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N-Prize
There's plenty of room at the bottom at the top. | |
[UPDATE 10th April 2008. The N-Prize
has now been taken to the Real World,
and can be found at www.n-prize.com.
Please visit the site for the latest version
of the rules.
Many thanks to [Wagster] and all at
pictureandword for setting up the site,
and to Jutta for allowing
reciprocal
linking.
To avoid confusion to visitors from the
N-prize site, Maxwell Buchanan would
like to confess that he is actually mild-
mannered scientist Paul H. Dear]
I suspect similar ideas have been
proposed before, so I'll delete this if
people think it's not worth discussing.
Actually, it may even not be an invention,
except that the invention is a
competition.
The challenge is to put a payload of
between 9.99 and 19.99
grams (that's the weight of 2-4 quarters
or
1-2 £1 coins) into orbit (defined as being
able
to complete 99 orbits or more before
re-entry or loss) for a total cost of
£999.99 or
less.
This is the cost of the launch vehicle,
payload, fuel, and any ground-based
systems
needed to support it, but excludes
development or prototyping costs. The
satellite has to be detected from earth by
some means, sufficiently to confirm that
it has completed at least 99 orbits. The
cost of the detection is not part of
the £999.99, and outside help may be
recruited.
The orbit needn't be regular or stable - it
just has to get there and stay up for 99
orbits. Prize value is £9,999.99. Other
rules may be imposed entirely at the
whim of the organizers, to block any
loopholes which go against the spirit of
the challenge. Entrants are strongly
advised to contact the organisers before
and during development.
Entrants are entirely responsible for their
own safety and that of others.
Compliance or otherwise with relevant
regulations is entirely the responsibility
of the entrants, who will be liable for any
costs, legal penalties etc arising from
compliance or lack thereof. Any costs
incurred in the course of complying with
regulations (for example, permits, safety
inspections etc) will be considered part
of the cost of the project, and must
therefore fall within the £999.99 limit.
Any legal costs, fines etc incurred
through non-compliance, however, will
_not_ be considered part of the cost of
the project.
Imaginative scavenging and borrowing is
encouraged, but only within the spirit of
the challenge. Broadly, extensive use of
salvaged or redundant space hardware is
unlikely to be permitted. In the same
spirit, a wealthy sponsor who custom-
builds something and then "lends" it to
the project or sells it at an unrealistically
low price, would breach the rules.
[***The above is the idea as posted.
Please see the updated rules at www.n-
prize.com***]
Starshine
http://www.azinet.com/starshine/
No batteries. It blinks. [Amos Kito, Feb 13 2008, last modified Feb 14 2008]
Planet You
Planet_20You
use the winning system to send these up one at a time [xenzag, Feb 14 2008]
HARP
http://en.wikipedia...g/wiki/Project_HARP
Cheaper than rockets ... [8th of 7, Feb 14 2008]
Another HARP link
http://www.astronau...ticles/abroject.htm
//I saw a show that said we (USA) built a small one// 176 feet a small one? You must be a Texan [coprocephalous, Feb 14 2008]
National Association of Rocketry
http://www.nar.org/
WP states licenses usually mimic these for other countries [MisterQED, Feb 15 2008]
Tripoli Rocketry Association
http://www.tripoli.org/
[MisterQED, Feb 15 2008]
Cool Balloon link covering some regs
http://vpizza.org/~jmeehan/balloon/
Detail of a guy launching a weather balloon [MisterQED, Feb 15 2008]
Weather balloon suppier
http://www.kaymont.com/pages/home.cfm
[MisterQED, Feb 15 2008]
(??) B.C. inventor wants to put pop bottle rocket into orbit
http://www.cbc.ca/c...0217/K021704AU.html
[tatterdemalion, Feb 18 2008]
Low Earth Orbit details
http://en.wikipedia...iki/Low_Earth_Orbit
[MisterQED, Feb 20 2008]
Energy Density - Lately my favorite page of Wikipedia
http://en.wikipedia...wiki/Energy_density
[MisterQED, Feb 20 2008]
Westphalia, Germany
http://en.wikipedia...th_Rhine-Westphalia
I have no idea what this has to do with anything, though. [jutta, Feb 20 2008]
Rockeloonannon
Rockeloonannon
[BunsenHoneydew, Feb 28 2008]
Are Amateur Orbital Rockets Possible?
