Perseverance Mars Lander

[enf]

Supposed to land Friday morning.....

[Uncle Fester]

Already there, damn, time flies.

What I don't understand is why not drop a rover in this crater:

and drill an ice core to look for traces of life.
Who knows they might even find 'yellow snow' well preserved

[trash]

What I don't understand is why not drop a rover in this crater:

Because it's like dropping your Holden Commodore onto the North Pole with an Ozito cordless duct taped to the tow ball.

The first is, it ain't going anywhere. Ice is slippery.
and this is probably mostly dry ice and relatively hard like rock
and it will be as thick as polar ice caps
If you have't noticed, drilling into the surface of Mars is a bit of a failure.
Then there is just the simplistic statement - it's a crap place to find life or history of it from the surface.
Even if you did get there, how are you going to analyse the material you're going to drill up?

There are a couple of minor reasons I can also think of like, it's latitude makes it a slightly harder place to land from Earth.
Space exploration isn't like Star Trek where they land anywhere they like. Some places take a lot more energy and effort to get to than others.
Even the moon, landing at the poles is more difficult than an equatorial landing.

Space - Making simple things really hard since 1951

[Uncle Fester]

Because it's like dropping your Holden Commodore onto the North Pole with an Ozito cordless duct taped to the tow ball.

The first is, it ain't going anywhere. Ice is slippery.
and this is probably mostly dry ice and relatively hard like rock
and it will be as thick as polar ice caps
If you have't noticed, drilling into the surface of Mars is a bit of a failure.
Then there is just the simplistic statement - it's a crap place to find life or history of it from the surface.
Even if you did get there, how are you going to analyse the material you're going to drill up?

There are a couple of minor reasons I can also think of like, it's latitude makes it a slightly harder place to land from Earth.
Space exploration isn't like Star Trek where they land anywhere they like. Some places take a lot more energy and effort to get to than others.
Even the moon, landing at the poles is more difficult than an equatorial landing.

Space - Making simple things really hard since 1951

Dry ice is quite soft, I can crumble it with my hands.
It might even dampen a harder drop of that Commodore.
Dry ice isn't slippery as it does not melt but sublimes straight to gas.
There is likely also dust on the surface, so I am quite sure the rover CAN move around.
Drilling ice has an advantage over rock as it can melt with the friction of the core drill.
I am talking about microscopic volumes here.
Once the core is lifted up the water could melt and be examined remotely with a robotic microscope.
Just a few drops from a metre or two down, depending on the dry ice depth.
I am looking for traces of bacteria, algae and possibly multicellular plankton critters.

[Uncle Fester]

BTW I think it is time the stop sending these awkward rovers and just send a bunch of Boston Dynamics "Spots".

They can be constantly re-programmed to do all sorts of tasks, they are swift, highly accurate and skilful and compared to the rovers relatively cheap.
Can run around on rough terrain, even attempt climbing smaller rock formations and if they tip over they can right themselves up with the arm.
Digging with them is a breeze and they could move stones and stuff around and see what is underneath, or even construct something.
Also required is to drop a box with a battery, transceivers and solar panels to unfold so the Spots can go and charge themselves and also fetch and bring back all the tools and samples they need.
They can equip themselves with any sensor with you want using some standardised port and transmit/receive the data through box.
As said send a whole bunch, they don't weigh anything near that one ton rover.
Doesn't matter if one or two fail.

The drone is nice for reconnaissance(those Chinese could be anywhere) but you need decent workers on the ground.

[trash]

Dry ice is quite soft, I can crumble it with my hands.

Earth dry ice. Not Mars dry ice. There's just a slight difference there.

BTW I think it is time the stop sending these awkward rovers and just send a bunch of Boston Dynamics "Spots".

You forgot - power hungry. The advantage of a rover is power efficiency.
But in general, spot offers no advantages for Mars exploration.

[qoute]
Unlike what Trash claims, it sure got there but the lander crashed due to an engine failure in the last seconds before touchdown.
[/quote]
I didn't say it was impossible or it had not happened. It's just harder to land there and not because it has anything to do with landing sites.
It has everything to do with orbital mechanics and the energy required to just get to the landing phase.

If you approach mars equatorially, you can take advantage of Mars's orbital velocity and subtract that from your spacecraft's velocity for a fuel saving on an orbital insertion. If you try to do that in a polar orbit you do not have that saving so even the orbital approach has to be different which is another fuel consideration.
Of course you can go for a direct entry which is common, again it requires the right approach and burn. Once in the atmosphere everything is the same except for the approach speeds and angle but those are still able to be factored in. The cost is really about the fuel. Small lander it's not a lot of difference, but a big lander the cost goes up in multiples. At the end of the day they are already picking the low hanging fruit first for life anyway.

