While the Starliner spacecraft (Boeing) is set to carry humans into orbit for the first time on June 1, the Crew Dragon (SpaceX) has been transporting astronauts for several years.
After numerous delays and setbacks, the first crewed mission of the Starliner spacecraft, developed by Boeing, is finally scheduled to launch to the International Space Station (ISS). NASA astronauts Butch Wilmore and Suni Williams arrived at the Kennedy Space Center in Florida on May 28. NASA and Boeing plan for Starliner to lift off at 11:25 PM on June 1 (Hanoi time). The spacecraft will ascend to orbit using an Atlas V rocket from United Launch Alliance, a joint venture between Boeing and Lockheed Martin.
SpaceX’s Crew Dragon docking at the ISS (left) and Boeing’s Starliner in orbit during a test flight in 2022 (right). (Photo: NASA).
NASA is confident in the success of Starliner, aiming to have a second commercial vehicle alongside SpaceX’s Crew Dragon for transporting crew to the ISS. Starliner, developed over many years, has faced several issues, causing it to lag behind Crew Dragon, which is currently the only American spacecraft capable of taking astronauts into space since the shuttle program ended over a decade ago.
If it passes the final test mission today, Starliner, along with Crew Dragon, will serve as NASA’s crewed spacecraft for upcoming missions. So, how do these two spacecraft differ?
Starliner Spacecraft
Boeing’s spacecraft consists of a reusable crew module and a single-use service module, designed for missions to low Earth orbit.
Starliner on the Atlas V rocket at Cape Canaveral, Florida, before its first test mission in December 2019. (Photo: Joe Raedle).
The crew module has a diameter of 4.6 meters, slightly larger than the Apollo command module that went to the Moon and Crew Dragon, but smaller than the crew module of the Orion spacecraft in the Artemis program, which is designed for deeper space missions. Starliner can carry a maximum of 7 people and dock with the ISS for up to 7 months. It features a traditional cockpit with physical buttons and switches, providing a familiar interface for astronauts.
Solar panels supplied by Boeing’s subsidiary Spectrolab are mounted on the back of the service module, generating 2.9 kW of power. The service module contains 4 Rocketdyne RS-88 engines that burn hypergolic propellant, enabling emergency escape in case of a launch anomaly. Starliner is designed to transport a maximum of 2,500 kg of pressurized cargo and 1,500 kg of unpressurized cargo.
The spacecraft has completed two uncrewed test flights: Orbital Flight Test 1 (OFT-1) and Orbital Flight Test 2 (OFT-2). OFT-1, which occurred in December 2019, faced a software issue that prevented it from docking with the ISS. In May 2022, OFT-2 successfully docked with the ISS after resolving a valve wear issue caused by nitrogen tetroxide interactions.
Crew Dragon Spacecraft
Crew Dragon consists of a reusable crew module and an integrated trunk, designed for missions to low Earth orbit and beyond. The crew module has a diameter of 4 meters, slightly smaller than the Starliner and Orion crew modules. Dragon can also carry up to 7 astronauts and dock with the ISS for a maximum of 7 months, similar to Starliner.
Crew Dragon docked with the ISS in May 2021. (Photo: NASA).
The cockpit is equipped with modern touch screens and several physical control buttons, providing astronauts with an advanced interface similar to the minimalist interior of Tesla electric vehicles. Solar panels mounted on the trunk provide 5 kW of power. The spacecraft is equipped with 8 SuperDraco engines that burn hypergolic propellant, enabling astronaut escape in case of a launch malfunction. Crew Dragon is also designed to carry a maximum of 6,000 kg of combined pressurized and unpressurized cargo.
Unlike Starliner, Crew Dragon has conducted both crewed and uncrewed flights. The first uncrewed test flight, Demo-1, took place in March 2019 and successfully docked with the ISS. The first crewed flight, Demo-2, occurred in May 2020, successfully transporting astronauts to the ISS, marking the first crewed orbital launch from the U.S. since the shuttle program ended in 2011.
