N-Prize

[BrianJ]

Thought this might be of interest.

From the website http://www.n-prize.com/

The N-Prize is a cash prize of £9, 999.99 (nine thousand, nine hundred and ninety-nine pounds and ninety-nine pence, sterling), which will be awarded to the first person or group to put into orbit, around the Earth, a satellite with a mass of between 9.99 and 19.99 grams, and to prove that it has completed at least 9 orbits. The cost of the launch (but not ground facilities) must fall within a budget of £999.99. Imaginative use of string and chewing gum is encouraged. Entrants are responsible for everything, organisers are responsible for nothing.

Any ideas?

Regards,
Brian

 

[Urwumpe]

Impossible to do with current technology. The materials don't exist and aerodynamics are not favorable for small payload masses.

 

[reverend]

I think fuel alone for this would cost in excess of 999... Of course the rocket body would also weigh in excess of 19.99g, so I guess this would also require a release mechinism, more mass... and also, I'm not sure a sufficiently powerful radio transmitter and powerpack could be incorporated for tracking to prove the 9 orbits, without the help of NORAD... I'm sure they'd be very interested though...

 

[simonpro]

I'm pretty sure £999.99 wouldn't be able to buy you enough fuel to get into orbit.

 

[reverend]

Atleast not with a Solid Rocket Motor.

By using LH2/LOX, you could skew the budget by implying the fuel was 'free' if you manufactured it yourself, in which case the 'ground equipment' necessary to make the fuel could be excluded from the budget.

The problem with that is the cryo equipment needed onboard the rocket to contain the liquid fuels. This would be very costly, and bulky.

Here's how I figured out that it couldn't work with a solid motor...

UK£ 999.99 = 1 980.0802 US$ (I needed this, Thanks Google Calculator)

The fuel I'm working with for my rockets is KNO3/Sorbitol/Red Iron Oxide. This is the cheapest fuel I know of, when evaluated on a basis of Cost divided by max deliverable ISP. This fuel cost me $1.90 per Pound (LB).

If the entire budget were spent on fuel alone, this would allow for 1042 LB's of fuel (472.709 kilograms).

This much fuel could build a motor like this
Grain mass453.876kg.1000.608lb.Total impulse622101.7N-sec.139861.0lb-sec.Average thrust54755.5N.12309.6lb.Thrust time11.361sec.Specific Impulse139.8sec.Motor ClassificationQ54755

Given... that's a nicely big motor, but definetely not close to what's needed for orbital velocity.

Here's some nice videos of Q size motors however:

[ame="http://youtube.com/watch?v=cuKKzG-JFWw"]YouTube - Q motor[/ame]

 

[BrianJ]

Impossible to do with current technology.

What!? Not even with an unlimited supply of chewing gum, string, sticky-backed plastic and squeezy-bottles?

Reverend, I thought you might have an angle on this. How much does your "Rocket Candy" fuel cost to make? EDIT: Wow, got the answer before I could even hit the post button...
Well, if it's too expensive we'll just have to....err...borrow some.

This guy has some interesting ideas:
http://groups.google.com/group/n-pr...-as-climbers-attack-everest-a-staged-approach

 

[Coolhand]

It seemed good until he mentioned launching the rocket *through* the lifting balloon... How would it punch through cleanly, without becoming caught in the material of the balloon? I mean know it's thin stuff but it's not going to have that much velocity relative to the balloon by the time it hits, It could get hung up in it - attempting to take the balloon with it into orbit. or even if it makes it through, if it's trailing any excess material i expect it'll quickly go off course. You'd have to find some way of going around the balloon, not though it, imo.

 

[Zatnikitelman]

Radio wise it would work. You don't need more than a watt or so to make good connection with the ground for a basic telemetry signal. By using high-gain ground antennas with great directionality, you could easily compute when this thing makes an orbit. Using even two tracking stations spaced out a few hundred feet on Earth would probably work, plus if you used a Ham frequency, you could drag every willing Ham on Earth into this
Many people use Altoids-can radios with power so low that their calculations for miles/watt are in the millions of miles!

