Huge Martian dust storm may be killing NASA’s Opportunity rover

NASA’s solar-powered
Opportunity rover is trying to wait out a global dust storm on
Mars.

NASA/JPL-Caltech/Cornell
Univ./Arizona State Univ.

• A global dust storm has been raging on Mars
  since June.
• The Opportunity rover began
  hibernating on June 10th to wait out the storm, but it has yet
  to wake up and call NASA.
• If the robot can’t get enough sunlight, its batteries
  may brown out or lack the electricity to power
  heaters.
• Blistering cold on Mars can snap electronic circuits inside
  Opportunity if they aren’t warmed.

A
global dust storm on Mars is threatening the future of NASA’s
Opportunity rover, the longest-lived robot on that planet.

The golf-cart-size vehicle launched toward Mars in June 2003,
landed in January 2004, and was supposed to last three months.
Today, the rover
is 15 years old and has rolled more than a marathon’s worth
of miles across the surface of the red planet using solar power.

But Opportunity now seems to be in trouble.

Thanks to the long-lasting global dust storm, which has now raged
for nearly two months, Opportunity fell asleep on June 10 and
hasn’t phoned home.

Global dust storms appear once every couple of years and shroud
the planet in a
dull-red haze, but NASA said this is “one of the most
intense” ever recorded.

“This is the worst storm Opportunity has ever seen, and we’re
doing what we can, crossing our fingers, and hoping for the
best,” Steve Squyres, a planetary scientist at Cornell University
and leader of the rover mission, told A.J.S. Rayl for a recent
Planetary Society blog post.

Why the dust storm is endangering Opportunity

Mars
in 2001 as it typically appeared (left) and how the red planet
looked after a global dust storm appeared
(right).

NASA/JPL-Caltech/MSSS

The Martian weather event has not only blocked light to
Opportunity’s solar panels, but also coated them in fine dust.
This one-two punch has dramatically lowered the rover’s ability
to store and use electrical energy.

Cold is a big issue on Mars, where winter temperatures can drop
to -100 degrees Fahrenheit near the equator. Such cold can shrink
bits of metal in electronic circuits and snap them.

Little buttons of nuclear
material called
plutonium-238 help keep Opportunity’s circuitry warm, but the
stuff doesn’t last forever and is well-decayed — so it’s not hot
enough to fully protect the rover’s systems. This means
Opportunity still needs electricity to keep its battery charged,
run circuit-warming heaters, and talk to NASA mission control
back on Earth.

Draining the batteries too low is also problematic. The longer
they’re inactive, the more electrical storage capacity they lose.
If the storm doesn’t break soon, and Martian dust devils don’t
blow the dust off Opportunity’s solar panels, NASA says there’s a
possibility the batteries could “brown out,” or suddenly dip in
voltage.

If that happens, or the rover can’t recover a variety of “fault
modes,” Opportunity will join the ranks of Spirit — its nearly
identical sister rover.

Spirit stopped talking to NASA in March 2010, during a Martian
winter. Engineers tried to regain contact with Spirit for more
than a year before calling it quits. (Spirit is now presumably
another dead robot on the red planet.)

Now for the good news

Simulated
images show what NASA’s Opportunity rover saw as a global Martian
dust storm blotted out the sun in June 2018.

NASA/JPL-Caltech/TAMU

NASA said in an August 16th press release that
“there’s reason to be optimistic,” since the storm appears to be
weakening. This could mean enough sunlight may soon hit
Opportunity’s solar panels to charge up its batteries and phone
home.

The agency also said that the batteries were in “relatively good”
working condition before the storm, so “there’s not likely to be
too much degradation.” Dust storms also tend to warm up the
environment, so that will help buffer against circuit-busting
cold.

Opportunity is “not out of the woods” yet, though. A
representative at NASA told Business Insider there is “no update”
on the rover’s status, which means the agency has yet to hear
back.

This is one of the longest periods a solar-powered robot has ever
hibernated on Mars to conserve energy. Opportunity has already
pushed its engineered lifetime by a decade and a half — and it’s
not getting any younger.

“Even if engineers hear back from Opportunity, there’s a real
possibility the rover won’t be the same,” NASA said. “No one will
know how the rover is doing until it speaks.”