Starliner

Meet Starliner, Boeing’s crew capsule developed for NASA’s Commercial Crew Program.

Boeing is one of two companies building commercial human spaceflight vehicles for NASA and will be the second to fly astronauts. Starliner is designed to carry up to seven people to and from the International Space Station on missions lasting up to six months. Boeing also plans to use it for private astronaut flights to the ISS and for independent free-flying orbital missions.

The Starliner capsule, named Calypso, can operate autonomously or be manually controlled.

Tech Specs

Launch mass: 13000 kg

Crew capacity: Up to 7

Diameter: 4.56 m (15.0 ft)

Length: 5.03 m (16.5 ft)

Design life: 60 hours (free flight). 210 days (docked)

Flight Heritage

First Flight

On December 20, 2019, Boeing’s Starliner launched in its first uncrewed orbital test (OFT-1) aboard a ULA Atlas V rocket. After separation, a software error caused Starliner’s Mission Elapsed Timer (MET) to sync incorrectly with the Atlas V booster (about 11 hours early), leading to a mis-timed orbital insertion burn, which used extra fuel and prevented rendezvous with the ISS.

During the flight, another software bug was discovered in the service module disposal sequence: an incorrect valve-mapping in the thruster control code that, if left uncorrected, could have caused the service module to bump back into the crew module after separation. There was also an intermittent space-to-ground communications issue that limited control from Mission Control.

After orbit testing, Starliner performed a deorbit burn, separated its service module, and reentered. It landed on December 22, 2019, at White Sands Space Harbor, New Mexico. A software patch was uploaded during flight to correct the disposal-sequence error, allowing for a safe separation and landing.

NASA and Boeing conducted a joint investigation and identified three key anomalies: the MET error, the service module disposal bug, and the intermittent communications link. The mission was shorter than planned and its failure to dock with the ISS led to a decision to perform a second uncrewed test flight.

Second Flight

On May 19, 2022, Boeing conducted Orbital Flight Test-2 (OFT-2), the second uncrewed test of the Starliner spacecraft, launching on a ULA Atlas V at 6:54 p.m. EDT. The capsule carried no crew, only the instrumented test device Rosie, and was flown to validate end-to-end systems after earlier issues prevented a previous launch attempt.

Starliner reached orbit but experienced two failed service-module thrusters during the insertion burn; backups compensated and the spacecraft continued toward the International Space Station. It performed automated approach and rendezvous procedures and docked on May 20, about 24 hours after launch.

The spacecraft stayed docked for several days, carrying NASA cargo to the ISS. Upon departure it completed four separation burns, then executed its deorbit sequence. After jettisoning the service module, the crew module reentered using its heat shield, parachutes, and airbags, landing at White Sands Space Harbor, New Mexico, on May 25, 2022, at 6:49 p.m. EDT. The mission lasted roughly six days and met NASA’s major test objectives, including ascent, docking, undocking, deorbit, and recovery performance.

Thrid Flight
On June 5, 2024, Boeing’s Starliner lifted off on its first crewed flight, the CFT, from Cape Canaveral at 10:52 a.m. EDT, carried by a ULA Atlas V rocket. Onboard were two NASA astronauts: Barry “Butch” Wilmore and Sunita “Suni” Williams, both veteran test pilots.

After roughly a 25-hour flight, Starliner docked to the International Space Station, connecting at the forward port of the Harmony module on June 6, 2024, at around 1:34 p.m. EDT. Once at the station, Wilmore and Williams carried out a series of manual and automated control tests to validate Starliner’s handling and systems.

However, the mission ran into technical problems: during docking, five of the 28 reaction-control thrusters failed to behave normally, though four were later reactivated. In addition, throughout the mission, Boeing and NASA detected helium leaks in the thruster system, both issues raised serious safety concerns about using Starliner to bring the crew back.

Because of that, NASA made a decision: instead of returning Wilmore and Williams in Starliner, the spacecraft (named Calypso) undocked autonomously from the ISS on September 6, 2024, with no crew onboard. After undocking, additional thruster tests were run, and though one of the twelve thrusters on the crew module failed during testing, redundancy remained.

