At the beginning of the mission, I was going to work in darkness and leaving with the sunrise. But now things have shifted enough that I’m going to work before the sun even sets, and leaving in the early morning darkness. Things have really slowed down after a flurry of activity after docking.
One of 6 small vernier thrusters that the space shuttle uses to maintain its attitude in orbit developed a leak soon after launch. To stop the leak, they had to close the valve that feeds propellant to the jet — which means it can’t be used anymore. Because of that, we’ve had to use the bigger primary jets to do everything. They’re bigger and dirtier, they use more propellant, and they’re more powerful, which means they create a bigger “jet plume” in space. That plume is a concern when we’re docked to the space station, because if we’re not careful, a bad jet firing could plume critical and delicate systems that the ISS depends on to function — things like radiators and solar arrays.
After the two vehicles are docked, we normally use the small shuttle thrusters to control the entire complex’s attitude and maneuver “the stack” (as it’s called) as needed. Using the big thrusters to do that had never been fully assessed, so after docking, the space station used its own thrusters on the Russian side of the vehicle to maneuver. That apparently used a TON of propellant, which is a big concern considering the fact that it’s not exactly easy to “refill” the tanks on a massive orbiting vehicle.
That led to a flurry of analysis of how to move the stack. Do we go off and do some analysis to see if we can use the big shuttle jets? Do we use the Russian thrusters again and use a bunch more propellant? Are there other options? Maybe the shuttle can undock from a different position than it normally does?
And THAT’S where we got busy.
Things have settled down though, and now I spend my nights catching up on a variety of other tasks that I’ve been putting off for far too long. This is shift number 7 of 11 for me, and while I am enjoying working a mission in the front room for the first time, I have to admit that I’m getting tired of only seeing Jose awake for 1-2 hours per day. Not seeing Jose makes me grumpy. But it won’t last much longer — undocking is Tuesday, and the day after that, we’re off to Seattle for a weekend full of fun. I can’t wait!
