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#1 2014-07-31 14:45:09

Void
Member
Registered: 2011-12-29
Posts: 6,975

One Piece Roton Crash Landers Without Bearings.

I am thinking that the whole device would spin on its way down.  For a heat shield, I might be at a loss, but the blades to a degree could provide surface area, and dissipate heat.  Perhaps critical areas would be coated with an ablative material.

Looking a bit like this:   _____________    <---Rotor
                                         |
                                         |
                                         |               <---Shaft
                                         |
                                         0               <---Payload

No Bearing.

The payload could be of a material desired such as copper, formed into a crushable sponge to absorb some of the impact.

Building up rotational speed as it falls, and as the atmosphere thickens becoming more effective in slowing the rate of fall.

Perhaps at the altitude just before impact some small rockets fire to increase spin, or perhaps in a more conventional manner to fire from the Payload/Shaft in a downward direction.

A sensor that determines when that rocket action occurs.  Possibly triggered by air pressure, or some other instrumentation.
The thing would not be easy to steer to a chosen location.

At some point duing the development of infrastructure when critical materials are needed but hard to obtain this might be useful.

Some of the structures, such as the blades might be hard to recycle into useful purposes, but the intention would be to have as much of the device serve a further purpose as possible.

01-August-2014:

I have thought of a possible steering mechanism.  Helicopter blades build up a static charge.

So if you had a conductive electrical drain path at about the center of each blade, and used some type of electronics to discharge the charge on a blade as it pointed in a certain direction of the compass, it might draw the whole device towards or away (I don't know).  I am thinking of SCR's, with electronic control, but the switching action would have to be very fast.

The drain for the charge could be the payload and shaft perhaps, but I don't know how well that would work.  Maybe some kind of hot cathode discharging into passing atmospheric molecules?

Anyway, maybe.

If there were a possibility that that could work, then the lander would have an on board electrical power source while it was dropping through the atmosphere.  (I hope)

I don't know what the gyroscopic effects would be either.   I don't know that it would be worthwhile to keep the impact soft.  Maybe a good wack on impact would be preferred, as it would help dissassemble the device.  Maybe the blades could be so constructed that they would bend and break at a preferred location and fly off away from the device.

Last edited by Void (2014-08-01 08:33:12)


Done.

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#2 2014-08-01 15:59:44

JoshNH4H
Member
From: Pullman, WA
Registered: 2007-07-15
Posts: 2,538
Website

Re: One Piece Roton Crash Landers Without Bearings.

What is gained by having the entry craft spin?  What payload would be able to handle these impacts that couldn't be obtained, more cost-effectively, by surface mining?


-Josh

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#3 2014-08-01 16:42:40

Void
Member
Registered: 2011-12-29
Posts: 6,975

Re: One Piece Roton Crash Landers Without Bearings.

Thats a fair question.

Yes, if a needed material can be obtained in an easier fashion, why do it?

I am only think of steps.

In step1, I presume that needed cargo is delivered to the first humans on Mars before they land, and after they land as needed.  If the device I described could be competitive with already planned methds, then use it.

In step 2, I would presume that the landing site would have been choosen for access to materials needed, but more than likely would not have the full spectrum of useful materials availible in a form that could be used at that level of industrial developement.  So, I choose Copper, but it may be that the landing site would have that mineral, but I am betting it won't have it in a form that is easily converted to useful metal, not unlil the infrastrucure has been better developed.  If not Copper, maybe Gold or Silver, rare Earth metals or something else.  So, economics would determine it.  If you had the material and the tools, and the labor force (Ability to manipulate a raw material into a finished material), then absolutely why do the roton thing?  But I have heard talk of hard landers before for certain materials, here is a hard lander (Maybe), and maybe it would work better than other designs for hard landers.

In step 3, the infrastructure would be built up sufficiently that such devices would seldom or never be used again.

But you are right to question it.  I am only proposing a supposed machine that might be a useful tool.  There is no proof yet that it is a useful or preferred tool.


Done.

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#4 2014-08-03 13:08:56

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: One Piece Roton Crash Landers Without Bearings.

This sort of thing might work on Earth where the air is thick.  Are you proposing this for Mars?  The air there is too thin for a fixed-wing aircraft to be practical.  Why would rotary-wing be any different?

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#5 2014-08-03 17:41:35

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,781
Website

Re: One Piece Roton Crash Landers Without Bearings.

I had considered something similar for Earth. For asteroid mining. The objective was to ensure the spacecraft was reused, not expended. So the entry vehicle had to be made of materials found on an asteroid. And simple enough to be made with left-overs from mining/refining the asteroid, and manufactured by unattended automated equipment. What I had considered was inconel heat shield, because NASA had identified inconel 617 for a metal heat shield. And shaped as a maple tree seed. That would auto-rotate, a single shaped vehicle with no moving parts that would act as helicopter.

Then Genesis had a problem: JPL used a traditional aeroshell (heat shield + back shell), with parachute. A helicopter was supposed to use a hook to grab the parachute while still in the air. But someone installed the accelerometer up-side-down. The computer got negative acceleration data, so never deployed the parachute. The helicopter crew watched helpless while the aeroshell passed them and crashed into the ground. The aeroshell split open, but JPL was able to recover usable samples. Most people consider this a failure, but I consider this to be a successful demonstration for asteroid mining. We don't need a maple seed shaped entry vehicle. A simple aeroshell is enough. And we don't need thrusters or parachute, just heat shield and back shell. Let it crash into a desert somewhere. A flat bed truck with a truck crane can pull it out of the ground.

The point is you don't need anything as complicated as a roton. If crash landing is good enough, then just use an aeroshell.

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#6 2014-08-03 19:53:08

Void
Member
Registered: 2011-12-29
Posts: 6,975

Re: One Piece Roton Crash Landers Without Bearings.

Hi guys, didn't notice your posts until now.

All right, I left myself some loopholes.  I did mention a possible rocket thruster added to the mix,  I was thinking a solid one that would ignite just before landing and keep the impact materials from becoming unrecoverable or contaminated by mixing with soil too much.  But I would prefer to find a hard lander method that would leave a recoverable/valuable material on the ground to retrieve.

Robert could be right, that is a complex machine, and I do have trouble figuring out what the rotors could be reused for.  Still I will not abandon it entirely, I will just like to hear more of alternate ideas.  My understanding would be that the rotors would act like a parachute.  I understand the parachutes are quite expensive.  I was hoping the rotors could be mass produced.  Actually, I was hoping that they could also be the heat shield to a degree.

I know I am out of your league both of you.  But if you dropped a spider from a high altitude on Earth, it can survive because of the surface area, the air drag being a large component of its character relative to it's mass.  If you dropped it on Mars it would splat, but if you felt a splattered spider was useful to you it would be available for recovery.

The flying saucer ballute thing just tested is also a potential variation.

I have seen ideas about landers that would be like sheets of paper.

Roberts idea might be best though.  I would like to get a low cost delivery of a needed solid state material  (No liquids or gasses).

I think this would be valuable during certain phases of development.

I have also thought of impacting the edges of dunes ice filled or not ice filled.  An angular impact.  However that requires extreme precision I think, and it might scatter the materials delivered too much.  I have also thought about a little bomb that fluidizes the ground before the device impacts (The bomb hits the surface first), so then you would
have a splash-down, but might get it burried too deep.  If it was a shallow deposit of sand on top of bedrock maybe that would be OK, but then you have to prep the site, and again your accuracy has to be very high.

If your stuff does splatter, perhaps a crater with walls would help.

The roton is rather complex I admit.  It was fun to think through it.


Done.

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