Any way to "hack" the Google Lunar X Prize? | Hacker News Reader

Any way to "hack" the Google Lunar X Prize?

47 pointsryanwaggoner63 comments

Warning: This question is likely so stupid that I'm going to wish I had posted it anonymously to avoid ridicule, but what the hell :)

I find the subject of space exploration and colonization fascinating, but the incredible costs for access to space seem to be a nearly-insurmountable obstacle to true progress in these areas. I've recently become interested in the Google Lunar X Prize and started looking at the teams who are competing. While these teams are probably going to accomplish some amazing things, I suspect they're going to do it on the back of tens of millions in funding...is that truly the only way?

I guess my question is something like this: is there any theoretical way to win something like the Lunar X Prize for $1 million? $100k? $10k?

Here are some ridiculous thoughts that I've had:

1. Using high-altitude balloons to cut down on launch costs.

2. Going small. Very small. Like a pound or two for the rover. Maybe smaller.

3. Getting the cost low enough that you can launch multiple missions, knowing that most will fail.

4. Travel to the moon over a period of months...would this reduce launch difficulty?

I'm sure I'm probably missing the scale of the problem here, and perhaps the simple laws of physics dictate that there's no cheap solution that we know of yet. Or is there?

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If your rovers were small enough, you might be able to make a gun-launched or gun-assisted scheme work. If you could engineer your probe/launch vehicle to withstand 20 Gs, for example, a linear acceleration at that level would get you to Mach 1.2ish in 400 meters or so. You come out of the barrel cleanly in ramjet territory and, what's better past the point where your shock wave angles are highly dependent on Mach number. You could start out in subcritical mode for the engine and progress through critical and supercritical, buying hardware simplicity with some loss of efficiency. You might even be able to shed some of the diffuser cowling in stages at the lip for a Q&D variable geometry engine. By the tme you hit M = 5-7, you'd probably be out of the atmosphere and would have to switch to rocket mode anyhow. Your mass fraction for the booster stage would be pretty amazing because you'd shaved 2000-2500 m/s off your delta-V with the gun/air-breathing phase. (That matters a lot to the rocket equation. I'll leave it as an exercise for the reader to work out the actual benefit.)

The limiting factors here are obtaining a guidance and control system that is small enough to fit down your (admittedly large bore) low-pressure launch gun. Also, your gun would have to be pretty dang straight or your vehicle would have to be wrapped in a vibration-absorbing sabot.

The benefits are: 1) Once you have the gun, you can launch as many as you like; 2) Mass fraction as mentioned above; 3)The possibility of production-lining launch vehicle construction.

Not that I've given this any thought.

BTW, Bruckner et. al. at the University of Washington have been working on a ram accelerator, a type of launch gun, for years. The only thing slowing them is funding. They omit an airbreathing stage in favor of obtaining all the Delta-V in one shot, subjecting the payload to 700-1e3 Gs.

Yea, building a massive electromagnetic riffle along the slope of a mountain in a third world country to repeatedly launch vehicles into space has been on my todo list since i first read "the moon is a harsh mistress."

Worked out great for Gerald Bull

Just throwing it out there, but what about the use of railgun or coilgun technology to accelerate the projectile?

EDIT - seems aaron above has already mentioned this while I was reading up on railguns... dammit :P

Worked for Jules Verne anyway.

Wait, it didn't. They missed the Moon.

I'm sure the State Department would love that. Trying to comply with ITAR alone could set you back until after the contest deadline.

Had the privilege of hearing a presentation by Brian Binnie, the test pilot for Scaled Composites (http://scaled.com) shortly before they won Ansari XPrize back in 2004.

His description of their team sounded like the ultimate group of hackers. And his description of their process sounded exactly like the questions you ask above... discarding all preconceived notions, how do we make this happen in the cheapest, simplest way possible?

He also advised that teams adopt a mantra of "Question, don't defend." In other words, it's more important to realize that something is wrong and get it fixed than to assign blame or respect egos.

Not a stupid question at all. I remember Cringely writing something about hacking that particular prize, as well... I'll add a link once I find it.

This is the link, although you'd have to go back a couple to get the beginning of the story: http://www.pbs.org/cringely/pulpit/2008/pulpit_20080530_0049...

