Mars Insight Lander on it’s last watts

[LeeG]

Too dusty on the solar panels.

https://www.space.com/nasa-insight-m...-weeks-to-live

The end is nigh for NASA's marsquake hunter.

So much dust is choking off the solar power supply to NASA's InSight lander that the Mars mission, which is operating well past its expiration date, is expected to fall silent very soon.

"The spacecraft’s power generation continues to decline as windblown dust on its solar panels thickens, so the team has taken steps to continue as long as possible with what power remains," NASA officials wrote in an update. "The end is expected to come in the next few weeks."

[Decourcy]

You’d think they would have thought about wipers…..

[L.W. Baxter]

elon has already offered a solution: squeegee with a really long handle

[ron ll]

The Martian Renault Dauphine?

[LeeG]

Mission was two years so four isn’t bad. I was disapointed about it’s hammer probe not being able to dig into the ground.

[Gerarddm]

#2: Not an outlandish thought. With all the experience we have now with Martian landers, you'd think that might be a viable option. How hard could it be? Wipers, or even a directed fan?

[Boatbum]

You’d think they would have thought about wipers…..

I think the issue is that during dust storms they still need power to keep the unit from freezing, They can reduce drain by shutting down all but the essential systems, but the issue remains that there won't be enough power left after the dust storm ends to power a wiper unit. At least that is my take on it.

[Jimmy W]

Fly that heli over to hover over it and blow off the dust.

[ron ll]

Don’t know why NASA just doesn’t ask us.

[CWSmith]

You’d think they would have thought about wipers…..

I don't think they expected it to last this long.

NASA builds for mission lifetime and then gets obsessive over testing. They consistently fall short when they could include larger fuel tanks and such. The logic can be difficult to understand.

[Decourcy]

Get the damn thing to shake like a wet dog!

[Keith Wilson]

NASA builds for mission lifetime and then gets obsessive over testing. They consistently fall short when they could include larger fuel tanks and such. The logic can be difficult to understand.

Obsessive testing is a very good idea when the thing is going to be 140 million miles from a repair technician. 'Consistently fall short'? The thing was designed for two years and it's lasted twice as long. Spirit and Opportunity were designed for 90 days and the first went for five years, the latter fifteen years. Perseverance is still going after four years. If that's 'falling short', give me more of it.

OTOH, figuring out some way to get the dust off the solar panels would indeed be a good idea.

[Breakaway]

Perhaps determine the polarity of the charge of the dust particles and then charge the solar panels with the same polarity?
I realize is would cost some amps, but perhaps less than the loss due to dust coverage.

Kevin

[CWSmith]

OTOH, figuring out some way to get the dust off the solar panels would indeed be a good idea.

This is what I meant by falling short.

I've spent 40 years working with teams building spacecraft and analyzing the data. I've seen a lot of working spacecraft die because they ran out of fuel.

Think about what the James Webb cost and now think about the fact that it dies when it runs out of coolant in five years. That's what I'm talking about.

[Boatbum]

Obsessive testing is a very good idea when the thing is going to be 140 million miles from a repair technician. 'Consistently fall short'? The thing was designed for two years and it's lasted twice as long. Spirit and Opportunity were designed for 90 days and the first went for five years, the latter fifteen years. Perseverance is still going after four years. If that's 'falling short', give me more of it.

OTOH, figuring out some way to get the dust off the solar panels would indeed be a good idea.

It turns out Martian wind does a pretty good job of that. It puts dust on and later takes it off. The problem occurs when the dust storm (like to one in 2018) lasts too long the batteries cannot keep the unit from freezing long enough to endure the storm. So after the storm is over, even if the panels are clear of dust, it is dead. They need to build a rover that can go completely dormant - full freeze and no power drain. Maybe it just powers on once a month to see if the panels are clear enough to power up all the systems. If not, back to sleep for another month.

[Bob Adams]

This is what I meant by falling short.

I've spent 40 years working with teams building spacecraft and analyzing the data. I've seen a lot of working spacecraft die because they ran out of fuel.

Think about what the James Webb cost and now think about the fact that it dies when it runs out of coolant in five years. That's what I'm talking about.

This is where having the Hubble serviceable by the shuttles was so wonderful. (yes I know the Webb lies outside of the orbital capabilities of the shuttles)

[Rapelapente]

My cent for next time: make the panel vibrate with a sort of buzzer when it's windy.
Cheap, light, few amps to have it running.
Trying to join the Woodenboat Forum NASA team

[LeeG]

I think the issue is that during dust storms they still need power to keep the unit from freezing, They can reduce drain by shutting down all but the essential systems, but the issue remains that there won't be enough power left after the dust storm ends to power a wiper unit. At least that is my take on it.

I was surprised to learn that the Mars helicopter Ingenuity uses 2/3 of it’s battery capacity just staying warm.

[AndyG]

Furthest maille ("chainmail") from Earth!

(The bottom of the seismometer cover).

Andy

[CWSmith]

I was surprised to learn that the Mars helicopter Ingenuity uses 2/3 of it’s battery capacity just staying warm.

The Ulysses spacecraft went into power sharing mode at the end of its life where only some of the instruments were turned on at any given time. Eventually, it could not keep itself from freezing and that was the end.

The funny thing is that the plasma that Ulysses was immersed in has a temperature of about 50,000 degrees Kelvin (Centigrade). There just isn't enough of it to actually hold the heat energy required to keep the spacecraft warm. Ten protons per cubic centimeter don't contain a lot of energy even if the energy per ion is high.

[robm]

The problem is, there is no such thing as "full freeze with no power drain". Even when dormant, there will be a few nanoamps (femtoamps?) of current required to keep whatever alarm clock running that will wake it up to see if the solar panel is clear. And I am not sure how well electronics work at -100 deg. F. That is well outside the rated range even for MIL-SPEC components, assuming they still make any.

I wonder that they don't make the charging circuit passive. If the panel is clear, the battery will charge, and eventually wake up the microprocessor.

[LeeG]

The problem is, there is no such thing as "full freeze with no power drain". Even when dormant, there will be a few nanoamps (femtoamps?) of current required to keep whatever alarm clock running that will wake it up to see if the solar panel is clear. And I am not sure how well electronics work at -100 deg. F. That is well outside the rated range even for MIL-SPEC components, assuming they still make any.

I wonder that they don't make the charging circuit passive. If the panel is clear, the battery will charge, and eventually wake up the microprocessor.

I imagine there must be a lot of research in making devices that can operate outside our happy zone of temps.

[AndyG]

I imagine there must be a lot of research in making devices that can operate outside our happy zone of temps.

Sure is. (Venus surface temperature electronics: building processors that would work in a kiln).

Andy

[robm]

I wouldn't say "a lot". -50 deg. C is about as low as they go, and +125, in commercial electronics. The old MIL_SPEC stuff was about the same, but was often found to be complete crap if actually tested. And it cost hundreds of times as much as commercial grade. That stuff that is rated for Venus is going to cost in the millions by the time they have a complete controller built - just for the parts, not counting development.

[CWSmith]

Most NASA components are designed to work at room temperature. Then the blankets and heaters are designed to keep their temperature in that range. James Webb is interesting because it is actually designed to run VERY cool.

[LeeG]

outerspace is not a friendly place.