Atlantis crew preps for entry
Keeping tabs on the weather, the Atlantis astronauts are preparing for re-entry and landing today at the Kennedy Space Center to close out the shuttle's 32nd and final flight.
Commander Kenneth Ham and his five crewmates have two Florida landing opportunities, the first around 8:48:14 a.m. EDT and the second at 10:22:58 a.m. Forecasters are predicting a chance for showers within 30 nautical miles of the runway for both opportunities, a violation of NASA's flight rules, and brisk winds out of the northwest.
But so far, off shore showers are staying out over the water and flight controllers are cautiously optimistic about getting Atlantis back to Earth later this morning.
"You got any advance intel on how the moisture's looking at the Cape?" Ham asked early today.
"Well, as you can imagine, we've been staring at the same radar screen for a couple of hours," astronaut Charles Hobaugh replied from mission control in Houston. "And it's actually looking pretty favorable. There are some spotty showers that are out over the water that are north, headed south, a chance of showers within 30 miles, but we think we'e got a pretty good fighting chance."
"Okey doke. 50-50," Ham quipped.
"That's right. Hopefully we're on the good side of that 50."
The first landing opportunity calls for a deorbit rocket firing at 7:41:59 a.m., a three-minute 10-second burn using the shuttle's twin orbital maneuvering system rockets to slow the craft by about 233 mph.
After a half hour free fall, Atlantis would plunge back into the discernible atmosphere 76 miles above the south Pacific Ocean at 8:16 a.m. The flight path would carry the ship across Central America and western Cuba before a steep descent up the Florida peninsula to the Kennedy Space Center.
Taking over manual control at an altitude of about 50,000 feet above the spaceport, the current plan calls for Ham to guide Atlantis through a sweeping 317-degree right overhead turn to line up on runway 33.
If the weather prevents an on-time descent, Ham, pilot Dominic "Tony" Antonelli and their crewmates - flight engineer Michael Good, Stephen Bowen, Piers Sellers and Garrett Reisman - can try again one orbit later.
The second opportunity requires a deorbit rocket firing around 9:17:24 a.m., setting up a landing at 10:22 a.m.
Atlantis has enough on-board supplies to remain in orbit until Saturday in a worst-case scenario. As a result, NASA is not staffing its backup landing site at Edwards Air Force Base, Calif., Wednesday or Thursday. If Atlantis isn't back on the ground by Thursday, however, Edwards will be staffed for a Friday attempt.
Here are timelines for both Wednesday landing opportunities at the Kennedy Space Center (in EDT; best viewed with fixed-width font):
Opportunity No. 1: Rev. 186 Deorbit to KSC
Opportunity No. 2: Rev. 187 Deorbit to KSC
Commander Kenneth Ham and his five crewmates have two Florida landing opportunities, the first around 8:48:14 a.m. EDT and the second at 10:22:58 a.m. Forecasters are predicting a chance for showers within 30 nautical miles of the runway for both opportunities, a violation of NASA's flight rules, and brisk winds out of the northwest.
But so far, off shore showers are staying out over the water and flight controllers are cautiously optimistic about getting Atlantis back to Earth later this morning.
"You got any advance intel on how the moisture's looking at the Cape?" Ham asked early today.
"Well, as you can imagine, we've been staring at the same radar screen for a couple of hours," astronaut Charles Hobaugh replied from mission control in Houston. "And it's actually looking pretty favorable. There are some spotty showers that are out over the water that are north, headed south, a chance of showers within 30 miles, but we think we'e got a pretty good fighting chance."
"Okey doke. 50-50," Ham quipped.
"That's right. Hopefully we're on the good side of that 50."
The first landing opportunity calls for a deorbit rocket firing at 7:41:59 a.m., a three-minute 10-second burn using the shuttle's twin orbital maneuvering system rockets to slow the craft by about 233 mph.
After a half hour free fall, Atlantis would plunge back into the discernible atmosphere 76 miles above the south Pacific Ocean at 8:16 a.m. The flight path would carry the ship across Central America and western Cuba before a steep descent up the Florida peninsula to the Kennedy Space Center.