Starliner performed a deorbit burn later that night (around 11:17 p.m. EDT), and safely landed at White Sands Space Harbor, New Mexico, early on September 7, 2024, concluding the mission.

Because of the unresolved thruster and helium issues, NASA opted to bring the two astronauts back on a SpaceX Dragon capsule instead. They returned on the Crew-9 Dragon in March 2025.

Courtesy of NASA, Boeing, and ULA.

A ULA Atlas V rocket will launch astronauts to the International Space Station (ISS) aboard Boeing’s CST-100 Starliner capsule. The Starliner will be launched from Space Launch Complex-41 at Cape Canaveral Space Force Station on Florida’s Space Coast.

Specs

Height: 58.3 m (191 ft) with payload fairing, 52.4 m (172 ft) with Starliner

Diameter: 3.81 m (12.5 ft)

Mass: 590,000 kg (1,300,000 lb)

Stages: 2

Dual-Engine Centaur: For CST-100 Starliner missions, the Centaur upper stage uses two RL10A-4-2 engines for additional thrust to accommodate the Starliner and shape the ascent trajectory toward the Space Station.

Launch Vehicle Adapter (LVA) and Aeroskirt: The LVA attaches the Starliner capsule to the Atlas V rocket and connects to the Centaur upper stage. The aeroskirt extends the Starliner’s aerodynamic surface, improving stability and performance during launch.

The Atlas V rocket is configured uniquely for the Starliner missions, without a payload fairing and with a special aeroskirt at the base of the Starliner. This configuration is designated as N22, which indicates no payload fairings ("N"), two solid rocket motors ("2"), and two engines on the Centaur upper stage ("2"). The dual-engine Centaur upper stage, which provides extra thrust for Starliner, is exclusively used for these missions. Although this variant is specific to Starliner, the dual-engine Centaur has flown more than 160 times on previous Atlas V versions with a single-engine configuration.

The launch of Starliner requires a more gradual ascent than typical Atlas V missions. This is done to ensure the safety of the Starliner and its future crews, allowing them to abort the mission at any point during launch if necessary. The Emergency Detection System (EDS) is in place to monitor various launch vehicle parameters, assessing the health of the rocket. Should any issues arise, the EDS can send an abort signal, allowing the Starliner to safely escape.

Photo courtesy of ULA

Space Launch Complex-41 is the east-coast home of United Launch Alliance’s Atlas V rocket. The pad hosted its first launch on December 21, 1965, and is currently being upgraded to support ULA's Vulcan rocket, with its first launch scheduled for no earlier than 2022. For several years, Vulcan and Atlas V will share the pad before Atlas V is retired.

From the 1960s to the 1990s, SLC-41 was used for the U.S. Air Force’s Titan III and Titan IV rockets. Over the years, it has served as the launch site for numerous significant missions, including the Helios probes to study the Sun, the Viking missions to Mars, the Voyager interstellar probes, the Mars Reconnaissance Orbiter, New Horizons to Pluto and the Kuiper Belt, and Juno to Jupiter.

The pad was also used to launch humans aboard Boeing's Starliner capsule, with the inaugural crewed mission occurring in June 2024.

Located on Florida’s east coast, Cape Canaveral is ideally situated to offer access to a wide variety of space destinations while launching over the open Atlantic Ocean, ensuring safety by avoiding populated areas on the ground. The Cape currently supports launches from four different rocket families: Atlas V, Delta IV, Falcon 9, and Minotaur. Additionally, launches of Vulcan from ULA and New Glenn from Blue Origin are scheduled to begin no earlier than 2024.

NASA's Kennedy Space Center, located on neighboring Merritt Island, and Cape Canaveral are often confused or referred to as a single location, but they are distinct government installations. Together, they are united under the name of a single operational area known as the Eastern Range for launch operations.

Over the years, the spaceport has been known by several names: Cape Canaveral Air Force Station (1949-1963), Cape Kennedy Air Force Station (1963-1973), Cape Canaveral Air Force Station again (1973-2020), and Cape Canaveral Space Force Station (2020-present).

Credit: ULA