CST-100 Starliner

CST-100 Starliner
NASA, Johnson Space Center · Public domain · source
Name	CST-100 Starliner
Manufacturer	Boeing
Country	United States
Function	Crewed spaceplane
Operator	United Launch Alliance; NASA; Boeing
First flight	2019
Status	In service

CST-100 Starliner is a crewed spacecraft developed by Boeing to transport astronauts to low Earth orbit destinations, principally the International Space Station and commercial space habitats. Funded under NASA's Commercial Crew Program and built by Boeing in collaboration with partners such as United Launch Alliance, the vehicle is designed for reusability, rapid turnaround, and compatibility with existing launch infrastructure like Cape Canaveral Space Force Station and Kennedy Space Center. The program sits alongside competitors and contributors including SpaceX, Sierra Nevada Corporation, and international partners such as Roscosmos and the European Space Agency.

Development

Development began after Boeing responded to NASA's 2010 solicitation under the Commercial Crew Development contracts, joining companies awarded in 2014 under the Commercial Crew transportation capability agreements. Boeing's history with crewed vehicles draws on work from programs such as the Space Shuttle, Apollo program, and partnerships with Lockheed Martin and Northrop Grumman. The CST-100 program involved aerospace suppliers including Aerojet Rocketdyne, Honeywell, Rockwell Collins, and Spirit AeroSystems. Major milestones included Critical Design Review, flight software integration with avionics suppliers, and tests at facilities like Johnson Space Center and Huntsville, Alabama testing centers. Delays and schedule adjustments occurred amid workforce changes at Boeing Defense, Space & Security and budget reviews by NASA Administrator offices; these affected timelines similar to earlier programs such as Constellation Program and Orion (spacecraft).

Design

The spacecraft is a reusable pressurized capsule sized to carry up to seven astronauts and cargo, featuring a service module, a forward docking mechanism compatible with the International Space Station's Common Berthing Mechanism and International Docking Adapter, and a heat shield for atmospheric reentry. Propulsion components include main thrusters from Aerojet Rocketdyne and reaction control systems inspired by designs used on Mercury and Apollo era vehicles. Avionics and flight-control systems were developed with suppliers like Honeywell and tested against standards from Federal Aviation Administration certification processes. Landing is achieved via parachute-assisted touchdown on land at sites such as White Sands Space Harbor and contingency sites including Edwards Air Force Base. Structural materials draw on composites from Spirit AeroSystems and thermal protection technologies used in programs such as Space Shuttle and Orion (spacecraft).

Operational History

Operational efforts focused on integrating the spacecraft with the United Launch Alliance's Atlas V vehicle, and later exploring compatibility with other launchers including configurations used by Vulcan (rocket). Key operational partners included NASA's Johnson Space Center for crew training, Kennedy Space Center for launch processing, and Cape Canaveral Space Force Station for pad operations. The program's trajectory was influenced by international flight manifest planning involving Roscosmos crew rotations and agency coordination with JAXA, CSA, and ESA for long-duration missions. Training regimens incorporated simulators from Boeing and facilities at Ellington Field and were aligned with standards set by NASA Astronaut Corps.

Missions

Test and crewed missions included uncrewed demonstration flights and crewed certification flights managed under NASA's Commercial Crew certification path. Notable mission phases paralleled the sequence used by vehicles such as Soyuz MS, Crew Dragon, and historical missions like STS-1. Cargo and crew rotations to the International Space Station formed the core operational manifest, with mission integration involving Mission Control Center, Roscosmos Mission Control Center, and the Global Positioning System and Tracking and Data Relay Satellite System networks for navigation and telemetry. Contingency abort profiles referenced historical abort scenarios such as those from Apollo 13 and emergency procedures similar to Soyuz TMA abort sequences.

Safety and Testing

Safety testing encompassed pad abort tests, integrated system checkouts, and software verification using techniques refined during work on Space Shuttle avionics and Apollo Guidance Computer legacy validation. Independent assessments were performed in coordination with organizations such as the National Transportation Safety Board-style review bodies within NASA and certification agencies similar to Federal Aviation Administration oversight for human-rating standards. Ground tests took place at facilities like White Sands Missile Range, Hampton, Virginia test stands, and thermal-vacuum chambers at Jet Propulsion Laboratory-style labs. Lessons from mishaps in aerospace history — including investigations into Space Shuttle Challenger and Space Shuttle Columbia — informed procedural updates and risk mitigation strategies.

Variants and Modifications

Planned variants include cargo-only configurations and potential modifications for higher-orbit missions to stations analogous to Tiangong space station and future concepts like Lunar Gateway logistics. Modifications explored integration with new launch vehicles such as Vulcan Centaur and potential systems upgrades drawing on technologies from programs like Orion (spacecraft) and commercial developments by SpaceX and Sierra Nevada Corporation. Corporate restructuring at Boeing and partnerships with suppliers like United Launch Alliance and Aerojet Rocketdyne influenced iterative changes similar to variant evolutions seen in programs such as Atlas V family upgrades and Delta IV heritage adaptations.

Category:Crewed spacecraft