Hypography X Prize Entry

[TheBigDog]

that would be awsome!

but wouldnt that divert from what we are trying to do?

Yeah, not something I plan on doing with our current effort, unless that becomes a mission requirement.:)

 

Bill

[Jay-qu]

Lots of cool ideas been thrown around, thats great to see :) but there is a little misunderstanding going.

 

Pyro I think you where under the impression that we would be trying to beam energy from earth to the moon with a MASER setup - I think the idea was to have the lander collect solar energy and then beam it out to the rovers.

 

Kayra, the wavelength doesnt increase over distance, nor need it. You need a bigger antenna at larger distances because of the inverse square law - the further you get from the MASER the less energy will reach you per square meter, ie the energy 'spreads' out. Increasing the size of the antenna is one way to counteract this.

 

While all these ideas are great, I think they are outside the requirements. If the rovers are equipped with the best batteries we can give them, whose to say that they will need a recharge before they can fulfill the requirements? If it does they I would suggest supplementing the power requirements with solar. Whether the panels be on the rovers themselves or on the lander (supplied to the rovers via some recharge mechanism) would depend on how much of an issue dust is. Obviously it would be simplest to have the solar on the rovers, this also reduces the chance of failure if the rover can operate independently of the lander.

[Roadam]

Well maybe someone misunderstood me. I was suggersting a method for refilling the rover if it comes back to "base" without the need for moving parts which comes with dust hazzard.

There are ceritainly quite a few posibillities to consider. Do we want a self sufficient rover or not? If not, there is an option for long range transmition of energy where line of sight is important, and "back to base" option which possibly limits the range of a rover.

There is also a question concerning how much goals we want to complete and whether the batteries alone could supply enough electricity.

How much power would one rover even need to drive over lunar terrain?

And one more thing: big wheels also mean that there isnt much space for solar panels.

[Jay-qu]

. If the rovers are equipped with the best batteries we can give them, whose to say that they will need a recharge before they can fulfill the requirements?

 

A laptop battery with a 30-year lifespan | SCI FI Tech for Tuesday, October 02, 2007 | SCIFI.COM

 

with things like this around the corner, why not?

 

EDIT:well I read around about this, and apparently its not around the corner, but purely theoretical on this scale :confused: I found a few primary articles touting they had achieved a few nano-watts of power.. not very useful!

[GAHD]

Doesn't the inverse square law only apply to fields, and not coherent beams? divergence in minimal in a directed beam...

 

EDIT:finally! Commercial nuclear batteries! I want those for my future house...and car.

[Jay-qu]

right you are GAHD, the tricky part would then be aiming it precisely while the rover is moving. A buffer would need to be included so that it doesnt continually lose power if the beam is aim slightly wrong. This also introduces more moving parts (even worse for multiple rover setup) - and its no longer off the shelf tech..

[GAHD]

buffer= battery

moving parts could be limited to optics, which in theory could be fluid (soon to be OTS)

[Jay-qu]

how well does conventional optics work with focusing and directing microwaves?

[TheBigDog]

The rover could always sit still during recharge. If we can recharge in line of sight then we vastly increase the area we can explore, or we can reduce the range of the rover on a single charge reducing the mass of batteries. How difficult would it be to mock up and test a solar powered mazer recharger? What range should we shoot for? Would 100 meters be sufficient, or do we want to shoot to the horizon on the moon? How far is the horizon from 2 meters?

 

Bill

[freeztar]

While I think the Mazer idea is classy, I also think it's too much (more stuff to potentially go wrong, more weight, etc.). Wouldn't dust be an issue with this also?

[CraigD]

:doh: I’m much enthused and in favor of TBD’s idea of aiming for a very long rover lifespan. Commercial recreational RC cars, the sort one pays to drive at amusement parks appear to have average lifespans of 10 or more years, so this doesn’t at first glance seem unreasonable.

 

I recall a much-talked about commercial venture in the 1990s proposing to put rovers on the moon, paid for primarily by entertainment companies, who would rent time controlling the rovers to anyone who wanted to drive on the moon. I don’t recall what became of that – clearly, it hasn’t yet born fruit – but, having been reminded, will see what I can find on the wonderful world wide web. :)

 

Barring a really big lander with a radiothermal or bigger nuclear power source, or an unprecedentedly ingenious scheme to keep solar cells on the rovers dust-free and functional (scratch-free removal of electrically charged, sharp, unerroded regolith seems a daunting task even for a human being!), I think this locks the design into the “recharge station” lander with solar cells above dust level (and strict protocols for not kicking up dust near it with a rover) version.