http://gramlich.net..._rockets/index.html
[MisterQED, Mar 18 2008]
The N-prize Web site
http://www.n-prize.com
Please visit the site for the latest rules. [MaxwellBuchanan, Apr 10 2008]
Attacking Space like Everest
http://groups.googl...t-a-staged-approach
Way too long to post here but hope it deserves the link [MisterQED, Apr 15 2008]
N-Prize in the New Scientist space blog: Whimsical 'N-prize' to spur ultra-cheap space launches
http://www.newscien...%20space%20launches
Well done, MaxwellBuchanan! [django, Apr 28 2008]
Amateur spaceshot success
http://en.wikipedia....22GoFast.22_Rocket
Never knew about this one [BunsenHoneydew, Apr 29 2008]
Radio report on N-Prize
http://www.abc.net....8/04/08/2210606.htm
Go to the topmost of the audio links on the left, starting about 5 minutes in. Regrettably no mention of the HB.... [MaxwellBuchanan, Apr 29 2008]
A Cult of Backyard Rocketeers Keeps the Solid Fuel Burning
http://www.nytimes....00&partner=homepage
[Klaatu, Apr 30 2008]
More blatant elf-promotion
http://archived.the...-BWB-2008-06-06.mp3
The Space Show 6th June, about N-Prize. [MaxwellBuchanan, Jun 07 2008]
Slashdot article
http://science.slas...06/17/1420213.shtml
nice work. front page of slashdot [xaviergisz, Jun 18 2008]
Another Mad Scheme
http://jca3.freeshe...pace/spacebets.html
Similar to N-Prize but self-funding. (An old fantasy of mine.) [jcatkeson, Jun 20 2008]
[link]
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<Zoolander moment>What is this? A space program for ANTS?!?</Zm> |
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Or uncles. Or anyone, in fact. |
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One problem with this is going to be to
get the necessary cooperation in
detecting the signal. The femtosatellite
is going to be in a (probably) uncertain
and unstable orbit, and will be emitting
a very weak signal at long intervals.
Detection would require a lot of
international co-operation, I imagine.
This in turn would require the challenge
to be well-publicised, such that
detecting the signal would become as
much of a sport as putting the thing up
there. Unless anyone has any smarter
ideas. |
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Nice, I was just coming home to post this, so I guess I like it (+), though the prize needs to be larger. The permits are going to cost a thousand or so. |
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Man those are strict weight limits considering the signal has to be "heard" from Earth. I think to only thing that efficient is a directed LED light and the receiver is a telescope. Still even for that I think you'd need a gyro so the LED is aimed roughly Earthward. |
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Could you use a reflective tail fin for direction? That would only fix one axis. |
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For 10 grams you can get a small solar panel, capacitor, timer, and a xenon flash tube. |
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// The permits are going to cost a
thousand or so.// The awarders of the
prize strongly discourage the seeking of
permits, and the cost of such permits
will be considered part of the cost of
the launch. |
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//Man those are strict weight limits //
We might consider revising this to read
"payload of at least 10 grams", though
the cost limitation would probably
favour lighter, more ingenious craft. |
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I like the idea of optical detection -
would it work? How easy would it be to
scan the skies for a flash tube at orbital
heights? |
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Starshine [Link] was in orbit at 390km, and covered in small mirrors (maybe 3cm dia.). I don't think it was much trouble for people to locate, when they had the track info. With an integral strobe, you wouldn't rely on a solar reflection -- so you could watch for it all night. |
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<slightlly off-topic> STARSHINE has to be the best case of an acronym that fits (too) perfectly with what it is. Do you think they came up with the abbreviation first, then tried to fit description to it? (For those who don't know, STARSHINE is Student Tracked Atmospheric Research Satellite Heuristic International Networking Experiment.)</sot> |
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You could just use 10 grams of radioactive material, that should be fairly easy to detect. |
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I believe the current cost of launching stuff into ordit is around $10,000/kg. I think a better competition would be that you have to get an amount of cargo into orbit for less than $10 per gram. So that would mean around 200 grams for £999.99. |
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That should be within the realms of possibility, after all, it's not brain surgery. |
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//it's not brain surgery//
This is why I had such a hard time breaking my addiction to this site years ago. That's rightous! |
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//You could just use 10 grams of radioactive material, that should be fairly easy to detect.// Would it? Isn't one of the nasty things about space is all the fun radiation blowing around, wouldn't it get lost in the rest of the radioactive background noise? |
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Each type of radiation has a frequency, including light. If you choose an element which emits a frequency which is distinct from the background radiation, and suitable for penetrating the atmosphere, you would have a better chance of detecting it than a light-emitting device of the same size. |
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I guess you could use a piezo crystal and a watch battery to emit radio waves at a specific frequency instead. |
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Fortunately for us, our atmosphere is totally opaque to alpha particle (helium nuclei) and beta particle (electron) radiation, and severely attenuates radiation all the way across the gamma band. For example, the Van Allen radiation belts are not detectable from the earth's surface. (The radiation part, anyway. Indirect measurements can be done with VLF radio.) Satellites have been developed that can spot radiation from a nuclear explosion, but they can't find geologic deposits of radioactive ores. (At least, not by means of emitted radiation.) |
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Just get rid of the weight limit, the cost limit pretty much sets a maximum weight and the stipulation for trackbility sets a minimum. |
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Oh yeah, and up the budget a little. Around here, $1000 / £500 would be a good budget if you wanted a vehicle that just might make it south of the river. It's not really going to get anything into space, no matter how ingenious you are. Maybe $10,000? |
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//I don't think it was much trouble for
people to locate, when they had the
track info.// Yes, but we may not have
any track information - remember,
we're not going for a precisely defined
orbit. |
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//radioactive material, that should be
fairly easy to detect. // Not from the
ground it won't be, alas. |
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//a better competition would be that
you have to get an amount of cargo into
orbit for less than $10 per gram//
Well, what I'm hoping for is for people
to be doing this from their back
gardens. As soon as you start trying to
launch heavier things, it becomes more
hazardous and perhaps less innovative. |
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// £500 would be a good budget if you
wanted a vehicle that just might make it
south of the river// |
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The budget is actually £999.99, and
stays. It is almost impossible to do it
for that, but 'almost impossible' is the
aim. Like the man said "Gentleman, we
haven't any money, so we will have to
think." |
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£999.99 buys a lot of aluminium,
electronic components and string.
