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#126 2019-04-01 19:57:48

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 11,336

Re: Airplanes on Mars

for SpaceNut #125

Magnesium strips the oxygen away from the carbon, leaving carbon behind.  The text said the engine is being (has been?) redesigned to avoid coating the turbine blades with carbon. 

From https://en.m.wikipedia.org/wiki/Composition_of_Mars

Based on these data sources, scientists think that the most abundant chemical elements in the Martian crust, besides silicon and oxygen, are iron, magnesium, aluminum, calcium, and potassium. These elements are major components of the minerals comprising igneous rocks

The exhaust from an engine running on magnesium would (I would think) be on the sooty side.  The carbon would exhaust as soot, and magnesium oxide would (presumably) float for some time in the atmosphere as a fine powder. 

To my surprise, magnesium oxide is used on Earth for medical purposes:
https://www.rxlist.com/consumer_magnesi … dition.htm

Magnesium oxide is an over-the-counter mineral effective as treatment for

The article also reports that magnesium is needed for normal human health.

(th)

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#127 2019-04-02 20:23:13

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,971

Re: Airplanes on Mars

SpaceNut,

Thanks for the interesting find.  I learned something new today.  I'm going to read more about that.

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#128 2020-06-10 16:19:04

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,331

Re: Airplanes on Mars

Another good post to add into a topic where it fits...

kbd512 wrote:

tahanson43206,

The primary problem with wings on Mars is that the air density at Mars sea level ranges between the Earth-equivalent of 100,000 to 130,000 feet.  Look at the ratio between gravity and atmospheric pressure.  The atmospheric pressure and forward velocity will determine the actual lifting force and drag generated as you fly through the air for any given wing design.  Sure, Mars' gravitational pull is only 38% of Earth's gravity, but the air pressure at Mars sea level is 11.5 millibars vs Earth's 1,013 millibars.  Are you going to be flying or stalling and falling from any greater altitude?  That's like 1/88th of Earth's atmospheric pressure, which you only get at Mars sea level, so your wings are going to be truly huge (and therefore heavy) or you're going to be flying really fast when you land.  No airliner wings would generate sufficient lift at subsonic speeds to keep the generated lifting force at or above the mass of the airliner at the atmospheric pressure at Mars sea level.  So, you either have to have an enormous wing that must be incredibly light and stiff or you have to have quite a bit of velocity to stay airborne at any altitude while staying subsonic, or some combination of both.  Mach 1 on Mars is also significantly lower velocity than on Earth.

The U2 was basically a jet-powered glider, but at 70,000+ feet, even with its enormous wings, it was basically 11 mph away from either exceeding the wing's structural integrity and ripping the wings off or stalling / diving / then ripping the wings off.  Modern carbon fiber composites are much better than Aluminum when strength / stiffness / mass per unit area of wing are considered, but still not good enough.  The Airbus Perlan II glider can actually do what you're talking about, meaning stay aloft at altitudes above 100,000 feet.  Perlan II has a pressurized cockpit with just enough room for 2 pilots wearing flight suits.  That glider's Vne is 434 mph and I think it can stay aloft at a bit more than half that speed at 100,000 feet.  Landing something that delicate faster than the Space Shuttle would be VERY interesting.  If it was made from CNT and BNNT, then perhaps it could land at normal airliner landing speeds.

If you break Mach, you'll probably rip the wings off the glider, so the numbers shown in the link below are not mere suggestions for any prospective Mars glider designers:

Speed of Sound on Mars

Airbus paid for the Perlan Project, but Windward Performance fabricated the machine for them:

Windward Performance Perlan II

Perlan II has an 84 foot wingspan and weighs 1,800 pounds.  If it was made from CNT and BNNT, it could weigh less than half of that and most likely land about as fast as an airliner does, at Mars sea level.  I'd love to see how that thing is packaged behind a heat shield of some kind.  Your guess about how well that would work is as good as mine, but the wings would likely have to fold.  Still, it would be cool to actually "fly" rather than "fall" to the surface of Mars.  I think airliners are pretty much out of the question, though.  Airships are doable, but also huge for the payload lifted.