 

I think we’re thinking too “inside the box” on the actual rover design – the picture forming in my minds eye so far from reading the read is of something like a vacuum hardened, long-range radioed, camera-equipped version of the various big-wheeled can’t-overturn popular children’s toys. The picture I want looks much the same, but is a hopper.

 

As nature demonstrates in the form of fleas, crickets, and grasshoppers, hopping is a great way to allow an otherwise small, slow machine to cover a lot of ground, and get a good look at it while doing so. My toy outdoor RC vehicles handle a 1 meter drop onto a hard floor with no adverse effects. Plugging in the usual mechanics, this is equivalent to a 4.5 m/s initial speed, which, under lunar gravity, gives an over 6 m vertical jump height, or an over 12 m horizontal one. A rover could image and cover a lot of ground that way, even ground challenging to its wheels. With a system capable of short of long hops, the rover would not even need wheels or other propulsion.

 

No rockets or other expendables (reaction mass/fuel) and energy/expensive systems would be needed – just a high-power “foot”, possibly using a spring and low power motor. If you’re really cunning, you could regain much of the energy on landing while reducing impact, making the system much more distance/energy efficient than any wheeled or legged rover.

 

On the power/charging issues, I think an inductive scheme is simplest and least failure prone. Embed wires in the “petals” of the lander, park a rover on a petal, and alternate the current to the wires, inducing a current in wires in the belly of the rover, charging its battery. Engineered correctly, resistance hearing of the battery could be balanced with radiative cooling to assure that it keeps within a good temperature range. Given that the Apollo Rovers ran on non-rechargable 1960s batteries without any thermal catastrophes, I’m pretty confident such a solution would work well – though it all needs to be tested in a vacuum chamber on earth prior to launching anything into space!

[freeztar]

As nature demonstrates in the form of fleas, crickets, and grasshoppers, hopping is a great way to allow an otherwise small, slow machine to cover a lot of ground, and get a good look at it while doing so. My toy outdoor RC vehicles handle a 1 meter drop onto a hard floor with no adverse effects. Plugging in the usual mechanics, this is equivalent to a 4.5 m/s initial speed, which, under lunar gravity, gives an over 6 m vertical jump height, or an over 12 m horizontal one. A rover could image and cover a lot of ground that way, even ground challenging to its wheels. With a system capable of short of long hops, the rover would not even need wheels or other propulsion.

 

I like this idea as an add-on, but I think we still need wheels. How else would the rover be able to accurately mate with the base-station's charging mechanism? In general, I think hoping would be good for getting distance and a better view, but wheels would serve the purpose of aligning the vehicle and compensating for any variation of linearity that a hoping mechanism might cause.

 

No rockets or other expendables (reaction mass/fuel) and energy/expensive systems would be needed – just a high-power “foot”, possibly using a spring and low power motor. If you’re really cunning, you could regain much of the energy on landing while reducing impact, making the system much more distance/energy efficient than any wheeled or legged rover.

 

I like the idea of recovering the energy, but that would probably require additional moving parts. And as far as success goes, it is inversely proportional to moving parts; which can malfunction, jam, or become crippled by temperature.

On the power/charging issues, I think an inductive scheme is simplest and least failure prone. Embed wires in the “petals” of the lander, park a rover on a petal, and alternate the current to the wires, inducing a current in wires in the belly of the rover, charging its battery. Engineered correctly, resistance hearing of the battery could be balanced with radiative cooling to assure that it keeps within a good temperature range. Given that the Apollo Rovers ran on non-rechargable 1960s batteries without any thermal catastrophes, I’m pretty confident such a solution would work well – though it all needs to be tested in a vacuum chamber on earth prior to launching anything into space!

 

I agree that inductance seems to be the most reliable route. By "petals" I'm assuming you mean the flaps that would unfold after landing? If so, that is what I had in mind as well. A small ramp would be at the ends of the "petals" which would allow the rovers to drive onto them. The charger and matching inductor on the rover would be large so the rover's approach accuracy is not important.

 

Does anyone here draw well? It would be nice to make some concept sketches with all the ideas so far.

[Kayra]

Outside the box is a fun place Craig :doh:

 

Recovery of energy would be more dependant on the surface I would think, but otherwise quite doable. All in all, it may resolve quite a few problems (while creating some of it's own).

