The NASA Village
Today in the NASA Village… When it’s Time to Capture a Dragon.
Meet the Systems Engineering Simulator. Upon entering the darkened dome one can forget for a moment the actual world isn’t floating overhead. This space can contain a physical Space Station mock-up cupola (like the picture below) an Orion crew station mock-up, or a multi-mission space exploration vehicle mock-up. It is a hybrid of virtual reality and physical structure. Perfect for practicing the rendezvous (approach) and capture. It is in this dome where we are trained to capture the capsules launched from Earth to station that come bearing gifts like food, clothing, and fuel.
So what’s the deal with these visiting cargo vehicles? Where in the world are they coming from and why do they all have different names?
The simple answer is that these cargo-carrying vehicles are a form of currency in the spaceflight world. Building a vehicle and loading it with materials to supply the crew is a part of the international agreement of participation. For the Japanese Space Agency (JAXA) and the European Space Agency (ESA), their vehicles are the HTV (H-II Transfer Vehicle) and ATV (Automated Transfer Vehicle), respectively. ESA’s ATVs have delivered cargo to the station and docked to the Russian segment using their docking system. During Expedition 16, Yuri and I monitored the first approach and docking of the ATV to ISS. Reminds me a bit of an X wing fighter from Star wars.
Progress is a capsule provided by the Russian Space Agency (RSA). It is launched on a Soyuz rocket, similar to the Soyuz rockets that launch the astronauts to station. A progress will commonly remain for a few months until the next Progress is about to launch. During this time docked to the station, after unloading all the valuable cargo, the capsule is filled with trash that will burn upon re-entry.
In addition, after Shuttle retirement, the US has purchased additional cargo carriers from Space X and Orbital. The capsule called Dragon comes from Space X. It is the only capsule that returns to ground, bearing scientific return samples or critical hardware from station. Cygnus is a capsule launched by Orbital.
Multiple of these capsules can be mated to the station at the same time. In the Dome, we practice for the arrival and capture, using the Canadian robotic arm, of HTV, Cygnus and Dragon.
These capsules are essential because they are the lifeline between the astronauts and the Earth. When something happens to a capsule, the crew onboard shares their supplies. However, important items like a lost spacesuit are irreplaceable.
Jeff Tuxhorn, widely known as Tux, was a Shuttle rendezvous trainer and has since become the rendezvous instructor for HTV, Cygnus and Dragon. We have the visual out the window view to illustrate the approaching vehicle (it looks big when it is coming at you!), as well as multiple camera views to monitor during the capture.
During Expedition 5 and 16, I helped install large truss elements that now hold the solar arrays. We also maneuvered a whole module to “rearrange” our living volume (we had to wait for Shuttle departure to put it in its proper place). At that time we didn’t have any visiting cargo vehicles like these currently resupplying station. And more importantly, there was no cupola when I was last on station, but now I get to enjoy the view from here!
Do you want more stories? Find our NASA Villagers here!