That's a little disappointing.

It starts out well: http://www.pbs.org/cringely/pulpit/2007/pulpit_20070927_0030... http://www.pbs.org/cringely/pulpit/2007/pulpit_20071214_0036... Then goes downhill: http://spacefellowship.com/News/?p=4718 . . . and culminating in the link your posted.

They could really do with pointing a few more links to their website: http://www.teamcringely.org/

I had a crazy idea too, and I'll probably get ridiculed, but what the hell.

I think it is fairly straightforward to get something tiny to the moon. The challenge comes in making it broadcast back to earth. For wireless transmissions, you need considerable bulk and you add a lot of cost.

Wouldn't it be cool if, instead, it was connected to earth by a ridiculously long insulated wire? Then you might even be able to cut down the size to well under a pound for the rover itself (not including the fuel needed to get there). It shouldn't have problems transmitting as long as the wire is insulated well enough, right?

Some back-of-a-napkin calculations lead me to believe that you wouldn't need more than 60 cubic miles to store enough wire to reach the moon (200,000 miles long, 1 inch thick).

what do you think? flame away :)

I think there'd be a problem with extreme temperature conditions as well as the fact that the moon is not in geosynchronous orbit

So IF you could find a wire long enough and insulated enough, how would your wire deal with the rotation of the earth? :)

the trans-equatorial railway express, of course, ol chap!

but, uh, (slightly) more seriously, if one big transmitter is the problem, then isn't the solution multiple small transmitters in the the same orbit, repeated at increasingly closer-to-earth orbits? then you could just run a wire up to a transmitter in geostationary orbit.

Sounds like the space elevator. The problem's that the moon and earth move back and forth too far, and space debris would kill it. You need a string made out of nano-carbon or another material harder than diamond.

Wouldn't it be cool if, instead, it was connected to earth by a ridiculously long insulated wire?

http://en.wikipedia.org/wiki/Specific_strength

Another way to quote specific strength is breaking length, also known as self support length: the maximum length of a vertical column of the material (assuming a fixed cross-section) that could suspend its own weight when supported only at the top. For this measurement, the definition of weight is the force of gravity at the earth's surface applying to the entire length of the material, not diminishing with height.

According to that article, the breaking length of steel is 26 miles, of kevlar 256 miles, and of carbon nanotube 4,716 miles.

Would that (the longer tube) take into effect the diminishing force of gravity on each additional mile?

Would that (the longer tube) take into effect the diminishing force of gravity on each additional mile?

No. From the description I quoted:

For this measurement, the definition of weight is the force of gravity at the earth's surface applying to the entire length of the material, not diminishing with height.

Sorry. Stupid.

Interesting idea, but wouldn't the weight of that much wire be more than the weight of a transmitter? Also, resistance in something that long would probably be an issue

Join the a-rocket mailing list for extremely high SNR discussion: http://www.arocketry.net/forum.html

Well, there's also the subproblem approach: (Note, I'm completely speaking out of my ass)

- Launch a string of relays between orbit & the moon. They may only work once a month, but that just means you have to have the judges there that day :-) Each one can be a control board, radio, and solar panel. Swarm satellites, I think they were called, only in a straightish-line.

- Make the actual lander dead, dead, dead simple. Like forward & turn-in-reverse RC car simple. Make it small & rugged, but put little/no control electronics onboard. Power (unless you can beam it in from a near-moon satellite into a battery pack -- it's fine to let the rover sit around 29 days, 23 hr, 45 min of the month, to let it charge), and receiver(s) to control the motor(s).

- Data transmission could be a controllable mirror, and a relay with a good camera!

But I guess this all really depends on another question: what's the cost to weight function? Purely linear? Is it cheaper to do two launches of weight W instead of one launch of weight 2W, over a minimal value for W?

If a launcher for a standard size object can be the primary cost of the system, we could launch relays and landers in swarms and leave the big money for the launcher. 10% success rate? Launch 15 to be sure.

Also, one situated between three high-altitude balloons would look pretty sweet.