 

[Paul1684]

Impossible to do with current technology. The materials don't exist and aerodynamics are not favorable for small payload masses.

I think it is possible, once you start to think outside the box (albeit a re-used cardboard box). First, to clarify, the £999.99 budget has to cover only the expendable items (hence, not any tracking systems or other ground facilities; nor any items which are recovered and reuseable, if you choose to go that way).

I agree, a ground-to-space direct launch is almost certainly not an option unless you go for reuseability - aerodynamics mean that you've got no advantage in making the thing small to suit the tiny payload.

However, a rockoon approach is very different. Aerodynamics are largely factored out, and what's left scales a lot more favourably with payload. In terms of expenditure per orbital mass, we're actually pretty generous here.

A few other points. (1) Failure *is* an option; forget redundancy and over-hardened systems, and accept a significant probability of failure (2) tracking - yes, by radio; but also yes optically - it can be a lot easier, if your final stage can tell you where the satellite is released and if you can recruit some help. (3) ebay and junkyards are your friends. (4) For everything you need to do, there's a cheap way, a safe way, a quick way and an easy way; these are usually four distinct options.

I've heard arguments already between some very relaxed happy people who think it just might be possible, and a lot of very tense unhappy people explaining why it's not. The fact that the arguments have generally dragged on for quite a while tells me that it's possible, remotely.

Feel free to drop by the N-prize group (linked from our "contacts" page). Sooner or later, we hope to get organised enough to have links to other sites, and we'd be honoured to include yours.

Best,
Paul (foolhardy optimist and N-prize founder)

 

[cjp]

Best,
Paul (foolhardy optimist and N-prize founder)

:speakcool:

Now that the founder himself is here, can I ask you a question?

Would it be acceptable to bribe some russian or chinese ground crew to hide your tiny satellite somewhere next to another satellite on a heavy launch vehicle? I'm sure those heavy russian rockets wouldn't even notice the extra weight.

 

[reverend]

I should note that I never said it wasn't possible, just not with a single rolid rocket motor... I do like the idea of orbital insertion via cannon... but not very practical if the technology was to ever have another use. You could shoot a solid hunk of highly radar reflective metal tracked by ground radar, but what real use would there be for this... an electronics package could not withstand the G forces experienced being accelerated to cannon style muzzle velocities in a split second.

This contest would definetly have it's big hurdles... I'm not sure the re-usable parts argument applies... this would imply that the parts are recoverable and intact.... this pretty much excludes whatever platform makes the orbital insertion, and a recovery of the first stage would be difficult to say the least. Unless you get into the realm of a fully reusable 'ship', but fuel for that would definetely exceed budget.

I'd like to say the task of putting a nanosat in orbit can be accomplished, and pretty easily I might add with a 2 or 3 stage rocket, with any kind of motor (solid, hybrid, liquid, or gaseous), but not within that budget. This wouldn't come close to covering the cost of even a cheap fuel, not to mention the rest of the rocket (the motor casing, rocket body, recovery systems, guidance and telemetry electronics and all that jazz). Who knows what 999GBP will buy by the time one of these nanosats would be ready to fly.

$10,000 would be a tight budget.
$100,000 would be plenty of room to work with, and might I add, still alot cheaper than the $600,000 India just charged it's patrons to put their nanosats in orbit.

 

[Andy44]

Actually, many cannon shells have electronics in their fuses, and some are even laser guided. So if you're not firing it too hard, that may work. All you need is a simple lo-jack transmitter, right?

 

[mjessick]

Is there a time limit? The longer you wait for the next year or so, the more dollars you can spend on the rocket (Based on exchange rate projections.)

 

[reverend]

The nano sat must be between 9.99 and 19.99 grams... This would be about the size of a 30-06 bullet... To get an idea of hwo much that is..., for those in the U.S... a Nickel weighs 5 grams... This means the satellite must have a total weight of 2-4 nickels. cannon I guess is out of the question, it would be more like a high powered rifle... I don't know enough about micro-electronics and whether or not something could be fit inside the bullet, but I would doubt it, especially not a lojack transmitter.

