posted 12-13-2006 02:57 PM               

quote:

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The first step in STS-116’s challenging job of rerouting power aboard the International Space Station is under way as the left wing of the solar array on the station's P6 truss has begun to slowly retract and fold up. The retraction began at 1:28 p.m. EST.

The folding of this 115-foot long solar array, which has been unfurled for more than 6 years, will permit the activation of a rotary joint on the P4 truss. The Solar Alpha Rotary Joint, or SARJ, enables the solar arrays on the P4 to follow the sun as the station moves through orbital sunrise and sunset.

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By the fourth attempt, the outlook was looking better and retraction continued for a solid three minutes:

Upon hearing from STS-116/Expedition 14 crew member Sunita Williams that the retraction was going smoothly, capcom Terry Virts replied from Mission Control: "That's good news. You've got a bunch of guys about to turn blue here..."

Retraction has been halted again, as guide wires were seen going slack and an orbital sunset is approaching.

The array needed to be retracted at least 40 percent to provide enough clearance for activation of the P4 rotary joint. The crew reported 17.5 "bays" (sections) of the array are still to be retracted, which is slightly more than the 40 percent needed.

NASA is now considering how to proceed as they await the next orbital sunrise in about 30 minutes.

posted 12-13-2006 04:08 PM               

There appears to be two problems encountered: either the array experiences a slack in its guide wire (as mentioned above) or the blanket folds incorrectly, as Mark Polansky described earlier:

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The best analogy we can give is probably what we've been using both here and on the ground is it's kind of like folding a map up. You have the folds in the paper, and if you start folding it and the fold is going the wrong way, you can try a little bit but there gets a point where it just bows out and there's nothing you can do other than to pop it back in place or unfold it and try again.

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posted 12-13-2006 04:30 PM               

The crew needs to move on to testing the rotary joint.

posted 12-13-2006 06:43 PM               

They will now proceed to the rotary joint test as ground controllers work to resolve the issues preventing the full retraction of the array.

The Solar Alpha Rotary Joint, or SARJ, enables the solar arrays on the P4 truss to follow the sun as the station moves through orbital sunrise and sunset.

posted 12-13-2006 08:25 PM               

quote:

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The International Space Station’s newest set of solar arrays is tracking the sun tonight, following partial retraction of a similar array that’s been the station’s primary power plant for six years. This event sets the stage for two challenging spacewalks by the STS-116 crew to rewire and reroute the station’s power system.

The Solar Alpha Rotary Joint (SARJ) and the new set of arrays are a part of the P3/ P4 truss segments that were installed onto the station in September during the STS-115 mission. The rotary joint enables the solar arrays to follow the sun and generate the maximum power possible. Activation of the SARJ occurred shortly before 8 p.m. EST, and a few minutes later the Mission Control Center in Houston notified the crew that the arrays were following the sun.

Throughout the day, the STS-116 crew and flight controllers worked together to solve problems that prevented the arrays from folding properly. The retraction activities of the arrays began at 1:28 p.m. More than 40 commands were sent to furl and unfurl the arrays in an attempt to properly align them. When the efforts concluded about 7:50 p.m., 13.5 of 31 bays had been folded, leaving the port arrays in a safe position that allowed the activation of the P4 rotary joint.

The crew also received word that Thursday’s spacewalk will take place as planned despite the problems retracting the P6 solar array. Mission Specialists Bob Curbeam and Christer Fuglesang, who conducted the mission’s first spacewalk, are scheduled to begin Thursday’s orbital stroll at 3:12 p.m. They will begin efforts to rewire the station, bringing power generated by the P4 arrays on line for use by the station's systems and prepare for more arrays to be added next year.

In preparation for the spacewalk, Curbeam and Fuglesang will again "campout" in the station’s airlock. The pressure will be lowered in the airlock to the pressure normally found on Earth 10,000 feet above sea level during the overnight campout. The procedure protects against decompression sickness as Curbeam and Fuglesang go to the even lower pressure of spacesuits on Thursday.

