https://www.space.com/40570-nasa-sending-helicopter-to-mars.html

NASA will include a small, autonomous helicopter in the agency’s upcoming Mars 2020 rover mission, officials announced today (May 11).
The craft will undergo a 30-day test campaign once it reaches the Red Planet to demonstrate the viability of travel above the Martian surface with a heavier-than-air craft.

“NASA has a proud history of firsts,” NASA’s administrator, Jim Bridenstine, said in a statement. “The idea of a helicopter flying the skies of another planet is thrilling. The Mars Helicopter holds much promise for our future science, discovery and exploration missions to Mars.”

The Mars Helicopter’s development began in 2013 at NASA’s Jet Propulsion Laboratory (JPL) in California. It’s just under 4 lbs. (1.8 kilograms), and its body is about the size of a softball, NASA officials said in the statement. It will carry solar cells to charge up in the light of the sun and a heating mechanism to endure cold nights on the Red Planet.

The helicopter’s twin blades will whirl at about 10 times the rate of a helicopter’s blades on Earth — at 3,000 rpm — to stay aloft in Mars’ thin atmosphere.

Yes I noticed that a couple of days ago.
I presume they are testing it in their big vacuum chamber.
Of course they can do it all by calculation but there’s nothing like reality checks.

If it works, this encapsulates the speed of progress

Thomas Zurbuchen, the associate administrator for NASA’s Science Mission Directorate at the agency’s headquarters in Washington, D.C., said in the statement. “After the Wright Brothers proved 117 years ago that powered, sustained, and controlled flight was possible here on Earth, another group of American pioneers may prove the same can be done on another world.

dv said:

https://www.space.com/40570-nasa-sending-helicopter-to-mars.html

NASA will include a small, autonomous helicopter in the agency’s upcoming Mars 2020 rover mission, officials announced today (May 11).
The craft will undergo a 30-day test campaign once it reaches the Red Planet to demonstrate the viability of travel above the Martian surface with a heavier-than-air craft.

“NASA has a proud history of firsts,” NASA’s administrator, Jim Bridenstine, said in a statement. “The idea of a helicopter flying the skies of another planet is thrilling. The Mars Helicopter holds much promise for our future science, discovery and exploration missions to Mars.”

The Mars Helicopter’s development began in 2013 at NASA’s Jet Propulsion Laboratory (JPL) in California. It’s just under 4 lbs. (1.8 kilograms), and its body is about the size of a softball, NASA officials said in the statement. It will carry solar cells to charge up in the light of the sun and a heating mechanism to endure cold nights on the Red Planet.

The helicopter’s twin blades will whirl at about 10 times the rate of a helicopter’s blades on Earth — at 3,000 rpm — to stay aloft in Mars’ thin atmosphere.

10 times the speed is 100 times the lift (approximately). Mars atmosphere is a little under 1% of the density of Earth’s so lift is comparable. Also, the torque on the motor scales the same way so all one needs is a motor of similar torque to one on Earth. Totally feasible.

but …

The blade velocity is high supersonic, so there’s the vibration problem to sort out. It ought to make one hell of a racket. So not to be flown near populated areas LOL.

Interesting …. it’ll have a bit of vibration happening as the downwash from the upper rotor will hit the lower one two every revolution. Probably not a big deal though. If I was doing it, I’d have the rotor blades pressurised to inflate them to the desired shape. That would keep quite light & stiff.

Spiny Norman said:

Interesting …. it’ll have a bit of vibration happening as the downwash from the upper rotor will hit the lower one two every revolution. Probably not a big deal though. If I was doing it, I’d have the rotor blades pressurised to inflate them to the desired shape. That would keep quite light & stiff.

An inflated blade wouldn’t take the load. It would be about the same load as a helicopter blade on Earth. An aircraft wing may get away with being inflatable but not a helicopter blade …

Unless. ..

If the blade had a top and bottom strip of titanium and the inflation was there for prestressing, pushing the two strips apart. Would that work on Earth?

Handy Hint #67

Don’t watch a video of a snail eating a lizard while you are eating your dinner.

Dang….that’s twice in 2 days I have posted in the wrong thread.

