The crew was waved off from its second and final landing attempt at 12:38 p.m. CDT when Mission Control sent word that rain showers were within 30 miles of the center accompanied by low clouds.
Shortly after the weather wave off, Entry Flight Director Norm Knight directed support for the backup landing site Friday at Edwards Air Force Base in California’s Mojave Desert. Knight intends to bring Atlantis home Friday to either Kennedy or Edwards.
The crew reopened Atlantis’ payload bay doors for its bonus day in space and executed a brief engine firing to adjust its orbit for the proper landing opportunities on Friday. The engine firing now enables the backup landing site at Edwards to be available, if required, ninety minutes earlier than previously planned when winds are expected to be calm.
There are multiple deorbit opportunities available for Atlantis’ astronauts tomorrow. The Florida weather forecast for Friday includes the possibility for more thundershowers. The Edwards forecast is favorable.
On Friday, landing preparations begin at 8:13 a.m. CDT, and the crew should close the payload bay doors at 9:36 a.m. If the weather cooperates, Commander Rick Sturckow and Pilot Lee Archambault will conduct the deorbit burn at 12:16 p.m. to allow Atlantis to free-fall out of orbit and begin its descent toward a landing at the Kennedy Space Center’s Shuttle Landing Facility at 1:18 p.m.
There is another landing opportunity on the following orbit, which would put Atlantis on the ground at Edwards at 2:49 p.m. or at Kennedy at 2:54 p.m. There are two additional opportunities at Edwards tomorrow.
Here are predicted times for tomorrow’s landing opportunities (all CDT):
ORBIT / SITE / DEORBIT BURN / LANDING
218 / Kennedy / 12:16 p.m. / 1:18 p.m.
219 / Edwards / 1:46 p.m / 2:49 p.m.
219 / Kennedy / 1:52 p.m. / 2:54 p.m.
220 / Edwards / 3:21 p.m. / 4:24 p.m.
221 / Edwards / 4:58 p.m. / 5:59 p.m.
Aboard the International Space Station, Expedition 15 Commander Fyodor Yurchikhin continued planned troubleshooting on the Russian segment’s central and terminal computers which malfunctioned during Atlantis’ visit to the complex. Yurchikhin disconnected jumper cables from one backup channel for each of the two computers that bypassed a secondary power switch and powered down the backup computers. He then attempted to restart those channels to see if they would run properly without the jumpers in place, but the procedure was not successful, confirming what flight controllers expected to see.
Russian specialists directed that the two channels remain off for the night without the jumper cables installed as they continue their systematic troubleshooting. Two other channels for each of the two computers continue to function flawlessly in support of Russian segment systems.
In addition, Russian flight controllers restarted the Elektron oxygen generation system, putting it into operation for the first time since the computer failures earlier this month.
Today’s troubleshooting procedure was designed to help Russian mission managers assess their plans for repair of the computer systems, including the likely replacement of components with new hardware to be flown on the next Progress supply ship due to arrive at the station July 24.