission, while successful, encountered multiple helium leaks and the failure of several reaction control system thrusters, extending the crew's stay at the International Space Station for additional testing and analysis.

Category:Spacecraft Category:Boeing spacecraft Category:NASA programs Category:Human spaceflight