Wicked Weather Problems Again Delay Space Shuttle Atlantis Launch
NASA announced today that once again it will delay the troubled launch of Space Shuttle Atlantis because of bad weather, putting it off into next month at least, with a hope that the spaceship can get off the ground before Sept. 7.
While the decision to scrub the Tuesday launch could be reversed, and a go for the launch could be given up until noon Tuesday, that would require a marked change in the weather outlook, which officials don’t see as likely.
The attempt to launch Atlantis into orbit is turning out to be as star-crossed as the launch last month of Space Shuttle Discovery was relatively trouble free.
Consider what’s happened with Atlantis, and what NASA has managed to overcome thus far:
A discovery was made that too-small bolts that for years have been holding a large antenna in place, forcing NASA to undergo a last-minute rush to change the bolts, even though at that point Atlantis already had been moved to the launch pad and was poised, vertical, for an ascent to the International Space Station (ISS). Although initially that repair job was thought to mean a two-day delay in the Atlantis launch, crews rushed to make the bolts fix, and they seemed for a while to have won their bid to keep the bolts problem from throwing the mission off schedule. NASA rose to the challenge, and the Sunday launch still might have been possible.
But then the innumerable electronic systems on Atlantis had to be examined, because a lightning bolt or two Friday struck near the shuttle. Although that huge surge of electricity in the storm meant NASA couldn’t make its planned Atlantis launch Sunday afternoon, NASA team members worked furiously in checking systems, so that the shuttle still might be able to launch tomorrow, two days late. Again, NASA rallied, and succeeded.
But Mother Nature had more nastiness in store, in the form of Hurricane Ernesto, swirling out of the Atlantic toward Florida. And that, in turn, meant that Atlantis likely will have to be taken to safety, rolled off the launch pad and back to the shelter of the Vehicle Assembly Building (VAB) before the storm could reach Kennedy Space Center, perhaps heading inside by midnight tomorrow. (There previously have been four similar rollbacks in the face of hurricanes or tropical storms threatening Florida.) Then the storm would have to arrive and pass. Then there would be another couple of days to roll Atlantis back to the launch pad and prepare for liftoff. It all could set things back by the better part of two weeks, if not months.
Talk about frustrating. The Atlantis ascent was hoped to be the mission to the ISS that would show NASA had eliminated potentially fatal troubles from shuttle launches that earlier had been caused by foam insulation ripping loose from external fuel tanks.
Now, NASA is confronted with major new questions for the space program.
First, when Atlantis finally does launch, will it be trouble-free as far as foam loss?
Second, how much of a delay–how many days lost–will the rollback of Atlantis to the VAB, and then roll out to return to the pad, cost NASA in its tightly choreographed schedule of 16 shuttle launches over four years to finish construction of the space station?
Finally, how will delays in launching Atlantis affect Russian plans to launch a Soyuz vehicle next month on a mission to the ISS? The Soyuz launch can be delayed only so long, because when Soyuz reenters the atmosphere, it comes down on land in Kazakhstan, and Russian search and rescue helicopters and crews need daylight to see the spacecraft as it returns. Every day of delay would push the Soyuz return further back into early morning hours, darker and darker.
Hopefully, any storm-caused launch delays won’t be too extensive, though uncertainties such as possible wind damage to the launch pad make it impossible now to set any new launch date. The window for launching Atlantis closes Sept. 13, but the goal would be to launch by Sept. 7 so as not to interfere with Russian spacecraft going to the ISS. Or the Atlantis launch could slip much further.
“Up to today, we were comfortable that would could make this [Sept. 7] window,” said Mike Suffredini, NASA station program manager, speaking in a briefing last night. But “starting today [Sunday],” NASA isn’t so confident that Atlantis will launch before the window closes.
This is a concern, because NASA faces pressure to complete construction of the ISS before 2010, when the space shuttle fleet will be retired, eliminating the only existing spacecraft capable of carrying large structural components needed to assemble the space station.
All of this has hit NASA leaders just at a time when they were hugely elated at the recent brilliant performance of the Discovery mission.
A flawless performance by Atlantis, NASA leaders still hope, could alleviate safety concerns over the shuttle fleet.
To be sure, some key NASA personnel still see further safety improvements needed before they will confirm shuttles as reliably free of danger caused by tumbling pieces of foam insulation.
