CRS-18 Dragon arrives at ISS with new docking adapter

The CRS-18 Dragon capsule rendezvous with the ISS. Credit: NASA

The CRS-18 Dragon capsule rendezvous with the ISS. Credit: NASA

Days after threading the needle with weather to launch, SpaceX’s CRS-18 Dragon spacecraft rendezvoused and berthed with the International Space Station.

Carrying 2,312 kilograms of cargo, including a new docking adapter for commercial crew spacecraft, the capsule took two days to catch up to the space station and place itself about 10 meters beneath the Destiny module. Then Expedition 60 NASA astronauts Nick Hague and Christina Koch remotely commanded the robotic Canadarm2 to capture the spacecraft at 13:11 UTC July 27, 2019.

Dragon launched into space atop a Falcon 9 rocket at 22:01 UTC July 25 from Cape Canaveral Air Force Station’s Space Launch Complex 40. It took less than 10 minutes for the partially-reusable two-stage rocket to place CRS-18 into orbit, beginning it’s two-day chase of the outpost.

Following capture, teams on the ground then remotely commanded the arm to position Dragon just below the Earth-facing port of the Harmony module in preparation for berthing. The spacecraft was officially attached to the ISS at 16:01 UTC.

This is the third time this particular spacecraft has visited the ISS and is the first time that a thrice-flown Dragon has made its way into space, having been used for the CRS-6 and CRS-13 missions in April 2015 and December 2017, respectively.

The ISS docking configuration following CRS-18 Dragon’s arrival. Credit: Orbital Velocity

According to NASA, the pressurized cargo in CRS-18 includes research and equipment such as the BioFabrication Facility, which is designed to print organ-like tissue in microgravity; and a Goodyear Tire Investigation, which hopes to better understand silica morphology for improved manufacturing and performance on the ground.

Also aboard is the Space Tango - Induced Stem Cells, investigation, which NASA says aims to observe culturing cells from patients with Parkinson’s disease and Multiple Sclerosis to “examine cell to cell interactions” in neurodegenerative diseases.

Possibly the most anticipated piece of hardware aboard CRS-18 is the third International Docking Adapter, also known as IDA-3, which is located in Dragon’s trunk.

IDA-3 utilizes an international docking standard and will compliment IDA-2, which is already attached to the outpost’s older Pressurized Mating Adapter-2 that NASA’s space shuttle orbiters used.

The new International Docking Adapters are designed to be compatible with SpaceX’s Crew Dragon and Boeing’s CST-100 Starliner spacecraft. As it is an international standard, any entity that creates a spacecraft with a docking ring to those specifications, which are public, can dock with the ISS or any other spacecraft using the standard.

NASA’s Lunar Gateway, Orion spacecraft and future lunar landers are all expected to utilize this docking standard.

IDA-3 being prepared for launch inside CRS-18 Dragon’s trunk section. Credit: NASA

IDA-3 being prepared for launch inside CRS-18 Dragon’s trunk section. Credit: NASA

IDA-3 is expected to be removed from the unpressurized trunk of Dragon sometime in August before being positioned in front of Pressurized Mating Adapter-3, which itself is located on the space-facing port of the Harmony module.

It will require at least one spacewalk by astronauts to finish the installation of the docking ring before it is certified for use by a commercial crew vehicle.

Having two at the ISS is expected to give not only redundancy in case a problem occurs, but the option for dual-docked commercial crew vehicles. This means expedition crews using these spacecraft can perform direct handovers to change personnel.

It also means privately procured spacecraft can dock for short periods of time with commercial astronauts, as NASA recently opened up the outpost for increased commercial activity.

According to Alan Boyle in a July GeekWire story, a NASA official said the first fully-private trip to the ISS could come as soon as October 2020 if Crew Dragon and Starliner, as well as paying customers, are ready.

NOTE: While this article was written by Derek Richardson, it was originally published at SpaceFlight Insider.


Derek Richardson

I am a space geek who loves to write about space.

My passion for space ignited when I watched space shuttle Discovery leap to space on October 29, 1998. Today, this fervor has accelerated toward orbit and shows no signs of slowing down. After dabbling in math and engineering courses in college, I soon realized that my true calling was communicating to others about space exploration and spreading that passion.

Currently, I am a senior at Washburn University studying Mass Media with an emphasis in contemporary journalism. In addition to running Orbital Velocity, I write for the Washburn Review and am the Managing Editor for SpaceFlight Insider.