Meadville Space Center

Orbiter Mars Direct => Planning => Topic started by: Iceversaka on November 29, 2005, 12:09:44 AM



Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Iceversaka on November 29, 2005, 12:09:44 AM
Here I would like to discuss concepts and ideas for the Mars Truck, as deployed from the SP-100 Nuclear Reactor.

I was thinking of redesigning the Mars Truck around this type of basic concept:
(http://www.orbitersimlandsat.com/images/traverse2.jpg)

This was the only way I could think of to carry the 3.5 ton SP-100 with a 1000 lb robot truck.

And yet deploy it upside down in a 10ft deep depression in the ground 500m to 1km away from the ERV across rough terrain.

Now we need to develop a self digging robot that can dig a 10 ft deep inverted conical depression in the sand.

I had the idea of using a bowl shaped platter with flattened edges and little servo gates on the rim. The bowl would jiggle into the sand collecting sand. Then extend upward and spin up. The gates would drop and the sand spins out in all directions radially, but not downward.

It repeats the process over and over again. The sand will fall inward creating the desired conical depression, eventually reaching the target depth ideal for the deployment of the SP-100.

The only problem I had with this concept was how to power the self digging robot. Solar panels won't work because it will be too deep, and sand is going to be all over.

The only other alternative I could come up with was to use the truck to deploy the digger, and turn the SP-100 reactor on, and attach a cable to the digger to power it. The cable would just follow with the digger as it drops deeper into it's own hole.

So the SP-100 would just be sitting on the forks of the front loader, powered up. Maybe we could safe it before dropping it into the inverted conical depression in the sand. Side ramping arms would extend outward and downward into the walls of that sand walled depression to hold the reactor in the center. Tarp covers along those legs could extend around the circumfrance to protect the base of the reactor from accumlating wind blown sand.

Diagrams and pictorals to come later.

Any thoughts? Questions?

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Urwumpe on November 30, 2005, 05:46:10 PM
i would suggest a simpler mechanic, like it gets used for some junk trucks here.

(http://www.ihlenberg.de/media/bilder/container_lkw2.jpg)

(http://www.transporte-neuwirth.at/bilder/Bilder/bild20.jpg)

This would of course make the truck only capable for moving special containers with its arm, but i think that is a fair price for a simpler mechanic system. Also such a arm could also be reused for later rovers, eg for transporting heavy equipment in containers.

For making the reactor drop upside down into a hole, i would suggest letting the reactor get grappled at its bottom, rotate it by 90 using a not reuseable deployment system (a small lever or swing-arm) on the ERV and deploy the arm on the rover completly (~160 from stored position) to insert the reactor into the hole.

Of course, this assumes that we can grapple the reactor without a fork lift - which should be possible if the reactor is positioned low enough and the rovers cargo platform is positioned high enough (ground clearance should push the design to a rather high cargo platform)

About digging a hole - how high are the chances that it would be possible to create a almost fitting depression by igniting a high explosive charge a few m below the surface? Drilling 2m is done even at solar power in acceptable times, and a explosion would create a more or less conical depression if the underground is not to hard. I think i can assume that the depression is not done in rocky underground?

Of course, this is a very "male" (can also be translated as "OH NO!") way of digging a hole, but as space flight is full of exploding devices - why not think about it?


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Warm Icepack on November 30, 2005, 06:23:31 PM
Quote from: Urwumpe

About digging a hole - how high are the chances that it would be possible to create a almost fitting depression by igniting a high explosive charge a few m below the surface? Drilling 2m is done even at solar power in acceptable times, and a explosion would create a more or less conical depression if the underground is not to hard. I think i can assume that the depression is not done in rocky underground?

Of course, this is a very "male" (can also be translated as "OH NO!") way of digging a hole, but as space flight is full of exploding devices - why not think about it?


Its entirely possible to rig a shaped charge, and this wins the award for fastest and most fun for the autonomous rover/pyrtotechnic guys.
And if the first one doesn't work? Throw a second one!

THe only problem is it won't create the most precise hole in the world. But that might be good enough.


Title: EXCELLENT!
Post by: Iceversaka on November 30, 2005, 08:32:21 PM
EXCELLENT IDEAS!!!

Thanks guys for the feedback!

I love the back-loader idea, works out even better than I thought it would. And the Chassis will be easier to fold, and maintain strength after the truck is deployed.

And I agree with the basic ideas of design for the truck.

