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darkback2
01-16-2009, 08:21 AM
A part of me...a big part of me doesn't want to jump in here...but here I go.

While I don't think many people on this website currently have the requisite skills, money, or time to do this project, why don't we look at it as a mental exercise. What would it take to make a robot capable of meeting these requirements. While there are parts that we probably couldn't actually afford, there are other parts that we could put together. How about a light weight frame? Or machined wheels. A number of people on this site have CNC mills and can weld aluminum(at what temperature does aluminum fail?). Again I'm not saying we would actually make a moon rover...This is just a mental exercise.

Heck...How about some CNC drawings/frame prototyping.

Adren/Alex/Tyb...If this post is in the wrong place then by all means move it.

Oops...I'm thinking tramp may have a new purpose in life...if people are willing.

Elios...Find out what we are up against...Climate/temperatures/dust issues/atmosphere...all of that.

Adren...sinse you have experience in this area...you can tell everyone where they went wrong.

In the least, we would all learn a lot through the process.

I was thinking..."why not just use off the shelf chips, and harden them...is that possible or would you have to use high current electronics?"

Chef Omega

Adrenalynn
01-16-2009, 02:46 PM
Chips aren't just hardened, they have built-in recovery. When cosmic radiation pounds electronics it changes bits in weird ways, Schrodinger-weird-ways. The energy involved is extremely high and nearly impossible to harden against. So electronics are built with internal error checking and redundancy. Now, of course, you could build external redundancy - but flying the weight involved is expensive - like exponentially expensive. The other concern with doing it externally is the quantum uncertainty as distance from one set to the next increases.

Some things are built to withstand it inherently, though. Thankfully, Compact Flash was _invented_ for the space program. It's already rated to fly internally. But then you run into the other problems - vibration and heat. Milspec rating is the minimum you'd fly. It's a bumpy ride on a rocket.

Remember that billions of dollars are riding on it working the first time every time, no matter what. Could a handful of amatuers survive the stigma that was attached to JPL and NASA when the Mars Rover didn't work?

lildreamer
01-16-2009, 03:37 PM
[cut for brevity sake...

I was thinking..."why not just use off the shelf chips, and harden them...is that possible or would you have to use high current electronics?"

Chef Omega[/quote]

here is a link from Nasa itself on hardening equipment- it will give you a very good idea on how NASA does it and why its soooo damm expensive....not to say you can't do it or as a group - the group can't do it but there is alot of factors you need to consider.
example from this article -

Link Nasa (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070018806_2007018253.pdf.)
The verification phase of this project will consist of

characterization of a large sample

(> 20 chips) including

the various mixed-signal components of the library as a
function of temperature from -180C to 120C. It will also
include radiation characterization (to a total dose of at least
300 krad); life testing at the temperature extremes (-180C
and 120C) for 1,000 hours; as well as over-temperature
cycle testing for a total of 100 cycles.
"
Actual site with a copious amount of info
http://ntrs.nasa.gov/search.jsp?N=4294716158

Adrenalynn
01-16-2009, 03:49 PM
lildreamer comes to us from a directly related forum that I've been on off-and-on longer than here. I consider his input on this topic exceptionally valuable. Thanks for the linkage, ld - that's a great resource - +Rep from me!

ROFL! Maybe the link was bad, maybe the cache is hosed, I haven't explored completely - but from one of the links above, the PDF contains this for me:

ReconfigurableortAnalogay_Integrated1=ircuitt- implementationafspacesysternsaperatingi

ROFL! Man, I don't know how much of an authority they are! They have data corruption right here on earth! ROFL!

lildreamer
01-16-2009, 04:05 PM
Ooops-- I apologize Adrenalynn
the lnk was to html page, encase some did not have a pdf reader, fixed the link to indicate the pdf file.
Hope everyone has a good weekend....keep warm and keep safe.

Adrenalynn
01-16-2009, 04:17 PM
Thanks, LD! No big, I just found it to be really funny. I'm so busy right now that maybe it's just hysterical laughter response. ;)

elios
01-17-2009, 07:35 PM
moooooooooon

finding some info on wiki atm... looks really interesting...

moooooooooooooooooooooooOOoooooooonnn rover!

Equatorial surface gravity (http://en.wikipedia.org/wiki/Surface_gravity) 1.622 m/s (http://en.wikipedia.org/wiki/Metre_per_second_squared) (0.165 4 g (http://en.wikipedia.org/wiki/G-force))

Surface temp. (http://en.wikipedia.org/wiki/Temperature)
equator
85N[5] (http://en.wikipedia.org/wiki/Moon#cite_note-Vasavada1999-4) min mean max 100 K (http://en.wikipedia.org/wiki/Kelvin) 220 K 390 K 70 K 130 K 230 K

from Kelvin to Kelvin Celsius (http://en.wikipedia.org/wiki/Celsius) [C] = [K] − 273.15 [K] = [C] + 273.15 Fahrenheit (http://en.wikipedia.org/wiki/Fahrenheit) [F] = [K] 9⁄5 − 459.67 [K] = ([F] + 459.67) 5⁄9 Rankine (http://en.wikipedia.org/wiki/Rankine_scale) [R] = [K] 9⁄5 [K] = [R] 5⁄9
Mass (http://en.wikipedia.org/wiki/Mass) 7.347 7 1022 kg (0.012 3 Earths[1] (http://en.wikipedia.org/wiki/Moon#cite_note-W06-0))