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#129 2021-04-27 20:19:31

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,331

Re: Airplanes on Mars

NASA is hoping to one day fly a plane or glider on Mars amid the ongoing success of the Ingenuity helicopter.BB1g6lHa.img?h=533&w=799&m=6&q=60&o=f&l=f


Meanwhile, the glider concept referred to by Berger is known as the Prandtl-M aircraft, or Preliminary Research Aerodynamic Design to Land on Mars.

NASA provided an update into the research of the Mars plane in June 2020, when Version 6.0 was built out of resin, fiberglass and carbon fiber. It was the second of three vehicles to be researched.

The glider, which had a wingspan of 13 inches, was dropped from a larger model plane from a height of more than 300 feet. Eventually all three models will be dropped from a weather balloon at a height of around 100,000 feet to simulate how they perform in the thin atmosphere of Mars.

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#130 2021-11-30 05:06:40

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 4,310

Re: Airplanes on Mars

Dramatic Video of Mars Helicopter’s Challenging Flight Captured by NASA’s Perseverance Rover
https://scitechdaily.com/dramatic-video … nce-rover/

NASA’s Mars Helicopter Could Revolutionize Off-Planet Exploration
https://futurism.com/nasa-mars-helicopter

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#131 2021-12-10 07:27:19

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 4,310

Re: Airplanes on Mars

A New Hydrogen Plane Can Fly Halfway Around the World Without Refueling

https://interestingengineering.com/the- … -emissions

NASA’s Mars Helicopter Ingenuity Still in Action

https://www.voanews.com/a/nasa-s-mars-h … 18907.html

New system will use drones to clean hard-to-reach solar panels

https://newatlas.com/drones/drone-solar-panel-cleaning/

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#132 2021-12-12 15:12:16

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,971

Re: Airplanes on Mars

Mars_B4_Moon,

A New Computer Model With Zero Actual Hardware Development Can Theoretically fly Halfway Around the World Without Refueling

That's exactly how the title of that article should read.

Whenever the very first prototype has completed its maiden flight, then it's an airplane, but not a moment before then.  Whether or not it will ever be practical to operate remains to be seen.  There are already high temperature solid oxide electrolysis fuel cells that run on kerosene and generate 3kW/kg to 5kW/kg that are more practical to operate, because they use existing Jet-A fuel and all the infrastructure built to supply kerosene.

At 5kW/kg, a 50MWe fuel cell would weigh 10,000kg.  The GE-90-115B generates around 110,000shp / 82MW of static thrust (zero forward velocity) and weighs 8,282kg.  The newer GE-9X weighs around 9,630kg and develops less thrust but a more efficient burn.  You have to add the weight of the electric turbofan engines to the 10t fuel cell weight.  The Wright "electric turbofan" is 10kW/kg, so 5,000kg, although 25kW/kg has been demonstrated by several electric aircraft motor manufacturers without superconductors or other nonsense, meaning straight Copper conductor and permanent magnets and Aluminum casings, so 2,000kg for 50MWe.  Your fuel economy savings over existing large turbofans is around 25%, because the thermodynamic efficiency of large state-of-the-art turbofans now sits at 50%.  The GE-90 generates about 1kWm (mechanical) from 2.5kWt (thermal).  The newer but very similar GE-9X is around 50% efficient, or 1kWm from 2kWt.