Also the Shaped charge should work out good enough. Just need to make sure it's sandy. I think that will work best rather than deal with the danger of collapsing walls and other debrie after or during deployment.

Last thing we want it to have the Mars truck fall into a hole in the ground with a badly deployed nuclear reactor.
 :lol:

Seth


Title: Re: EXCELLENT!
Post by: Urwumpe on December 01, 2005, 02:33:02 AM
Quote from: Iceversaka
EXCELLENT IDEAS!!!
Also the Shaped charge should work out good enough. Just need to make sure it's sandy. I think that will work best rather than deal with the danger of collapsing walls and other debrie after or during deployment.

Last thing we want it to have the Mars truck fall into a hole in the ground with a badly deployed nuclear reactor.
 :lol:



Well, with a shaped charge, we still have to look carefully at the hole before we can place the reactor there, but i think waiting a few hours until the mission control can give its OK is not a high price. Still less risk as having the only digger close to the hole and have it changing the underground below it.

The underground could get analysed by seismometers close to the ERV or in the rover for finding the best spot to make the depression. A seismometer package is already making sense for surface science on the ERV, and if the ERV has one, the rover only needs something to "hammer" on the ground.

What would also still be needed is some kind of bulldozer tool to cover the reactor in soil after its placed in the hole for stabilizing it - correct me if i am wrong, but i think the soil cools the reactor better as the thin athmosphere around it. And as the hole would be far away from perfect, covering the reactor with soil could improve its stability better than having some strange leg and strut constructions to do the same job.

And of course we need something else... Its already very painful on earth: We have to make sure that the bulldozer does NOT cut the power cable while working. ;)


Title: Burried Reactor
Post by: Iceversaka on December 06, 2005, 06:29:17 PM
Agreed, this is a much better idea!

I'm also in favor of a blade of some kind. I'm just not sure if it can be included in the first ERV.

I suppose if we all agree to include a plow of some kind then I'll be sure it gets in there.

Something that also needs to be decided soon.

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Urwumpe on December 07, 2005, 02:23:01 PM
Well, i would say, we should try to reduce the mass of specialized tools on the Rover. I would prefer using one (or even two, like the SPDM of the ISS) general purpose manipulator arm(s) on the rover, which is powerful enough for some simple digging action (it does not need to dig the whole hole) and which can also be used for some finer tasks, like laying cables or connecting adapters.

By using multiple tools for the end effector, this arm can be adapted to the various tasks.

Also, not all tools need to be contained in the rover, with such a arm, it would be possible to swap tools between ERV and a toolbox on the rover.

The arm could eg use a drill tool to dig a 2m hole into the surface, place a shaped charge into the hole and after the explosion, use a bagger tool to trim the hole to the fitting dimensions and later help covering the reactor with soil. Such a arm could also use a special plow tool for laying the power cable.

The main problem i see is, that this arm needs to reach deep enough for getting to most locations inside the nominal reactor depression without needing the rover to change its position (which often one of the most dangerous maneuvers for manned baggers - i have seen lots of such events myself, where a bagger dropped into the hole because the earth started moving under him)

Something like a blade needs to be a special tool, i don't see a away to stick this on a RMA.

Also i think that the payload handling should be a job for a special system, which has much more power, but is not as dextrous as the arm used for digging. maybe its possible to use the payload handling "arm" for some course digging action, too. But i just can't think of a scenario and a fitting tool - maybe removing heavy stones.

Also interesting would be the question for me (as it has impact on the position of such a dextrous general purpose arm), if the rover can be used for exploration and science for months after the ERV has landed by reloading its power cells with power from the reactor.  For doing this, it could use the arm for plugging / unplugging a power cable into the ERV (not the reactor itself - i would prefer keeping it buried and untouched)

Also, the unmanned rover could still be useful after the Hab landed - for assisting during EVAs or do some simple jobs, which don't justify an EVA. Or it could get towed by the manned pressurized rover during long range missions and carry science equipment, which does not fit on the manned rover.

After all, the rover is lots of expensive landed mass on mars - using it only for a few hours is possible, but not appreciated.  As long as the rover is still functioning, it should be possible to use it.


Title: Mars Truck Options
Post by: Iceversaka on December 07, 2005, 06:31:54 PM
Well I consider this a truck, not a rover. Though I suppose the terms are slightly interchangeable in this case.
 8)

I can see a number of different scenarios for the lifting mechanism.

1) lifting and deploying the reactor from the truck bed horizonal position to the vertical in the hole. This is it's primary purpose.

