spaceflightnow.com
1930 GMT (3:30 p.m. EDT)
Atlantis astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper are "camping out" in the space station's Quest airlock module to prepare for their spacewalk tomorrow. This is a new procedure that will help spacewalkers get ready for excursions outside the station.
Tanner explains the campout in this pre-launch interview:
"Before any EVA, because we go from a pressure of in the station 14.7 psi, which is the same atmospheric pressure at sea level here, we need to scrub as much of the nitrogen out of our bloods as we can before we go down to a suit pressure of about 4.3 psi, 100 percent oxygen. There are a number of ways to do that. We have done it by breathing 100 percent oxygen for four hours in the suit; that takes a lot of time. We also have a protocol referred to as the exercise protocol that accelerates this denitrogenation process by use of exercise, and that is a bit cumbersome on the crew and the ground to monitor the protocol. And you were exercising a little bit before you go out and do more exercise, so we wanted to try a protocol that has been around for quite a while but never really used referred to as campout.
"It's a modification of the type of protocol we've used on the shuttle for years, where we depress the shuttle down to 10.2 psi from 14.7 and leave the crew at that pressure for up to days. In the one case of the Hubble missions, they stayed at 10.2 the whole mission until landing. That reduced pressure helps purge some of the nitrogen without any extra effort other than just your normal breathing and sleeping activities.
"So we are going to try this new protocol, and for each EVA the EVA crew will camp out, if you will, in the station airlock and depress the airlock only -- you cannot depress the entire station to 10.2; it's not certified to go to that pressure -- but you can depress the airlock down to that pressure, and the crew sleeps overnight. As long as you're in the airlock at 10.2 for eight hours and 40 minutes, I believe the number is, then you have met the requirement to, to be at that lower pressure long enough to purge nitrogen.
"Now, that's the upside. The downside is that you probably have to go to the bathroom in the morning, and so we will do what we refer to as a hygiene break. For that break you must put on an oxygen mask. We repressurize the station airlock so that we can open the hatch, and then while wearing this oxygen mask, you go to the bathroom and come back in and the total amount on the mask is 70 minutes, I believe.
"Once you get back in the airlock, depress it again down to, to 10.2, and if you've achieved your 70 minutes on the mask. Then you can take the mask off and do a normal suit-up, just like you would if it was a, a shuttle 10.2 protocol. We do this primarily to save time in the day. We think we can get out the door and start the EVA at least an hour sooner than we could on the exercise protocol, a couple of hours sooner than the four-hour-in-suit protocol.
"EVA day is a hugely long day: it's like getting up at six in the morning and, and doing all the activities that you need to do to get ready to go to work, but you don't go to work until noon, and then, you work, work until about seven in the evening, and then have another couple of hours of activities to, to finish up from what you did at work before you can relax and go to bed, so that's a very long day. We are trying to shorten the morning time a little bit, get out to work sooner, and give ourselves a little bit more leeway on the back side of that day for things that might go wrong or other activities that we want to try to get done early."
spaceflightnow.com
MONDAY, SEPTEMBER 11, 2006
High-resolution photographs of the shuttle Atlantis' underbelly shot today during final approach to the international space station show the orbiter's heat shield tiles are in good shape with no obvious signs of damage.
Agency engineers decided late today that additional heat shield inspections, a move that would have triggered a one-day mission extension, were not required.
2230 GMT (6:30 p.m. EDT)
A gallery of images from this morning's unberthing of the solar array truss from the shuttle's payload bay is available here.
http://spaceflightnow.com/shuttle/sts115/060911truss/trussgallery.html