Flattening (http://en.wikipedia.org/wiki/Flattening) 0.001 25 Circumference 10 921 km (equatorial (http://en.wikipedia.org/wiki/Equator)) Surface area (http://en.wikipedia.org/wiki/Spheroid#Surface_area) 3.793 107 km (0.074 Earths) Volume (http://en.wikipedia.org/wiki/Volume) 2.195 8 1010 km (http://en.wikipedia.org/wiki/Cubic_metre) (0.020 Earths)for those who dont know:

degrees kelvin eg.130 K. is really cold... 0 k is absolute 0 you cant get colder than that. thats when the electrons freeze around the atom... brrrrr.... and your beloved creation falls apart in a mass of atoms...

Atmosphere

Main article: Atmosphere of the Moon (http://en.wikipedia.org/wiki/Atmosphere_of_the_Moon)
The Moon has an atmosphere so thin as to be almost negligible, with a total atmospheric mass of less than 104 kg.[35] (http://en.wikipedia.org/wiki/Moon#cite_note-34) The effective surface pressure of this small mass is around 3 10-15 atm (http://en.wikipedia.org/wiki/Atmosphere_%28unit%29) [36] (http://en.wikipedia.org/wiki/Moon#cite_note-35). This pressure varies, of course, with the diurnal moon cycle. One source of its atmosphere is outgassing (http://en.wikipedia.org/wiki/Outgassing)the release of gases such as radon (http://en.wikipedia.org/wiki/Radon) that originate by radioactive decay (http://en.wikipedia.org/wiki/Radioactive_decay) processes within the crust and mantle.[citation needed (http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)] Another important source is generated through the process of sputtering (http://en.wikipedia.org/wiki/Sputtering), which involves the bombardment of micrometeorites, solar wind ions, electrons, and sunlight.[28] (http://en.wikipedia.org/wiki/Moon#cite_note-L06-27) Gases that are released by sputtering can either reimplant into the regolith (http://en.wikipedia.org/wiki/Regolith) as a result of the Moon's gravity, or can be lost to space either by solar radiation pressure or by being swept away by the solar wind magnetic field if they are ionised. The elements sodium (http://en.wikipedia.org/wiki/Sodium) (Na) and potassium (http://en.wikipedia.org/wiki/Potassium) (K) have been detected using earth-based spectroscopic methods, whereas the element radon (http://en.wikipedia.org/wiki/Radon)222 (222Rn) and polonium-210 (http://en.wikipedia.org/wiki/Polonium-210) (210Po) have been inferred from data obtained from the Lunar Prospector (http://en.wikipedia.org/wiki/Lunar_Prospector) alpha particle (http://en.wikipedia.org/wiki/Alpha_particle) spectrometer.[37] (http://en.wikipedia.org/wiki/Moon#cite_note-36) Argon (http://en.wikipedia.org/wiki/Argon)40 (40Ar), helium-4 (http://en.wikipedia.org/wiki/Helium-4) (4He), oxygen (http://en.wikipedia.org/wiki/Oxygen) (O2) and/or methane (http://en.wikipedia.org/wiki/Methane) (CH4), nitrogen (http://en.wikipedia.org/wiki/Nitrogen) (N2) and/or carbon monoxide (http://en.wikipedia.org/wiki/Carbon_monoxide) (CO), and carbon dioxide (http://en.wikipedia.org/wiki/Carbon_dioxide) (CO2) were detected by in-situ detectors placed by the Apollo astronauts.[38] (http://en.wikipedia.org/wiki/Moon#cite_note-37)

Surface temperature

During the lunar day, the surface temperature averages 107C, and during the lunar night, it averages -153C.[39] (http://en.wikipedia.org/wiki/Moon#cite_note-38)


This is legal. From wikipedia. makes sense at my end, ask questions if you need it to be "translated"

Adrenalynn
01-17-2009, 09:10 PM
[clip]whereas the element radon (http://en.wikipedia.org/wiki/Radon)–222 (222Rn) and polonium-210 (http://en.wikipedia.org/wiki/Polonium-210) (210Po) have been inferred from data obtained from the Lunar Prospector (http://en.wikipedia.org/wiki/Lunar_Prospector)
...
ask questions if you need it to be "translated"

Sure - what happens when you bombard static memory with polonium?

elios
01-17-2009, 10:47 PM
"Alleviate the dirt and dust-attraction problems caused by electrostatic charges with these proven static neutralizers. The polonium 210 element emits alpha particles (positively charged helium atoms) that collide with molecules of air, creating a supply of oxygen and nitrogen ions sufficient to neutralize both positive and negative static charges."

polonium is a anti-static. that help?

