Astronauts ready Atlantis for final re-entry

Editor's note...
  • Posted at 01:49 AM EDT, 07/21/11: Astronauts ready Atlantis for final re-entry
CBS News

KENNEDY SPACE CENTER, FL--Awakened by the rousing strains of Kate Smith's "God Bless America," the Atlantis astronauts are rigging the shuttle for it's final re-entry to close out three decades of shuttle operations. There are no technical problems of any significance and forecasters are predicting ideal weather.

Flight controllers at the Johnson Space Center early Thursday work through shuttle re-entry preparations for the last time. (Credit: NASA)
"Good morning, Atlantis," astronaut Shannon Lucid radioed from mission control late Wednesday. "And the wakeup music this morning was for the entire crew, and it was also for all the men and women who put their heart and soul into the shuttle program for all of these years."

"Hey thanks, Shannon, what a classic patriotic song, it's so appropriate for what will likely be the shuttle's final day in orbit," commander Christopher Ferguson replied from orbit. "Thank you to America for supporting this program. We'll see you on the ground in a few short hours, hopefully."

Flying upside down and backward over the Indian Ocean, Ferguson and pilot Douglas "Chunky" Hurley plan to fire the shuttle's twin braking rockets for three minutes and 17 seconds starting at 4:49:04 a.m. EDT (GMT-4), slowing the ship by about 223 miles per hour to drop out of orbit and set up a landing on runway 15 at 5:56:58 a.m.

A second landing opportunity is available one orbit later, at 7:32:55 a.m. if the weather or some other issue prevents an on-time re-entry. NASA is not staffing its backup landing site at Edwards Air Force Base, Calif. If Atlantis doesn't make it home Thursday, the crew will remain in orbit an additional day and land Friday on one coast or the other.

But the weather appeared ideal early Thursday and entry Flight Director Tony Ceccacci was optimistic about bringing Atlantis' 33rd and final mission to a close.

Assuming an on-time deorbit rocket firing, the shuttle will plunge into the discernible atmosphere at an altitude of about 75 miles above the southern Pacific Ocean around 5:25 a.m., enduring the hellish heat of re-entry as it descends along a northeasterly trajectory back toward the Kennedy Space Center.

The flight path will carry Atlantis high above Central America, across the Gulf of Mexico just west of Cuba and on to Florida, approaching the Kennedy Space Center from the southwest.

Ferguson plans to take over manual control at an altitude of about 50,000 feet above the Space Coast, guiding the shuttle through a sweeping 240-degree left turn to line up on runway 15 for the shuttle program's final landing.

Here are timelines for both landing opportunities (in EDT; best viewed with fixed-width font):
(Source: NASA)

Orbit 200 descent to KSC (07/21/11)
Deorbit burn duration: 3:17
Deorbit change in velocity: 223 mph


12:49 AM......Begin deorbit timeline
01:04 AM......Radiator stow
01:14 AM......Astronaut seat installation
01:20 AM......Computers set for deorbit prep
01:24 AM......Hydraulic system configuration
01:49 AM......Flash evaporator cooling system checks
01:55 AM......Final payload deactivation
02:09 AM......Payload bay doors closed
02:19 AM......Mission control 'go' for OPS-3 software load
02:29 AM......OPS-3 transition
02:54 AM......Entry switch list verification
03:04 AM......Deorbit maneuver update
03:09 AM......Crew entry review
03:24 AM......Commander, pilot don entry suits
03:41 AM......Inertial measurement unit alignment
03:49 AM......Commander, pilot strap in; mission specialists don suits
04:06 AM......Shuttle steering check
04:09 AM......Hydraulic system prestart
04:16 AM......Toilet deactivation
04:29 AM......Mission control 'go' for deorbit burn
04:35 AM......Mission specialists seat ingress
04:44 AM......Single APU start

04:49:04 AM...Deorbit ignition (altitude: 239.8 miles; dT: 3:17; dV: 223 mph)
04:52:21 AM...Deorbit burn complete

05:24:50 AM...Atmospheric entry (altitude: 75.7 miles; velocity: mach 25)
05:29:45 AM...1st roll command to left
05:41:13 AM...1st roll left to right
05:43:58 AM...C-band radar acquisition
05:50:12 AM...Velocity less than mach 2.5 (altitude: 83,600 feet)
05:52:22 AM...Velocity less than mach 1 (altitude: 47,000 feet0
05:53:11 AM...Start left turn to runway 15 (altitude: 35,300 feet)
05:56:58 AM...Landing

(Source: NASA)

Orbit 201 descent to KSC (07/21/11)

06:05 AM......Mission control 'go' for deorbit burn
06:11 AM......Mission specialists seat ingress
06:20 AM......Single APU start

06:25:44 AM...Deorbit ignition (altitude: 240.7 miles)
06:29:01 AM...Deorbit burn complete

07:00:44 AM...Atmospheric entry (altitude: 75.7 miles)
07:05:38 AM...1st roll command to left
07:17:57 AM...1st left to right roll reversal
07:19:55 AM...C-band radar acquisition
07:26:05 AM...Velocity less than mach 2.5 (altitude: 84,100 feet)
07:28:16 AM...Velocity less than mach 1 (altitude: 46,800 feet)
07:28:46 AM...Start left turn to runway 15 (altitude: 39,200 feet)
07:32:55 AM...Landing