SpaceX: International Space Station Gears Up to Dock Crew Dragon

The International Docking Adaptor is go.


The International Space Station took one giant leap toward commercial crew operations this week.

On Wednesday, NASA astronauts Nick Hague and Andrew Morgan completed a six-and-a-half-hour spacewalk to install the second and final international docking adaptor. The adaptor is part of the agency’s commercial crew program, which will enable SpaceX and others to dock their capsules to the space station and move the crew to and from Earth.

It’s all part of NASA’s plan to use private companies to transfer astronauts between the space station and Earth. Since the shuttle program ended in 2011, NASA has been using Russian Soyuz rockets that take off from Kazakhstan’s Baikonur Cosmodrome. These seats cost $81 million each to rent.

Time is of the essence, as NASA’s contract with Roscosmos expires in September 2020. SpaceX is hard at work on its Crew Dragon capsule, while Boeing is working on the CST-100 Starliner. SpaceX successfully completed its “Demo-1” unmanned test launch in March 2019, which contained 400 pounds of cargo and a dummy suit collecting data. The next steps are to complete a manned flight test dubbed “Demo-2,” before embarking on the first crewed flight to the space station.

Nick Hague and Andrew Morgan installing the International Docking Adaptor.


Why the International Docking Adaptor Matters

If you have a modern smartphone, chances are you need an adaptor to use headphones with it. Once you plug the adaptor into your manufacturer’s port, though, you can attach wired headphones from practically any manufacturer.

That’s a good way to think about the international docking adaptor, designed to support the international docking standard. It’s essentially a giant ring that sits on top of the pressurized mating adaptor, connected to the space station’s Harmony module, and converts it from the APAS-95 standard used by the NASA shuttle program.

The adaptor is meant to be a more long-term solution to the conundrum of getting capsules to join with the pressurized mating adaptor. It could not only support commercial spacecraft, but international crafts from other countries. The Boeing-built adaptor measures 42 inches tall and 63 inches wide. Once extras like docking targets and laser retro-reflectors are fitted to the outside, the whole diameter will measure 94 inches.

Once it arrives from Earth, the station uses a robotic arm to move it one foot away from the front of the adaptor. Unfortunately, unlike plugging in your headphone adaptor, wiring up the adaptor takes a bit more effort. Astronauts are sent to attach tethers and connect it to the adaptor.

The first adaptor was connected in August 2016. Hague and Morgan attached the second of the two adaptors earlier this week. The spacewalk started at 2:59 p.m. Eastern time and lasted six hours and 32 minutes. During their walk, the pair also made adjustments to the space station’s wireless internet. This was the fifth spacewalk for 2019, Hague’s third spacewalk ever, and Morgan’s first-ever spacewalk.

The SpaceX Crew Dragon.


Unfortunately, it’s unclear when the new adaptors will see action. SpaceX’s capsule has faced a number of issues during tests, including a rare titanium failure in April and a parachute failure in May.

Hans Koenigsmann, SpaceX vice president of build and flight reliability, admitted in July that “by the end of this year, I don’t think it’s impossible, but it’s getting increasingly difficult.” In the meantime, astronauts Robert Behnken and Douglas Hurley have been training at SpaceX’s headquarters for the first manned flight.

Boeing has yet to complete the first hurdle, an unmanned test flight. The Government Accountability Office warned in June that “both contractors have run into chronic delays,” urging the agency to come up with a backup plan in case the pair experiences any further delays.

While the space station is ready for a new era in spaceflight, the participants may stay on terra firma for a while yet.

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