Adrenalynn
01-17-2009, 11:18 PM
No, I was more hoping you'd explain the effect it would have on SRAM - something that couldn't be googled, cut, and pasted - ie. your translation, not google's translation. Google's translator spits out some pretty garbled stuff generally. ;)

elios
01-17-2009, 11:40 PM
lol. i'm fouteen years old... im not sure how im meant to explain that... i meant in laymans terms lol

Quantum
01-18-2009, 02:45 AM
the other thing is chips for space cant have and air in them. this creates pressure inside of them. the pressure from gravity keeps them together in our atomsphere. But once you leave it(atomsphere) the pressure inside if any will blow that chip in half. its not feasible to make a airtight container at least from what im thinking

I dont have any experince in this area so i may be totaly wrong(most likely i am).

Adrenalynn
01-18-2009, 03:08 AM
Air also contains water vapor, which will crack the chip apart before the vacuum will. Ice isn't nice. ;)

Hence the reason you use positive pressure nitrogen.

elios
01-18-2009, 08:11 PM
i though my job was to gather information on the environment...? ;) not give a full explanation on how different elements react to our chips :D

darkback2
01-18-2009, 10:15 PM
I was looking at the panasonic tough books. They are rated to -60F...well below freezing. They are also rated for a 3 foot drop. Perhaps that would be a good start for a computer for processing. Is there any way to shield the computer? How well does lead shielding work?

elios
01-18-2009, 10:29 PM
tin foil.... you can get lead foil

Quantum
01-18-2009, 11:13 PM
Your dealing with a different type of radiation than on earth. In space atoms get stripped down to the nucleus and this lead I believe doesn't protect against as well as gold. Something along the lines of .00006 plating of gold should reflect these guys.

All of NASA's stuff is protected with gold unless they have something they keep secret.

Plus lead is so darn heavy it makes everything more expensive.

And using military spec chips wont cut it either.

I know I am so negative against this. But its something that you don't save pennies one.

Remember every system you create needs a back up because if the first goes your shit out of luck. Then you
have a paper weight on the moon or mars.

Paul

elios
01-18-2009, 11:20 PM
that is so true. but you can get lead foil as thin at tin/aluminum foil. saw it on a mythbusters episode: can you really make a lead balloon fly? they succeeded.

Quantum
01-18-2009, 11:25 PM
Yea but i don't think lead reflects them. and gold is better with handling higher temps than lead.

This is going to go thru a heating up and cooling down cycle that with start to destroy stuff with cracks.

i don't think aluminum will cut it in space either. My guess is a titanium or some type of carbide mix material. This is out of my scope. not sure on it

elios
01-19-2009, 12:39 AM
okay. well, carbide is easy enough to get at my end (member of NZSS(caving) and NZSAR cave(for SARex's only tho :()). and it is a bi-product of the steel industry im told. but you dont want to mix carbide and water! big no no no! (it sublimes into a highly flammable gas)

Adrenalynn
01-19-2009, 01:34 AM
We're going to wrap a laptop up in tin foil and blast it to the moon... Wonder if JPL ever thought about that?

All the components in it were built in a high vacuum or were nitrogen evacuated, right?

elios
01-19-2009, 01:57 AM
yes. thats what i got out of it... ;)

Adrenalynn
01-19-2009, 02:40 AM
>> yes. thats what i got out of it...

Could you link me to where you found that a Toughbook's components are vacuum evac'd or nitrogen pressurized, please? I'd like to see at what level and facility and where they're certified.

lildreamer
01-19-2009, 09:40 AM
Ok since we are getting bit by the bug...I know Iam
lets look at this like any other project - what is the xprize/google's criteria for the moon rover

a) goals
b) environment

once we establish that, they will dictate what
b) technology
c) resources
d) cost

we can use and incur

$20 million prize - I think from a engineering standpoint means you will either double or triple your expense based on the prize. But I'm used to small potatoes I haven't worked on larger projects/ budgets than half a mill - and that was in LAN/Communication equipment as a contractor several years back.

Here's an example of radiation hardened equipment RAD750 - http://en.wikipedia.org/wiki/RAD750
very popular board used by NASA - cost $200,000 thats just the board, forget your subsystems and power modules.

but if we are speculating then cost can be ruled out - or if we are trying to be realistic lets set a budget right off the bat and jam/cram/modify based on our budget.

sound reasonable? - I think this exercise will be a fun learning experience for all of us....

edit: oops just reread the OP and this is a mental exercise - I thought this was still $$$$$rover thread...I apologize...

darkback2
01-19-2009, 10:26 AM
Lildreamer...

Yes it is just a mental exercise...but that doesn't mean your not welcome to give us your input. I know next to nothing about anything. I suppose I could help with frame design, but not much more. If you know about chips and stuff that would work then please contribute.

Adren...Nitrogen is to keep the chips from freeze thaw cracking in the cold right? I'm not sure if the tough books chips are made with nitrogen, but they are good to negative 60 degrees F. That suggests that freeze thaw would not be a problem.

I know water is heavy, but could water be used as a shield?

Finally...Lead Acid batteries are out. Lithium Ion are supposed to be good at extreme temperatures... but not sure how extreme. The moon rover buggy thingy used silver/potassium Hydride batteries, but they were non-rechargeable.

Also, the Mars rovers use a heating element at night to keep some of the vitals warm. I know it would add weight, but could that be a possibility?

lildreamer
01-19-2009, 12:21 PM
Hi Darkback2

I really don't want to be a stick in the mud,...but are we all aware of the environment we are heading into and the goals Google/Xprize is looking for?

1) goals
http://www.googlelunarxprize.org/lunar/about-the-prize/rules-and-guidelines

COMPETITION GUIDELINES: To win the Google Lunar X PRIZE, a team must successfully land a privately funded craft on the lunar surface and survive long enough to complete the mission goals of roaming about the lunar surface for at least 500 meters and sending a defined data package, called a “Mooncast”, back to Earth.






PRIZES: The total purse of the Google Lunar X PRIZE is $30 million (USD).

GRAND PRIZE: A $20 million Grand Prize will be awarded to the team that can soft land a craft on the Moon that roams for at least 500 meters and transmits a Mooncast back to Earth. The Grand Prize is $20M until December 31st 2012; thereafter it will drop to $15M until December 31st 2014 at which point the competition will be terminated unless extended by Google and the X PRIZE Foundation
SECOND PRIZE: A $5 million Second Prize will be offered as well, providing an extra incentive for teams to continue to compete, and increasing the possibility that multiple teams will succeed. Second place will be available until December 31st 2014 at which point the competition will be terminated unless extended by Google and the X PRIZE Foundation
BONUSES: An additional $5 million in bonus prizes can be won by successfully completing additional mission tasks such as roving longer distances (> 5,000 meters), imaging man made artifacts (e.g. Apollo hardware), discovering water ice, and/or surviving through a frigid lunar night (approximately 14.5 Earth days). The competing lunar spacecraft will be equipped with high-definition video and still cameras, and will send images and data to Earth, which the public will be able to view on the Google Lunar X PRIZE website.
MOONCAST: The Mooncast consists of digital data that must be collected and transmitted to the Earth composed of the following:

High resolution 360º panoramic photographs taken on the surface of the Moon;
Self portraits of the rover taken on the surface of the Moon;
Near-real time videos showing the craft’s journey along the lunar surface;
High Definition (HD) video;
Transmission of a cached set of data, loaded on the craft before launch (e.g. first email from the Moon).
Teams will be required to send a Mooncast detailing their arrival on the lunar surface, and a second Mooncast that provides imagery and video of their journey roaming the lunar surface. All told, the Mooncasts will represent approximately a Gigabyte of stunning content returned to the Earth.
If you have any questions about the Rules, you can read the Official Q&A here (http://www.googlelunarxprize.org/lunar/about-the-prize/official-guidelines-q-a).

2) environment - Space/Moon Surface
Gravity:

The gravitational acceleration of the moon is 1.63 m/s2,[1] (http://en.wikipedia.org/wiki/Gravity_of_the_Moon#cite_note-0) about 16.7% that of earth's (a)
Temperature:

Lunar day, averages 107°C, (224.6°F)
Lunar night, averages -153°C, (-243.4°F) (a)
Radiation:

The surface of the Moon is badly exposed to cosmic rays and solar flares, and some of that radiation is very hard to stop with shielding. Furthermore, when cosmic rays hit the ground, they produce a dangerous spray of secondary particles right at your feet...When galactic cosmic rays collide with particles in the lunar surface, they trigger little nuclear reactions that release yet more radiation in the form of neutrons. The lunar surface itself is radioactive! (b)
Radiation Source Energy Flux (cm-2s-1) Penetration Depth
cosmic ray 1-10 Gev/nucleon 1 few meters
solar flares 1-100 Mev/ nucleon 100 1 cm
solar wind 1000 ev/nucleon 108 10-8 cm(c)



Soil:

The lunar regolith is chemically composed of several elements and compounds in varying concentrations. The carbon, hydrogen, and nitrogen found in the soil are almost entirely due to implantation by the solar winds. Unlike most Earth soils, the lunar soil has high concentrations of sulfur, iron, magnesium, manganese, calcium, and nickel. Many of these elements are found in oxides such as FeO, MnO, MgO, etc. Ilmenite (FeTiO3), most common in the mare regions, is the best source of in situ oxygen. ... Particulate size - 26% of the soil is composed of grains less than .020 mm (C)
Atmosphere:

The moon does posses an atmosphere but at 10^-14 of that of Earth. (c)
plus lets not forget the ride there and the G forces our package will have to endure.
This should give everyone a little bit of an understanding of the harsh environment we are trying to create a rover, to safely land, to move in and send video back home.