Taking over manual control at an altitude of about 50,000 feet above the spaceport, the current plan calls for Ham to guide Atlantis through a sweeping 317-degree right overhead turn to line up on runway 33.
If the weather prevents an on-time descent, Ham, pilot Dominic "Tony" Antonelli and their crewmates - flight engineer Michael Good, Stephen Bowen, Piers Sellers and Garrett Reisman - can try again one orbit later.
The second opportunity requires a deorbit rocket firing around 9:17:24 a.m., setting up a landing at 10:22 a.m.
Atlantis has enough on-board supplies to remain in orbit until Saturday in a worst-case scenario. As a result, NASA is not staffing its backup landing site at Edwards Air Force Base, Calif., Wednesday or Thursday. If Atlantis isn't back on the ground by Thursday, however, Edwards will be staffed for a Friday attempt.
Here are timelines for both Wednesday landing opportunities at the Kennedy Space Center (in EDT; best viewed with fixed-width font):
Opportunity No. 1: Rev. 186 Deorbit to KSC
Deorbit ignition: 07:41:59 AM (dV: 233 mph; dT: 3:10) Crossrange: 679 miles Range from atmospheric entry to KSC: 5,021 miles Turn angle: 317-degree right turn to runway 33 Landing: 08:48:14 AM
Ground tracks for the shuttle Atlantis' first landing opportunity
Wednesday. (Credit: NASA TV)
EDT...........EVENT
12:20 AM......Crew wakeup
03:41 AM......Begin deorbit timeline
03:56 AM......Radiator stow
04:06 AM......Mission specialists seat installation
04:12 AM......Computers set for deorbit prep
04:16 AM......Hydraulic system configuration
04:41 AM......Flash evaporator cooling system checkout
04:47 AM......Final payload deactivation
05:01 AM......Payload bay doors closed
05:11 AM......Mission control 'go' for OPS-3
05:21 AM......OPS-3 entry software transition
05:46 AM......Entry switch list verification
05:56 AM......Deorbit maneuver update
06:01 AM......Crew entry review
06:16 AM......Commander, pilot don entry suits
06:33 AM......Inertial measurement unit alignment
06:41 AM......Commander, pilot strap in; others don suits
06:58 AM......Shuttle steering check
07:01 AM......Hydraulic system prestart
07:08 AM......Toilet deactivation
07:21 AM......Mission control 'go' for deorbit burn
07:27 AM......Astronauts strap in
07:36 AM......Single hydraulic power unit start
07:41:59 AM...Deorbit ignition
07:45:09 AM...Deorbit burn complete
08:16:28 AM...Entry interface
08:21:26 AM...1st roll command to left
08:34:47 AM...1st roll left to right
08:35:14 AM...C-band radar acquisition
08:41:43 AM...Velocity less than mach 2.5
08:43:56 AM...Velocity less than mach 1
08:44:09 AM...Right turn to runway 33
08:48:14 AM...Landing
Opportunity No. 2: Rev. 187 Deorbit to KSC
Deorbit ignition: 09:17:24 AM (dV: 233 mph; dT: 3:10) Crossrange: 360 miles Range from atmospheric entry to KSC: 5,055 miles Turn angle: 280-degree right turn to runway 33 Landing: 10:22:58 AM
Ground tracks for the shuttle Atlantis' second landing opportunity
Wednesday. (Credit: NASA TV)
EDT...........EVENT
08:57 AM......MCC 'go' for deorbit burn
09:03 AM......MS seat ingress
09:12 AM......Single APU start
09:17:24 AM...Deorbit ignition
09:20:34 AM...Deorbit burn complete
09:51:15 AM...Entry interface
09:56:11 AM...1st roll command to right
10:06:31 AM...1st right to left roll reversal
10:09:58 AM...C-band radar acquisition
10:16:28 AM...Velocity less than mach 2.5
10:18:41 AM...Velocity less than mach 1
10:19:12 AM...Right turn to runway 33
10:22:58 AM...Landing