Dust covering solar panels threatens to end InSight mission
The InSight science team has revealed that the amount of dust that presently covers the solar panels on the Mars lander has now reduced their available power by about 80%, and if a dust devil doesn’t soon blow the dust off they will have to shut the spacecraft down sometime in the next ten months.
“The dust accumulation on the solar arrays has been considerable. We have about 80% obscuration of the arrays,” said Bruce Banerdt, principal investigator for the InSight mission at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, according to SpaceNews.
Banerdt showed the impact of the declining power levels during a June 21 meeting of NASA’s Mars Exploration Program Analysis Group. When InSight landed near the Martian equator in November 2018, he said, the robot was generating roughly 5,000 watt-hours of power. Today that level is less than 700 watt-hours.
None of this is a surprise. Both the Opportunity and Spirit rovers faced the same problems. Both however were able to recover because periodically a dust devil would fly over the rover and clear the dust from the solar panels.
InSight however has not so far been lucky. While it has seen many nearby dust devils with its camera, none has come close enough to sweep the solar panels clean.
As the power has declined they have shut off various systems in order to keep the lander’s prime instrument, its seismometer, operating continuously. Engineers have also been using the scoop on the lander’s robot arm to try to dislodge some of the dust, with only a very very limited success. If the panels are not cleared soon, however, engineers will eventually be forced to shut everything down.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The InSight science team has revealed that the amount of dust that presently covers the solar panels on the Mars lander has now reduced their available power by about 80%, and if a dust devil doesn’t soon blow the dust off they will have to shut the spacecraft down sometime in the next ten months.
“The dust accumulation on the solar arrays has been considerable. We have about 80% obscuration of the arrays,” said Bruce Banerdt, principal investigator for the InSight mission at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, according to SpaceNews.
Banerdt showed the impact of the declining power levels during a June 21 meeting of NASA’s Mars Exploration Program Analysis Group. When InSight landed near the Martian equator in November 2018, he said, the robot was generating roughly 5,000 watt-hours of power. Today that level is less than 700 watt-hours.
None of this is a surprise. Both the Opportunity and Spirit rovers faced the same problems. Both however were able to recover because periodically a dust devil would fly over the rover and clear the dust from the solar panels.
InSight however has not so far been lucky. While it has seen many nearby dust devils with its camera, none has come close enough to sweep the solar panels clean.
As the power has declined they have shut off various systems in order to keep the lander’s prime instrument, its seismometer, operating continuously. Engineers have also been using the scoop on the lander’s robot arm to try to dislodge some of the dust, with only a very very limited success. If the panels are not cleared soon, however, engineers will eventually be forced to shut everything down.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
For over $800 million, you would think they could of spent the extra cash on a mechanical wiper or some sort of cloth or duster the robot arm could pick up and dust with. I know its a weight game but it seems silly to have an almost billion dollar instrument rely on a random gust of wind.
Perhaps all future rovers will have helicopters capable of hovering over the solar panels to blow away the dust.
watt-hours of power?
Seems they don’t know the difference between power and energy
Hi Kyle,
The nominal contract cost was only $500 million. Alas, the seismometer built by CNES turned out to have a flaw in its vacuum chamber, so it had to be sent back to France for repair, and that drove up the final bill to close to $800 million. (Should CNES have had to foot the bill for all cost overrages? I tend to think so, but that’s not how it was structured.)
But that aside, the fact remains that the solar panels *have* worked for a good deal longer than the original mission duration. Everything they are getting now is “bonus time.” NASA and JPL could rightly argue that it did what it was designed to do, and then some, so why risk capability creep (and thus, cost creep) by adding on a system for cleaning solar panels just to keep the probe going for far longer than its funded mission?
Still, it’s clear now that dust is an issue for solar panels on the Red Planet, and as tech improves and costs drop, it may be worthwhile at some point to add such a capability for longer term robotic missions, if it can be done for little additional cost or mass. Of course, for the manned settlement SpaceX plans to establish, you would already have the advantage of the most agile solar panel cleaners of all – humans!
I’m not an engineer by any stretch of the imagination, however:
I found an article stating the Insight solar panels provide 600 – 700 watts of power per day in full sunlight.
Just wondering: why not sacrifice a few experiment packages to make room for some sort of compact wind generator? It would be a light-weight windmill / wind-powered generator designed to take advantage of what appears to be fairly consistent Martian winds.
If I can buy a 600W (peak) DC12V wind generator kit from Wall Mart or Amazon at about 20 – 25 kg out of the box., why can’t NASA engineer a compact fold-up unit built with lightweight carbon-fiber materials and an ultra-lite powerful generator? Elon Musk would’ve done it!
I mean, if you’re spending over a billion dollars on a Martian probe only to have it die because its solar panels got a little dusty, why not spend a couple of million extra (or eliminate something else to save money and weight) and add a wind generator? Now our probes can keep on operating for many years, as long as there’s enough wind to periodically drive the wind generators long enough to bring the batteries up to full charge.
We Are Borg wondered: “why not sacrifice a few experiment packages to make room for some sort of compact wind generator?”
There are always tradeoffs and compromises in any engineering project. Sacrificing experiments for more power could negate the need for that additional power, as there would be fewer instruments competing for that power. In addition, for the same mission cost, less exploration would be done.
Keep in mind that the atmospheric density on the surface of Mars is a couple of orders of magnitude lower than on the surface of the Earth. A wind turbine that generates 600 Watts on Earth may generate closer to 10 Watts on Mars, so the scientists, engineers, managers, and other planners need to ponder the question of how many kilograms of experiments and instrumentation are worth the sacrifice in order to gain an extra 10 Watts (as long as the wind blows).
When proposing these kinds of missions, part of the planning includes mission duration. If Spirit and Opportunity are designed to for 90-day missions, then any additional time and exploration is a bonus, but can also be a problem, as additional mission time requires additional resources (e.g. people and computers on the ground, time used on the Deep Space Network radio dishes). To pay for these resources, the mission teams must justify mission extensions, and sometimes the decision makers say “no.”
The Viking landers were eventually shut down even though both landers continued to operate, even if as mere weather stations. At some point, the additional data is not worth the expenditure of the necessary resources, which become more important to spend on other, newer probes and satellites, whose data are more valuable than the data from the older ones.
Even the Voyager spacecraft are rarely contacted, despite their unique locations, because their data does not change much from day to day.