2) We could put the whole assembly in the middle of two girders as part of the flat-bed frame, that would allow the main hydrolic, with a little extra motion control to swing vertical, and apply a drill bit on one end to drill straight down, and install the shape charge under ground where it will be most effective.

3) Swing it back to the horizontal and drop is slightly below the frame, add two more pistons under the frame, and we can attach a single smart plow. One that can function like a traditional plow for dragging through the soil and making trenches. Straighten the blades and you have a plow that can be used to grade the surface, thus make roads, or act as a earth-mover....err mars-mover.
 :lol:

There you have your trencher, can still push sand and rocks around fill-in the hole around the reactor, burry the cable, ect...

Nice thing about this plan is the plow will fold up and fit in the bay, should save enough weight that we can still include the semi-flat bed adapter and manned assembly rack; unpressurized mind you, and it all works out with just one multi-purpose and multi-functional chassis, minimum modifications and should still fit in the mass specs, barely...I hope!

How does that sound?

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: aftercolumbia on December 08, 2005, 05:58:08 PM
I think I found the sucker:

http://www.bobcat.com/products/pdf/T140.ctl.pdf

Careful...it's 4MB...I don't know why.

On the reactor...it'd be a bit of a drag...literally, but we might be able to get a little trailer for it.


Title: Folding Plow
Post by: Iceversaka on December 08, 2005, 07:59:54 PM
Are you refering to the folding plow? or the Front loader?

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Warm Icepack on December 09, 2005, 06:36:29 PM
Quote from: aftercolumbia

On the reactor...it'd be a bit of a drag...literally, but we might be able to get a little trailer for it.

 :D
I'm not sure there's any easy way to do the reactor deployment with a single vehicle. I also wonder how a trailer will function in overly sandy or rocky terrain.


Title: Trailer
Post by: Iceversaka on December 09, 2005, 08:48:08 PM
Why would we want to add more vehicals to an already complicated plan?

Keep it simple. The only reason I made the suggestion of the extra features is because we can make them work with only small modifications to the system.

Just a little tweeking and we get like 3 or 4 extra VERY useful features.

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Warm Icepack on January 11, 2006, 01:01:03 AM
Why not just give the reactor wheels and its own motor?

Digger vehicle makes hole, reactor rolls straight in, gets covered in sand, pumps power into ERV.


Title: SP-100 Digger
Post by: Iceversaka on January 11, 2006, 06:24:04 AM
Would be a good idea, except there isn't enough space in the bay for the wheels, suspension system, and drive motor and the reactor. We barely have enough room for the reactor and a spool of cable.

Unless you can fold a half ton truck capable of carrying the multi-ton SP-100 into half a cubic meter.

That one bay, after the reactor and spool are in, has enough space for wheels the size of a go-cart golf cart. And a suspension system about the same size. If you install the truck next to the reactor, you have a bit more space. Maybe the size of the current MER rovers, hardly enough to carry the reactor for half a kilometer or more through sandy rocky martian terrain while dragging a cable.

But the other bay has the space of a small appartment room and about 1.5 meters high, tiped on the side. Plenty enough to fold up a half ton truck that just might be able to carry the SP-100, barely!

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: aftercolumbia on January 27, 2006, 06:46:35 PM
I thought that the wheels sat astride reactor on the trailer (beside, not underneath, like a wedge/invertible BMW fighting robot.  With rocker-bogie type suspension, the motors would be inside the wheels, and the body would be jacked up after deployment.  If the vehicle is wedge shaped, (fitting both the bay and the cone shape of the reactor), the "rear" wheels would be astride the reactor, the "front" wheels astride the heat sink near the outside door.

One thing that we must bear in mind is that the reactor can't be activated prior to deployment for plenty of reasons...neutron traffic in the ERV would be a nightmare and with LH2 deuterium and normal hydrogen potentially moderating the reaction and affecting criticality...that would be bad.  The beryllium oxide poison plug needs to be removed first (we wouldn't be able to fly without it because range safety and environmentalists would freak, not to mention myself.)

One thing is that we really don't need a hole in the ground for it.  We'd find a scientifically uninteresting area and deploy it there.  One thing is that we'd probably pick a really boring landing site, unlike MER and MSL for the simple reason that we have ten times as much mobility on foot as a robotic rover.  Our speeds are in kilometres per hour rather than kilometres per week, we can go quite a ways to an interesting spot (our mission exploration area would probably exceed that of the MER landing probability ellipse.)  If we selected a landing site near a scientifically interesting area, and put the wacky terrain outside the landing zone, to drive to it later, even the Elysium site, which the MER investigative team utterly     d, would become exciting.

