NASA Chooses The Lesser Of Three Evils
ANN REALTIME REPORTING 12.22.06 17:40 EST:
After foregoing a first landing opportunity earlier this
afternoon, the space shuttle Discovery touched down in a murky
twilight at precisely 17:32 EST at Kennedy Space Center
today ending a thirteen-day mission for STS-116 and
Discovery's 33rd trip to space.
The NASA rule book says night begins at sunset plus 15 minutes,
so the crew will have to log this one as a day landing.
Forecast weather at both KSC and backup landing site Edwards
AFB, CA for today threatened to preclude landing at either, but a
last minute improvement in Florida's weather allowed the
orbiter to sneak in.
STS-116 Commander Mark Polansky fired
Discovery’s jets at 16:26 EST to begin the descent to
While at the ISS, the Discovery's crew continued the
construction of the space outpost adding the P5 spacer
truss segment during the first of four spacewalks. During two more
spacewalks astronauts rewired the station’s power system
from a temporary to a permanent configuration.
Managers added a fourth spacewalk to manually retract a
recalcitrant solar array that had folded improperly.
Discovery also delivered a new crew member and more than two
tons of equipment and supplies to the ISS, most of which were
located in the new SPACEHAB cargo module. Almost two tons of
equipment no longer needed on the station returned to Earth
Discovery is set to launch again in October as part of
STS-122 delivering the European Space Agency's Columbus
Laboratory to the International Space Station.
ANN joins the rest of America in saluting the flight and ground
crews that made this successful mission possible!
14:15 EST: NASA has chosen not to
attempt a landing during its 15:56 EST window of
opportunity at the Kennedy Space Center in Florida.
Storms in the area of KSC have made the weather situation too
fluid for NASA's conservative flight controllers.
The agency's next opportunity is around 17:30 EST at either KSC,
Edwards AFB, CA or White Sands, New Mexico. The current observation
at EDW indicates light westerly winds, but the latest forecast
for the period calls for a direct crosswind of 12 gusting
to 18 knots. The shuttle has a 15 knot crosswind
NASA used one of its extra mission days -- normally reserved to
give the agency more landing options during times of poor weather
or other unforseen circumstances -- for an additional spacewalk to
manually retract a balky solar panel.
ANN will continue to update this story as it develops. Keep
checking back for the latest!
09:00 EST: Although engineers and managers at
NASA have operationally cleared the shuttle Discovery for a landing
today, the agency is still unsure of exactly where the orbiter is
to set down.
NASA's entry director Norm Knight told the Associated Press, "As
we get closer, we'll have much more certainty on what we're really
A massive weather system wreaking havoc with Holiday travelers
for the past few days has now moved east of the Mississippi
bringing clouds, wind and rain from the gulf coast to Canada.
NASA's primary landing site is Kennedy Space Center in Florida.
The orbiter has two opportunities to get into KSC, the first at
15:56 EST, the second at 17:32 EST. The National Weather Service is
currently forecasting SSE winds at 17 mph with low clouds and
showers. Visibility is expected to worsen into tonight.
Edwards AFB, CA is NASA's first backup landing site, but
managers are concerned about the crosswinds there. The orbiter has
three opportunities for landing at EDW, 17:27 EST, 19:00 EST and
20:36 EST. Forecasters there are calling for west winds at 25
gusting to 35 knots. A landing on runway 22 would make for
crosswinds 50 degrees off runway heading -- the shuttle has a
maximum crosswind capability of 15 knots.
NASA's last choice is White Sands, NM at 17:27 EST, or 19:02
EST. Although the weather there is forecast favorable for landing,
agency managers really don't want to land there. The lack of
equipment there to service the shuttle post-flight will delay its
return to Florida -- up to two months NASA is saying now. That
might jeopardize the Discovery's next scheduled launch in October
of next year.
If NASA opts for White Sands it would be only the second time
ever. The last time was in 1982 (below) and technicians
complained the shuttle was contaminated by the fine sands on the
runway. The powdery substance also sifted its way into the
orbiter's brakes causing damage.
As for the crew, they continue landing preparations started
yesterday. All flight controls check good and the final inspections
of the shuttle's heat shield are complete with everything checking
green so far.
"I have a lot of things to worry about on this flight that I can
control, and the weather is something I can't," Discovery commander
Mark Polansky told reporters from space. "I'm ready to land at any
of the three sites."
NASA says it wants to get the shuttle down today or tomorrow as
its fuel cells will run dry after Saturday.
Flight controllers in Houston have made their choice of landing
sites clear -- apparently they all want to go home for the
They transmitted their selection to the Discovery's crew in
rewrite of the familiar Christmas song, Let It Snow:
"Oh, the weather at KSC is frightful. But at White Sands, it's
so delightful. And since we have to land. Land White Sands, land
White Sands, land White Sands."
Who says engineers have no sense of humor?
Keep checking back today as ANN follows the Discovery's journey