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Safety analysis needed to clear shuttle's tank repairs BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: March 12, 2007
And that assumes a detailed, yet-to-be-completed analysis shows repaired foam high above the shuttle won't come off in flight and, if any does, the timing and expected debris size won't pose any significant additional risk of catastrophic impact damage to the shuttle's heat shield. "The jury is still out on that," said one NASA manager. That's at least in part because some of the damaged insulation up near the tip of the fuel tank needs to be repaired by spraying on new foam, a so-called "non-standard" procedure that will require test sprays on a mockup before engineers are cleared to attempt repairs on the flight hardware. Relatively shallow pits and dings can be repaired by "sand-and-blend" techniques and in cases of moderate damage, foam can be poured into depressions and then sanded as required.
After erecting access platforms, engineers used a grid system to characterize and pinpoint damage across all areas of the tank. NASA managers initially were concerned they might have to move Atlantis to a tank slated for use by the shuttle Endeavour this summer, a tank not scheduled for delivery until early April. Moving to a new tank would have delayed Atlantis's launch to around June 21. NASA's damage assessment is not yet complete, but during meetings late last week, engineers said they were much more optimistic about making repairs in the Vehicle Assembly Building, with Atlantis still attached, and avoiding a more lengthy delay to late June. But that assumes the engineering analysis provides confidence the non-standard repairs can stand up to the aerodynamic and thermal rigors of launch and won't pose an additional impact threat. And it assumes the major players in launch decisions, including the astronaut office, concur. More meetings are planned this week to discuss schedule options and as of this writing, NASA managers do not yet have a credible target launch date. Tank repairs aside, the shuttle cannot fly until after the April 7 launch of a space tourist and a fresh crew to the space station and the April 20 landing of the lab's outgoing crew. Here is the schedule of upcoming events for the Russian missions to and from the international space station:
DATE.......EDT...........EVENT
03/15/07...TBD...........Space station reboost maneuver for Soyuz launch
03/27/07...TBD...........23 Progress undocks from Zvezda aft port
03/29/07...TBD...........Soyuz TMA-9 relocation from
Zarya nadir port to Zvezda aft port
04/07/07...01:31:03 PM...Soyuz TMA-10/ISS-15 crew/space tourist launch
04/09/07...03:03:00 PM...Soyuz TMA-10 docking at Zarya nadir port
04/20/07...06:11:00 AM...Soyuz TMA-9/ISS-14 crew/space tourist undocking
04/20/07...09:30:00 AM...Soyuz TMA-9/ISS-14 crew/space tourist landing
The current shuttle launch period closes May 21 based on temperature constraints related to the station's orbit. The next launch period after that opens June 9. As of late last week, three broad options were on the table: A launch in late April; a launch May 11 after an arbitrarily chosen 45-day VAB repair flow; and a launch June 21 with a new tank. While NASA has not ruled out a late-April launch, that appears to be a long shot at best given the repairs and supporting analysis that is required. The May 11 date was little more than a rough guesstimate, sources said, and was not based on any actual repair scenarios. Until the damage assessment is complete, there is no way to generate a credible repair flow and launch processing schedule. That said, "the real, no-kidding expectation is mid May," an official said today. For the record, here are the current manifest options for launches May 11 and June 21: 05/11/07: STS-117/ISS-13A (S3/S4 solar array/truss element) 07/19/07: STS-118/ISS-13A.1 (S5 truss element) 10/25/07: STS-120/ISS-10A (Node 2 connecting module) 12/29/07: STS-122/ISS-1E (European Columbus research module) 02/07/08: STS-123/ISS-1J/A (Japanese experiment module) 04/24/08: STS-124/ISS-1J (Japanese Kibo research module) 07/24/08: STS-119/ISS-15A (S6 solar array element) 10/23/08: STS-125 (Hubble Space Telescope servicing mission) 11/20/08: STS-126/ISS-ULF-2 (logistics mission) 06/21/07: STS-117/ISS-13A (S3/S4 solar array/truss element) 08/26/07: STS-118/ISS-13A.1 (S5 truss element) 11/29/07: STS-120/ISS-10A (Node 2 module) 01/24/08: STS-122/ISS-1E (European Columbus research module) 03/20/08: STS-123/ISS-1J/A (Japanese experiment module) 05/30/08: STS-124/ISS-1J (Kibo Japanese research module) 09/18/08: STS-119/ISS-15A (S6 solar array element) 