by Boeing’s CST-100 Starliner is scheduled for its first flight into space with astronauts on May 6, 2024. This flight and several others will take place under contract with NASA, as part of a program to transport astronauts from Earth to the International Station Space (ISS) and back.
After years of delays, a successful flight would give the United States its second operational spacecraft to carry astronauts to low-Earth orbit, after SpaceX’s Crew Dragon.
If two different spacecraft are available, a backup option is available if something goes wrong with one of them. So it will secure access to space for astronauts from American soil. Although Starliner will currently fly to the ISS, it could make trips to commercial space stations in the future, such as the one being built by the Houston-based company Axiom Space.
Getting to space, however, has never been easy. For Starliner, that’s an understatement. The project began back in 2010 as part of NASA’s Commercial Crew Program (CCP) when Boeing, along with SpaceX, and Sierra Nevada, were selected to develop spacecraft that could provide access to low-Earth orbit and on the ISS.
The CCP’s design requirements were that the spacecraft had to be able to safely transport at least four astronauts to and from the ISS, remain stuck there for at least 210 days, and 24 hours provide at least life support should it occur. emergency return to Earth from orbit.
However, the project has been delayed, including supply chain issues, and the COVID-19 pandemic. The original contract called for Starliner to be certified for orbital operations with astronauts in 2017. However, the first orbital flight test, without astronauts, did not occur until December 20, 2019.
It was intended to be an eight-day mission where the spacecraft would dock with the ISS, before returning to Earth. During the flight, a clock on board the spacecraft experienced a technical malfunction, causing the rocket engines to fire – moving the craft into the wrong orbit. It failed to reach the ISS and returned to Earth after only two days.
Read more: Boeing’s Starliner is about to launch – if successful, the test will mark an important milestone for commercial spaceflight
After lengthy investigations and technical solutions, Boeing agreed to rerun the unmanned flight test at its own expense. Test Flight 2 was launched on May 19, 2022 – two years after SpaceX’s Crew Dragon made its first successful crewed flight to the ISS. This time, the Starliner flight was successful. The spacecraft arrived at the ISS and docked on May 21, 2022, where it remained for four days, before returning safely to Earth.
Meanwhile, SpaceX has successfully launched nine flights to the ISS carrying astronauts and four commercial flights carrying a mix of civilians and astronauts from other countries. The May 6 flight will be carried by two experienced NASA astronauts. They are Sunita “Suni” Williams and Butch Wilmore. Both flew on the space shuttle and the Russian Soyuz spacecraft.
A new suit
They will wear distinctive blue flight suits with a flexible hood rather than a solid one, unlike most previous designs. The lightweight materials allow the astronauts to perform sensitive tasks such as using a tablet despite having gloved hands.
A flight suit is designed to be worn only within the pressurized environment of the spacecraft, not outside it, and only during ascent to and return from orbit. However, they provide protection and life support to the astronauts if the capsule depressurises during these most dangerous phases of the flight.
Better mobility, lighter weight and better dexterity, as well as a very wide view out of the hood visor, have made these suits very popular among the astronauts who have tested them.
Starliner itself consists of a crew capsule and a service module. The upper capsule is the part that people carry and is made of aluminum alloy. It can accommodate up to seven astronauts, or four astronauts with up to 100kg of cargo.
The crew capsule is reusable, meaning it can be sent back into space after completing a mission, and is designed to make at least 10 flights into orbit. One innovative design feature of the spacecraft is the lack of welded parts. The crew capsule is made up of two parts that are bolted together, rather than welded, to improve structural strength.
The service module houses the electrical power systems, and four Rocketdyne rocket engines. These are designed to quickly separate the spacecraft from the Atlas V launch rocket in the event of an emergency during ascent into space. They are also used to maneuver the spacecraft once it reaches orbit.
Once in orbit, Starliner is capable of fully automated flight to, and docking with, the ISS, without any intervention from astronauts on board. However, astronauts can take manual control of the spacecraft if necessary. Once at ISS, Starliner is designed to remain docked at the station for up to seven months.
When it’s time to return to Earth, the crew will get back into Starliner and separate from the ISS. Just before entering the atmosphere, the service module is disconnected and set aside. The crew capsule then uses a combination of heat shields and parachutes to slow its speed, before landing. The landing is mitigated for the crew by the use of airbags.
This is different from the return method used by NASA’s Orion spacecraft, which will be used to visit the Moon, and SpaceX’s Crew Dragon, both of which splash down at sea. By returning to the ground, Starliner does not need to deploy special ships to sea to retrieve the spacecraft.
Despite the delay, Starliner appears to be a very capable modern spacecraft, providing the US with a second way to reach the ISS and any commercial successor in the coming years. A lot is riding on a successful performance on May 6.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Gareth Dorrian does not work for, consult with, share in, or be funded by any company or organization that would benefit from this article, nor has he disclosed any affiliations relevant beyond his academic appointment.