Many interesting thoughts here. A few comments:

It is very difficult to make a launch vehicle powerful enough of your own. No matter how you do it, you will need a good deal of propellant for lunar transit, descent and landing. This means the launch mass is bound to be relatively high. Also, your launch vehicle has to be capable of reaching orbital velocity (approximately mach 22). Even the best amateur rockets, to my knowledge, have only achieved around a fourth of this velocity, and that is with no payload.

Ion drives aren't practical for a mission like this for a number of reasons. For a full discussion of why, please see this article: http://openspacex.org/2008/10/06/escaping-the-grip-of-mother...

If you are interested in having your ideas seriously considered, please consider joining Team FREDNET, an open source team in the Google Lunar X PRIZE. Most everyone are welcome: http://www.teamfrednet.org

What's the breakdown of costs... my intuition is that the biggest number is from launch (especially fuel) but am I wrong?

Yes, the launch is the real cost driver for space economics. Launch costs alone are in the neighborhood of $10,000/kg for large American providers and somewhat less in other providers/countries. I believe no one has come close to the $1,000/kg mark yet.

Because launch is so expensive, people then spend a lot more money making sure the payloads are ultra-reliable (launching a replacement is just too expensive). Because costs are so high, there isn't enough business to really get good economies of scale (yet...go SpaceX!) - so a lot of money goes into design and testing of new rockets that will only see 10-100 units built.

As for launch itself, fuel is pretty cheap - turbopumps are expensive. It is the high-precision machining of parts that ends up costing you. If you can reuse the hardware, then you get savings for future launches and everyone is happy.

the breakdown of costs... my intuition is that the biggest number is from launch (especially fuel)

The fuel cost for any given launch is virtually zero. http://yarchive.net/space/rocket/fuels/fuel_costs.html

Smaller is probably better. I read something in Forbes (or maybe Fortune Small Business) about a guy who is building small rockets capable of launching things like science experiments and people's ashes into space. He's apparently one of the first clients of Spaceport America.

I don't think they were capable of deploying satellites or additional stages, but perhaps a similar design could.

Another thing to consider would be having the planetary transmitter be a separate module from the rover, allowing a smaller rover, and a smaller lander. The rover would then just need a less powerful radio. The more powerful transmitter could be landed separately, or even remain in orbit.

High altitude balloons are great fun. I am working on a rocket launch mechanism for one in my spare time. Costs are really low.

http://www.hobbyspace.com/NearSpace/index.html

Thermal protection and heat dissipation will most likely be a hard problem.

Getting a lander to survive into the lunar night is a big challenge in its own right.

If it can't survive the night, that places other constraints on the mission.

Why is it hard to survive the night? Because of the coldness? Why would the coldness be a problem? Even if the machine couldn't operate in such a low temperature, can't it just hibernate until day?

So ... IANARS (I Am Not A Rocket Scientist) ...

The lunar night is about 2 weeks long. The night-time surface temperature is about -230 C to -150 C.

I'm not sure how long it would take a lander to cool down at local sunset, but it might be pretty fast. That kind of cooling can create stresses and actually break mechanical connections or electrical components.

It's a lot warmer at about 1 m under the surface, but you have to get there somehow.

What if we rethought the design of the "rover" to make it smaller and the whole launch mass less? I don't think there's a requirement for a four or even three wheel rover. Instead, we could use a clear double inflatable ball with an instrument package and a motor inside. This allows for a < 10lb/5kg rover. We could pack dozens of these in several rockets to the moon. Redundancy would be in our favor. Kind of like moving from big-iron servers to farms.

This is my inspiration for the double inflatable ball: http://www.hammacher.com/publish/72182.asp

Employing high-altitude balloons to cut down on launch costs is potential feasible, as traditional launches can run into the tens of thousands of dollars (or more) per lb.

One potential problem with going small on the rover end is that the prize stipulates that the rover must travel a prescribed distance on the lunar surface, and going too small will make traversing distance a much greater obstacle that it already is. Additionally, how would one power the antenna necessary to communicate with earth (I am thinking specifically of battery power only, and I think it would in and of itself weigh more than a pound)?

traditional launches can run into the tens of thousands of dollars (or more) per lb.