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posted 12-14-2006 11:30 AM               

It reminds me very much of the STS-61 1st Hubble repair when Story, J. Hoffman and Kathy Thornton were replacing the Solar Arrays back in 1993. These panels are useful in they generate power from the sun into electricity. On STS-61, they had a few problems.

posted 12-14-2006 12:11 PM               

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Kind Regards

Douglas Henry

posted 12-14-2006 01:33 PM               

STS-116
P6 port array retraction (currently partially retracted)
STS -117
P6 port starboard array retraction
2nd Starboard truss element installed (S3/S4) and solar array deploy
STS-118
3rd Starboard truss element (S5) installed
STS-120
P6 relocation, connection to P5 and solar array deploy

Therefore this mission is the first in a sequence of missions that stows these solar arrays on P6, relocates P6 to P5 and then re-deploys the arrays again.

posted 12-15-2006 12:53 AM               

NASA thinks it may. During Leroy Chiao's stay aboard the ISS during Expedition 10, his style of exercise using the Interim Resistive Exercise Device (IRED) located in the Unity node was observed to "excite" the P6 arrays. In other words, they began to exhibit a very small wiggle.

This vibration may be just what is needed to fully retract the P6 port array. Therefore, later this morning, before 10am CST, NASA will have a member of the ISS Expedition 14 crew exercise using the IRED in a manner similar to Chiao (more of an aerobic workout rather than the typical upper body strengthening). This test will be used to determine if an attempt at fully retracting the array while a crew member exercises will be staged later on Friday.

Before anyone exercises though, NASA also plans another type of "wiggle" test by slightly moving the array's beta gimbal.

posted 12-16-2006 09:44 AM               

From NASA:

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The crews of Space Shuttle Discovery and the International Space Station tried again to refold an accordion-like solar array with help from engineers and flight controllers on the ground, but none of the techniques succeeded in clearing the jam.

The final attempt of the day came at 8:04 p.m. CST when Expedition 14 Flight Engineer Sunita Williams deployed the P6 solar array blanket slightly and then retracted it the same distance. This left 14 of the array’s 31 bays in their storage box, the same condition in which they started the day.

After the deployment and retraction technique made no significant progress in clearing the jam, the team briefed the crew on an inspection task that is being planned for use at the end of the mission’s third spacewalk. The task would be added only if the rest of the electrical rewiring activities planned for the excursion go smoothly. Mission managers have not yet decided whether a fourth spacewalk will be attempted, but the inspection task on the third spacewalk could provide information valuable to those making the decision.

Earlier in the day, flight controllers “wiggled” the solar arrays using the beta gimbal assembly, a rotating mechanism on the truss, and the crew worked out vigorously on an a resistive exercise device. Both techniques were attempts to jostle the guide wires and stainless steel grommets that are believed to be the cause of the stalled retraction.

The third spacewalk is scheduled to begin at 1:37 p.m. CST Saturday. During the excursion, Mission Specialist Bob Curbeam and Williams will finish rewiring the station’s power system, stow three Service Module Debris Panel bundles, install an adjustable grapple bar and, if time permits, troubleshoot the problem with the stuck array. The spacewalk will be Williams’ first.

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posted 12-16-2006 06:47 PM               

Having concluded STS-116's efforts to rewire the space station's electrical systems and having accomplished the other tasks scheduled for STS-116's third EVA, mission specialist Bob Curbeam and Expedition 14 flight engineer Sunita Williams have ascended the P6 truss where Beamer is pushing on the box into which the P6 port array folds.

The hope is to ease tension in apparently misaligned guide wires, which could lead to an additional attempt to retract the array.

posted 12-16-2006 07:48 PM               

That was followed by a succession of shakes and retractions, stopping as necessary when it appeared to either Beamer or Suni that the grommets or guide wires were in danger of (or were) snagging again. Eventually, it became necessary for Suni to also take turns at shaking the array from her side.

Beamer shook the array wing 13 times and Suni 19 times.

posted 12-16-2006 09:45 PM               

quote:

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Originally posted by divemaster:
However, I wish both of them had a "big stick" with them to knock the guide wire

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posted 12-18-2006 01:37 AM               

The Beamer Shake that was successful during the third spacewalk on Friday will be replaced by the Beamer pull, flip and push as he uses tools to pull guide wires, flip grommets and push panel hinges. (If necessary, the spacewalkers will again shake the panel.)

