Shuttle cleared for Wednesday landing; good weather expected
By WILLIAM HARWOOD
CBS News
KENNEDY SPACE CENTER, FL--Forecasters are predicting windy but acceptable Florida weather for the shuttle Discovery's return to Earth Wednesday and with virtually no technical problems of any significance, entry Flight Director Tony Ceccacci said "we feel pretty comfortable" about getting the orbiter home on time from its 39th and final flight.
Discovery has enough on-board supplies to remain in orbit until Friday at the latest, but with a favorable forecast Ceccacci said NASA only planned to staff the Kennedy Space Center Wednesday. If the weather takes a turn for the worse and Discovery fails to make it home on one of two landing opportunities, the astronauts will remain in orbit one more day and land Thursday, on one coast or the other.
"It's Florida and it's always 50-50 there, but just based on what the weather guys are forecasting, we feel pretty comfortable" about landing Wednesday, Ceccacci said.
If all goes well, commander Steven Lindsey and pilot Eric Boe will fire Discovery's braking rockets at 10:52 a.m. EST (GMT-5) during the crew's 202nd orbit, setting up a half-orbit plunge back to runway 15 at the Kennedy Space Center. The deorbit rocket firing will last two minutes and 36 seconds, slowing Discovery by about 194 mph, just enough to drop the far side of its orbit deep into the atmosphere.
Assuming an on-time rocket firing, Discovery's trajectory will carry the orbiter over the southern Pacific Ocean on a northeasterly path across Central America and just west of Cuba before crossing the Florida coast near Sarasota for the final descent to the Kennedy Space Center.
After a sweeping left overhead turn, touchdown on runway 15 is expected at 11:57 a.m. A second landing opportunity is available one orbit later at 1:34 p.m.
Ceccacci said the forecast is generally favorable for both Wednesday opportunities, but the outlook changes dramatically Thursday as a frontal system moves across Florida. Electrically charged anvil clouds are expected for the first Thursday opportunity with a chance of showers one orbit later.
"As far as the forecast for KSC Wednesday , they're trending very well and looking very promising," Ceccacci said. "With that, and with the next day's forecast, my plan tomorrow is just only call up KSC. If we needed (an extra day ) for whatever reason we had to wave off tomorrow, end of mission plus one would become 'pick 'em day,' we would come home (somewhere)."
The forecast for Edwards Air Force Base, Calif., and Northrup Strip in New Mexico is favorable Thursday and Friday.
Here are timelines for both of the crew's landing opportunities Wednesday (in EST; times are approximate):
CBS News
KENNEDY SPACE CENTER, FL--Forecasters are predicting windy but acceptable Florida weather for the shuttle Discovery's return to Earth Wednesday and with virtually no technical problems of any significance, entry Flight Director Tony Ceccacci said "we feel pretty comfortable" about getting the orbiter home on time from its 39th and final flight.
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| The shuttle Discovery departs the International Space Station Monday after its 13th and final visit. (Credit: NASA) |
"It's Florida and it's always 50-50 there, but just based on what the weather guys are forecasting, we feel pretty comfortable" about landing Wednesday, Ceccacci said.
If all goes well, commander Steven Lindsey and pilot Eric Boe will fire Discovery's braking rockets at 10:52 a.m. EST (GMT-5) during the crew's 202nd orbit, setting up a half-orbit plunge back to runway 15 at the Kennedy Space Center. The deorbit rocket firing will last two minutes and 36 seconds, slowing Discovery by about 194 mph, just enough to drop the far side of its orbit deep into the atmosphere.
Assuming an on-time rocket firing, Discovery's trajectory will carry the orbiter over the southern Pacific Ocean on a northeasterly path across Central America and just west of Cuba before crossing the Florida coast near Sarasota for the final descent to the Kennedy Space Center.
After a sweeping left overhead turn, touchdown on runway 15 is expected at 11:57 a.m. A second landing opportunity is available one orbit later at 1:34 p.m.
Ceccacci said the forecast is generally favorable for both Wednesday opportunities, but the outlook changes dramatically Thursday as a frontal system moves across Florida. Electrically charged anvil clouds are expected for the first Thursday opportunity with a chance of showers one orbit later.
"As far as the forecast for KSC Wednesday , they're trending very well and looking very promising," Ceccacci said. "With that, and with the next day's forecast, my plan tomorrow is just only call up KSC. If we needed (an extra day ) for whatever reason we had to wave off tomorrow, end of mission plus one would become 'pick 'em day,' we would come home (somewhere)."
The forecast for Edwards Air Force Base, Calif., and Northrup Strip in New Mexico is favorable Thursday and Friday.
Here are timelines for both of the crew's landing opportunities Wednesday (in EST; times are approximate):
Orbit 202 ground tracks to Kennedy Space Center (Credit: NASA)
Rev. 202 deorbit to KSC
Deorbit dT: 02:36
Deorbit dV: 194 mph
EST...........EVENT
06:52 AM......Begin deorbit timeline
07:07 AM......Radiator stow
07:17 AM......Astronaut seat installation
07:23 AM......Computers set for deorbit prep
07:27 AM......Hydraulic system configuration
07:52 AM......Flash evaporator cooling system checks
07:58 AM......Final payload deactivation
08:12 AM......Payload bay doors closed
08:22 AM......Mission control 'go' for OPS-3
08:32 AM......OPS-3 transition
08:57 AM......Entry switchlist verification
09:07 AM......Deorbit PAD update
09:12 AM......Crew entry review
09:27 AM......Commander/pilot don entry suits
09:44 AM......Inertial measurement unit alignment
09:52 AM......Commander/pilot strap in; others suit up
10:09 AM......Shuttle steering check
10:12 AM......Hydraulic system prestart
10:19 AM......Toilet deactivation
10:32 AM......Mission control center 'go' for deorbit burn
10:38 AM......Mission specialists seat ingress
10:47 AM......Single APU start
10:52:09 AM...Deorbit ignition
10:54:40 AM...Deorbit burn complete
11:25:57 AM...Entry interface
11:30:48 AM...1st roll command to right
11:38:04 AM...1st roll right to left
12:44:00 AM...C-band radar acquisition
11:51:11 AM...Velocity less than mach 2.5
11:53:23 AM...Velocity less than mach 1
11:54:13 AM...Right turn to runway 15
11:57:44 AM...Landing
Orbit 203 ground tracks to Kennedy Space Center (Credit: NASA)
Rev. 203 Deorbit to KSC
Deorbit dT: 02:31
Deorbit dV: 188 mph
EST...........EVENT
12:09 PM......MCC 'go' for deorbit burn
12:15 PM......MS seat ingress
12:24 PM......Single APU start
12:29:24 PM...Deorbit ignition
12:32:00 PM...Deorbit burn complete
01:01:58 PM...Entry interface
01:06:47 PM...1st roll command to right
01:21:10 PM...C-band radar acquisition
01:23:53 PM...1st right to left roll reversal
01:27:34 PM...Velocity less than mach 2.5
01:29:43 PM...Velocity less than mach 1
01:29:55 PM...Right turn to runway 15
01:34:10 PM...Landing