$8.90/lb. http://neverworld.net/truax

http://news.ycombinator.com/item?id=429099

assuming we take SpaceX on their word, that the "Falcon 1 is the world’s lowest cost per flight to orbit of a production rocket", and take the cost and payload weight right of the website, then for a 1010 kg payload at $9.1M, that works out to be roughly, $4095 / lb.

from: http://www.spacex.com/falcon1.php

Employing high-altitude balloons to cut down on launch costs is potential feasible

How would high-altitude balloons reduce launch costs?

Not by much. Most of the energy cost of a launch to Earth orbit involves getting to orbital velocity. Getting an object that high is pretty easy by comparison.

(Get out your physics textbook and compare the kinetic energy of something going Mach 24 to the potential energy of something dropping 100 km.)

I'd expect a mistake like this from a high school student or a freshman. If you're not clear about this, then you have a perhaps a bit of homework to do before posting questions about space to a social news site that prides itself on informed, intelligent discussion.

Perhaps start with Zubrin's _Entering Space_. Any number of books about the space program will do as well.

I don't think a person should "do his homework" before asking a mere thought-provoking toy question. However naive the question, it has potential for informed, intelligent discussion.

Not if you're off by an order of magnitude!

It's entirely logical: you just have to think outside the box (big enough baloon vs. small enough vehicle: plus it overcomes some of the niggly "near ground" effects [why do you think so many next-gen space vehicle designs launch from Airplanes??])

The physics is there and probably workable.

(EDIT: my initial thoughts would tend towards a high altitude launch of several smaller sized vehicles that re-assemble on the lunar surface... or interact there. S o for example someone above mentions the comms issue: a static relay planted on the surface interfacing with a seperate rover device would probably work well. In fact I would launch 2 or 3 of each type (assuming cost could be kept low) to ensure that you got at least one functioning pair :D)

Jet airplanes also give you something like 600 mph of initial velocity. In the case of Pegasus and Space Ship One, they are like the first stage rocket.

The Rocket Equation is pretty nasty. When your required delta-v goes up, your reaction mass requirement goes up faster than a polynomial function. Saving the initial 600 mph is very significant. Balloons -- only sounding rockets use those, but they don't do anything but gain altitude anyhow. If you need escape velocity or orbit, then they are pretty much useless. (You might as well build a slightly bigger rocket.)

Please actually do the physics before you post vacuous statements like:

The physics is there and probably workable.

People are having "intelligent discussions" about balloon assisted launch? Eternal September has gotten to HN!

I have done the physics: or spoken to people that have.

In fact I have seen a successful small rocket launched from a 100 ft high ballon platform (the physics is painful but it is possible).

Other ideas like centrifuge acceleration I know have been discussed: and I personally see potential in them (Ammers & Myers, Oxford University Press, 2006 I think: I'll try and dig out a reference #).

With equal respect I suggest you actually try to think outside the box before posting vacuous statements stating it is impossible.... ;)

EDIT: BTW you do know NASA have recently been exploring the possiblity too.... admittedly for low earth orbit sattelites (and i know that a major problem is breaking that barrier - but it is proof of an initial concept....)

The crucial data is that ballons can carry rockets to a MUCH higher altitude than planes. The reduced drag at that altitude means a lot less propellant is needed (and even a solid fuel propellant could suffice).

NASA has plans for a ballon that can carry up to a ton of equipment to a height of 33Km which is pretty good!

You've also missed the point of the airplane: 600MPH is frankyl nothing (4% of the speed required for LEO). The important thing is the lowered drag and kinetic requirements to get the payload to LEO.

I have seen a successful small rocket launched from a 100 ft high ballon platform

That was a sounding rocket. As Stcredzero wrote in the message you responded to, "Balloons -- only sounding rockets use those." http://en.wikipedia.org/wiki/Sounding_rocket

http://www.astronautix.com/lvs/rockoon.htm

I present to you Cambridge University no less...

http://en.wikipedia.org/wiki/CU_Spaceflight

And NASA are at work on a system to launch pico and micro satelites in near earth orbits.

I present to you Cambridge University http://en.wikipedia.org/wiki/CU_Spaceflight

Why are you presenting that? Did you read that page? It discusses the launching of sounding rockets (rockets that go up, not into orbit). Is there anything about orbital launch, or orbital speed, there?