There must be an atmosphere on the moon,

There is an atmosphere but not a lot of it.
I can't remember the composition. Hydrogen and Helium make up most of it. Pressure is about 2e-12 torr which is what I call a "damn hard vacuum"
My pumps go down to 1e-7. Which "suck a balling ball through 10ft of garden hose" kind a vacuum.

However a bullet shot outside from a normal 0.22 calibre rifle aimed up at 30-45˚ angle could reach well over 100km range and easily hit a dome and pierce it or other random targets.

I'm kind of surprised it's not further than that, but I suppose it's just a .22. Have you crunched some numbers to see if it is correct?

I can't help myself, I have to crunch the numbers for fun anyway.
.22 is about 500m/s and Mars gravity about 3.7m/s/s. which means it's 135 to apogee if shot straight up.
s=ut+1/2at^2 == 500 - (0.5 * 3.7 * 135^2) = ~34km altitude.

For 45 degrees we use 354m/s. which gives us 95.5 seconds to apogee at 17km and 191 seconds flight time.
We'll ignore air friction. 191s x 354m = ~68km.

Turns out it's less. But that is an average .22 velocity I just picked.
Of course we can go magnum, hornet or my personal fave, wildcat

Now did somebody say spot?

[Uncle Fester]

You forgot - power hungry. The advantage of a rover is power efficiency.
But in general, spot offers no advantages for Mars exploration.

The rover only seems efficient because it is slow but it is also very heavy, so I will question the efficiency to work load ratio here.

Spot's base weighs 32.5kg (on Earth), lets say 50kg with arm and gun (to fire holes in the ice )
20 spots could do a hell of a lot more than a single rover and without having to be extremely careful before you consider even moving the rover a single meter. Pretty sure Spot can crawl out of small but unexpected deep craters that would bog or tip over the rover and losing a few spots won't really matter.

I did say we need to drop a power pack to charge the Spots, better in nuclear form especially for polar expeditions.
Spot (or two Spots) could also carry expansion battery packs with foldable solar panels to distant locations to increase the accessible range.
Essentially they would become the first inhabitants and workers.

Oh did I mention cost: 2.2Billion for the rover. Spot costs $74K, probably cheaper by the dozen. Plenty left for batteries, transceivers, mining tools, test equipment and drones.


EDIT: just when I was thinking about contacting JPL and Boston dynamics I did a duckduckgo search and :



I am always too late

Happened last time when I contacted them with a suggestion to install wipers on the solar panels of the Opportunity rover, kind of like those fine brushes you use to clean vinyl records that self clean themselves when they pass over an edge.
I was told the idea had merit but I had contacted them TOO LATE to allow for any further additions.
Opportunity DID fail likely due to dust eventually covering the panels but it lasted way longer than expected as the wind managed to keep them clean which was unexpected at that time.
Maybe with my wipers it could still be active today.

[trash]

Hang onto your hat Hink, we're going to keep you amused for a while yet.

The rover only seems efficient because it is slow

No, it's efficient because it has wheels. Wheels are way more efficient than legs.
Consider the energy used to walk compared to riding a bike which carries the extra overhead of the bike's weight.

but it is also very heavy, so I will question the efficiency to work load ratio here.

Did I say wheels? Overcoming the friction of the axel for a truck takes a lot less energy than moving a leg capable of supporting the same weight.
Hehe... you're pushing shit uphill with a pointy stick, if you put wheels on it..... it ain't going to look as weird as legs either.

20 spots could do a hell of a lot more than a single rover and without having to be extremely careful before you consider even moving the rover a single meter. Pretty sure Spot can crawl out of small but unexpected deep craters that would bog or tip over the rover and losing a few spots won't really matter.

I did say we need to drop a power pack to charge the Spots, better in nuclear form especially for polar expeditions.
Spot (or two Spots) could also carry expansion battery packs with foldable solar panels to distant locations to increase the accessible range.
Essentially they would become the first inhabitants and workers.

pull that spot over to the side of the Martian autobahn !

20 spots... Lets start at the bottom.
Perseverance produces ~110W/hr it uses about half of that

Spot uses 400W/hr four times what Perseverance produces. x 20 = 8kW/hr or 192kW/day consumption.
2000 times as much power.
Where do you think you're going to get that from? The sun? Lets do those numbers.
So a day on Mars is about the same as Earth, so you can assume that because there is no cloudy weather on Mars you'll get 5 hours of useful sunlight.
But the sun is 1/4 the brightness, so that means four times as many panels.

Spots have a run time of 90 minutes, and two hours to charge which means in 6 hours of useful sunlight you get two runs of 90 minutes.
600Whr capacity charge 2 hours = 300W per spot x 20 spots = 6000W of solar. x4 to compensate for Mars sunlight means you need 24kW of solar panels on the ground.
You know how those spots weigh 32kg each, their support panels alone weigh a tonne. Did you forget the cost of the fuel to get them into space and then onto the surface, then unpack them all and ..... I think you just engineered yourself into a corner.

