NASA hoping for May 15 shuttle launch
But managers keeping door open for a slide in that date
(CNN) -- Managers of the space shuttle Discovery said Tuesday they are leaving the door open for a slide in the scheduled May 15 "return to flight" launch, though NASA continues to work toward that date in the wake of the 2003 Columbia disaster.
Minor issues with shuttle processing have postponed the rollout of the orbiter to the launch site, leaving little room in the schedule for any further delays, they said.
"We have scheduled the fifteenth of May as our targeted launch date," said Michael Kostelnik, the deputy associate administrator for international space station and space shuttle programs.
"But it should be clearly understood that this is a 'not earlier than' date, which gives us the earliest opportunity we can bring all of the processing elements together and have a credible window to get to the international space station."
Kostelnik spoke on a conference call with reporters to answer questions about NASA's "return to flight" progress.
Space shuttle program manager Bill Parsons agreed.
"Right now is not a time to make a decision about whether we can make the fifteenth or not. We need to continue processing, and somewhere, the middle of next month, we can decide whether we are on track to make the fifteenth or not."
The shuttle fleet has been grounded since the space shuttle Columbia broke apart over Texas while on landing approach to Florida's Kennedy Space Center on February 1, 2003.
The following August, the Columbia Accident Investigation Board (CAIB) officially concluded that insulating foam flew off the shuttle's external fuel tank during lift off, striking and cracking a panel on the orbiter's wing. When the shuttle re-entered the atmosphere, searing hot gases seeped into the wing and incinerated the spacecraft.
Since then, NASA has been implementing a series of recommendations laid out in the Columbia report in order to return the shuttle fleet to service, and get on with the process of assembling the international space station.
For at least the next two shuttle missions, NASA has committed to daytime launches so that high-resolution images can be taken of any foam or other debris shedding from the external tank during liftoff.
Because the shuttle must also launch on a very specific trajectory to rendezvous with the space station, the daytime requirement strictly limits possible launch dates and times.
NASA has targeted a launch window that runs from May 15 to June 3. If the shuttle does not launch in that time interval, the next open window is July 12-31.
The most vexing problem facing NASA as it works thorough the CAIB recommendations has been developing effective techniques to repair precisely the type of structural damage that doomed Columbia.
The underside of a space shuttle is covered with insulating tiles, and the edges of the wings are clad with reinforced carbon-carbon (RCC) panels.
They make up the "thermal protection system" (TPS) designed to protect the shuttle during the heat of re-entry. Prior to the Columbia accident, astronauts had no way to inspect for and repair damage to the TPS in space.
In order to stop the external tank from shedding debris during launch, engineers have modified its design, and changed how they apply the insulating foam to it.
NASA also has developed processes for inspecting the exterior of the shuttle for damage in orbit. But, while they've tested some RCC plug and crack-repair procedures, and tile-repair techniques, NASA managers say they still don't have a way to fix a hole if they find one.
As a fall back plan, in the event of an in-orbit emergency astronauts will use the international space station as a "safe haven," where they can await a rescue mission. (Full story)
NASA Safety and Mission Assurance Chief Bryan O'Connor also announced in Tuesday's teleconference that NASA will now factor public safety into its landing procedures.
In the event NASA decides to attempt a landing of a shuttle that is known to have been damaged or that is malfunctioning, the designated landing site will be the White Sands Missile Range in New Mexico.
That location is more remote than the Kennedy Space Center in Florida or Edwards Air Force Base in California, and would presumably involve flying over more sparsely populated areas.