Russia slashes space station ship trip to just six hours
Faster route for 2,600kg craft beats usual two-day jaunt
Russia's space agency Roscosmos has successfully tested a new route that gets its spaceships to the International Space Station in an eighth of the time it usually takes.
The Progress M-16M zipped up to the ISS in just six hours – four orbits – instead of the two days – 34 orbits – it normally takes cargo-craft to reach the station, even though it was fully loaded with over 2,600kg of fuel, oxygen and supplies.
The shorter transit plan was tested with a cargoship, but if all the boffins are happy with it, it could be used for manned missions, drastically reducing the amount of time it takes 'nauts to get to and from the ISS for the shift change.
A Soyuz-U rocket blasted the Progress off at 8.35pm BST and the ship locked onto the Pirs docking compartment at 2.18am BST. It's one of three cargo-crafts berthed with the ISS at the moment, including Japan's H-II Transfer Vehicle-3 and Europe's ATV the Edoardo Amaldi.
The other Russian ship that had been docked to the station, the now trash-filled Progress 47, released late on Monday and is orbiting the Earth for a few weeks of engineering tests before it destructive re-entry into the Earth's atmosphere over the Pacific Ocean. ®
Any chance of any detail on the reason why the previous approach required so many more orbits? Why did the boffins not use this quicker approach route in the first place?
Sigh, there was a large list of issues the NASA guy talked about yesterday, and none of the websites are covering it.
This route takes a lot more launch precision. The new window is about 1 second long, so no unusual holds or issues, or you're out of the game.
Second, it collapses any sort of time to fix issues in orbit. You go straight from launch to rendezvous w/o any sort of breather in-between.
Third, it requires a little more out of the flight control system. Until recently, Soyuz didn't have much in the way of a guidance system, but now they've gone to an actual digital autopilot with real computers.
So they have not had launch/in-flight issues with Soyuz/Progress for a long time, so they figured it's not much of an issue any more.
The slow route
Taking two days over getting there means the launch window can be longer and timing of the various engine burns and staging events can be a bit looser. Some of the Gemini flights in the 60s even demonstrated first orbit rendezvous, but that requires everything to go perfectly. With the number of launches (getting on for 2000) and the amount of development (50+ years) that has happened with the Soyuz launcher it's likely the current version has tolerances well within what's needed for the shorter trip.
On the other hand, the longer trip gives crew a chance to get over any space sickness before trying something complicated like a docking. So far there's no reliable way to tell who will and who won't be affected by it, and someone who was fine on one flight may be barfing the next time up. Two days by no coincidence whatsoever is how long it takes to get adapted.