Plans call for Curbeam to work from the end of the station’s Canadarm2 to reach specific areas of the solar array. From the arm, Curbeam can use Kapton tape-insulated tools, including a scraper, needle-nose pliers and an extended bail puller to free up the array for retraction.

Fuglesang will work from the truss to assist Curbeam and shake the solar array, as was done in Saturday’s spacewalk, if needed. He will also take photographs of the solar array wing on the other side of the truss to document its configuration before its retraction on the next joint shuttle and station mission.

Astronauts Suni Williams and Joan Higginbotham will operate the station’s robotic arm during the spacewalk. Pilot Bill Oefelein will serve as the spacewalk coordinator.

posted 12-18-2006 05:30 AM               

Am I correct in assuming that the reason they can just "poke the folds" with their gloved hands as the array retracts is because of electrical shock?

I hope the 117 crew is already practicing the 4th EVA techniques for March.

posted 12-18-2006 08:11 AM               

quote:

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Originally posted by KSCartist:
Am I correct in assuming that the reason they can just "poke the folds" with their gloved hands as the array retracts is because of electrical shock?

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quote:

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I hope the 117 crew is already practicing the 4th EVA techniques for March.

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posted 12-18-2006 01:46 PM               

quote:

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Originally posted by KenDavis:
I was wondering why NASA didn't fly 4 spacewalking MSs and alternate the spacewalkers (as with Hubble missions)?

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posted 12-18-2006 02:28 PM               

After making his way to the P6 array and climbing into a foot restraint at the end of the station's arm, Beamer began his first inspection of the port solar wing. His discovery: a fray in the guide wire.

posted 12-18-2006 03:00 PM               

Bringing in Beamer for a closer look revealed that the wire was not caught on any grommet but rather the pulley and reel into which the wire recedes.

Ground controllers had Beamer try to pull on the wire with needle nose pliers to see if the reel would catch and pull in the slack. Instead, the wire became even more unfurled.

posted 12-18-2006 03:32 PM               

Beamer was moved away to begin retracting the array. Motion however, had to be stopped due to a stuck grommet and Christer moved in for a successful shake.

posted 12-18-2006 04:25 PM               

Retractions and shakes continue, with Christer moving from side to side of the array mast to assert pressure where needed.

posted 12-18-2006 05:29 PM               

The spacewalkers, astronauts inside Discovery, the station crew, and ground controllers are now visually inspecting the folded array panels to check that they are lined up and that the latches are in position before retracting the final bay.

posted 12-18-2006 06:08 PM               

Though the arrays are retracted, Beamer has spotted a guide wire slightly sticking out (left, center photo above) of the blanket box.

posted 12-18-2006 06:35 PM               

The final bay was folded about 5:53 p.m. CST.

Bob Curbeam is now ranked #5 on the list of spacewalkers by time spent outside. The top 10 list is now:

1. Anatoly Solovyev
2. Jerry Ross
3. Steve Smith
4. Joe Tanner
5. Bob Curbeam
6. Nikolai Budarin
7. Jim Newman
8. Yuri Onufriyenko
9. Talgat Musbayev
10. Piers Sellers

posted 12-18-2006 06:46 PM               

Humans are learning to do construction in space. Think of how this EVA will help as Man has to dock and manuver multi vehicles in LEO prior to heading for the Moon or Mars.

posted 12-18-2006 07:58 PM               

quote:

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Originally posted by Robert Pearlman:
Bob Curbeam is now ranked #5 on the list of spacewalkers by time spent outside.

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Is there an official list kept somewhere that includes the times spent outside? Also, does it include lunar EVAs too?

posted 12-18-2006 08:15 PM               

quote:

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Originally posted by mjanovec:
Is there an official list kept somewhere that includes the times spent outside? Also, does it include lunar EVAs too?

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posted 12-18-2006 08:48 PM               

Those screen shots are just incredible - thanks for posting them along with your comments! This EVA has been one of the most exciting and promising things we've seen from humans in space in a while. From Conrad & Kerwin's "just do it!" efforts on the Skylab solar shield to the Hubble repair missions and now this, I think Larry's comments are absolutely correct about the human presence in space exploration.

posted 12-19-2006 12:59 AM               

All of these were used to insure that the array's guide wires were not being snagged by grommets. A grommet, with guide wire passing through, is pictured here: