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Posted: Thu Mar 10, 2011 7:31 am
by John Hunt
Egress

Based upon Joe's 3D rendering of the lander, I am imaging that the Prospecting Lander would essentially be a box with high-set rockets and legs & feet. As I understand it, inside would be small Scouts and a larger Rover with a digging arm and on-board assay equipment. (correct me if I am wrong).

Given this arrangement, I am imagining that egress of the Rover and Scouts would be that a door of the box would drop open and become a ramp. Then the Scouts and Rovers would disconnect a latch which secures them to the box, and one-by one roll off onto the lunar surface.

Is this basically how egress would work?

I am imagining that the Main Rover (with a digging arm and assay equipment) and several small Scouts (with small superficial "pincher" scoops underneath them) would travel together along the ridge of the crater looking for the safest way down. As they make their way into the crater, they leave tracks which will become trusted paths.

If one of them gets stuck, any of the other rovers would be able to help the other get unstuck by bumping it or perhaps the Main Rover would be able to use its arm to push a Scout around.

I am also imagining that the different rovers would be able to connect with each other electrically in order to transfer charge. Especially this would be true from the Main Rover to the Scouts. Perhaps this could be done with a magnetic connector such as Macintosh laptops use. If so, then my suggestion is that these connectors be as high up on the equipment so as to minimize the amount of dust that gets on them, or perhaps better, that they be covered unless they are transferring charge.

They travel in a group. I am imaging three Scouts and the Main Rover. The Scouts would be in front of the Main Rover with one straight ahead of the Main Rover and the other two in front but to the Right and the Left about 10 feet from the Central Scout. If one gets stuck, then the others don't have to travel very far to help unstick it. I think that the Main Rover would assist only as a last resort. If any of the Scouts come upon a rock they would prefer to go around it if possible.

If any experience low radio connectikon with the Lander, all would immediately begin retracing their steps and seek an alternate path which would continuously maintain radio contact.

The Main Rover initially remains in the sun while the three Scouts travel in a line creating trusted paths.

The Scouts sample superficial regolith and bring it back to the Main Rover where the sample is transferred to the scoop of the Main Rover for assay. The Scouts are recharged by the Main Rover. They then travel back into the shadow exploring other areas and conducting superficial sampling.

If the Scout sampling yields favorable results, then maybe they could travel along the shadow's edge and sample other areas.

After the initial exploration just inside of the shadowed areas, the Main Rover and Scouts (when fully charged) could enter the shadowed areas along a previously scouted (and trusted) path.

At the stopping point, the Main Rover uses a digging arm to sample sub-surface regolith for assay. If sub-surface assays are much richer in ice than superficial samples, then, perhaps, the Scouts might stop conducting superficial samples unless there is a correlation between superficial and sub-surface samples.

The Main Rover (led by the Scouts) would probe deeper and in more varied parts of the shadow until it was running (not frighteningly) low on charge. It would then drive back to the sun for a full recharge.

This process of sampling areas would continue until malfunctions terminated the entire operation.

Posted: Thu Mar 10, 2011 6:15 pm
by joertexas
The cargo box will have two hinged sides that will drop down to act as ramps. I've also considered having the box attached to the lander with explosive bolts so it can be dropped if the lander gets into trouble. That way, the cargo box has a chance of surviving a crash. i don't know if this is a viable option, though. Also, the cargo box will have spring loaded outriggers to help keep it upright on landing. Again, given the mass involved, I don't know if this idea is viable, either.

A communications rover will also be included. This rover is about four times the size of the scouts, and carries a more powerful tranceiver that can link with the lander, the orbiter, or even earth directly. The comms rover would position itself to maintain radio contact witih the other vehicles, acting as a relay station.

Also, a portable solar panel array will be deployed by the backhoe, probably on the hill north-northwest of the landing site. This array would have recharging jacks for the vehicles, and would have to be manually repositioned from time to time to follow the sun. We could also consider a turntable arrangement, but the payload mass limits may not support it.

JR

Posted: Thu Mar 10, 2011 10:30 pm
by John Hunt
How many Scouts?

Posted: Fri Mar 11, 2011 5:28 pm
by joertexas
[quote=""JohnHunt""]How many Scouts?[/quote]

I hope we can take at least three. The jury is still out on the final cargo capacity - I'm still running test flights in Orbiter. There isn't a lot of room for error...

JR

Illumination at the landing site

Posted: Sat Mar 17, 2012 6:21 pm
by joertexas
The question came up about using equipment from the lander during ground operations. The answer points to a larger issue - how much sunlight is available in the area.

relevant data:

http://www.space.com/957-perfect-spot-moon-base.html

http://www.youtube.com/watch?v=45lfRi7wtDA

http://lroc.sese.asu.edu/news/uploads/n ... _thumb.png

http://target.lroc.asu.edu/da/qmap.html - select Orthographic north pole projection here. If you click and drag on the image, it will reference the NAC images that cover the area. Pick the Right NAC camera, because the left camera's images are backwards.

The issue is, we have to land close to the permanently sunlight areas, and maintain direct line of sight to Earth for communications (especially because the rovers have to be teleoperated), and be as close as possible to places where water ice may exist. To top it off, we need a very smooth and obstruction free place for the lander to set down.

Therefore, I picked 89.55N 30W as the landing spot. The problem is, the lander can't move after it touches down, and it will lose sight of the sun after a while. Of course, we will pick the most advantageous time of the lunar year, but it does limit the mission's operating timeframe.

Thoughts?

JR

so where is everything located?

Posted: Sat Mar 17, 2012 10:38 pm
by Engineer
Do you have a mock up concept of the rover's and colar trailer's position on the lander? I'd like to know how its all laud out and what angle you're going to be going down the ramps at.
:cool:

Posted: Sat Mar 17, 2012 11:24 pm
by joertexas
[quote=""Engineer817""]Do you have a mock up concept of the rover's and colar trailer's position on the lander? I'd like to know how its all laud out and what angle you're going to be going down the ramps at.
:cool: [/quote]

I have 3D models of the ground equipment - except for the small rovers. The cargo box is 2m x 3m x 1.5m tall. Everything has to fit in there. I'll generate some additional pics and post them.

JR

Posted: Sun Mar 18, 2012 6:41 pm
by joertexas
Here's a horribly basic pic of the lander with the cargo ramps deployed. As you can see, my models need help :eek:

JR

Posted: Sun Mar 18, 2012 10:53 pm
by Engineer
Its not exactly what I was looking for. I'm wondering how every thing is going to be placed on the lander. how are the small scouts going to be deployed, will they be stacked on the main rover? what about the solar trailer? knowing the layout is going to help a lot
:cool:

Posted: Mon Mar 19, 2012 3:27 am
by joertexas
[quote=""Engineer817""]Its not exactly what I was looking for. I'm wondering how every thing is going to be placed on the lander. how are the small scouts going to be deployed, will they be stacked on the main rover? what about the solar trailer? knowing the layout is going to help a lot
:cool: [/quote]

The cargo box is 3m long by 2.5m wide by 1.5m tall, with a 2.5m by 1.5m ramp door in each end. The backhoe fits in a 2.5m wide by 2m long space by lifting the blade and folding the backhoe arm.

The solar panel trailer fits into a 1.8m wide by 1m long by 1.5m tall space behind the backhoe.

The scout rovers and the comms rover sit nose to tail on the floor on each side of the solar panels trailer. Each scout rover is 320mm x 254mm x 156mm, and the comms rover is 597mm x 387mm x 380mm. Everthing is arranged so it can drive off the cargo box floor.

JR