NASA is sending Helicopter to Mars , the numbers!!

originally posted by: Soylent Green Is People

originally posted by: rickymouse
If it doesn't work, it would not be the first time NASA made an expensive mistake. The thing about their mistakes is that someone else pays for them and they gain money for everything they do, even if it does not work. I am sure that they will make two and one will be stationed on earth somewhere where it looks like Mars.

I think they should push the envelope sometimes. Not with lives, but I don't really have a huge problem with them occasionally using cutting-edge technologies (rather than tried-and-true ones) if they do so in a semi-responsible manner.

I mean, I don't want them throwing taxpayer money at pie-in-the sky ideas that have a low probability of working, but pushing the boundaries, if done so carefully, is what I think a Government Agency (or government-adjacent agency) should be doing. They need to be cutting-edge because non-government companies are too risk averse due to their need to always be watching the bottom line.

Our government needs to watch their bottom line too, I don't think watching it got us twenty one trillion in debt.

Yeah the debt would be all those Wars the Republicans seem to always get a boner for... that and giving massive tax cuts for the most wealthy.

You know, if the Church paid tax in the US, you'd have enough money to cover NASAs budget about 2-3 times over very year... but... yeah cant tax the church! who else would tell people to vote for your favourite candidate

originally posted by: rickymouse

originally posted by: Soylent Green Is People

originally posted by: rickymouse
If it doesn't work, it would not be the first time NASA made an expensive mistake. The thing about their mistakes is that someone else pays for them and they gain money for everything they do, even if it does not work. I am sure that they will make two and one will be stationed on earth somewhere where it looks like Mars.

I think they should push the envelope sometimes. Not with lives, but I don't really have a huge problem with them occasionally using cutting-edge technologies (rather than tried-and-true ones) if they do so in a semi-responsible manner.

I mean, I don't want them throwing taxpayer money at pie-in-the sky ideas that have a low probability of working, but pushing the boundaries, if done so carefully, is what I think a Government Agency (or government-adjacent agency) should be doing. They need to be cutting-edge because non-government companies are too risk averse due to their need to always be watching the bottom line.

Our government needs to watch their bottom line too, I don't think watching it got us twenty one trillion in debt.

I agree with that in principle. That's why I said they need to push the technological envelope -- but do it responsibly.

Seriously, I think government should be the one who gets into cutting edge research an development on many different types of technologies, and then allow the public reap the benefits of that R&D through products private industries bring to market that are based off of that government R&D.

Technological advancements within our society would happen much more slowly if research was 100% based on making sure that there was always a direct link to a positive monetary Return on Investment.

originally posted by: Soylent Green Is People
Technological advancements within our society would happen much more slowly if research was 100% based on making sure that there was always a direct link to a positive monetary Return on Investment.

Ding ding ding... correct.... oh yeah, word to the wise, its already mostly that way aaaaand is only getting worse with time.

a reply to: neo96


Tp produce lift the rotors will have to spin at such speeds, they will break apart, unless they have lied about the density of the atmosphere. Taking off at twelve thousand feet in a plane on Earth can be arduous, or even on a hot day where the air is less dense . Something doesn't fit.

originally posted by: anonentity
a reply to: neo96

Tp produce lift the rotors will have to spin at such speeds, they will break apart, unless they have lied about the density of the atmosphere. Taking off at twelve thousand feet in a plane on Earth can be arduous, or even on a hot day where the air is less dense . Something doesn't fit.

Some turboprop airplane props can spin at 9000 or 10,000 RPMs -- 3 times faster that this Mars helicopter -- without breaking up. A small single-engine airplane (like a Cessna or Beechcraft) have a prop that normally spin at 3000 RPMs. A prop on a plane does not do the same job as the rotors on a helicopter, but the point is that 3000 RPMs will not create unbearable stresses on a rotor no larger than the size of an airplane propeller.


As for the Mars Copter:
The body of the Mars Helicopeter will be small and light (I read it would be the size of a softball or grapefruit). Since gravity is only 1/3 that of Earth, it would require less lift to operate than it would on Earth. That's why they claim a 3000 RPM rotor will suffice.

3000 RPMs is fast for a full-size helicopter rotor, which spins at about 500 RPMs, but 3000 RPMs is not really that fast for quad-copter drones and such -- in fact it's quite slow. Hobbyist quad-copter drones can spin at 25,000 RPMs or more without the rotors breaking apart (the no-load RMPs for the electric motors can be as high as 30,000 RPMs but the load of the spinning rotor slows that down).

Granted, one way a hobbyist's quad-copter keeps its rotors from failing is by having small rotor blades -- and due to the very smaller rotor size, several of them are needed to provide lift.

However, this Mars copter will have two rotors (counter-rotating and stacked, but still two) that are very large compared to a hobbyist quad-copter drone, so the total amount of airfoil cross-section is so much greater than the airfoil cross sections of all of a quad-copter drone's four rotors combined.

There are a few trade-offs (good and bad). The bad trade-off is that a large rotor will experience more centrifugal stresses than a small one, so it can't spin at 25,000 RPMs, or it might fail. That's probably one reason why they chose only 3000 RPMs. One good trade-off is that the air is thinner on Mars, so there is less air resistance to cause those stresses -- so the rotor is desgn to survive the 3000 RPMs. Add to it that the rotors will be a higher-tech material than you find at your hobby store

So Larger rotor = a greater airfoil cross section. And then (as I mentioned before), the gravity on Mars is 1/3 that of Earth, so less lift is required than would be required on earth for someting of the same mass. And then there''s the fact that the mass of the Mars copter will be kept at a minimum by making the body as small as possible, but still do the job -- and that job is to look ahead of the rover (such as to see "on the other side of the hill") to give drivers a better idea of where to go next.

a reply to: Soylent Green Is People


Yes but it still is virtually a vacuum, unless its got some special tech?

originally posted by: anonentity
a reply to: Soylent Green Is People


Yes but it still is virtually a vacuum, unless its got some special tech?

It's like Earth's atmosphere at 100,000 feet. The highest a helicopter can fly on Earth is about 40,000 feet.

That's why the Mars helicopter needs to be small and light and have the relatively large dual rotors that spin at high speeds (high for a helicopter).

In addition, the ratio of the total length of airfoil on the rotors (the total length of the surface that provides lift) relative to the weight will be much greater than a traditional helicopter or drone copter. And let's not forget that Mars' Gravity is 38% that od Earth's.

All that (relatively large rotors, high RPMs, light-weight body, lower gravity) means a greater lift-to-weight ratio compared to traditional helicopters or traditional drone copters.

And the atmosphere might be thin, but it is NOT non-existent. That matters a great deal. Mars' thin atmosphere is still thick enough to suspend dust during dust storms.

a reply to: Soylent Green Is People


It's the eternal thing on ATS it seems:

"Here is the science that explains how it works" vs "I don't understand how it works so I'm gonna call it fake".

a reply to: oldcarpy


Ok where is the test in a vacuum chamber , where the air has been expelled down to Martian levels, which will be in a plane on a parabolic curve which drops the gravity down to a third of earths?

a reply to: anonentity


You are probably asking to see something that does not exist. Why would they do this anyway? You can work these things out theoretically with math and science but anyway here is some more about this proposal:

Space.com