Well HN I am a bit disappointed in this "cant be done" give up attitude... I assure you it can and will be done.

I assumed you'd have the initiative to follow the links and read up on CU Spaceflight.... but apparently not (hint: that was a hint).

If that's not good enough then lets go with NASA... http://academy.grc.nasa.gov/2008/group-project/new-launch-te...

They also have a design for a ballon to reach 110,000 feet which could carry up to a ton of equipment. I'm thinking centrifuge or "gun" launch at the altitude might go well :D

Well HN

Hacker News?

I am a bit disappointed in this "cant be done" give up attitude.

What are you referring to?

I assure you it can and will be done.

What can be done? Orbital launch from a balloon? If the subject is orbital launch from a balloon, why did you post a link to the Wikipedia article on CU spaceflight?

I assumed you'd have the initiative to follow the links and read up on CU Spaceflight

Which links? The Martlet Project link http://www.srcf.ucam.org/~cuspaceflight/martlet.php says, "The aim of the Martlet Project is to develop a small sounding rocket system that will be launched from a helium balloon." There is nothing there about orbital launch from a balloon. Do you know what a sounding rocket is?

Please post the specific links that you think have to do with orbital launch from balloons.

I posted one, the NASA link: which is research into exaclty what we were talking about.

CU Spaceflight is launching a new test flight later this year: I was told (by an ex-team member actually) that it was intended to pave the way for orbital launches.

As to what I was referring to: I meant the off hand dismissal of every piece of work towards launching from Balloons... I agree sounding rockets (yes I know what they are thanks ;)) are not orbital devices - but it proves the groundwork and paves the way to more exciting stuff.. surely.. dismissing such data offhand seems a little unhackerish and uninspired :(

To clarify my point... (as it seems to have got lost in the noise) - There have been no orbital launches from balloons to date - There HAVE been sub orbital launches to date - NASA (and possible CU) are looking into launching orbital devices from balloons - NASA have plans for a Balloon which will be able to carry a ton of equipment up to a "launchable" height. - My conclusion from this is that far from being impossible it is perfectly within possibility, probably with our current technology.

@all Sorry to feed the trolling.. now that my point is clear I shall move on ;) :D

You've also missed the point of the airplane: 600MPH is frankyl nothing (4% of the speed required for LEO).

Small increases in speed would indeed be relatively unimportant in regard to only a final stage. When, instead, an increase in speed affects an entire rocket stack, it becomes important, since lower stages are exponentially more massive than upper stages. For the same reason, it can be important to launch from the equator, since equatorial launch provides 465 m/s of speed, not only for the final payload, but for the entire rocket stack.

More accessible challenges can be found here, including a tether for a space elevator and an astronaut glove.

http://news.ycombinator.com/item?id=442634

There has to be a way, I used to think about this, too...

Not sure if balloons get you that far, though. I think mostly you can avoid the friction of the air to some extent, but if I remember correctly, the altitude where you still have air to float a balloon in is only a tiny fraction of the stationary orbit altitude.

Just a thought right now: what about nanobots? Perhaps something could be made so tiny that it doesn't even fall down... kind of like a balloon without a balloon. Not sure if it would still be workable without an atmosphere...

Yeah unfortunately the altitude isn't really the problem. It's high speeds that you want. The altitude just gets you away from the atmosphere which will stop you achieving the high speeds.

Maybe since fuel isn't so expensive it isn't such an issue anymore, but I really like the idea of somehow powering a vehicle with solar power. The nice thing about velocity is that without friction, you can get really fast over time even with relatively weak acceleration. No idea whatsoever how to accelerate a rocket with electricity alone, though... Is it even possible? I think NASA has some models, but for long distance stuff...

Lookup "Ion Drive". If you end up on a Star Wars site, you've missed; there's a real such thing that has flown in real space.

You can't launch on an Ion drive, though. (Even if you made it powerful enough, that would mean irradiating the entire launch area with instantly-lethal radiation, not a terribly social thing to do.) The way to a solar-powered launch is that you use solar power to create the rocket fuel, which in the simplest case is simply cracking water into H and O.

