CST-100: Boeing’s New Spacecraft

Some of us who have vivid memories of famous spacecraft and rockets that ‘had their day’ in the consciousness of the world may wonder what prominent space agencies are working on today that in stature could match their former technological achievements. If any of us have found ourselves pondering this point then an inverted little ‘spinner-top-like’ craft currently in production for NASA is worth a look, and it originally went by the designation CST-100, now it is known as Starliner.

An artist's impression of new Boeing CST-100 in orbit (Image credit: Boeing via NASA)

An artist’s impression of the new Boeing CST-100 Starliner in orbit. The corrugated panels on the service module are thermal radiators. The nozzles of the four Launch Abort System thrusters are protruding from the underside of the spacecraft. Other thrusters are accommodated in the “doghouses” spaced around the service module. (Image credit: Boeing via NASA)

 

Aerospace giant Boeing is currently one of two American companies (the other is SpaceX) contracted under NASA’s Commercial Crew Program (CCP) which aims to make human spaceflight services available to both commercial and government customers. CPP is achieving this by employing the space industry’s own innovative capabilities in conjunction with NASA’s 50 years of human spaceflight experience.

 

Larger than Apollo but smaller than Orion: CST-100 spacecraft mock-up at Boeing, Houston. CREDIT: NASA/Markowitz

Larger than Apollo but smaller than Orion: CST-100 Starliner spacecraft mock-up at Boeing’s Houston facility. Apollo spacecraft were built by North American Aviation which after changing its name to Rockwell was absorbed into Boeing, so perhaps the CST-100 can be regarded as a son of Apollo.
(Image credit: NASA/Markowitz)

 

The three factors heading Boeing’s design brief are for it to produce a crew transportation vehicle that is safe, cost-effective, and reliable. The Crew Space Transportation (CST)-100’s job will be to carry up to seven passengers (or a mixture of cargo and crew) to various destinations in low-Earth orbit, such as the ISS or the Bigelow Station that is currently in development. Its name is in part a reflection of Boeing’s aircraft heritage and a reference to the Karman Line that marks the edge of space 100km above the Earth’s surface. However with its design engineers were not just prepared to ‘play safe’ and follow traditional lines of construction, the team at Boeing have been thinking outside the box and are currently employing new assembly methods to build a spacecraft they feel is worthy of the title ‘next generation’.

 

CST-100 about to dock with the ISS (artist impression). (Image credit: Boeing)

A CST-100 Starliner about to dock with the ISS (artist’s impression). The new spacecraft’s design has been optimised for its role as a taxi to the ISS. It could not be used to take crews beyond LEO and back without substantial modifications.
(Image credit: Boeing)

 

At a glance the Starliner spacecraft appears to be reminiscent of Boeing’s former Apollo-era capsules, but on closer inspection there is a lot less to support this comparison as may have been first imagined. With a spun-formed shell for the craft now firmly on the table, the designers have in one fell swoop completely eradicated the welding-related structural risks that would otherwise be associated with this type of capsule. This break from the past also potentially kills three other birds with the one stone; the capsule’s overall mass becomes significantly reduced, along with the production timescale, and also by implication therefore the cost.

Although due to launch initially on an Atlas V rocket, the forward-thinking design team are keen to make the vehicle as flexible as possible, and available for use in the maximum number of scenarios. To this end the Starliner will be ‘launch vehicle agnostic’, or have the ability to be launched on other types of rocket as well. Other design advances include upgraded thermal protection techniques and the incorporation of wireless internet to both facilitate docking with the ISS and crew communication. The craft will also have a ‘Pusher Abort System’ allowing for its occupants to escape safely in the event of an emergency during launch or ascent to orbit.