Unless the landing is a disaster, we don't need a cross country trailer and deployment vehicle.

Seth, I don't know what your asking "front loader" or "folding plow", because both could describe a bobcat.  Also, this computer is a piece of  :!: :!: :!: :!:  and won't download the file.  The bobcat is a little one man vehicle with big wheels for its size and a low stature.  The tool is held on two arms astride the cabin, which is entered and exited through the front.  It can carry a plow bucket, forks, or, I hope, a jig that's hooked up to our reactor so we can drag it out by the vehicle rolling backwards.


Title: Hey Terry
Post by: Iceversaka on January 30, 2006, 11:38:20 PM
Hey Terry,

Sorry I haven't responded sooner.

I think the idea Dennis had was the best one to go with.

There are several reasons the truck cannot go in the same bay as the reactor.

1. It would add greater unbalance to the ERV.
2. It would reduce the flexability of the truck to act in another manner for the crew and the goals of exploration and/or construction when they arrive.
3. It would mean the truck is smaller and we would have to eliminate the plow/blade idea.

My responses are off the top of my head and I haven't really taken the time to build my arguments because real life is getting in the way again.

I'll try and respond more later.

Seth


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Warm Icepack on February 07, 2006, 11:10:31 PM
if not a full fledged drivetrain, can the reactor at least be given some wheels? I say this because I think the lift and carry to the site may be a problem.
I am also somewhat hesitant to suggest this, given I have helped hook a jeep to the back of a motor home. It is a pain-in-the-arse process to link two vehicles together, and requires several lurching stop-start-reverse adjustments typical of a new driver learning to parallell park.

However, would this not be a better option, to back the reactor-trailer thing into a hole in the ground, then shovel sand over it as opposed to lifting a multi-ton reactor with a light truck (the embarassment if the truck flipped over on mars), placing said reactor on truck, lifting off and placing in hole with the same truck.

All of this makes me lean towards the shaped charge idea again...

EDIT: on reflection wheels would still present the massive suspension problem. Back to square one then...


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: aftercolumbia on March 16, 2006, 05:04:59 PM
From Orbiter and I-war experience, and watching so many truck drivers dock their trailers, I can attest to the fact it would be easier to do this on the ground than on orbit, and most other plans rely on orbital docking over Mars.

Also, burying the reactor is problematic, as its proper operation depends on being able to reject waste heat.  It should be possible to run it in the open during the high powered propellant production phase, and then bury it after, when a smaller amount of power is needed  There is an environmental thing too.  If it is buried under Martian dirt, there is more Martian dirt to absorb neutrons and become radioactive.  With the reactor unburied, many of those will radiate into space, or at least into the sky, where if absorbed, the isotopes so produced would be scattered all over the planet in a much more diffuse and safer manner.  Carbon and oxygen radioactive isotopes are much less dangerous than the ones from iron...and there is a lot of iron in that dirt too.


Title: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: Iceversaka on March 16, 2006, 05:19:52 PM
Quote from: Warm Icepack

EDIT: on reflection wheels would still present the massive suspension problem. Back to square one then...


Not only that, but there really is no room in the reactor bay for anything else.

It's already tight around the reactor housing. Don't forget there is also a 1km spool of high capicty wire in that bay as well.

Terry, I don't know where you are getting the idea of orbital docking over Mars....this really has nothing to do with the truck at all.

I think it would be possible to run the reactor on the surface. It would have to be laid on its side, and rolled to an orientation, or have the pointy nose of the thing lifted off the ground so the radiators could be attached. A small folding tublar assembly should do this effectively.

I might not run quite as effecient for long term nuclear fuel use, but then again its only for ERV fuel production. And it doubles as a on-flight verifiction phase as well, prior to burring.

So this sounds good to me.
Then a small drill and shape charge should do the trick.

I think we have ourselfs a viable plan at this point.

Any objections?
Seth


Title: Re: Mars ERV Truck (SP-100 Deployment Ideas)
Post by: aftercolumbia on July 20, 2006, 04:45:27 PM
Terry, I don't know where you are getting the idea of orbital docking over Mars....this really has nothing to do with the truck at all.

 :awwcrap4253: :Duh!39835: :yuck4543: :ziplip543: :what343: I'm never going to figure out how this happens so frequently...I was comparing docking trucks with docking spacecraft...not suggesting it.