ref:
a) http://en.wikipedia.org/wiki/Moon
b) http://science.nasa.gov/headlines/y2005/08sep_radioactivemoon.
c) http://www.tsgc.utexas.edu/tadp/1995/spects/environment.html

(i apologize for the long post....)

metaform3d
01-19-2009, 12:48 PM
I used to work at Lockheed in the department that developed the solar physics instrument for Spacelab-2, which flew on STS-51-F. I didn't build space hardware (I did CG scientific visualization, natch), but a lot of guys around me did. The most elementary test they did was to "bake" components in a vacuum chamber. They'd set up some subsystem with a test load, pump out all the air and turn on the oven. Strange things could happen. Once a relatively benign plastic they were using "outgassed" something awful, leaving a slick of oil all over their fancy instrument and the chamber itself. Took them a long time to clean.

As I recall they used somewhat dated electronics since they were known to be spaceworthy. The CPU was a 68000 clone, and it used magnetic core memory (look it up!). The whole thing probably had less power than a modern microcontroller. It would be interesting to know what was used on the Mars rovers.

As for a Lunar mission, I think the bulk of the cost is going to be getting to the moon. The rover will be only a small fraction of the budget, although ironically the lighter it is the more expensive it can be. A larger payload increases thrust requirements exponentially, so every dollar spent reducing the mass of the rover (and landing systems) pays off with many dollars of launch vehicle costs.

So the goal for the rover is not to be cheap, but to be light. Spec out the absolute minimum mass that could accomplish the mission objectives, and then find space-qualified hardware to fit the requirements. This means you'll be most likely using the very highest engery-density Lithium batteries, the most efficient solar cells, etc.

lildreamer
01-19-2009, 01:14 PM
..... It would be interesting to know what was used on the Mars rovers.
As for a Lunar mission, I think the bulk of the cost is going to be getting to the moon. The rover will be only a small fraction of the budget, although ironically the lighter it is the more expensive it can be. A larger payload increases thrust requirements exponentially, so every dollar spent reducing the mass of the rover (and landing systems) pays off with many dollars of launch vehicle costs.

So the goal for the rover is not to be cheap, but to be light. Spec out the absolute minimum mass that could accomplish the mission objectives, and then find space-qualified hardware to fit the requirements. This means you'll be most likely using the very highest engery-density Lithium batteries, the most efficient solar cells, etc.

(cut for brevity sake)

Sojourner (on Mars) used Intel 80C85 (RHA version)
Spirit and Oppurtunity Rovers used BAE RAD6000 (25MHz Max)
the Bae Rad750 has a higher bandwidth and processing performance /MIPS.
http://www.baesystems.com/BAEProd/groups/public/documents/bae_publication/bae_pdf_eis_sfrwre.pdf
http://www.baesystems.com/ProductsServices/bae_prod_s2_rad6000.html

edit:
side note interesting link to
http://www.cpushack.net/space-craft-cpu.html gives a good listing of the CPU's that went out into space...

lildreamer
01-19-2009, 01:29 PM
just a side note:

http://nssdc.gsfc.nasa.gov/nmc/masterCatalog.do?sc=MESURPR

The rover, which has been named "Sojourner" is a six-wheeled vehicle, 280 mm high, 630 mm long, and 480 mm wide with a ground clearance of 130 mm, mounted on a "rocker-bogie" suspension. The rover was stowed on the lander at a height of 180 mm. At deployment, the rover extended to its full height and rolled down a deployment ramp at about 05:40 UT on 6 July 1997 (1:40 a.m. EDT). The rover was controlled by an Earth-based operator who used images obtained by both the rover and lander systems. Note that the time delay was between 10 and 15 minutes depending on the relative position of Earth and Mars over the course of the mission, requiring some autonomous control, provided by a hazard avoidance system on the rover. The on-board control system is an Intel 80C85 8-bit processor which runs about 100,000 instructions per second. The computer is capable of compressing and storing a single image on-board. The rover is powered by 0.2 square meters of solar cells, which will provide energy for several hours of operations per sol (1 Martian day = 24.6 Earth hours). Non-rechargeable lithium thionyl chloride (LiSOCl2) D-cell batteries provide backup. All rover communications were done through the lander

The Mars Pathfinder mission cost approximately $265 million including launch and operations. Development and construction of the lander cost $150 million and the rover about $25 million.

for those who might of been interested....:robotsurprised:

metaform3d
01-19-2009, 01:48 PM
Just to deep-end a little more, a lunar rover mission can be characterized by several phases: boost, transit, descent, roving.

Boost: the most expensive phase and, unless you're an aerospace firm or a major government, the one you have the least control over. You probably need to get your vehicle to GTO -- geostationary transfer orbit -- to start the next phase. I can't find stats for that, but it's probably between $10K and $12K per pound, the cost for getting satellites to LEO and GSO, respectively (http://www.futron.com/pdf/resource_center/white_papers/FutronLaunchCostWP.pdf).

Transit: getting from Earth orbit to Lunar orbit or Lunar close approach. Here you have a lot of opportunities to save on mass. Ion engine or solar sail are probably your best bets; slow and steady but very light. Also really complicated and can easily fail. You can either try to use the same engine to ease into Lunar orbit or you can "fall" into a fast close approach.

Descent: decelerating to the Lunar surface and touching down. The lander needs retro rockets to kill all its orbital speed so it won't smash on impact, but this causes it to fall so it needs braking rockets as well. Airbags have proven to be good shock absorbers which cuts down on fuel mass for landing. Still, a large fraction of your mass budget will be allocated to this phase.

Roving: making a 500 meter trek and sending some video. The rover on the surface is the ultimate payload, and it would be nice if it could do a lot while it was there, but to claim the prize it really has to do very little. Survive the trip and the landing, send telemetry, take some pictures, drive around the block. As I said before, the main goal of the rover, as with all the other systems, is to be a light as possible.

To break even I'd shoot for a $12 million boost, which puts the total vehicle mass at 1000 pounds. I'd allocate another $7 million on transfer and descent, and maybe $1 million on the Lunar package, including the base station and rover. The total Lunar payload can't be more than about 50 pounds, of which the rover should be about 5.

lildreamer
01-19-2009, 02:08 PM
Just to deep-end a little more, a lunar rover mission can be characterized by several phases: boost, traversal, descent, roving.

Boost: the most expensive phase and, unless you're an aerospace firm or a major government, the one you have the least control over. You probably need to get your vehicle to GTO -- geostationary transfer orbit -- to start the next phase. I can't find stats for that, but it's probably between $10K and $12K per pound, the cost for getting satellites to LEO and GSO, respectively (http://www.futron.com/pdf/resource_center/white_papers/FutronLaunchCostWP.pdf).

Traversal: getting from Earth orbit to Lunar orbit or Lunar close approach. Here you have a lot of opportunities to save on mass. Ion engine or solar sail are probably your best bets; slow and steady but very light. Also really complicated and can easily fail. You can either try to use the same engine to ease into Lunar orbit or you can "fall" into a fast close approach.

Descent: decelerating to the Lunar surface and touching down. The lander needs retro rockets to kill all its orbital speed so it won't smash on impact, but this causes it to fall so it needs braking rockets as well. Airbags have proven to be good shock absorbers which cuts down on fuel mass for landing. Still, a large fraction of your mass budget will be allocated to this phase.

Roving: making a 500 meter trek and sending some video. The rover on the surface is the ultimate payload, and it would be nice if it could do a lot while it was there, but to claim the prize it really has to do very little. Survive the trip and the landing, send telemetry, take some pictures, drive around the block. As I said before, the main goal of the rover, as with all the other systems, is to be a light as possible.

To break even I'd shoot for a $12 million boost, which puts the total vehicle mass at 1000 pounds. I'd allocate another $7 million on transfer and descent, and maybe $1 million on the Lunar package, including the base station and rover. The total Lunar payload can't be more than about 50 pounds, of which the rover should be about 5.


OUCH -
my visa nearly imploded upon reading the figures for LEO and GTO....
So when you factor in the cost to get you there $20 million prize is not even enough to recoup launch costs.:eek:

edit: She weighs in at a sleek 11.5kg (25lbs) and is about the size of a milk crate - Pathfinder on Mars
http://mars.jpl.nasa.gov/MPF/roverpwr/power.html

jes1510
01-19-2009, 02:13 PM
OUCH -
my visa nearly imploded upon reading the figures for LEO and GTO....
So when you factor in the cost to get you there $20 million prize is not even enough to recoup launch costs.:eek:

edit: She weighs in at a sleek 11.5kg (25lbs) and is about the size of a milk crate - Pathfinder on Mars
http://mars.jpl.nasa.gov/MPF/roverpwr/power.html


Dude I would be extremely surprised if you could build the hardware for under $10 million once you get all the of the testing labs involved.

lildreamer
01-19-2009, 02:30 PM
my outburst - is really based on the prize Google is providing and the amount of time, money and effort that would have to go into this project. Since it's really a mental exercise - money is no object then :)
I figure since Pathfinder was such a success; using a rover and base station combination maybe would be an ideal start.
Mimicing what NASA did basically means staying with tried and true.
Realising you are entering 1/6 the gravity well of Earth as compared to Mars which is a little over 1/3 of Earths we might save a little on fuel cost.

soo what have we accomplish so far....

Adrenalynn
01-19-2009, 02:32 PM
The money isn't to be made on the Google prize. The money is to be made on the endorsements.

Adrenalynn
01-19-2009, 02:48 PM
Sorry, Meta, we've already figured out that we're spending 7.9lbs of your 5lb budget on a laptop, and another 3lbs wrapping your laptop up in foil...