What you do with it is up to you. |
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"I want a rail gun, to these specifications, and a 20 gram pellet made of pure chromium metal enclosing a microtransmitter broadcasting on AM 500Hz. Can I borrow your rail electrification transformer farm for a second?" |
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[UnaBubba] The would be a valid
solution. Imaginative borrowing of
hardware can form part of the deal,
provided that the loan is reasonable and
in the spirit of the competition. The
loan of equipment should not involve
unusual expense on the part of the
lender (eg, a corporate sponsor is not
allowed to construct a railgun for your
launch, and then "lend" it to you in
exchange for publicity), and each case
will be judged on its merits. |
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I suspect, though, that a 19.99 gram
projectile will be either melted or
stopped by air resistance shortly after it
leaves the railgun. |
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That would depend on its aerodynamics. |
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For that money, it might be possible to build a 10mm calibre "Hochdruckpumpe" - type multistage gun barrel. That might just be able to fling a small projectile into LEO. |
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But stand well clear when you fire it ..... |
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//I suspect, though, that a 19.99 gram projectile will be either melted or stopped by air resistance shortly after it leaves the railgun//
A multi-stage sabot round?
A sort of high velocity matrioshka |
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//A multi-stage sabot round?// by all
means, as long as you can build it within
weight and cost. |
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I thought about railguns but I assumed the magnetic field would fry any electronics in the projectile. Would it? Can it be sheilded? Or did they ever perfect a diamond semiconductor? |
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The supergun idea is also a good one especially since I saw a show that said we (USA) built a small one which went pretty high but they lost funding to build the "real" one. I'd love to buy the old one for the price of scrap. Then create a sabot round for my own micro satelites. |
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//might be possible to build a 10mm
calibre
"Hochdruckpumpe"// This I like,
especially if it can come with umlauts.
Don't forget you've got to get
sidewaysness as well as uptitude in order
to acheive orbit.. |
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Re. the HARP project and other "guns", I
don't think it's going to work. First, the
£999.99 has to cover *all* the
hardware, including whatever stays on
the ground. Second, all of these launch
systems use very heavy projectiles to
ensure that air resistance is not
disasterous. |
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Although the rules don't stop you from
using a sabot around a lightweight
femtosatellite, you're still going to need
to launch several hundred pounds of
stuff. Even if the sabot itself costs less
than £999.99 to make, you're looking at
a huge launch facility. |
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The only solution I can see as working is to launch one of those high altitude weather balloons to 170k ft and then launch a solid fueled rocket to get the last 70 miles up and get all the sidewaysness that you will need. |
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I'm all for yogic flying. I really like the idea of 8 minutes of 4.5g yogic acceleration in a vacuum environment. <cue sideways-travelling lotus-position maharishi whoosh> |
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//The only solution I can see as working
is...// Yes, that sounds like a plausible
solution. |
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//Fire your object at an existing
satellite, and make it stick to it.// Not
allowed, alas. Your device has to be
self-contained and self-sufficient, and
can't piggyback on anything during the
launch or orbit. In any case, I would
have thought that hitting a satellite on a
£999.99 budget was optimistic. |
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//Do the subsequent legal costs count
in the £999.99 limit?// No. Costs for
complying with regulations are counted,
but not legal costs or fines for non-
compliance. |
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Balloon and mini rocket would be the go. Surprised no-one has ever done it. |
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//Balloon and mini rocket would be the
go.// I agree. I was thinking of the
following. The satellite will be three
disc-shaped solar cells, intersecting to
form a sort of sphere. The electronics
will be on a postage-stamp-sized
board, glued to one of the panels near
the middle, and will consist of an
accumulator to store charge, and a
transmitter which fires for a second or
so once enough charge is built up.
