I told you not to park our spacecraft there!
September 5, 2015 10:46 AM   Subscribe

"Hey, we're in the parking spot of the Soyuz crew that's arriving tomorrow, so we gotta move our spaceship."
posted by Brandon Blatcher (13 comments total) 8 users marked this as a favorite
 
alternate side parking rules have reached new depths of inconvenience.
posted by poffin boffin at 12:21 PM on September 5, 2015 [5 favorites]


As cool as those astronauts are you can tell from the comment that they were pretty jazzed to take spaceship ride. I sure would.
posted by sammyo at 12:41 PM on September 5, 2015


So, uh, why not just put the new arrival in the empty spot? I mean I get that they're better at this than I am in KSP, but it's not like TMA-18M isn't going to have to do all the same things it would have if they would have docked it to the Zvezda itself?
posted by Kid Charlemagne at 2:34 PM on September 5, 2015


I was wondering the same thing KC, and spent a good half-hour trying to figure it out.
Here's some more info, but they don't explicitly answer the question: spaceflight now. Note the comment about 6 hour docking is explained a little more here: space.stackexchange

My best guess is that they need to do some orbital adjustments and would rather use fuel from 16M, a craft leaving soon, than from one that just arrived?

Or, it's easier/safer for a newly arrived craft to match speed/rotation on the space-facing port than the rear one. Not sure why that would be though.
posted by stobor at 3:55 PM on September 5, 2015


I though the Poisk port was on the Earth-facing side. Why it's easier, I dunno. Maybe because you're in a slightly lower orbit and thus will be be going a little faster than the station?
posted by RobotVoodooPower at 4:38 PM on September 5, 2015


Seems to be a preference thing-the ISS managers prefer Soyuz in some spots for easier access by crews in case of emergencies. Other ports are preferred for Progress ships, which do a lot of the boosts for the station.
posted by Brandon Blatcher at 4:49 PM on September 5, 2015


It looks like they moved TMA 16 to the aft port, since it'll be used in about a week to take a crew home, leaving that port for a Progresd to dock to for easy station boosting and/or attitude control.

Meanwhile the newly arrived TMA 18 is parked at a port it can stay at until it leaves in March of 2016.
posted by Brandon Blatcher at 5:17 PM on September 5, 2015


They should just install TAC Fuel Balancer.
posted by Kid Charlemagne at 7:10 PM on September 5, 2015


Fuckin' dope.
posted by Stonestock Relentless at 8:11 PM on September 5, 2015


I still can't get over how fast that thing is moving
posted by cacofonie at 8:56 PM on September 5, 2015


I'm sure this is not unlike when you're 14 and your dad hands you the keys and tells you to go move the car from one spot in the yard to another. It's only a short distance, but damned if you don't feel a bit excited.
posted by Brodiggitty at 11:07 PM on September 5, 2015


I still can't get over how fast that thing is moving

The video is sped up. It took about 20 minutes in real time.
posted by Brandon Blatcher at 11:59 PM on September 5, 2015


So, uh, why not just put the new arrival in the empty spot? I mean I get that they're better at this than I am in KSP, but it's not like TMA-18M isn't going to have to do all the same things it would have if they would have docked it to the Zvezda itself?

I haven't gotten a fully 100% solid answer to this yet myself -- I have guests in town and have been spending my time eating and drinking and talking rather than hovering over MeFi. I apologize to you all for my dereliction of duty. :-)

Certain docking ports support the Russian auto docking feature and have more clearance, and since this is a manned flight, they obviously prefer the one with the most clearance, since a docking FUBAR could kill the crew in very little time. There's also power/cooling/comm interfaces in the docking adapters. Since the Soyuz is also the lifeboat of the station, they want the manned Soyuz on docking adapters that require the least maneuvering to get away from the station, so it appears that cargo craft will dock and then be moved to docks that are harder to reach by the remote arm, while manned craft will dock and stay so that if they have to get away fast, they can just move away in a -X, -Y or -Z direction, relative to the ISS, and not have to dodge the truss, radiators or solar arrays on the way out if they leave in a hurry. I'll also bet that the manned Soyuz are almost always kept at the same spot for drill reasons. In an emergency, you don't want to play "guess where the lifeboat is." By keeping the manned Soyuz in the same docks, you can run the lifeboat drill the same way every time.

That's speculation as to why. I'll let you know if I find anything different.

There are currently two kinds of docks on the station, the Russian APAS-95 and the US PMA. The IDS that was flying aboard the Space CRS-7 flight was meant to convert one of the PMAs to the new NASA Docking System, which is compatible with the International Docking System Standard, and thus, also compatible with APAS-95. That didn't make it, but they have the parts to make a replacement. PMA-2 and 3 will be converted, PMA-1 has, IIRC, Harmony permanently docked to it. The advantage the PMA has is that it's a much bigger diameter opening, so moving equipment through it was much easier, which was handy during the construction phase, and NASA has noted that this pattern of having a larger dock during construction that you convert to a standard dock after completion may be repeated in later stations.
posted by eriko at 8:09 AM on September 6, 2015


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