Also, if it actually used a 30-06 rig, that means that we wouldn't have to worry about the last 800m/s or so of deltaV for orbit injection. This helps quite a bit. I suppose more black powder could be used to achieve even higher velocities.

Again... the benefit of shooting a bullet into space is...?

I'm pretty sure no 'useful' electronics could be included in such a small size, and I doubt none that could withstand the G-force involved... The laser guided and satellite guided artillery is fired from a howitzer. The size of the shell provides enough room for electronics and padding?

 

[Andy44]

Hmm, yeah, but how would you even track something so small? This contest seems self-defeating. Why not allow bonus points for bigger satellites?

 

[simonpro]

I think it is possible, once you start to think outside the box (albeit a re-used cardboard box). First, to clarify, the £999.99 budget has to cover only the expendable items (hence, not any tracking systems or other ground facilities; nor any items which are recovered and reuseable, if you choose to go that way).

So the £999.99 covers only the satellite, plus whatever bits of rocket you use to put it up, but that you don't get back.

A few other points. (1) Failure *is* an option; forget redundancy and over-hardened systems, and accept a significant probability of failure (2) tracking - yes, by radio; but also yes optically - it can be a lot easier, if your final stage can tell you where the satellite is released and if you can recruit some help. (3) ebay and junkyards are your friends. (4) For everything you need to do, there's a cheap way, a safe way, a quick way and an easy way; these are usually four distinct options.

The problem is, ebay rarely has anything that would be much use for something like this. I've just done a quick search for items that (off the top of my head) I'd need to complete this challenge. I found absolutely none of them.

The fact that the arguments have generally dragged on for quite a while tells me that it's possible, remotely.

anything is possible until you consider any form of budget. Hence why I'm not signing up until Denmark gets more fasvourable exchange rates

 

[ijuin]

I'm pretty sure no 'useful' electronics could be included in such a small size, and I doubt none that could withstand the G-force involved... The laser guided and satellite guided artillery is fired from a howitzer. The size of the shell provides enough room for electronics and padding?

Hmm, yeah, but how would you even track something so small? This contest seems self-defeating. Why not allow bonus points for bigger satellites?

Given that this is a demonstration satellite, a simple transponder sending out an omnidirectional radio signal at tens of milliwatts and powered by a watch battery should be a sufficient payload.

What about plain old kerosene/LOX fuel? The LOX can be listed as free if you produce it on-site, and last I heard kerosene was still only about US$1.00 a kilogram.

 

[thomasantony]

The PSLV launch charged $12000/kg for the nanosats. That would mean 20g -> $240. Doable?

~Thomas

 

[reverend]

The PSLV launch charged $12000/kg for the nanosats. That would mean 20g -> $240. Doable?

~Thomas

Sorry I must have misunderstood this
USD 0.6 million was charged for the nano satellites

 

[Urwumpe]

The main problems you will have to counter:

- You will always need a rocket engine. If not for leaving earth, at least for a apogee maneuver to stay in orbit.
- The structures of a rocket stage do not scale for lighter payloads. You need to get some structural strength for keeping the liquid fuel pressurized or allow the solid fuel to combust and in a small scale motor, you only have two useful options: Solid or pressure fed (regardless which kind of liquid engine you finally use - monopropellant, bipropellant or hybrid).
- Drag will be significant higher for smaller rockets compared to larger rockets. That is because of simple geometry (If you make the rocket 50% lighter and keep the density as high as before, the area will only drop by 37%) and the viscosity of air.
- Aerodynamic heating will be far worse for smaller vehicles as for larger. You have more surface per kg rocket mass. A cannon which manages to accelerate the payload to 3500 m/s and lets it get in contact with the air at only 10000 m altitude (a really fictional scenario), would expose the outer shell of the projectile to a heat flux of 10.72 GW/m². Thats the power output of a larger nuclear power plant on each square meter.
- Rocket equation says: Even for a small 20g payload, you would need a roughly 10 ton launch vehicle, because you can't make the structures as light, as you would want them. Even if the payload is just a transponder on the final rocket stage.