Because the transmitter does not run
continuously, I'm guessing that the
components can be run above their
normal operating limits to maximise
power. |
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The launch platform is a helium (or, if
cheaper, hydrogen) balloon. Suspended
below it is a 2m string, forking into an
inverted Y at the bottom. The legs of
the Y are unequal, and from them
hangs the launch shaft. Thus, the angle
of the shaft to the horizontal will be
pretty accurately maintained. (We don't
care whether the thing fires north,
south, east or west - hence, no need for
guidance or targetting). |
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The rocket itself has a hole up the
middle, and is basically impaled on the
launching shaft (lighter than a tube).The
rocket will have no gyros, but is
stabilized by spin: the propellant and
vents are arranged such that the first
half-second of burn fires from two
sideways-directed vents, starting the
rocket spinning before it leaves the
shaft. The rest of the burn then
provides forward thrust only. |
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The rocket flies until it runs out of
propellant - no precise control. The
satellite itself is slotted into the nose of
the rocket, and retained by a spring clip
somewhat similar to the mechanism of
a retractable ball-point pen. When the
rocket accelerates, it compresses a
spring (click!) and then, when it runs
out of propellant and stops
accelerating, a lighter spring simply
pings the satellite clear of the empty
rocket. |
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How's that for simple? Doable for
£999.99?? |
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//Surprised no-one has ever done it.// Un-surprise yourself. Google "rockoon". It's what James Van Allen was up to when he first found traces of those radiation belts. |
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The "rockoon" links look very
promising.
Altitudes of up to 80km with heavy
payloads, which is only a shade below
low
earth orbit. They say a major drawback
is
lack of control over the balloon but,
since
we don't care, this isn't a problem at all.
All looks pretty feasible to me. |
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I will gladly make the prize money
available for a real N-prize, if anyone
has any ideas on how to make it real.
It'd have to find a home outside the HB,
though - I'm sure Jutta wouldn't want to
be impllicated if someone gets a lump
of rocket on their head. |
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Please let me design the site if you do! I love doing spacey graphics. |
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[MB] very good, except we dearly care about the direction the rocket launches. As the launch vehicle is already travelling roughly with the spinning Earth at 1000 mph, we want to add to that speed and head due east. |
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Also I'm wondering about the solar cells. I have to look this up, but they said 100 orbits. At the low end of LEO, 100 orbits isn't that long. A lot of satelites orbit every 90 minutes. We will be lower and faster. 100 orbits may only be a day or so. Also are the solar cells we buy able to operate in space? Heat extremes, etc.? |
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And BTW, what does the N stand for? |
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[wags] you're on for the website if this
takes off. |
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[QED] //we want to add to that speed
and head due east.// Ah, yes, good
point. Hold the moon-landing. OK, so
we have two choices. Either we put a
directing mechanism on the launch
balloon; or we put a simple compass in
it, and set it to trigger the rocket when
it happens to be pointing east (at the
top of its travel, of course). I think the
latter will be lighter/cheaper/more
reliable. |
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//Also I'm wondering about the solar
cells.// If batteries would do the same
job for a day (and for less weight) then
all well and good. I think regular solar
cells would survive, but we could check.
The only real issues would be vacuum
and temperature fluctuation; I don't
think the launch would be too violent,
and I doubt that solar UV or other
radiation would be a problem for a day
or two. |
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//what does the N stand for?// It
stands for "next to no money", and also
for the nines (9.99-19.99g, 99 orbits,
£999.99...) |
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Does anyone know anything about the
legalities of shooting things upward?
Model rockets are no problem, and nor
are toy helium balloons - are these
things controlled according to weight or
altitude? And what's the worst penalty
you can face (in the UK, US, or
wherever)? The overall aim is to
discourage over-compliance and damn
the consequences, and allow for a little
natural selection amongst really dumb
rocketeers, without seriously
jeopardizing innocent bystanders. |
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I'm assuming that detection
of the orbiting satellite would require
the cooperation of radio-astronomers
or the like, but I'm guessing they might
be willing to play along. |
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I think it should be reasonably easy to gyro stabilize the launcher so that it always points the rocket east without adding too much weight. As for the limits on rockets, there are many. I'd suggest looking at an issue of "High Powered Rocketry" magazine or borrow one from [8/7] who probably has a subscription. I haven't looked in a couple of years, and I'm sure it is nationally dependant, but such things as fuel load , fuel types and metal housings are strictly limited on a graduated license scale. Weirdly enough I wonder if the rules still apply since you will be launching the rocket outside of national airspace (doesn't it stop at some altitude). |
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//also for the nines (9.99-19.99g, 99 orbits, £999.99...)// |
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I swear it said $1000 when it was posted... |
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[wags] Rockoon == inflation |
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//I swear it said $1000 when it was
posted...// It did. Actually I think it was
"£1000". I've also made a few
minor edits to the rules. |
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What we need is publicity - some way for
people to find out about the N-prize,
perhaps by having Google find the X-prize
and the N-prize mentioned together on
the same web page. If only there were
some way. |
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//I think it should be reasonably easy to
gyro stabilize the launcher// but why
not just let it wander, and fire when it
happens to be pointing the right way? |
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//graduated license scale.// Well, as
long as we don't kill anyone important.