Solar panels are orders of magnitude away from being able to launch themselves in real time. Take a solar panel, compute its mass, compute how much energy it can generate in a day, convert that to potential energy in Earth's gravitational field, and you'll get a sense of the maximum speed a panel could possibly rise with perfect conversion of energy to height (which we have no idea how to do anyhow). I haven't done the math but if you get a rise rate of more than a few inches a second during the brightest part of the day I'd be surprised.

You can't broadcast from something that only weighs a pound or two.

The launch is by far the most expensive part, so going multiple trips isn't really an option.

The folks who won the Urban Grand Challenge have a great approach: http://astrobotictechnology.com/ http://www.youtube.com/user/AstroboticTechnology

This might sound strange, but instead of radio broadcasts, what about the possibility of doing broadcasts with bursts of light utilising lasers?

I guess my thought is based off the old idea that you could intercept data off a modem by reading its LED at some considerable distance - and just upscaling it with more powerful tech.

http://applied-math.org/optical_tempest.pdf

I realise that it would be near impossible to have the Earth visually see the transmission on a consistent basis, so what about a satellite in earth's orbit that essentially matched the moon's orbit, creating some kind of relay station.

what about a satellite in earth's orbit that essentially matched the moon's orbit

L1. http://en.wikipedia.org/wiki/Lagrangian_point

doesn't it also have to move?

and isn't the point to make some progress in spacefaring?

it would be near impossible to have the Earth visually see the transmission on a consistent basis

How do you figure?

Or better yet, use a passive element on the moon side. There are optical reflectors up there from moon missions that people can bounce (large) earth based lasers off of. Imagine one of those with a single LCD film over it. You can then selectively polarize the reflected light at virtually zero power use. It won't be a fast bit rate, the LCD could to 100bps easily, but I wonder what the atmospheric scattering does to the wavefront.

> I realise that it would be near impossible to have the Earth visually see the transmission on a consistent basis, so what about a satellite in earth's orbit that essentially matched the moon's orbit, creating some kind of relay station.

Expensive.

I think you could design something that could communicate that weighed less than a pound.

You have line-of-sight, and at the earth end you can build (or just rent) a huge antennea and use huge amounts of energy to send the signal. Think about how they talked to pioneer and so on -- those are much further away, and we detect billionth of watt signals, and blast huge signals back out.

I think the optical communication is interesting, because earth bound telescopes might be able to pick up several super LEDs. The bandwidth doesn't have to be huge -- you can morse code that light very slowly, 2 seconds on is a 1 and 1 second on is a 0, or even slower. It can take a week to transmit, and only transmit when the moon is in shadow, to be sure to give good contrast.

If commands must be sent to it, radio will be the best I suspect. So much work in the history of radio has gone into learning how to make big, power transmitters and tiny, cheap receivers. You will have to have a key embedded in your rover so that some joker doesn't send it the wrong commands for you.

I thought about this google challange thing, and I figured a tiny rover with motors from cell phone vibrators, an atmel chip wrapped in foil, a capacitor storage and tiny photocell, would be best. It would be less than the size of a pack of cigarettes, you would aim for a smooth part of the moon to the extent that you could aim, and hope that it move in spurts over the course of a few months. You might be able to drag a thin hair-like copper wire in order to get a longer antennea for receiving.

It might cost 10k per pound to launch to low earth orbit, but I don't think you can buy 1 pound for 10k dollars. In anycase, if you were in low earth orbit, how would you get to the moon ? You could try to do the solar sail thing, maybe agmented by a tiny occasionally firing ion thruster powered by photovoltaics, but in low earth orbit the sails will have some drag that might pull you in before you ever get started.

So I still think you need a million or more dollars, and the orbit to moon part is not solved.

If a company were formed to do this, and shares were sold to raise money; if the share holders could vote on officers and major decisions the way the Debian community does, or via a system such as www.DeliberativeAssembly.com; I might invest never expecting to see my money back, but hoping the effort would lead to something interesting.

By "invest", I mean one stock should be between $100 and $1000 dollars, and I would by one.

If you really want to attempt this, the correct approach would be to approach the problem from the perspective that gravity is the force you have to defeat. Find a way to reduce this force significantly and you may find a cheap solution.

For example, magnets defeat this force. Look for things that can work against gravity even in the absence of air.

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