[meteorite-list] Spirit Mars Rover Reaches Hills, Opportunity Goes Deep

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Jun 14 19:24:52 2004
Message-ID: <200406142313.QAA00974_at_zagami.jpl.nasa.gov>

http://www.space.com/missionlaunches/rovers_update_040613.html

Spirit Mars Rover Reaches Hills, Opportunity Goes Deep
By Leonard David
space.com
13 June 2004

The Spirit and Opportunity rovers have each entered a new stage of
exploration on Mars.

For Spirit, the robot has pulled up at the base of the Columbia Hills,
following a record-setting trek across the landscape of Gusev Crater.
Meanwhile, on the other side of the planet at Meridiani Planum, the
Opportunity rover is studying science-rich targets within the sloping
walls of the large impact crater dubbed Endurance.

Both Spirit and Opportunity are in good health. Engineers at the Jet
Propulsion Laboratory (JPL) in Pasadena, California -- home base for
rover mission control -- are now plotting strategies to have the
machines "winter over" on Mars in a few months, picking up rover duties
later in the year.

The hills are alive

"We have arrived," said Mark Adler, Spirit mission manager at JPL, as
the robot reached its destination. Spirit has wheeled across Gusev
Crater some two miles distance from its original landing zone in January.

"We're there. We're at the hills now and already see new things there
that we haven't seen before," Adler told SPACE.com. At what is called
West Spur, the rover is being steered slightly up the hill to inspect
various targets, he said, including one rock labeled "Pot of Gold".

Scientists are eager to scour the area for evidence of possible ancient
water activity.

The long-term plan for Spirit is to drive south, along the base of the
Columbia Hills to a spot labeled "Lookout Point" -- about 50 feet (15
meters) up the feature. At that location, Spirit will have a
tourist-like panoramic view, even grabbing camera shots of what's behind
the hills for signs of layering.

Drive-in viewing

At the Endurance Crater at Meridiani Planum -- a stadium-sized hole in
the martian surface -- Opportunity is purring along, carefully making
its way down the steep crater wall.

While some wheel slippage is being seen as expected, Adler added: "We'll
be able to dive in and drive out of the crater - no problem."

After wheeling over the crater's rim, Opportunity drove about 20 feet (6
meters) before stopping at a rock. That feature is being studied to
contrast its geological makeup with data accumulated at Eagle Crater,
acquired by the robot where it first landed.

At Eagle Crater the rover found small-scale rock textures and evaporite
mineral compositions, showing that a body of salty water covered the
site long ago.

Rock layers deep within Endurance are thicker and older than those
inspected at the shallow Eagle Crater - the main scientific temptation
for dispatching Opportunity to wheel inside the feature. By scrutinizing
deeper rock layers, the environment of an earlier Mars could be revealed.

Step at a time

>From its current position, Opportunity is to continue its drive about 10
feet (3 meters) deeper into Endurance Crater, arriving at a pre-selected
primary science target by Tuesday.

"Of course, the scientists are already looking past that," Adler said.
"If they want us to keep going, we'll evaluate if it's safe and the
slopes are good, and the rocks are still providing the kind of traction
that we need," he stated.

Adler said that Opportunity's robotic arm, tipped with science sensors
and a Rock Abrasion Tool (RAT), is evaluating the terrain the robot is
about to drive upon. "We take it a step at a time - feeling out in front
of us with the arm as we go down deeper into the crater."

Depending on what the roving Mars machine finds and observes within
Endurance Crater, "we'll stay there as long as it takes to get the
science we want - if we can do it safely," Adler said.

Starting over again

Adler said the Mars robots are performing well.

"Just in the past couple of days, both Opportunity and Spirit arrived at
new places with new things to do. It's like their missions are starting
over again," Adler said.

JPL robot experts are keeping an eye on a wheel motor on Spirit. Higher
currents in that motor suggest friction is at work. "We're starting to
take some actions and see what we can do about that," Adler said.

Around mid-September, the rovers will face minimum energy from a Sun low
on the martian horizon. Sunlight is needed to power the robots through
solar cell-laden wings mounted on each mobile spacecraft.

Robot handlers are scripting a plan for the rovers to "winter over" on
Mars. "Somewhere around late August or so - we may want to get the rovers
into a position where we'll maximize their solar energy," Adler said.
"That means rolling them onto slopes, rocks, or hills such that the
solar panels are tilted towards the north, where the Sun is at that time."

By angling rover solar panels toward the north through September and
October, the robots are expected to be up and operating by late October
or November, Adler said.
Received on Mon 14 Jun 2004 07:13:34 PM PDT