 

Artist’s illustration: CST-100- type spacecraft mounted on top of a United Launch Alliance Atlas V rocket for NASA’s CCP programme. CREDIT:  NASA (via Wikimedia Commons)

Artist’s illustration: CST-100- type spacecraft mounted on top of a United Launch Alliance Atlas V rocket for NASA’s CCP programme.
(image credit: NASA via Wikimedia Commons)

 

Another major departure from previous spacecraft piloted by astronauts is that the Starliner will require less input from its crew along the way to operate it. For this reason its interior will be able to have a much more aesthetically pleasing, futuristic appearance, devoid of the walls of switches and buttons that previously told of a heavy dependence on manual control. Boeing’s director of Crew and Mission Systems, Chris Ferguson puts it like this: “When these guys go up in this, they’re primary mission is not to fly the spacecraft, they’re primary mission is to go to the space station for six months. So we don’t want to burden them with an inordinate amount of training to fly this vehicle. We want it to be intuitive.”

 

Astronaut Randy Bresnik in the iconic launch and re-entry suit about to test ergonomics inside a mock-up CST-100 capsule in Texas. (image credit: NASA via Wikimedia Commons)

Astronaut Randy Bresnik in the iconic launch and re-entry suit about to test ergonomics inside a mock-up CST-100 capsule in Texas.
(image credit: NASA via Wikimedia Commons)

 

The Starliner therefore disposes of hefty crew manuals, and in their place provides astronauts with tablet technology. Boeing’s blue LED “Sky Lighting” (as developed for the Boeing 787 Dreamliner airliner) on the inside will also add to the hopefully serene and welcoming environment for its crew to enjoy. Boeing has already conducted two four-hour mock-up sessions with astronauts Randy Bresnik and Serena Aunon wearing the orange launch-and-entry flight suits, testing manoeuvrability inside the craft. A former NASA astronaut himself, Chris Ferguson feels the astronauts’ input into the spacecraft’s development is critical: “They’re the ones who will take our spacecraft into flight (so)… We’ll probably make one more go-around and make sure that everything is just the way they like it.” So just how well are things going? Well the Starliner design has now successfully completed a wind-tunnel test and a second parachute drop test on the Delamar dry lake bed in Nevada. Demonstrating operation of the capsule’s whole landing system, after being released from beneath a helicopter at 14000 ft (4.25 km), the drogue parachute deployed followed by the main parachute following which the CST-100 gently descended and kissed the ground on a cushion of six inflated airbags. Moreover, the United Launch Alliance (ULA) is beginning to construct parts for the two rockets that will launch the CST-100 spacecraft in 2017.

 

CST-100 interior: In this orientation, with the ‘back wall’ of the capsule misleadingly looking like ‘the floor’, astronauts would be strapped into their seats lying ‘on their backs’ for launch.  CREDIT: NASA/Markowitz

Starliner interior: In this orientation, with the ‘back wall’ of the capsule misleadingly looking like ‘the floor’, astronauts would be strapped into their seats lying ‘on their backs’ for launch.
(image credit: NASA/Markowitz)

 

Although fitted for taking a crew to space, AV-073 (or the 73rd Atlas V that will be built) is to serve in the initial unmanned orbital test flight of the Starliner spacecraft only. This test is an essential requisite of the CST-100 project however because until now, this rocket has only ever lifted robotic probes, satellites and Martian rovers to space. The second rocket to be built, AV-080 (or the 80th Atlas V booster) on the other hand will take the CST-100’s first human cargo actually into space and up to the International Space Station. Albeit, also a test only, the mission’s crucial objectives will only have been met when, over the course of a few days, the systems of the Boeing spacecraft have been assessed in terms of performance and then the CST-100Starliner  returns its crew safely back to the USA. In terms of the progress in the CST-100 project, perhaps Ferguson’s words paint the picture the best: “The last time we were at this stage of development for a human spacecraft was in the 1970s when we were building the Shuttle.”

 

In May 2015 NASA awarded Boeing a contract to send a crew to the ISS in late 2017. This will be the first NASA mission to the ISS launched from the US since the Shuttle was retired in 2011.

(Article by Nick Parke, Education Support Officer)

Further Reading

CST-100 page at Boeing.com