Anyway, only those who fail are liable to
be prosecuted - who's going to have
the nerve to charge the world's first
backyard satellite launch facility owner? |
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//why not just let it wander, and fire when it happens to be pointing the right way? //
I haven't done model rockets for years, really decades, but I do remember a bit of a delay between trigger and launch, so if for some reason this thing starts spinning on the string, you could be way off. |
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Yes, true. However, the sensor that
fires the rocket will be on-board to
reduce delays. Also, the balloon itself
will be very wide, which must limit the
rate it's likely to spin at; as long as the
rocket-tube-tether is linked
unswivellingly, spin should be limited.
Failing that, have the direction sensor
detect rate of spin also, and not launch
when spin is high. |
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Of course, weight penalties on the
balloon are not as harsh as on the
rocket or satellite, but I'd still like to
keep things as simple as possible. |
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I'm just checking some prices and stuff.
Helium for a 10ft diameter balloon is
going to cost about $30. |
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Does anyone know what is used for the
skin of high-altitude helium balloons?
In photos it looks like polythene, but
would this not become very brittle at
high (cold) altitudes? |
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Can anyone think of any part of this
system which is going to cost more
than $100 in materials? |
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[EDIT - thanks for the balloon link, QED.
Looks as if US regulations are not a
problem at all! Note that the latex
weather balloon is not designed for very
high altitudes - it doesn't allow enough
expansion to avoid bursting.] |
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Mylar is the best material for helium balloons. It's less porous than most plastics / rubber and stronger. |
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To ensure you launch due east you merely have to make the launch platform of something highly magnetised. I would also make it reasonably heavy, to minimise the problems of "equal & opposite reaction" causing guidance issues, upon firing. |
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I believe there's a fair bit of hydrazine doing fast laps of Earth right now, if you want to save on fuel costs. |
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//Can anyone think of any part of this system which is going to cost more than $100 in materials?//
The rocket propellant and the helium to get the rather large rocket up to 150k feet. |
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I don't entirely get the hydrazine
reference? |
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Re the mylar balloon, isn't mylar a
favourite because of its low helium
porosity? Since that won't be a factor
on a short flight, would some other
material be lighter/better? |
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Regarding the satellite itself, a balloon-
type mylar reflector might do for that
too. 20 grams lets you make a roughly
foot-wide balloon of 0.1mm Mylar,
which could be inflated in orbit. The
"Echo1" satellite was a 100ft mylar
balloon, and was bright to the naked
eye from earth. We'd have only
1/10,000th the area, but I suspect it
would still be easy to spot with a small
ground-based telescope. |
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[wags] - "N-prize.com" is not yet
taken.... |
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Hello halfbakers ! [my first post, so I'm nervous - hope I'm filling the right box in here !] |
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WRT facing East, and getting maximum lateral speed, how about trying to get the balloon up into a jetstream before launching the rocket. Or do these occur too low in the atmosphere ? How high will a ballon go ? |
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Obviously some fins on the launcher would keep it in line in the airflow |
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// I don't entirely get the hydrazine reference? //
There's going to be quite a lot of it soon when the US blows up one of its own satellites. |
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//how about trying to get the balloon up
into a jetstream// Unfortunately, the jet
streams are way too low (about 10km).
But welcome to the HB, VaquitaTim. |
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[QED] thanks for the weather balloon
supplier link. Theirs only go up to 40km,
alas - mainly because they're sealed. I
believe high-altitude balloons are
launched "flaccid" and expand greatly as
they climb. |
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//The rocket propellant and the helium to
get the rather large rocket up to 150k
feet.// Well, it's not going to be a rather
large rocket, I was thinking more along the
lines of rather small. Helium is about $37
per 1000 cubic feet. Rocket propellant is
as cheap as your imagination. |
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Why pay for helium when hydrogen is cheaper and has better lift? |
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True. So, we save $30 by electrolysing
water - sounds like a good deal to me.
Maybe we should reduce the budget to
$99.99..... |
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[wags] I just bought n-prize.org,
and .com, and .co.uk and .info.