What if they inflated the bag over the blade with the lightest gas ?

Could the rotor vibration be controlled by mag lev ?

Tau.Neutrino said:

What if they inflated the bag over the blade with the lightest gas ?

Create a chamber within the blade for the lightest gas.

Will it need an anchor device of some kind of its feet for landing to hold it in winds?

mollwollfumble said:

Spiny Norman said:

Interesting …. it’ll have a bit of vibration happening as the downwash from the upper rotor will hit the lower one two every revolution. Probably not a big deal though. If I was doing it, I’d have the rotor blades pressurised to inflate them to the desired shape. That would keep quite light & stiff.

An inflated blade wouldn’t take the load. It would be about the same load as a helicopter blade on Earth. An aircraft wing may get away with being inflatable but not a helicopter blade …

Unless. ..

If the blade had a top and bottom strip of titanium and the inflation was there for prestressing, pushing the two strips apart. Would that work on Earth?

I was thinking more along the lines of having a rigid spar (or two) and inflate the rest. I reckon the load will be a lot less as surface G is around 0.38 on Mars, so the load will be only 37% of what it is here. Also, if you spun the blades quickly enough the centrifugal force will keep them rigid enough.

Is it an issue at all, 3000rpm isn’t that high.

AwesomeO said:

Is it an issue at all, 3000rpm isn’t that high.

Aye laddie, but they wanted it to stay up.

Tau.Neutrino said:

Will it need an anchor device of some kind of its feet for landing to hold it in winds?

No. The low air density means the wind force is low. The wind speeds for high winds on Mars are about the same as on Earth, give or take a factor of two, so the load due to wind is less by a factor of 60 or so.

Tau.Neutrino said:

Could the rotor vibration be controlled by mag lev ?

Perhaps, but I wouldn’t like to be around when someone tries it. How would the vibrations be damped? By computer feedback of electromagnet strength?

Spiny Norman said:

I was thinking more along the lines of having a rigid spar (or two) and inflate the rest. I reckon the load will be a lot less as surface G is around 0.38 on Mars, so the load will be only 37% of what it is here. Also, if you spun the blades quickly enough the centrifugal force will keep them rigid enough.

OK. You have heaps more experience that I have when it comes to this. PS. I did once propose inflatable emergency stabilisers (like a rocket tail) for passenger aircraft, but that was only for, say 20 to 50% of the speed of sound.

AwesomeO said:

Is it an issue at all, 3000rpm isn’t that high.

I wonder what the Mach number would actually be.
The speed of sound on Mars is around 240 meters a second, a bit lower than the 340 meters a second on Earth.
What’s the diameter of these blades? Less than 1 metre. If that’s a standard cubesat in the animation then close to 0.6 metres.
That gives a tip speed of (0.6/2)*3000*2*pi/60 = 94 m/s.

Oops, I was totally wrong, this is flying way subsonic.
Oops oops oops. AwesomeO is right.
That’s much easier to arrange.

Could a Blimp fly on Mars?

Could a parachute be deployed above the rotors?

Could the parachute be hauled back in by slow rotation of the rotor or another motor?

Tau.Neutrino said:

Could a Blimp fly on Mars?

Yes on Mars, Venus and Titan.

Yes (hot air balloon) on Jupiter, Saturn, Uranus, Neptune.

Only with extreme difficulty if at all on Pluto, Io or Triton.

Tau.Neutrino said:

Could a parachute be deployed above the rotors?

Could the parachute be hauled back in by slow rotation of the rotor or another motor?

Do you want to try that on Earth first?

There are problems. One is the distance a parachute needs to drop before it opens. It is an interesting idea, though. Like a grappling hook without anything other than the air to hook on to. James Bond should be the first to try one out.

What about a powered glider instead of a helicopter

Cymek said:

What about a powered glider instead of a helicopter

Yes. That’s been proposed (with construction sketches) in the SciFi book “Long Mars” by Terry Pratchett and Stephen Baxter.

Here’s a Mars glider design from NASA.

and another Mars glider design from NASA

NASA’s Helios aircraft flew at an altitude comparable to that which would be required for flight at “ground level” on Mars.