 

A continuous bounce? or Jump.. land.. right itself.. aim.. and jump again? (DRASTICALLY simpler to design)

Here is one that can travel about 5 miles on a tank full, and is about the size of your head. Half the tank size to make room for an oxidant as well as fuel, still leaves lots of room.

News Release - Sandia hoppers leapfrog conventional wisdom about robot mobility

 

Could electrostatic pulses of alternating charge drive off the particulate on a surface? They did find that the substance was highly charged from the Sun.

 

Power: It looks like MASER's are still something in the future, not the now:)

A good battery should be able to get the little fella to 1,300 meters, and even to 5,000 without needing a recharge. That is your money maker.

Build the rover with that in mind, and tack on a recharge system AFTER it meets that requirement.

 

Polar navigation on the moon can be accomplished by having the base station PING a radio signal. nothing fancy, and the rover will always know how to get home.

 

I strongly believe that the first mission will require a minimalist approach to hardware and systems. We are not NASA, and I doubt we will have (or be able to procure) the resources on a first run to accomplish everything I see in this thread. The simplest method that will accomplish the goals (as defined by the X-Prize foundation) is the most likely to succeed, and MUCH more likely to be the FIRST to succeed.

 

I understand the desire to accomplish so much, but come back with a successful mission under your belt and then you can line up the capital to pursue the dreams.

 

Just my perspective :)

[freeztar]

A continuous bounce? or Jump.. land.. right itself.. aim.. and jump again? (DRASTICALLY simpler to design)

Here is one that can travel about 5 miles on a tank full, and is about the size of your head. Half the tank size to make room for an oxidant as well as fuel, still leaves lots of room.

News Release - Sandia hoppers leapfrog conventional wisdom about robot mobility

 

Excellent link, Kayra!

These may or may not be available for sale at the project due-date though. If a "homegrown" method prevails, then I say let's do it! Otherwise, it is either too expensive or too futuristic.

Could electrostatic pulses of alternating charge drive off the particulate on a surface? They did find that the substance was highly charged from the Sun.

 

I was pondering this myself. I was thinking of my old air ionizer that blasted all the dust onto the wall where it was pointed, 2m away.

 

Power: It looks like MASER's are still something in the future, not the now:)

A good battery should be able to get the little fella to 1,300 meters, and even to 5,000 without needing a recharge. That is your money maker.

Build the rover with that in mind, and tack on a recharge system AFTER it meets that requirement.

 

Agreed!

 

I strongly believe that the first mission will require a minimalist approach to hardware and systems. We are not NASA, and I doubt we will have (or be able to procure) the resources on a first run to accomplish everything I see in this thread. The simplest method that will accomplish the goals (as defined by the X-Prize foundation) is the most likely to succeed, and MUCH more likely to be the FIRST to succeed.

 

I understand the desire to accomplish so much, but come back with a successful mission under your belt and then you can line up the capital to pursue the dreams.

 

+1

[GAHD]

hmm, what about a mag-lev wheel system? takes most friction out of the loop and cuts out a lot of moving parts.

 

I've got an idea for a cast bismuth(or other diamagnetic) combination tire/rim with staggered permanent magnet insets, combined with a permanent magnet and winding encrusted axle.

 

Pros: no dust in the bearings, proven concepts, solid-state, reduction of mechanical complexity while essentially maintaining the same electrical complexity.

 

Cons: thermal ranges of magnets, math to figure out the optimal windings, custom build on all fronts, unconventional

[TheBigDog]

OK, here are a couple of requirements of mine.

 

1) Target mass for each rover is 5kg. I think that is generous for the mission that we know so far.

 

2) We want diversity in our rovers for the sake of gathering empirical data about lunar mobility. Non mobility parts will be standard, radio, cameras, etc.

 

3) Each rover will be capable of completing one of the primary missions on its initial charge, so even if the recharging method fails we still have a successful mission.

 

4) There should be four rovers as a minimum.

 

5) A design team can make their rover self charging, but must stay in the 5 kg limit.

 

6) We will have rules about maneuvering near the lander to prevent damage and kicking up dust.

 

7) All rovers using the lander for power will utilize the same methods.

 

That is all for now.

 

Bill

[Jay-qu]

I think 4 is a good number. I think each rover should be a clone of each other, that way we make all the rovers able to complete all the basic tasks. This introduces the best possible redundancy and would also decrease manufacturing costs of the rovers themselves.

 

The official competition rules are released next Thursday guys! then the game begins!