NASA's 3D Solid Oxide Fuel Cell is 2.5kW/kg and 7.5kW/L, but they have prototypes producing up to 3kW/kg and have indicated that 5kW/kg is feasible using the same tech.  More importantly, it's easy and fast to produce to nearly any dimensions and does not require Hydrogen reforming (think sheets of corrugated cardboard laid at 90 degrees, made from high temperature YSZ-laden ceramic metal) and operates at 1,400C (very hot).  That puts it 6,666.6L for 50MWe, or 235.43 cubic feet.  For comparison purposes, a single aux fuel tank inside Boeing's 747-400ER is 12,151L, and the 747-400ER carries 2 of those, in addition to the fuel in the wings and tail (I think they quit putting fuel in the tail for some reason, though).

By using a kerosene, you don't need thermal insulation over huge fuel tanks and your fuel economy improvement, say 20% after losses are taken into account, eliminates so much fuel mass that your fuel cell and electric turbofan arrangement is probably a wash, meaning the aircraft weighs and therefore performs almost exactly like a modern airliner, but burns 20% less fuel than GE-9X for equivalent performance.  On the downside, your aircraft is now carrying a pair of 10t very high temperature fuel cells (combustor can hot), but they're very compact and your fuel consumption reduction means smaller wings and less structural reinforcement are feasible, so less drag.

Long story short, you basically have a wash on weight, but a considerable volume reduction and induced drag reduction.  20% less fuel burn is also a staggering amount of jet fuel- 48 billion gallons vs 60 billion gallons per year.  20% of your fuel in a 747-400ER is 11,400 gallons, so your fuel cell volume is 324% offset.  The fuel capacity / volume that you give up by replacing said fuel tank volume with the fuel cell is more than 3X offset, and then you get a 20% fuel efficiency improvement on top of that, so the wings will be smaller, the drag will be a lot less as a result, and that's a virtuous circle in aircraft design.  Holding onto such hot fuel cells will require considerable insulation, so I would say that your volume offset is likely nearer to 300% and maybe a bit less than that.  Beyond that, you now have a lot of weight in the fuselage that the wings can't support to reduce spanwise bending loads, because putting large / hot fuel cells in the wings is impractical (not enough volume, or too much surface area and therefore heat loss- and those suckers need to remain hot to operate efficiently and cool down slowly after the flight to prevent cracking).

In any event, I think I've shown that this concept is technically feasible without invoking cryogenics, superconductors, or other Unobtanium materials, which drastically reduces fabrication and maintenance costs.  Maintenance is a critical aspect of airline services, and by eschewing highly reactive and explosive fuels (as good as that would be to have) / cryogenics / superconductors / other wildly impractical nonsense, we can save at least 20% on fuel per year through simple math, but even more than that after significant reductions in induced drag (drag from generating aerodynamic lift) is taken into consideration.  The "whiz-bang" of my take on this concept is strictly limited to high temperature ceramics and insulators, so that no other extreme technology is required.  The lightweight / high-output electric motors are increasingly mature technology, and all pilots who have flown behind such power plants indicate that they're as smooth as turbines and utterly reliable.  The use of cryogenics and superconductors and LH2 fuel is best left for the generation of airliners following the SOXE / SOFC generation- crawl / walk / run.

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#133 2022-06-26 08:52:20

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 4,310

Re: Airplanes on Mars

Mars Ingenuity Helicopter Earns its Developers the Collier Trophy
https://www.machinedesign.com/news/arti … ier-trophy

Hydrogen Can Become the New Aviation Fuel, As Mitsubishi and Hokkaido Want To Show
https://www.autoevolution.com/news/hydr … 91718.html

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#134 2022-06-26 09:59:19

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,070

Re: Airplanes on Mars

The Martian atmosphere is so thin that aircraft would need to travel at supersonic speed to generate sufficient lift.  Landing at those speeds would be highly dangerous.  However, the hyperloop would work better on Mars as vacuum is already available.  The track could be made from compressed stabilised dirt and rock with a steel cover.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#135 2022-07-02 15:07:28

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 4,310

Re: Airplanes on Mars

Engineers design motorless sailplane for Mars exploration

https://news.arizona.edu/story/engineer … xploration

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