Space is not easy. It's hard. Spot is deigned to work on Earth. In space he's a dead dog.
The first Martian dust storm and you have a lot of dead hardware not withstanding nasty wear and tear and no servicing. Spot is also not space hardend.

So lets to the mythbusters thing and see if we can't engineer the fuuk out of spot.
We're going to probably just go with a fission reactor. The three that jump to mind are RORsat, Topaz and SNAP. You might like to consider their electric power supply, their weight and the cost and factor that up and then work out how much to put it on Mars. Suddenly that "little" fission reactor is not so little.
And again you have to scale it for the task. And still, the range is limited to the proximity of the supply. 4kph with 45min range is 3km radius.
You just cannot plunk these things down like road flaps on Mars, even the small ones.

Oh did I mention cost: 2.2Billion for the rover. Spot costs $74K, probably cheaper by the dozen. Plenty left for batteries, transceivers, mining tools, test equipment and drones.

Lets say a nice round figure like $2.7 Billion USD. And it's srvice life design is 2 years.
I'm going to be lazy here because I already know the planetary society did a summary of this large spend.

EDIT: just when I was thinking about contacting JPL and Boston dynamics I did a duckduckgo search and :

Yes, that is a much more suitable task for them. What do you think it will cost to build a Mars Spot?
The speed of travel is an advantage and a disadvantage. That on the fly processing power comes at a cost.
The tradeoff will be between idle running power and continually moving in a race against time.

Exploring caves on Mars will be not unlike snorkeling on Earth. How long can you hold your breath and swim under water out and back coving as much distance as possible. You're going to want to see Boston Dynamics do this on earth first. Start from a location outside of the cave, charge, go in and come out , recharge and go back in. You might start to see this one dimension form of exploration is rather limited. You'd think a quad copter can do that job cheaper. $74k for spot and $300 buck for a drone. Oh hang on, then why do you think it cost $85 million for a Mars RC Helicopter?
Lets face it, you know as well as I do that $74k is gunna scale

At the end of the day you engineer the best solution possible for the task to be performed with constraints on cost, size and weight. And in space there are no second chances. Every action is you last chance. Spots will surely find an application, but exploring Mars, nope it's just not their gig.

Maybe with my wipers it could still be active today.

There are a few issues there. The first is you assume they will work. That's extra weight, power and point of failure.
You might imagine if a small rover is buried, wipers are not going to help. On a big rover, big panels you need big wipers.
But this is a game you can play at home. Buy yourself a solar cell and build a cleaning system powered by the solar cell so it can clean itself when you throw fine dirt on it. Amusing how impractical this is on Earth, now imagine those scaled costs for Mars. Limit your power by four and keep the weight to a minimum.
It might just be simpler to fold them up and hibernate.

Solar panels are cheap, simple, a little heavy, limited by sunlight and a bit clumsy in terms of spacecraft power supplies.
The bottom line is that wipers are probably just not practical.

As Rovers get bigger, so does their demand for power. RTG's are smaller, but low power with limited lifespans.
They behave a bit like pocket sized 24 hour solar panels. With batteries you bank the power budget to a point.

Fission reactors are heavier but offer more power but also need more shielding for their operation and are limited by their fuel.
Each has advantages and disadvantages. The Juno mission is a good example of where they weighed up these options and went with Solar for one reason more than others. There wasn't enough fuel available.

[Tiny]

Perseverance is not alone. China & UAE have missions arriving at the same time.



You can watch the landing of perseverance at

or at including schedule

[Uncle Fester]

Perseverance is not alone. China & UAE have missions arriving at the same time.

...hence my hint with the reconnaissance mission

The Chinese mission Tianwen-1 has basically the same objectives as Perseverance but it is not expected to 'persevere' that long

They both want to collect samples that are expected to be picked up and sent to Earth for analysis in 2030, IMO somewhat disappointing and makes my case for sampling and remotely analysing submersed water in craters even stronger. Not even drilling any more, just a thin tube with a heating element on it's tip that sucks up the water once it reaches it.

is expected to land where the lander did in 1976 !

Have we REALLY come that far since then?

The which is just an orbiter sent with a Japanese rocket, seems to me a bit more like a prestige and recognition thing.

[enf]

...hence my hint with the reconnaissance mission

The Chinese mission Tianwen-1 has basically the same objectives as Perseverance but it is not expected to 'persevere' that long

They both want to collect samples that are expected to be picked up and sent to Earth for analysis in 2030, IMO somewhat disappointing and makes my case for sampling and remotely analysing submersed water in craters even stronger. Not even drilling any more, just a thin tube with a heating element on it's tip that sucks up the water once it reaches it.

is expected to land where the lander did in 1976 !

