This
story was updated at 7:43 a.m. EDT.
Astronauts aboard
the space shuttle Discovery are due for some much-deserved time off Sunday as
NASA engineers draw up new plans for the crew's last spacewalk at the
International Space Station.
Discovery's
seven-astronaut crew is scheduled to take about a half-day off to rest up from a
packed spaceflight that has only become busier from daily changes to an
already shortened mission plan.
"We're
ready to start the day," Discovery skipper Lee Archambault radioed Mission
Control this morning. "We know it's a little bit of a lighter day, but I'm sure
you guys had a busy night overnight with a lot of planning."
The crew's latest
hurdle is the upcoming spacewalk, a planned
Monday excursion to pay a service call on the space station and move gear
into position for the next construction flight.
An
incorrectly placed restraint pin thwarted efforts by astronauts to set up a
spare parts platform in
a Saturday spacewalk, leaving cargo carrier half-deployed and tied down
with tethers when they ran out of time to fix it and set up a second platform.
Mission managers worked through the night to replan Monday's spacewalk to wrap up the
unfinished work and has divers in the water of its immense swimming pool used
for spacewalk training to come up with the best repair plan.
"We will
respect the crew's off-duty time," space station flight director Kwatsi
Alibaruho told reporters late Saturday. "They've accomplished an incredible
amount already, so they've certainly earned some time off."
Break
time in space
Discovery
launched toward the space station on March 15 and arrived last Tuesday to swap
out one member of the orbiting lab's crew and install the outpost's final
set of U.S. solar arrays. The mission was delayed a month by technical
concerns with the orbiter only to have its launch pushed back four days by a
gas leak.
The delays
cut a day and a spacewalk from the shuttle crew's already packed mission in
order to complete the construction before a Russian Soyuz ferrying carrying
more astronauts arrives later this week, so today's scheduled half-day off
should come as a welcome relief.
At least
one Discovery astronaut may spend his free time floating down the space version
of memory lane.
Shuttle
astronaut John Phillips is the lead space station robotic arm operator on
Discovery's crew, but he also spent six months living aboard the orbiting
laboratory in 2005.
"Who knows,
maybe I'll get to spend the night in the little cubby that I slept in while I was
there if no one's sleeping in it now," Phillips said before flight. "I want to
go try some of that good Russian space food in the galley, and maybe I'll run
on their treadmill."
Japanese
astronaut Koichi Wakata, who launched aboard Discovery to begin a three-month
mission at the station, is due to spend part of his day familiarizing himself
with his new orbital home, NASA officials said. Wakata is the first astronaut
from Japan to live aboard the station long-term and is replacing NASA
spaceflyer Sandra Magnus, who will return home aboard Discovery to complete her
own four-month mission.
Some of
Discovery's astronauts will discuss their flight so far with reporters on Earth
during a series of television interviews.
Later today,
the astronauts will conduct a full test of the station's urine recycler, which
appears to be in good working order after two days of repairs. On Friday,
astronauts replaced a broken
distillation assembly in the urine recycler, which spins like a centrifuge
to begin filtering urine back into drinking water. A day later they turned it
on while empty in a dry shakedown run.
"It sounded
really nice and quiet," Magnus said after the replacement. The old distillation
unit made loud vibrations when spinning until it broke down for good last
December.
The
station's urine processor is part of a larger system designed to collect
astronaut urine, sweat and condensation from the cabin atmosphere and filter it
through a seven-step process back into pure drinking water.
Alibaruho
said astronauts will fill the repaired urine processor with stored urine and
then begin the recycling process, which should take four or five hours. If the
device continues to operate well, water samples from the overall system will be
taken later in Discovery's flight to be returned to Earth.
NASA wants
to test the water samples and certify the station's water recycling system for
human consumption in order to help support larger, six-person crews at the
outpost later this year.
"Basically,
that unit is functioning normally," Alibaruho said.
Discovery
has passed the midpoint of its 13-day mission to the space station. The shuttle
is slated to undock from the orbiting lab and land on March 28.
SPACE.com
is providing continuous coverage of STS-119 with reporter Clara Moskowitz and
senior editor Tariq Malik in New York. Click here for mission updates
and SPACE.com's live NASA TV video feed.
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