CAPE CANAVERAL, Fla. - With Tropical
Storm Ernesto headed their way, NASA officials decided Tuesday to haul the space shuttle Atlantis
off its launch pad, effectively delaying the space agency's plan to resume
construction of the International
Space Station (ISS).
After several launch delays from an initial
Aug. 27 target, NASA shuttle officials opted to err on the side of safety
and roll Atlantis back into the shelter of the cavernous Vehicle Assembly
Building (VAB) here at the Kennedy Space Center. The orbiter will be safe in the
52-story VAB from Ernesto's tropical storm or hurricane force winds, which are
expected to batter Atlantis' launch site by Thursday, NASA officials said.
"The rollback essentially is a
decision to slip launch by a couple of weeks at least," NASA spokesperson Bruce
Buckingham told reporters here at KSC once shuttle managers made the call after
a morning weather briefing. "It could have gone either way up to the last
minute."
While NASA could conceivably ready
Atlantis once more for flight within its original launch window - which closes
on Sept. 13 - the agency has repeatedly stated its intent to loft the shuttle
and its STS-115 astronaut crew towards the ISS by Sept. 7 to avoid launch and
landing conflicts associated with a Russian Soyuz crew change mission set to
fly on Sept. 14.
"We essentially have a daylight
launch window from Oct. 20 through Nov. 15," NASA launch integration manger LeRoy Cain, currently heading Atlantis' STS-115 Mission
Management Team, said Monday. "Only a portion of that is good for the [external
tank] separation as well. Somewhere in there is where we're looking in terms of
trying to understand what we'd be willing to do to expand our launch capability
in October."
NASA has
said the optimum dates to photograph the external tank separation after launch occur
between Oct. 26 and 27 and one day on Dec. 23.
NASA space station officials are
still negotiating with their Russian counterparts to determine if the Soyuz
flight could be pushed back to Sept. 18 - which would require a returning Soyuz
spacecraft to land in darkness - to give Atlantis extra time to fly its ISS
construction flight, which will be the first since late
2002.
"Those discussions are continuing,"
Buckingham said of the U.S.-Russian ISS negotiations.
The earliest Atlantis could be back
on the launch pad and primed for flight would be near the end of its lighted
launch window, some time between Sept. 9-12, NASA has said.
Atlantis' STS-115
mission will launch a 17.5-ton of trusses and solar arrays to the ISS to
kick off at least 15 planned shuttle flights to complete the orbital laboratory
by Sept. 2010, when NASA plans to retire its three-shuttle fleet.
Buckingham said Atlantis'
six-astronaut crew - commanded by shuttle flight veteran Brent Jett - left KSC
earlier today and are returning to NASA's Johnson Space Center (JSC) for
additional training during Atlantis' launch delay. NASA officials at JSC told SPACE.com
that it is unknown at this time whether the astronauts will leave quarantine
conditions until a specific launch date is set.
Rolling back
NASA's massive crawler carrier
vehicle lifted its 12 million pound load of Atlantis, its boosters and fuel
tank and their Mobile Launch Platform, and began the 10-hour trek to the (VAB)
at 10:05 a.m. EDT (1405 GMT). In order to ferry Atlantis into High Bay 2 in the
VAB - a more than four-mile (6.4-kilometer) trip - the crawler is being pushed
to its maximum speed of one mile per hour until it has to make a turn to move
around the VAB towards its designated slot.
Shuttle planners hoped to tote
Atlantis into the VAB's High Bay 3, which faces KSC's two shuttle launch pads, but that space is already
occupied by a crawler laden with a Mobile Launch Platform and a
partially-stacked solid rocket booster. Attempts to shift that vehicle Monday
failed when the crawler broke down, NASA officials said.
For Atlantis, that high bay change
tacks on at least three extra hours to what NASA launch director Michael Leinbach estimated would be a day-long trip.
Leinbach said Monday that everything boiled
down to weather.
Space shuttles at the launch pad
cannot stay in place when faced with the prospect of sustained tropical storm
force winds in excess of 40 knots, but must be moved before then since a
rotating shell that guarding orbiters from weather cannot be moved during such
strong winds.
KSC's surrounding area is under tropical
storm and hurricane warnings in anticipation of Tropical Storm Ernesto's
arrival, as well as its potential to gain strength before making landfall in
Florida.
Compounding today's decision, Leinbach said, was the potential for afternoon
thunderstorms and lightning threats arriving at KSC while Atlantis was between
the launch pad and the VAB.
"I don't think there was any
contention at all," said Buckingham, NASA's KSC spokesperson, who listened in
on today's rollback discussion. "I think there was a lot of professionalism, a
lot of determination to make the right decision."
A total of 16 shuttles have been
rolled back from their launch pad in NASA history, though only four have done
so due to impending tropical storms or hurricanes.
Atlantis weather woes
Weather has plagued NASA's STS-115
launch preparations. Strong afternoon thunderstorms battered the KSC area days
before Atlantis' initial Aug. 27 launch target.
On Friday, a
bolt of lightning - one of, if not the, strongest to ever it a
shuttle-laden pad - struck a cable at Atlantis' Pad 39B launch site, prompting
launch delays as engineers checked the orbiter's systems for signs of damage.
"There was a collective sigh of
frustration with the weather," NASA astronaut Doug Wheelock,
who is set to launch toward the ISS aboard Atlantis next year, told SPACE.com.
"So I think some folks are disappointed."
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