Cmdr. Pam Melroy asked Mission Control if they could speed up the end-of-day planning a bit on this week's space shuttle mission.
"I am trying to get everyone to bed early tonight," she radioed fellow astronaut Tony Antonelli on the ground in Houston.
It's tough getting everyone to bed on time in space. If you think getting a 2-year-old tucked in to bed after bath time and story time is tough, try dealing with seven grown-up astronauts who are in space for 14 days and don't want to waste any time doing something as mundane as sleeping.
There is only so much time after work to look at the Earth and turn somersaults when you are weightless. And the astronauts have a bit of extra work on their hands.
They discovered that a large ball joint, used to point solar panels on the space station, seems to be rubbing up against something. It's using more power than normal and vibrating the solar array. Astronaut Dan Tani found metal shavings inside the joint when he opened it up during a spacewalk Sunday.
The crew has been told their mission will probably be extended by one day. Flight controllers want to dedicate the fourth of five planned spacewalks to troubleshoot the solar array joint. Is it a design flaw or a small problem? Engineers don't know yet, and may not know until the samples of metal shavings are brought back to Earth.
It's enough to keep you up, even if you aren't having the experience of a lifetime.
In an interview from orbit, pilot George Zamka told ABC News that he was having a hard time going to sleep. "I think somebody said it is Christmas every night. We are having a good time up here -- just like Christmas Eve, it is tough to get the kids to bed because we are just having a blast, and there is always one more thing we can get done and we keep pushing it just a couple of minutes."
Doug Wheelock is one of the spacewalkers headed out Wednesday to finish moving another massive solar array. "Pam isn't kidding about lights out -- she keeps us focused," he said from space. He knows he needs a good night of sleep, and he and his spacewalking partner Scott Parazynski are camping out in the space station airlock to get ready for the spacewalk.
What does it mean for the space station if the solar array is not fixed? Mike Suffredini, space station program manager, said this problem has the potential to shorten the life of the International Space Station.
The vibration, he said, creates "fatigue" on the structure of the station. It could stop engineers from keeping the station operational past 2015.
However, Suffredini said dealing with this problem is just another day in the life of maintaining an orbiting outpost like the station.
At the moment, the solar arrays are producing enough power to run the space station, and analysts are working to figure out how much power will be needed for a new laboratory module coming up on the Space Shuttle Atlantis in December.
The plan is to insert a day between the fourth and fifth spacewalk, which would bring Discovery home Wednesday, Nov. 7, NASA said.