

Ask HN: How hard would it be to put a small satellite in orbit? - sirdogealot

I&#x27;m not talking anything large here.<p>I fondly remember spending weekends at the local closest-avilable-abandoned-field with my father and shooting model rockets into the sky.<p>I think we used engines in the B or C range, but I remember there were companies promoting FFF and GGG versions which were simply way too expensive for me as a kid.<p>This was ~20 years ago so I am assuming the technology has improved since then.<p>What would it take to send a model rocket with a small radio-controlled satellite into orbit?<p>I&#x27;m thinking like a 0.25Kg package at most. Just an arduino with a solar panel and a radio transmitter.
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avmich
Start with Tsiolkovsky equation. Pick a fuel - that determines the speed of
exhausting gases. Choose the number of stages - since you're trying to reduce
complexity, you can't rely on good mass ratios. Obviously those things are
related.

When you'll try to make payload - and rocket - small, you'll find that some
parts of the rocket reduce their mass in proportion to the total rocket mass,
and some other parts don't. Tanks are usually the biggest parts by mass in an
orbital rocket - and they scale down rather well, to a certain limit. Engines,
however, could scale worse. That will affect your mass ratio, and at some
point your payload will become zero.

This is the main problem with current state of the art in high power rocketry
(if you want to launch a satellite, you have to have more than 8 km/s delta-V,
and this is enough to qualify it as a high power rocketry). Some parts - like
control circuits and some sensors - advanced greatly since late 1950-s, and
you can have a whole control system in a really small and a lightweight
package. But engines, valves - you'll have to have valves - and, after some
point, tanks (because you can't have too thin of a wall without breaking in a
real flight) will stop scaling. You'll likely find that it's about the same
mass of a rocket which can launch 1/4 kg to orbit or 1 kg to orbit.

Elon Mask proved that $90 millions are enough to build a half-a-ton payload
rocket from scratch. May be - may be - $1 million is enough to build and
launch a smallest rocket from scratch. Hard to say... but it's definitely more
than $100 thousands today.

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cweagans
Very very very difficult. If you have to ask this question, you don't
understand the monumental amount of work required. That's really blunt, but
that's kind of how it is.

A better, cheaper option would be to purchase a Cubesat. A lot of privately
purchased Cubesats qualify for free transportation through NASA (in fact,
there were five of them aboard the most recent SpaceX ISS resupply mission).
In terms of cost, effort, etc, this is certainly the cheapest option available
to you.

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Mankhool
"A smaller 45-meter, 350 mm caliber gun was completed for testing purposes,
and Bull then started work on the "real" PC-2 machine, a gun that was 150
meters long, weighed 2,100 tonnes, with a bore of one meter (39 inches). It
was to be capable of placing a 2,000-kilogram projectile into orbit."

[http://en.wikipedia.org/wiki/Gerald_Bull](http://en.wikipedia.org/wiki/Gerald_Bull)

~~~
sirdogealot
Interesting, that's almost exactly how Isaac Newton surmised gravity if I am
not mistaken.

I wonder what the dimensions of the gun required to send a payload 8,000 times
smaller into orbit would be?

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shiftpgdn
I'm not sure if this offer is still active but this will give you an idea of
the difficulty:
[http://armadilloaerospace.com/n.x/Armadillo/Home/News?news_i...](http://armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=376)

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brudgers
To get you started, Tsiolkovsky rocket equation:

[http://en.m.wikipedia.org/wiki/Rocket_equation](http://en.m.wikipedia.org/wiki/Rocket_equation)

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clayrichardson
We're trying to solve that problem for smaller payloads (1 - 200kg), using
reusable stages. Hit me up via contact info in my profile, and we can chat
about it.

EDIT: Forgot words.

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jqm
A rocket would be difficult and prohibitively expensive.

How about a balloon?
[http://www.newscientist.com/article/mg21929340.300-lowbudget...](http://www.newscientist.com/article/mg21929340.300-lowbudget-
way-to-send-your-stuff-into-space.html)

Of course that doesn't really get the thing into orbit...

There are services that will send your stuff up for you on rocket launches. I
don't remember specifics but I believe they start at about 10K which is pretty
reasonable.

~~~
vhiremath4
Which services get stuff into orbit at 10k? That's phenomenal pricing IMO.