Unfortunately I have no idea how to
establish a website. |
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Get someone to set up a domain hosting and we'll load Joomla! onto the page and get started. Joomla! is open source so it's free software. |
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[wags], do you have a hosting solution handy? I've done a fair bit of content management work with Joomla! but I buy the setup and template readymade. |
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Domain hosting..... Joomla!...... right....
hang
on. Will investigate... |
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//I just bought n-prize.org, and .com, and .co.uk and .info.// Once again the Buchanan's take occupation of lands they have no specific intentions of using, apart from croquet and fox hunting that is. |
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I hadn't noticed any foxes on N-prize.org,
but I'll check. I also claim the mineral
rights. |
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[UB] and [wags], if you're serious about
helping with the website, I'm interested. I
have no idea what I'm getting into here,
which is the perfect starting place. |
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Not sure if this could be done within the weight limit, but a possible solution to the verification-of-orbits question could be to have the satellite take a sequence of Earth photos to establish "At 2:30 I was here, at 2:31 I was HERE, at 2:32 I was HERE...." Once 99+ orbits are complete, transmit these photos. In order to prove these are real photos and not not pre-recorded or Photoshoped, they would have to be compared to actual weather patterns, the known positions of aircraft in flight or ships at sea, known traffic jams, large gatherings of people (and their cars) at outdoor venues such as ampitheaters, sports stadiums, or campaign/protest rallies etc. Obviously a very high-res camera would be required to obtain verifiable details. |
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[gardner] I suspect that the weight
penalty would indeed be a problem.
And, if you can transmit photos, you
could transmit a locating signal. |
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[UB] and [wagster] the outfit I bought
the domains from also offers hosting
(telivo.com) but I don't know which
package I need. I'm happy to buy
whichever one I need. Presumably,
after that, anyone with access to the
site can upload pages? |
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Yup, that's about right. I can provide hosting, but it would probably be easier for you to host it where you bought it from. You shouldn't need much webspace for this - 100Mb should be more than sufficient. |
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Shall we take this to email if it's going to get in-depth? Mine is on my profile page. Drop me a line. |
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To email it has been taken. I have the
feeling that we're creating a monster here,
but the important thing is probably not to
be too sober when any important decisions
are taken. |
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Do you think there will be trouble down the line with the name being similar to Nobel Prize? I Googled N-Prize and got a lot of references to the Nobel. |
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I can't imagine there being a problem; the
Nobel may be referred to sometimes as
the "N-prize" colloquially, but I don't think
there's any risk of confusion. In any case,
I've got the domain name, so hah! |
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Great link [tatterdemalion], the best part is, ""I've already got the thing half-built," he said." |
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//Imaginative scavenging and borrowing is encouraged// |
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So I can just super-glue my coins to the next US space mission? |
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// Broadly, extensive use of salvaged or redundant space hardware is unlikely to be permitted// |
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Full rules will be available shortly on n-
prize.com |
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I think the hardest part will be to accelerate this thing up to n-gazillion metres per second, so that it actually stays up there.
What are we talking about - 8000m/s? |
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Nearer 7500m/s for the lowest low-earth
orbit. A handgun can sent a bullet at
something like 1500m/s, so you're looking
at five times that, in terms of speed, or 25
times that in terms of kinetic energy for a
satellite of comparable mass. |
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Surely accelerating something very light in a total vacuum can't be that hard? I think ion drives are good at this kind of shennanigans. |
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It shouldn't be that hard. However, an ion
drive is way too slow (your satellite is
going to re-enter long before the ion drive
has done much good). |
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Has anyone done the math to find out a rough guess as to how many model rocket engines will get us from 170000 ft to orbit assuming no air drag? |
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Depends on the final payload and on the
rate at which mass is shed during the
ascent. Ideally you want a staged rocket.
Even then it'll be close or impossible with
those motors, since their energy density is
quite low. |
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//Has anyone done the math // |
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To start out on the math, google "rocket equation". You're going to need a delta-v of nearly 10km/sec in order to get into low earth orbit, because a fair amount of your velocity gets killed off in getting your potential energy (altitude) up. |
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//how many model rocket engines// - answer: model rocket engines in any configuration will fail. They don't have a high enough specific thrust, and they don't have a high enough fuel fraction (the cases are too heavy). |
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You're going to have to use something other than a black powder fuel. There are high-energy solids that can do it, but they are very very picky about production and are not cheap and hard to control. There are liquid fuel engines in several configurations which are capable, but require pumping & metering & throttling & mixing & cryogenics & tankage & plumbing & are very un-cheap. A possibility might be a hybrid - a solid fuel grain with a liquid oxydizer (as in Rutan's design - but note that he got to less than orbital altitude with *zero* velocity at the top - he needed about another 7500m/sec of delta-v to make that into an orbit) but having one with a sufficiently stable burn profile to not blow up / go asymmetrical / blow out chunks of unburned fuel grain is still quite in the realm of experimental. |
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Plus, please remember that solving all the problems of putting a payload in orbit entails solving every one of the problems posed in the building of an ICBM. Regardless of your intentions, think for a moment on whose attentions that is going to bring to you. |
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//Regardless of your intentions, think
for a moment on whose attentions that
is going to bring to you.// On the one
hand, true. On the other hand,
bollocks. The aim is to do the nearly
impossible against overwhelming odds
with almost no budget and for virtually
no reward. Did the Wright brothers
worry about governmental dissapproval
when they invented the Model-T light
bulb? Did Edison fret about military
uses of the spinning jenny? No!