In 2003, as Space Shuttle Columbia launched, foam insulation ripped free, and a piece of it hit a leading edge of a wing on the orbiter vehicle, punching a hole in the wing. Later, as Columbia began returning to Earth, the fiery gases of re-entry rushed into the wing, melting components to cause structural failure. The shuttle and crew were lost Feb. 1, 2003.
That prompted a pause in the shuttle program, and a years-long pause in assembling the space station, while NASA developed and provided multiple safety steps designed to reduce foam insulation loss. That included removing protuberance air load ramps on the outside of the fleet of external fuel tanks, and reworking the ice frost ramps. Those safety moves were put in place for the Discovery launch last month.
The hope still is that the Atlantis launch on the STS-115 mission, similarly, would see no huge chunks of foam rip loose from the external fuel tank. Hopefully, if any foam pieces that did fly off the tank, they would be small, and tear off late enough in the Atlantis ascent that they wouldn’t have damaged the orbiter vehicle even if they had hit it, again following the pattern set by the Discovery ascent.
The multiple storms besetting the Atlantis launch are yet another example of how problematical weather can be in the hot, humid atmosphere of Florida in summer. Even Discovery, for example, was delayed by threatening thunderstorms before it finally lifted off.
In clearing Atlantis for launch, NASA Administrator Michael Griffin had the unanimous backing of senior NASA leaders. That wasn’t the case, however, in the Discovery mission.
Then, Bryan O’Connor, NASA chief safety and mission assurance officer, and Chris Scolese, chief engineer, voted “no go” for the Discovery mission, saying they felt there still was a chance the orbiter vehicle could be damaged during ascent, even with the safety improvements. They wrote their “no go” recommendations in papers after a flight readiness review panel met.
Griffin responded by saying that he values disparate opinions, seeing that as a way to avert unforeseen problems, but said there was a reasonable chance that the safety measures would work well.
He was proven right by the clean condition of Discovery as it rolled to a stop on the runway in a hot Florida sun, with no major damage.
And this time, O’Connor and Scolese voted for sending Atlantis aloft, while still saying that they wish to see further safety improvements.
Among those safety gains, NASA might apply titanium to parts of the ice frost ramps, to prevent liberation of foam insulation, a material that must be applied to the external fuel tank to keep the freezing-cold fuel and oxygen from causing ice to form on the outside of the tank. Ice ripping off the tank could pose a far greater hazard to the orbiter vehicle than the foam insulation.
Aside from all the steps to prevent damage from occurring in the first place, NASA also instituted a process of ensuring that if damage nonetheless does occur, it will be detected, averting a fatal decision to attempt reentry with a damaged shuttle.
When, eventually, Atlantis finally arrives at the ISS, the space station will monitor the arriving shuttle for damage, including its underside. Then, robotic arms will snake out with sensors and check repeatedly for any minute damage to the orbiter, especially in the critical areas such as leading edges of the wings and the nose.
This procedure worked smoothly when Discovery attained orbit and docking.
Additionally, Atlantis will undergo a post-undocking inspection, to check for any damage that might have been inflicted by incoming micrometeorites during its orbits around Earth.
Challenging Missions Ahead
The Atlantis launch, when it finally occurs, will provide a starter’s gun to signal the start of a race to finish construction of the space station, where winning that race will require each planned shuttle mission to go off like clockwork between now and 2010, when the shuttle fleet is slated to retire.
It won’t be replaced until sometime in the next decade, when the Crew Exploration Vehicle (CEV) will begin duty, not only going to low Earth orbit, but going to the moon, Mars and beyond.
However, the CEV won’t be able to lift the huge structural components needed for the ISS. That is a job for the shuttles, with their huge cargo bays.
For example, Atlantis will be able to accommodate in its cargo bay the giant 35,000-pound, 45-foot-long (when folded up) P3/P4 truss to be added to the space station, a girder- like structure of awesome size. The new piece will include a set of giant solar arrays, batteries and associated electronics. There will be three spacewalks to hook up the truss and prepare the arrays for operation.
The Atlantis crew will be Commander Brent Jett, Pilot Chris Ferguson, and mission specialists Joe Tanner, Dan Burbank, Heide Stefanyshyn-Piper and Canadian Space Agency astronaut Steve MacLean.
During extra vehicular activities, or spacewalks, the truss will be attached to the space station by Tanner and Stefanyshyn-Piper, aided by crew members inside operating the robotic arms.
Another component to be added to the ISS artificial moon will be the Solar Alpha Rotary Joint (SARJ), with Burbank and MacLean spacewalking.