Independant studies by the SRI Group rate the OPERATING temp range of the Toughbook from -20F to +140F. I'm not sure how we decided the toughbook was adequate, btw. According to: http://www.solarviews.com/eng/moon.htm - Max surface temp is: ~253.4deg F and min surface temp is: -387.4deg F.
The means are 224.6deg F [day] and -243.4 deg F at night.

If the toughbook is able to withstand OPERATING temps from -20 to +140 and our means are -243 (10+ TIMES the capability) and 224.6 (almost 2 times the capability) - how was it we decided that was a good idea again?

lildreamer
01-19-2009, 02:48 PM
In other words make the rover look like a Giant Coke a Cola can and have it transmitt "I like to teach the world..."
I'm Sure Coke would love that ...????? hmmmm and make the base station look like a vending machine....

Adrenalynn
01-19-2009, 02:49 PM
NOW you're thinkin'!

metaform3d
01-19-2009, 02:52 PM
my visa nearly imploded upon reading the figures for LEO and GTO....
So when you factor in the cost to get you there $20 million prize is not even enough to recoup launch costs.:eek:No one's going to make a profit doing this. My breakeven figures are kind of a joke too. Realistically you'd need at least $20M for boost and the same again for the vehicle. The prize can be thought of more as an R&D credit. It's an incentive for investors who think that someone else is going to pay part of the cost of developing valuable patents. If you can get Coke to pay a few million to get their logo on the moon that doesn't hurt either.

A non-traditional approach that might be interesting to explore would be using micro rovers. Instead of a big multi-wheeled box you send one or more tiny lightweight bots. If you can the mass down to a few grams it takes only hobby-scale rockets to get it from GTO to the Lunar surface, and a small amount of thrust and shock absorption to make a survivable landing.

For roving instead of wheels you make it jump. A tiny motor winds up a spring, and releasing the spring propels the robot forward. It could easily cover 100m at a time, albeit without much accuracy, but the prize doesn't specify where you go just how far. You snap a photo at the apogee of the jump when it's moving slowest. So the whole thing is just a camera, a transmitter, one motor, a spring system, a solar cell, a battery and maybe accelerometer.

The signal would be weak so you'd need a relay of some sort. Something small could be sent trailing the probe by a day or so, and it would relay the signal until it crashed on the moon.

darkback2
01-19-2009, 03:52 PM
Ok...two things.

I don't think we have to worry about cost so much, because all that was asked about and for was a rover. Second, we are not actually going to make the rover! I say we may explore making parts of it if possible...but only to see if they will or will not work for some aspect of the project.

Metaform...the idea of a lot of tiny jumpers is cool...but would possibly amplify the original problems of dealing with:

A) huge temperature ranges...
B) Radiation
C) Launch and impact

Now one thing we can consider would be a hybrid of the original and metaform's ideas.

What if the rover had little pucks that it could drop. The pucks would have a small motor, and be capable of taking a 360 degree panaramic shot of their surroundings. They could then transmit back to the rover/base module. The pucks would only have to work for a half minute or so, and if the robot had enough of them...

Now as for temperature regulation, I was thinking...all of the sensative electronics could be sealed inside of a gold plated aluminum box. The box could be filled with nitrogen to keep it pressurized. A supersaturated saline solution or oil of some kind could be heated or cooled using a thermocouple attached to the solar cells. The solution would then be pumped through the electronics chamber either helping to cool it off in there, or heat it up. The whole thing would have to be painted white to reflect sunlight...

DB

metaform3d
01-19-2009, 04:00 PM
Here's some numbers. Worst-case lunar approach is lunar escape velocity: 2400 m/s. Soft landing using solid rockets (250s specific impulse) takes a mass ratio of 2.7. So a 10-gram payload would need 27 grams of propellant. Adding support electronics, overhead and safety margin let's assume a conservative 75 grams for the lunar-descent package.

Low Earth orbit to lunar approach requires a delta-V of about 2500 km/s, about the same mass ratio again. So to send our 75 gram payload moonward takes 200 grams of solid propellant. That makes the lunar transit package say 350 grams total.

We want to send three rovers for redundancy, plus another 75 gram package for the relay transmitter, plus 25% overhead is 1.8 Kg -- 4 pounds. Lifting that to LEO would take no more than $8K per pound -- $32,000. That's in the high-end hobby range, and could make a profit if development costs could be kept low.

