CAPE
CANAVERAL, Fla. -- Seven
astronauts are spending what is expected to be their last full day in orbit
aboard NASA's space shuttle
Discovery today as their 13-day flight to the International Space
Station (ISS) draws towards its close.
Discovery's
STS-116 astronauts, commanded by veteran spaceflyer Mark Polansky,
will put their orbiter through its reentry paces during a series of flight
systems checks later today in preparation of their planned Friday return.
"It was a
true team effort, and I think this mission really showed that," Polansky told
flight controllers Wednesday. "We are really looking forward to getting back to
see a great holiday."
NASA
mission operations representative Phil Engelauf said
Wednesday that Discovery appears to be in fine shape for a Friday landing. The
results a final
inspection of the orbiter's heat shield are expected to be announced during
a NASA mission status briefing later today.
In addition
to their standard pre-landing Flight Control Systems checks, Discovery's
STS-116 crew will spend time today stowing some last-minute cargo items and
setting up a special recumbent seat for European
Space Agency astronaut Thomas Reiter. Unlike the Discovery astronauts, who
have been in orbit for just over 11 days, Reiter is returning to Earth after
almost half a year of in space as an ISS crewmember [image].
Small
satellites take flight
Discovery
astronauts successfully launched two small
payloads from the aft end of the shuttle's cargo bay late Wednesday and
plan to deploy one more before the end of today.
STS-116
mission specialists Christer
Fuglesang and Joan
Higginbotham fired a pair of spring-loaded experiments into orbit to kick
off experiments sponsored by the U.S.
military.
At 7:19 p.m. EST (0019 Dec. 21 GMT), they unleashed
the Microelectromechanical System-Based (MEMS) PICOSAT Inspector (MEPSI). The
payload featured two tiny vehicles--each the size of a coffee-cup--lashed
together with a tether and designed to test a low-power satellite's ability to
inspect larger spacecraft in close proximity.
"Houston, we have a successful MEPSI
deploy," Fuglesang said.
At 8:56
p.m. EST (0156 Dec. 21 GMT), the astronauts deployed the Radar Fence
Transponder (RAFT): a pair of five-inch (12.7-centimeter) wide cubes built by
students for the U.S. Naval Research Laboratory to test the limits of the
military's Space Surveillance Radar Systems in Texas, Alabama and Arizona. The
small cubes are also designed to relay messages for display across the Internet
as well a being capable of beaming a digitized voice, NASA officials said.
MEPSI took
photos of Discovery, which were later relayed to the shuttle's crew, as it
departed and RAFT was successfully detected by its users as it passed over Oregon, Mission Control reported.
"OK!" Polansky
exclaimed. "Everybody's happy."
The
astronauts are expected to deploy a small atmosphere-observing satellite dubbed
ANDE at about 1:19 p.m. EST (1819 GMT) today.
Landing
preparations
Polansky
and his crewmates are due to land at one of three NASA shuttle runways either in Florida, New Mexico or California.
While exact
landing site, however, will depend on weather conditions at the time, NASA is
hoping to put Discovery down here at the Kennedy Space Center (KSC), where the
shuttle launched
spaceward on Dec. 9, to minimize turnaround time and costs.
Engelauf said
flight controllers plan to attempt a 3:56 p.m. EST (1856 GMT) landing at KSC during Discovery's first return
window Friday, which occurs during the shuttle's 202nd orbit around
Earth. A subsequent orbit offers landing opportunities at KSC, White Sands Space Harbor in New Mexico and Edwards Air Force Base in California--in that order--though the
target runway would likely be tapped before Discovery is due to leave orbit, he
added.
"More than
likely we will pick a site to aim for on each [revolution] and get in there," Engelauf
said, adding that the window in which to fire Discovery's engines to make any
of the three landing strips spans only six minutes. "It's a really short
decision time and you pretty much have to make your mind up before you get
there."
An
off-going shift of mission controllers commended the STS-116 crew's work after
their successful ISS construction mission to install
a new piece of the ISS, rewire
the outpost's power grid and deliver a new
astronaut and cargo for the station's Expedition 14 mission. Discovery's
crew also wedged in an extra spacewalk to furl away a
stubborn ISS solar array.
"The
flexibility you guys maintained to finish this mission was outstanding," said NASA
astronaut Kevin Ford, serving as spacecraft communicator for the first of three
flight controller shifts working with Discovery's crew. "Have a Merry
Christmas, happy holidays and you guys have a safe trip home."
advertisement