Have we REALLY come that far since then?

The which is just an orbiter sent with a Japanese rocket, seems to me a bit more like a prestige and recognition thing.

Whilst I agree with the ideas, the engineering challenges are immense. If you keep adding more and more then you never get an orbiter/lander.

An engineer wants to land on a safe space. A research scientist wants to land on the side of a mountain or in a narrow valley. Compromise is necessary to achieve something.

[Uncle Fester]

An engineer wants to land on a safe space. A research scientist wants to land on the side of a mountain or in a narrow valley. Compromise is necessary to achieve something.

Ha ha, yes, I am an engineer but I always had to listen and do what my bread giver wants.
None or very little compromise, otherwise they would go to somebody else.

The only polar mission to Mars I could find is here:


Unlike what Trash claims, it sure got there but the lander crashed due to an engine failure in the last seconds before touchdown.

From this I could not find any more polar missions or plans for such in the future, which IMO is not clever thinking.

Life can not be found on Mars due to lack of an Ozone layer and consequently high levels of UV radiation leading to strong peroxides and perchlorate all over Mars, except maybe on the poles, particularly in shaded craters where very little UV light exists.
Any form of life could have sustained much longer there or even still exist in microbial form.

I would focus ALL missions on the poles.

Searching anywhere else for life is just a waste of time/resources/money.

Planing for colonisation is not, but then again that would also be better done near such craters for so many reasons that go far beyond the scope of this thread.

[RogerTheDoger]

Helicopter flights on Mars.
see

[lsemmens]

This bit got me

Ingenuity, a four-pound helicopter, will attempt the first ever flight in another planet’s atmosphere when it reaches Mars.

I would have thought that "The Eagle" was the first ever flight, ok, technically, it was on a moon....but! Or did Neil Armstrong and "Buzz" Aldrin just jump back onto the command module. Hey! I've just had a thought, maybe NASA have just slipped up and have finally admitted that those conspiracy nutters who say we never went to the moon are right, after all......

[Uncle Fester]

This bit got me
I would have thought that "The Eagle" was the first ever flight, ok, technically, it was on a moon....but! Or did Neil Armstrong and "Buzz" Aldrin just jump back onto the command module. Hey! I've just had a thought, maybe NASA have just slipped up and have finally admitted that those conspiracy nutters who say we never went to the moon are right, after all......

The moon is considered NOT to have an atmosphere.

A drone or helicopter or anything depending on wings could not fly there.

[lsemmens]

Aww c'mon Fester, never let facts get in the way of a good story!

[enf]

NASA releases HD video of the landing......

[hinekadon]

buzz aldrin had wings so do rockets and butterflys and jet planes ?so we cant plant anything on the moon as theres no bees to pollinate them -so how did the cow jump over it then now you are gunna tell me theres no easter bunny arent you , Ive seen a photo of santa flying past the moon so you must be wrong and otherwise it was a waste of time going to kindy cos the teachers are liars
bet your too chicken to tell the teachers that they made me sit in the corner when i tried !!!

[Uncle Fester]

buzz aldrin had wings so do rockets and butterflys and jet planes ?so we cant plant anything on the moon as theres no bees to pollinate them -so how did the cow jump over it then now you are gunna tell me theres no easter bunny arent you , Ive seen a photo of santa flying past the moon so you must be wrong and otherwise it was a waste of time going to kindy cos the teachers are liars
bet your too chicken to tell the teachers that they made me sit in the corner when i tried !!!

A rocket has no wings. They provide no lift. I do not consider the V1 and cruise missiles as rockets.
Those fins shift the centre of pressure towards the tail while the rocket stage is still in Earths atmosphere, totally useless on the moon and not very useful in the low pressure atmosphere of Mars.

Hmm... never been to kindy.
Can't even remember being in a school before year 3.
My first memories are building Daleks with egg cartons and the ubiquitous toilet plunger and collecting black powder from dud firecrackers and trying to build rockets with that and taking everything apart I could get my grubby hands on.
I also don't remember experiencing pain when my dad whipped me with his belt which was not because of my 'experiments' and breaking everything but because I didn't play the clarinet properly.
On the contrary he bought me a Jetex PAA loader, which I still own today. Unfortunately the cost of the solid fuel pellets was prohibitive for a 9-10 y/o back then.

So it seems we have experienced a different kind of education.

Oh yeah and I did see Santa when we were on a ship, he had my dad's slippers on.

Anyhow before MTV 'explodes' today we could all hear in the news, for the first time ever, the sound of another planet that DOES have an Atmosphere!

.

[hinekadon]

Now that means that cruise missiles are a waste on the moon cos they cant steer them to the target ? so where do they go? lol and theres no birds on the moon as well, so where/how do the moon angels get around ?