11/20/08: STS-125 (Hubble Space Telescope servicing mission) 12/18/08: STS-126/ISS-ULF-2 (logistics mission) As this writer's own "option exercise," here is the STS-117 flight plan adjusted for a May 11 launch. As with a March 15 launch, major mission events would take place in the late night/pre-dawn hours U.S. time (times in EDT and mission elapsed time): DATE/TIME......DD...HH...MM...EVENT 05/11/07 Fri 07:18 AM...00...00...00...STS-117 launch Fri 01:18 PM...00...06...00...Crew sleep begins Fri 09:18 PM...00...14...00...Crew wakeup 05/12/07 Sat 01:43 AM...00...18...25...Heat shield inspection begins Sat 01:18 PM...01...06...00...Crew sleep begins Sat 09:18 PM...01...14...00...STS/ISS crew wakeup 05/13/07 Sun 03:59 AM...01...20...41...Shuttle docks with space station Sun 06:18 AM...01...23...00...S3/S4 solar array truss unberthing Sun 08:33 AM...02...01...15...S3/S4 handoff to station robot arm Sun 01:18 PM...02...06...00...STS crew sleep begins Sun 09:18 PM...02...14...00...STS crew wakeup Sun 11:18 PM...02...16...00...S3/S4 installation 05/14/07 Mon 03:08 AM...02...19...50...EVA-1: Airlock egress Mon 09:33 AM...03...02...15...EVA-1: Airlock repressurization Mon 01:18 PM...03...06...00...STS crew sleep begins Mon 09:18 PM...03...14...00...STS/ISS crew wakeup 05/15/07 Tue 12:48 AM...03...17...30...1A solar array mast deploy to 100 percent Tue 02:18 AM...03...19...00...3A solar array mast deploy to 100 percent Tue 01:18 PM...04...06...00...STS crew sleep begins Tue 09:18 PM...04...14...00...STS/ISS crew wakeup Tue 11:03 PM...04...15...45...P6-2B solar array retraction attempt 05/16/07 Wed 02:18 AM...04...19...00...EVA-2: Airlock egress Wed 02:58 AM...04...19...40...EVA-2: P6-2B retraction assist (if needed) Wed 08:43 AM...05...01...25...EVA-2: Airlock repressurization Wed 12:48 PM...05...05...30...STS crew sleep begins Wed 08:48 PM...05...13...30...STS/ISS crew wakeup Wed 11:48 PM...05...16...30...P6-2B retraction window opens (if needed) 05/17/07 Thu 03:13 AM...05...19...55...P6-2B retraction window closes Thu 12:48 PM...06...05...30...STS crew sleep begins Thu 08:48 PM...06...13...30...STS/ISS crew wakeup 05/18/07 Fri 01:48 AM...06...18...30...EVA-3: Airlock egress Fri 08:13 AM...07...00...55...EVA-3: Airlock repressurization Fri 12:18 PM...07...05...00...STS crew sleep begins Fri 08:18 PM...07...13...00...STS/ISS crew wakeup Fri 11:18 PM...07...16...00...Crew off duty time 05/19/07 Sat 06:33 AM...07...23...15...Joint crew news conference Sat 07:33 AM...08...00...15...Farewell ceremony Sat 07:48 AM...08...00...30...Egress and hatch closure Sat 11:48 AM...08...04...30...STS crew sleep begins Sat 07:48 PM...08...12...30...STS/ISS crew wakeup Sat 11:56 PM...08...16...38...Shuttle undocks from space station 05/20/07 Sun 03:58 AM...08...20...40...Starboard wing survey Sun 10:48 AM...09...03...30...ISS crew sleep begins Sun 06:48 PM...09...11...30...STS crew wakeup Sun 09:48 PM...09...14...30...Cabin stow Sun 10:48 PM...09...15...30...Flight control system checkout Sun 11:58 PM...09...16...40...Reaction control system hotfire 05/21/07 Mon 10:18 AM...10...03...00...STS crew sleep begins Mon 06:18 PM...10...11...00...Crew wakeup 05/22/07 Tue 01:25 AM...10...18...07...Deorbit ignition (orbit 171) Tue 02:27 AM...10...19...09...KSC Landing |
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MISSION INDEX |
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Battered by an intense hail storm six days earlier, space shuttle Atlantis retreated off launch pad 39A and returned to the cavernous Vehicle Assembly Building on March 4 to undergo thorough inspections and repairs.
The STS-117 astronauts meet the press during the traditional pre-flight news conference held at the Johnson Space Center a month prior to launch. The six-person crew will deliver and activate a solar-power module for the International Space Station.
After a six-hour trip along the three-and-a-half-mile crawlerway from the Vehicle Assembly Building, space shuttle Atlantis arrives at launch pad 39A for the STS-117 mission.
Space shuttle Atlantis emerges from its processing hangar at dawn February 7 for the short trip to the Vehicle Assembly Building at Kennedy Space Center's Complex 39.
This documentary takes a look at the technical aspects of Project Mercury, including development of the capsule and the pioneering first manned flights of America's space program.
The voyage of Apollo 15 took man to the Hadley Rille area of the moon. Astronauts Dave Scott and Jim Irwin explored the region using a lunar rover, while Al Worden remained in orbit conducting observations. "Apollo 15: In the Mountains of the Moon" is a NASA film looking back at the 1971 flight.
