June 15, 2007
Creative Problem Solving
“Things don’t always go as planned,” Commander Sturckow noted during an onboard press conference yesterday. The damage to the shuttle’s thermal protection, the recalcitrant P6 solar array that won’t fold up nicely, and the failure of the Russian computers that has caused attitude control issues are all on the list of challenges that the STS-117 and ISS Expedition 15 crews face this week in space.
The shuttle damage will hopefully be repaired during today’s spacewalk. Bru will maneuver Danny Olivas on the end of the shuttle’s robotic arm out to the work site on the port (left) side of the tail. JR will be out there to assist Danny if needed.
Mission Control’s “team 4” (teams 1-3 are traditionally ascent, orbit, and entry) put together the creative repair procedure that uses surgical staples and a suit-repair sewing kit. The decision to do the repair during EVA 3 was made on Wednesday, giving the crew only one day to go over the procedure and practice it. Bru used an onboard laptop to practice the arm movements, and Danny put his suit gloves on and stapled and stitched some blocks of foam together. Amazing! Imagine giving a couple of pillow forms to two six-year-olds, donning thick garden gloves and a motorcycle helmet, and laying on the floor with a staple gun. Could you staple the pillow forms together as the kids wiggle and squirm around above you, simulating the freefall environment? How about using a needle and thread?!
If that task weren’t hard enough, imagine doing it inside a 727 with the world (including all the major networks, your family, and those of the other crewmembers) watching and knowing that if you mess it up, you and all the passengers on board might die during landing!
Oh, and while you’re at it, try to ignore that once-in-a-lifetime show the colorful planet Earth is putting on in the background. As Swanny said during the Thursday conference, the view can be “overwhelming.” But he managed to get his work done. “You have to stop and take a look at it, and then get back to your task.”
The crew know what is at stake, and are enthusiastically meeting the challenges. When I tuned in last night at midnight, I was surprised to see Suni had not gone to bed yet—she was up troubleshooting the computer problem. The problem began when the new solar array was connected, so mission control in Moscow suspects that somehow electrical signals are being misinterpreted or otherwise interfering with the computers. All the different connections had to be checked one by one, and Suni cheerfully took on the task, gathering frequency readings with a handheld device.
This computer problem is potentially as serious, or even more so, than the shuttle repair because without the computers, the space station can’t control its attitude. Usually, gyroscopes steer and steady the station. But the gyros sometimes get overloaded like they did earlier this week during the addition of the new solar wing. During those times, and when it is necessary to maneuver out of the way of orbital debris, the thrusters are needed. The shuttle’s thrusters are being used as a backup system currently, but Atlantis has a limited amount of fuel to use for this purpose. Bill Gerstenmaier, NASA’s associate administrator for spaceflight, told the Houston Chronicle that “There is an extremely remote chance this problem would lead us to abandon the station.” He added, “We’re a long way from that scenario.” Let’s hope that remains true!
And then there is the P6 array. This array sticks out to the starboard side. (It is scheduled to be moved to the port side on a later flight which is why it is named P6, for Port number 6.) It has been providing power to the station since 1999, and is apparently resisting having its job taken over by the new S3/S4 array. It has been shut down, and must be retracted so that the S3/S4 array can spin around the Y axis (to track the Sun) without running into it. Repeated attempts to get it folded back into its box failed yesterday. The crew commanded the mast to retract, then extend, wiggling it like you might shake a map to get the creases back in the right places. The array is about half-way retracted now. The crew suggested to Mission Control that based on the success clearing some of the problems during EVA2, that if they had some spacewalkers out there, they could “unstick” the guide wires and be done in about an hour and a half. Mission Control concurred, and added this task to the next spacewalk.
With all these additional tasks added to EVA3, EVA4 will be necessary to finish all the tasks originally planned for the spacewalk. The original schedule was for the shuttle to leave the station Sunday and land on Tuesday. Now the plan is to do another spacewalk on Sunday, leave on Tuesday and land next Thursday, June 21. But if anything goes wrong with the repair, or the Russian computer issue is not solved, that could change.
Dealing with changing circumstances in a challenging environment: that’s what spaceflight is all about. It’s exciting, dangerous, and also inspirational. As Bru noted during the conference, kids in middle and high school today will be the ones exploring the Moon and Mars. And Commander Sturkcow wisely pointed out that solving problems like they are doing on this mission is just the kind of experience that the crew and ground teams need to prepare for those trips.
With training in science and engineering, experience working in difficult environments, creative problem solving, and courage to face the unexpected, there is no limit to what humans can accomplish in space.
Posted by m_dyson at June 15, 2007 12:36 PM