SpaceX’s CRS-18 mission delivers a new automated docking adapter to the ISS — here’s why that matters

SpaceX is set to fly its CRS-18 resupply mission for the International Space Station later today (or tomorrow depending on weather). One big, important part of its cargo is the new International Docking Adapter built by Boeing, otherwise known as IDA-3. This new docking station will offer new types of standard ports that are designed to work with Boeing’s CST-100 Starliner and the SpaceX Crew Dragon, and any other ISS-destined spacecraft to follow.

Thanks to these new standard ports and sensor arrays found on the IDA-3, the new docking station will be able to dock with these new spacecraft autonomously, without any assistance required by astronauts on board the ISS. That’s a big upgrade from today, when the final docking procedure for spacecraft like the Dragon cargo capsule making the trip today typically involves astronauts making use of the space station’s Canadarm2 robotic arm to capture the capsule and bring it in for the final connection.

This is actually the second brand new docking adapter with this automated docking capability to be delivered to the International Space Station — the first, IDA-2, was installed in 2016 and was actually already used by SpaceX during its list uncrewed Dragon crew capsule test flight. That mission, Crew Dragon Demo-1, flew in March, with a successful docking procedure taking place with IDA-2 on March 3.

Canadarm2 actually gets a chance to shine with this delivery, however, since it’ll be used to unload IDA-3 and set it in place on the ISS’s Harmony module in preparation for its permanent installation, to be performed by astronauts via spacewalk later this year.

Once installed, IDA-3 will provide twice the automated docking capability for the ISS for future crewed missions, allowing for a lot more opportunities for future ISS missions of all stripes.

In case you’re curious about the numbering, there was indeed an IDA-1 — this was supposed to be the first docking port of its kind attached to the ISS, but was destroyed when the Falcon 9 rocket for SpaceX’s CRS-7 resupply mission exploded due to a second-stage failure post-launch in 2015.