Anyone want to try to make a 10-gram lunar flea?

lildreamer
01-19-2009, 04:13 PM
becareful now micro is cool an all but when your dealing with regolith at .020 mm a few grains can jam up your micorobot. The surface majority is below 1mm - .020 mm. Think talcum powder but a little more
abrasive. Loading springs and launchin one self is cool as well but your dealing with 1.6 m/s for G, don't want to launch into space.
Movements are exaggerated in that environment - look at all the Apollo footage. Having Jimminy Cricket jumping around might not be a good idea - but ...lets do a De Bono and brain storm.... so far teams are using; multi legged bots, 4 - 6 wheeled bots,...extremely low gravity what can we do?

edit: hmmm looking at that makes me think yeah 2.5 km/s regardless of mass maybe Jimminy won't launch into space but - it could work in our favour, using a cam like gear and rotate the motor once would launch you just a few feet where on earth it would be a few inches ...need to crunch the math. The other part is if not balanced we could be flying all over the place....

metaform3d
01-19-2009, 04:19 PM
Metaform...the idea of a lot of tiny jumpers is cool...but would possibly amplify the original problems of dealing with:

A) huge temperature ranges...
B) Radiation
C) Launch and impactI'm not sure that's true. Smaller things are often more resilient. Recall that's how John Harrison won the longitude prize. Instead of trying to make pendulum clocks that would work at sea, he invented the spring-driven pocket watch. The tiny mechanism was impervious to the rocking motion onboard ship and kept perfect time.

Likewise smaller devices are often stronger than scaled up versions. Toy cars can handle impacts that would mangle their larger doppelgangers. Landing something small on the moon probably allows for a wider ranges of impact speeds than something large, and I believe I can back up with numbers that launching a tiny lander would be much, much cheaper.

As you say though, it's just an amusing exercise.

metaform3d
01-19-2009, 04:48 PM
becareful now micro is cool an all but when your dealing with regolith at .020 mm a few grains can jam up your micorobot. The surface majority is below 1mm - .020 mm. Think talcum powder but a little more
abrasive. Loading springs and launchin one self is cool as well but your dealing with 1.6 m/s for G, don't want to launch into space.
Movements are exaggerated in that environment - look at all the Apollo footage. Having Jimminy Cricket jumping around might not be a good idea - but ...lets do a De Bono and brain storm.... so far teams are using; multi legged bots, 4 - 6 wheeled bots,...extremely low gravity what can we do?The lunar dust is very nasty stuff. Very fine, very abrasive (no erosion to knock off the sharp edges) and statically charged. On Apollo it clung to the astronauts and all of their gear. Of course, you have the same problem with wheeled rovers only worse. There are multiple hubs that have to be able to do complete rotations without getting any dust in them. The flea just has a hinge which can be completely enclosed.

Agreed the forces would have to be scaled for lunar gravity. The low gravity would also work to the advantage of keeping it small since lower forces are required to move. It would only need small kicks to right itself if it landed upside down.

Jumping or skipping is a very efficient motion in low gravity, so whatever size of rover I would still endorse it.

darkback2
01-19-2009, 07:17 PM
Sorry, Meta, we've already figured out that we're spending 7.9lbs of your 5lb budget on a laptop, and another 3lbs wrapping your laptop up in foil...

Independant studies by the SRI Group rate the OPERATING temp range of the Toughbook from -20F to +140F. I'm not sure how we decided the toughbook was adequate, btw. According to: http://www.solarviews.com/eng/moon.htm - Max surface temp is: ~253.4deg F and min surface temp is: -387.4deg F.
The means are 224.6deg F [day] and -243.4 deg F at night.

If the toughbook is able to withstand OPERATING temps from -20 to +140 and our means are -243 (10+ TIMES the capability) and 224.6 (almost 2 times the capability) - how was it we decided that was a good idea again?

Sorry Adren, no one said wrapping a laptop in tinfoil was a good idea. and no one has decided on anything. We are all just tossing out ideas.

That said we did put people on the very same moon right? How did they survive? Wouldn't they just burst into flames and then freeze into a burnt up block of charcoal ice? Oh wait...they had space suits...

I know...lets just send kidbot in a space suit. I'll even lend him my camera.
:p

lildreamer
01-19-2009, 08:32 PM
driving home tonight several ideas struck me - frog, build the movement like a jumping frog, low gravity definite in our favour, Hamster ball, rolls around on the surface top opens up reveals camera take pictures close up and roll around to your destination, hamster ball really struck my fancy....

Rudolph
01-19-2009, 09:11 PM
Put kidbot in a hamster ball? He'd probably love that :)

darkback2
01-19-2009, 10:32 PM
driving home tonight several ideas struck me - frog, build the movement like a jumping frog, low gravity definite in our favour, Hamster ball, rolls around on the surface top opens up reveals camera take pictures close up and roll around to your destination, hamster ball really struck my fancy....

Holy Canolie...Hamster ball...why would it have to open at all? There were these ball robots at the last robogames. I believe I read an article about them in a magazine once...seamed pretty cool, and exhibited some swarming behaviors. One problem would be charging them...it would be hard to get large flat solar panals on a ball...You could charge the base station and then power the balls through...I don't know microwaves or something...the other thing... would be rolling over difficult terrain...would it be possible to have the ball have two treads on the outside that could rotate around the ball? There is another rover thing that is ball like, only two arms extend out distorting the treads on the outside.

One of the benefits of a ball is that the inside could be pressurized with an inert gas. One side could even have a pyrex lens. Thus the ball could simply roll where you want , and never have to open to take a picture.

I was also thinking we could have positive pressured lube for any moving joints. Eventually we would run out of lube...but if we had a few days supply...