Space shuttle Atlantis cleared for Thursday landing
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 20, 2006
The Atlantis astronauts were cleared today for a day-late landing Thursday at the Kennedy Space Center after a tedious robot-arm inspection showed the ship's heat shield was in good shape.
"We are cleared for entry," shuttle Program Manager Wayne Hale told reporters during a noon news conference. "Nothing was found to be missing or damaged from the thermal protection system, the heat shield of the space shuttle Atlantis, or, in fact, any other part of the shuttle Atlantis.
"So we feel very confident that we're heading for a good landing opportunity tomorrow morning. The weather forecast is excellent, whereas today is not, in Florida, a good day to land so we spent our day profitably making sure everything is ready to come home."
The unusual inspection was ordered and the flight extended one day after an unknown object, presumably from Atlantis, was spotted early Tuesday flying just below the shuttle. A second bit of debris was seen later, along with several smaller objects.
More of the same was spotted today, but the inspection using cameras on the shuttle's robot arm and a 50-foot-long sensor boom showed the heat shield was in good shape. Whatever the debris might have been, Hale said, it did not come from any place critical for a safe re-entry.
"All those items came from the space shuttle, they didn't come from some other place," Hale said. "We're too far from the station now, we're not orbiting in the same orbit exactly with it or the Soyuz or the Progress (supply ship), so the things we have seen that are drifting away at a very low speed, or co-orbital, with the shuttle came from the shuttle.
"As for exactly where they came from, we'll continue to look at that. I expect that we will probably wind up still scratching our heads after we get on the ground where some of this came from. We have been looking at it for quite a long time and all the obvious things, we fixed. So it just appears to be an artifact of human occupancy that we leave detritus around. We're going to continue work on that."
The inspection showed a protruding tile spacer called a "gap filler" and a plastic shim, both seen earlier in the mission sticking up from between adjacent tiles on two external tank propellant feedline doors in the belly of the shuttle, had worked their way free and were no longer visible.
Engineers speculated Tuesday that the plastic shim might have shaken loose during hydraulic system tests early Tuesday and floated away, becoming the first of the two mystery objects spotted by the crew and flight controllers. Hale said that remains a possibility.
"This is most likely the culprit," he said, holding up a plastic shim similar to those used on the shuttle. "It's not a guarantee and I don't know that we'll ever be able to positively prove it. It was there before, it's not there now, it was most likely shaken loose during the flight control system checkout. We probably will never know for sure."
As for the smaller bits of debris spotted near Atlantis, lead flight director Paul Dye said it was not unusual for small items inadvertently left in the shuttle's cargo bay during maintenance to work free and float away during a mission. While such "foreign object debris," or FOD, is typically seen early in flight, it was not surprising that Atlantis, making its first flight since 2002, might be carrying a bit more debris than usual, engineers said.
Here is an updated entry timeline for the crew's two opportunities to land in Florida Thursday (in EDT):
DATE/EDT REV 186 DEORBIT TO KSC 01:14:23 AM Begin deorbit timeline 01:29:23 AM Radiator stow(MS) seat installation 01:45:23 AM Computers set for deorbit prep 01:49:23 AM Hydraulic system configuration 02:14:23 AM Flash evaporator cooling system checkout 02:20:23 AM Final payload deactivation 02:34:23 AM Payload bay doors closed 02:44:23 AM Mission control 'go' for OPS-3 entry software load 02:54:23 AM OPS-3 transition 03:19:23 AM Entry switchlist verification 03:29:23 AM Deorbit data update 03:34:23 AM Crew entry review 03:49:23 AM CDR/PLT don entry suits 04:06:23 AM Navigation system alignment 04:14:23 AM CDR/PLT strap in; MS suit don 04:31:23 AM Shuttle steering check 04:34:23 AM Hydraulic power unit (APU) prestart 04:41:23 AM Toilet deactivation 04:49:23 AM Vent doors closed for entry 04:54:23 AM Mission control 'go' for deorbit burn 05:00:23 AM MS seat ingress 05:09:23 AM Single APU start 05:14:23 AM Deorbit ignition (dT: 2:44; dV: 207 mph) 05:17:06 AM Deorbit burn complete 05:49:47 AM Shuttle falls into discernible atmosphere (400k feet) 05:54:41 AM 1st roll command to left 06:03:58 AM 1st left-to-right roll reversal 06:14:53 AM Velocity less than mach 2.5 06:17:04 AM Velocity less than mach 1 06:17:32 AM Shuttle on the HAC 06:21:28 AM Landing DATE/EDT REV 187 DEORBIT TO KSC 06:30:51 AM MCC 'go' for deorbit burn 06:36:51 AM MS seat ingress 06:45:51 AM Single APU start 06:50:51 AM Deorbit ignition 06:53:35 AM Deorbit burn complete 07:25:21 AM Entry interface 07:30:12 AM 1st roll command to left 07:43:46 AM 1st left-to-right roll reversal 07:50:24 AM Velocity less than mach 2.5 07:52:35 AM Velocity less than mach 1 07:53:23 AM Shuttle on the HAC 07:56:57 AM Landing
Here are the remaining landing opportunities at Kennedy, Edwards Air Force Base, Calif., and Northrup Strip at White Sands, NM (all in EDT):
DATE ORBIT BURN LANDING SITE 09/22 201 04:02 AM 05:10 AM KSC 09/22 202 05:37 AM 06:45 AM KSC 09/22 203 07:07 AM 08:15 AM EDW 09/22 203 07:09 AM 08:16 AM NOR 09/22 204 08:43 AM 09:50 AM EDW 09/22 204 08:45 AM 09:52 AM NOR 09/22 205 10:19 AM 11:26 AM EDW 09/23 217 04:24 AM 05:32 AM KSC 09/23 218 05:56 AM 07:03 AM NOR 09/23 218 06:00 AM 07:08 AM KSC 09/23 219 07:30 AM 08:37 AM EDW 09/23 219 07:32 AM 08:39 AM NOR 09/23 220 09:06 AM 10:13 AM EDW
"At the end of this exciting mission, I just have to remind everybody that we are back in the (space station) assembly business," Hale said. "I couldn't be prouder of the team. This is one of the most complex missions that's ever been flown in space. ... It has been an outstanding effort."
"We're set up in a very good way for the next set of assembly flights. There are about six in a row here that we really need to pull off in fairly rapid order without major problems in order to keep the assembly going."
Next up is launch of the shuttle Discovery in December on a mission to rewire the space station's electrical system, to ferry a fresh flight engineer to the outpost - Sunita Williams - and to bring European Space Agency astronaut Thomas Reiter back to Earth.
The current launch target is Dec. 14, but Hale said launch managers at the Kennedy Space Center are looking into the possibility of moving the flight up one week to avoid having a mission in progress over Christmas.
"We have asked the team to evaluate the potential of working a little bit extra hard, getting perhaps a week ahead, looking at a Dec. 7 potential launch date and thereby letting our folks have the Christmas holidays off," Hale said. "If that's not an incentive, I don't know what is."
Looking ahead to a series of critical flights in 2007 to build out the station's solar array truss, Hale said "if we are able to pull them off with even half the success that we saw on this flight, we will have a great year in 2007 and I think we will be well down the road to getting the space station assembled on time."
The official crew patch for the STS-115 mission of space shuttle Atlantis to resume orbital construction of the International Space Station.
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