The aerospace industry is currently focused on the Boeing CST-100 Starliner as it undertakes its most critical objective: the Crew Flight Test (CFT). This mission marks the first time the Starliner spacecraft carries astronauts to the International Space Station (ISS), a major milestone for NASA’s Commercial Crew Program.
The Crew Flight Test is the final hurdle Boeing must clear before NASA certifies the Starliner for regular rotational missions to the ISS. While SpaceX has been ferrying astronauts since 2020, NASA has maintained a strict requirement for two independent US commercial space transportation systems. Starliner is the second piece of that puzzle.
This mission profile involves launching the capsule from Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida. The spacecraft rides atop a United Launch Alliance (ULA) Atlas V rocket. This is significant because it marks the first time in history that the Atlas V family of rockets has been used for human spaceflight.
Once in orbit, the spacecraft performs a series of maneuvers to test its thrusters, communication systems, and manual control capabilities. The primary goal is to dock autonomously with the forward port of the ISS Harmony module.
For a test flight of this magnitude, NASA selected two of its most experienced veteran astronauts. Both are former US Navy test pilots with extensive experience on the Space Shuttle and the ISS.
The Starliner differs significantly from the Space Shuttle and its contemporary competitor, the SpaceX Crew Dragon. It is designed to be reusable up to 10 times with a six-month turnaround time between flights.
The path to this crewed flight was not a straight line. Boeing faced several years of delays following the uncrewed Orbital Flight Test (OFT-1) in 2019, which failed to reach the station due to a software clock error. A successful uncrewed re-flight (OFT-2) occurred in May 2022.
However, prior to the crewed launch, engineers discovered two critical safety issues that required immediate rectification:
Boeing teams spent months removing thousands of feet of this tape and applying protective barriers to areas where removal was too risky. These fixes were mandatory to ensure the safety of Wilmore and Williams.
You might wonder why a second spacecraft is necessary if SpaceX is already operational. NASA operates on a policy of “dissimilar redundancy.” If the Crew Dragon fleet were grounded due to a technical anomaly, the US would lose its independent access to the ISS without a backup.
By certifying Starliner, NASA ensures continuous access to the orbiting laboratory. The original contract values highlighted the different approaches, with Boeing receiving approximately \(4.2 billion and SpaceX receiving \)2.6 billion to develop their respective vehicles. Starliner provides the assurance that scientific research and station maintenance can continue regardless of issues with a single launch provider.
How does Starliner land? Starliner is the first American orbital capsule designed to land on land rather than water. It uses heat shields for re-entry, followed by parachutes to slow descent, and finally deploys large airbags to soften the touchdown in the desert.
Is the Atlas V rocket safe for humans? Yes. The Atlas V has a 100% mission success rate spanning over 90 launches for satellites and robotic probes. For the Starliner mission, ULA added an Emergency Detection System (EDS) to monitor engine health and trigger an abort if necessary.
How long will the mission last? The baseline timeline for the Crew Flight Test includes a stay at the International Space Station for roughly eight days. However, the spacecraft is capable of remaining docked for up to 45 days during this test phase if weather or technical issues delay the return.
What happens after this flight? Once the spacecraft returns safely and NASA reviews the data, the agency will likely certify the system for “Starliner-1.” This will be the first operational six-month rotation mission, joining the regular schedule alongside SpaceX missions.