Launch and be damned. |
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Also, I might point out that if a
schmuck in a shed can put something
into orbit for under a grand, it's in
everybody's interests to have it out in
the open. |
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//Regardless of your intentions, think for a moment on whose attentions that is going to bring to you.
//
Richard Branson? |
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I didn't say "stop immediately, because al-Qaeda will abduct you and extract your secrets nasally" - I just said 'consider'. If you think the Wright brothers' feat could be accomplished today without Homeland Security having palpitations, you are an optimist. |
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If you have a chance to come to Utah (the Bonneville Salt Flats) in early September, you'll want to attend "Hellfire" - an international amateur rocket launch. You'd get to see rockets where just the solid fuel grain alone runs over a thousand bucks. (I take my little $10 model out, fly once, and sit back and watch the other guys burn a month's pay in 4 sec. I once got to stand next to a guy whose 14 ft. $3000 rocket failed to deploy 'chutes - absolutely beautiful machine, stunning paint job, turns over at 7k feet and comes straight into the salt at over 500 knots. He cried for about a half hour, then committed to "do it again next year".) |
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I'm agreeing with [lurch]. This contest could be re-named as an anti-satellite-weapon challenge without being re-written. I like it, and I've a couple of new ideas, but no matter how I put the parts together, they keep coming out a weapon. |
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// I just said 'consider'. // Well, I
disagree
with that too. Too many people
consider
too much. Sometimes it's just right to
pretend we're back in democratic days
and
plain do things. Sometimes it's nice not
to
think about who's watching over your
shoulder. The very idea of an
organisation that calls itself "Homeland
Security" (why not "National Security"?)
gives me the heebie jeebies, and I don't
even live there. |
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But thanks for the invite to Hellfire -
sounds fun! |
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//On the one hand, true. On the other hand, bollocks.// |
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//This contest could be re-named as an
anti-satellite-weapon challenge without
being re-written.// Well, only if you
find a way to add guidance, not just to
the launch system but also to a satellite
weighing less than an empty coke can. |
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By this reasoning, nobody except the US
Government is allowed to develop
anything that can go upwards. To
quote (for the second time) my great
great aunt Agathenia, bollocks. |
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Good point, as always, [MB]. My bullocks, there. |
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You can't get into orbit without guidance. |
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If you want to be at the minimum altitude for orbit, say for example you give yourself +/- 10 km leeway, and you want to do 100 orbits, then you have to be going in a direction which will allow you to still hit that 10 km slot at the *end* of 100 orbits. So, it's going to need to be, at a minimum, accurate enough to hit a 10 km slot at (40,000 km * 100 orbits) = 4 million kilometers distance. |
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Even saying you could do one orbit without guidance would be like saying that trans-oceanic airliners don't need navigation systems, just point in the general direction and go. |
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//You can't get into orbit without
guidance.// You certainly can. You
need
to make sure you've got enough velocity
and you need to be pointing in roughly
the
right direction. Beyond that, it really
doesn't matter. You need very good
guidance to get into a *particular* orbit,
but that's an entirely different kettle of
wild herring. |
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Or perhaps you meant that you can't get
into orbit without suitable mentoring? |
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The number of possibilities of your orbit depends on how much space there is between your altitude and the atmosphere. If you're at minimum altitude, you have a very narrow range of directions you can fly. Higher buys you more leeway, but it takes even more thrust to get there. |
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One item that causes a problem, but is non-obvious, is that you can't make your orbit *not* pass through the point where you were when you last altered your orbit. If you are in a circular orbit, and fire your thrusters when you cross Ecuador, for example, then on your next orbit you will pass over Ecuador at the exact same altitude as before. Your velocity will be different, but not altitude. Your altitude will be different over Sumatra, and if you fire again over Sumatra, you can change your altitude over Ecuador. |
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To sum up, a circular orbit requires, at minimum, an original boost and a circularization a half orbit later. Otherwise, your payload will attempt to fly through its launch point. (And when I say 'circular' here, I don't mean 'within five balls two of a perfect circle', I mean 'close enough to get back to point A without an unplanned re-entry'.) |
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Yes, true. If you want to keep at
minimum altitude, you don't want your
orbit too eliptical, hence the 'roughly
the right direction'. But that's not the
kind of guidance you need in order to
hit something. |
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The kind of energies you need to get a
small mass into orbit from an upper-
atmosphere starting point are not
orders of magnitude greater than those
you get from a handgun. The kind of
