PASADENA, Calif. —
NASA's Phoenix Mars Lander is set to flex its robotic digging arm for the first
time after a one-day delay due to a communications glitch, mission scientists
said Wednesday.
Commands to deploy Phoenix's
scoop-tipped robotic arm were uploaded to the probe today, even as scientists pored
over the newest images of the spacecraft's Martian arctic landing site. The new
images were beamed to Earth Tuesday evening after the Mars Reconnaissance
Orbiter (MRO) switched
off its radio antenna earlier the same day for a still unknown reason.
Despite the
communication glitch though, Phoenix is doing just fine, mission scientists
said at a press briefing.
"The spacecraft is in
excellent health, absolutely excellent health," said Phoenix project manager
Barry Goldstein of NASA's Jet Propulsion Laboratory (JPL).
The craft landed in Vastitas
Borealis plains of Mars on Sunday evening to begin its $420-million mission to
dig into the rock-hard layers of water ice beneath the Martian soil of the
planet's arctic region. It is designed to test the soil and ice for signs that
the water was once liquid, and to see if it could have created a habitable
zone for microbial life at some point in the past.
Mission controllers
sent Phoenix its first instructions to move its robotic arm this morning. They plan
to unstow the arm in stages over the next two days. The arm contains four
joints: a "shoulder" joint that can move the entire arm up and down and from
side to side, an "elbow" joint that also moves up and down and a "wrist" joint
that moves the scoop on the end of the robotic arm.
The first step of
unstowing the arm, expected to occur this afternoon, involves moving the scoop
towards the arm with the wrist joint, which will release a spring-loaded pin
that kept the arm restrained during Phoenix's August launch and Sunday landing,
Goldstein said.
While it seems like a
minor movement, "it's actually a very critical activity," said Robert Bonitz,
the Phoenix robotic arm manger at JPL.
Mission scientists
hope to receive images of the arm's initial movements during their
downlink with NASA's Mars Odyssey orbiter late tonight.
Because of the MRO antenna
glitch, mission controllers are now using Odyssey to communicate with the
lander indefinitely. Scientists had planned to use both orbiters throughout the
mission, depending on which had a better communication angle during a
particular orbit.
"This is a contingency
that we've always planned for," Goldstein said. "As it stands, we're in fine
shape."
Goldstein said that digging
with the robotic arm is unlikely to start before early next week and that
the team is working slowly to make sure each stage is done correctly.
"If [digging] doesn't
get done in the early part of next week, please be patient with us, we are
going to do it," Goldstein said.
Phoenix sent more
images of the surrounding Martian terrain on Wednesday morning, including a
color image that it took as part of a back-up command sequence it used when it
failed to receive instructions from MRO on Tuesday morning.
The image adds to the
360-degree panorama scientists are building from the snapshots taken by Phoenix's
stereo camera. They expect a low-resolution, black-and-white panorama to be
completed today, with a higher-resolution, color panorama being completed in a
few weeks.
NASA's next Phoenix mission briefing will be broadcast live
on NASA TV at 2:00 p.m. EDT (1600 GMT) on Thursday, May 29. Click
here for SPACE.com's Phoenix mission coverage and
a link
to NASA TV.
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