guidance and communication
equipment you need is not significantly
more complex than the electronics in a
mobile phone. |
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Commercial, scientific and military
satellites need to actually do stuff and
stay in the right place, and this
increases their cost and weight by
orders of magnitude. All we want to do
is to send a matchbox about a hundred
miles up and make it go round a few
times. Everything works in your favour
when you sacrifice weight and
functionality, by exponential rather than
linear factors. |
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That doesn't necessarily hold all the way down to zero size. |
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Here, let me tell you what your first show-stopper will be. You've launched rockets, seen them launched, it all looks pretty simple. The standard model rocket, the 3FNC (literally "3 fins and a nose cone") makes it appear so natural that you light a rocket, and it goes up. However, there's magic going on there. It's the fins. You use a launch rod to keep the rocket pointed up until it is moving fast enough that any deviation from moving in a straight line puts air flow against the fins, creating a force couple which corrects the line of flight back where the nose cone is pointing the way. |
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However, you would like to simply start out with no air resistance by firing from above the sensible atmosphere. Or, at the very least, passing above it. What, then, keeps your rocket pointed even in the "general direction" you would like it to go? Nothing. In real rockets, this is accomplished by a horizon scanner or a gyroscope, controlling a gimballed rocket nozzle and/or a set of vernier rockets. Without that guidance system, your problem is no different from balancing a nail on its point. It may work for a moment, but your rocket's thrust is not going to be utterly turbulence-free, and thus is doomed to tumble. |
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My version of the N-prize would be to fly a rocket with no fins or drag stick (read this as "stable in vacuum") to 1000 meters for the same price as you're saying for orbit. |
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What is the viability of hosting a kind of single shot LONG (2-3M) barrelled rifle? Use a .50 caliber cartridge and sabot the bullet. The pressure would be lower due to the lighter round, so the barrel wouldn't have to be as heavy. |
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[lurch] that which you say is true. My
intention (see earlier anno) was to spin
the entire rocket about its axis, gyro-
wise. However, if it needs a gyro for
stability, then it can have a gyro for
stability. It's up to the entrant to figure
out how to machine a gyro within
budget, or how to imaginatively
'repurpose' a VCR head or a 12V-driven
microfuge for that function. |
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Incidentally, rockoons relied mainly on
fins for directional stability, though
granted they were only scraping the
edge of space. |
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[QED] you mean a ballistic launch from
under a high-altitude balloon? Yes, that
may be feasible. One concern might be
recoil of the gun (and consequent mis-
targetting), but I expect you could get
around that problem. You've also got to
have a satellite hardened against the
acceleration, whilst also being detectable
in some way from earth. But possible, I'd
have thought. |
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For a simple rocket could you acheive stability
on-the-cheap by starting with an electronic tilt sensor from a digital camera? These seem incredibly sensitive and could control the direction of the rocket by, for example, discharging a small capacitor into one of a number of tiny explosive charges (e.g.a 'cap') on the side of the rocket.
The other thing that occurs to me is that you can do a lot in under 10 grams - my son's remote-controlled helicopter has an IR receiver, some control electronics, a battery, the helicopter body, two rotors, two electric motors and it still weighs less than 10 grams. |
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Excellent thinking, Hippo. The point about
the ten-gram helicopter is very well taken,
and of course that ten grams includes a
propulsion system which, provided we can
kick it off in the right direction, the
satellite shouldn't need. Can we register
you as an entrant? |
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ooh yes, I'd be keen (despite knowing nothing about rocketry, propulsion systems, navigation,
three-dimensional geometry, radio, radar, aeronautics, etc. - I'm good at countdowns though). |
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You bought "your son" a PicooZ helicopter for Christmas too, [hippo]? |
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Christmas 2006, yes - and it was the PicooZ model - absolutely amazing. |
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//despite knowing nothing about....// A
healthy dose of ignorance is a tremendous
advantage in these circumstances. |
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//A healthy dose of ignorance is a tremendous advantage in these circumstances//
I don't want to discourage anyone, but this is rocket science, so we all probably start with a healthy dose of ignorance. |
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To that point, I just found out that purely cannon launch is out. We need ~7km/s speed for LEO and even HARP only got to 1/4 of that, so we are back to rocket science. |
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Oh and my favorite number so far is orbital energy = 32.1MJ/kg. You may want to look at the energy density link to see what kind of power you will need for the trip. |
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Yes, but it all depends on the mass of
the projectile and other stuff. Some
gas-guns used for testing impact at
orbital velocities have achieved >7km/
s. |
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