Doing real science with N-Prize sized satellites...thoughts?

What if you make a piece of aluminium foil to the shape that reflects the most radio waves. The question is, what shape would that be?

The shape with the most surface area!

Monroe

Look at NASA's Echo satellites
http://en.wikipedia.org/wiki/Echo_satellite

They were made to reflect microwaves


Iain
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http://kiwi2space.blogspot.com

The thinnest commercial al foil is 6.35 µm thick and weighs 17.2 g/m2.

This gives us approximately 1 square metre of al foil to work with. A square piece of foil stiffened around the edges may just be big enough to see through a telescope?

The actual satellite has to be actuive. However, if you are refering to simply the launcher...

Well er... No, you just have to prove it orbit's at least 9 times. At one point we were going to just watch for re-entry and calculate the number of orbits. It would have a long tail and an unusual angle. Some metals even burn diffrent colors. Consider most meteors are the size of a grain of sand and you get a prettty good visibilty (if it's dark!) with 20g. Haystack radar could definatly see a 1-meter reflector. actually a 10cm reflector might be tracked (empty cigarette pack with foil on it).

Monroe

I have re-read the rules but could not find that the the satellite needs to be active, so I assume that a passive reflector would suffice?

If it does indeed need to be an active satellite, I have yet to find a transmitter that small capable of sending signals that far.

Oh, perhaps the rules have change. I was under the impression that it has to be active, but if it doesn't...

Does that mean a larger 'chase satellite' could verify the orbits?

Unfortunately you cannot use a larger chase satellite to verify the orbit, but there is nothing stopping you from launching your own separate experiment...

So, I can launch anything as my entry, as long as it's below 19.99 grams and I have a way of verifying it completed 9 orbits without the use of any other satellite in space?

That sounds just about possible. The actual prize sat wouldn't be able to do any science, but I want a launcher capable of putting 100g into orbit, not merely 20g, so I'd have 80g left over for another sat (to test reentry). That's if I ever get a team together and launch one.

Oh! you guy's are starting to get it! Good. Worry about reaching orbital velosity and you have it licked! Can you find a way to do that really cheap? Now your thinking and you can do this. Design your rocket use everything you can to prove it can make it to orbit. Start a website and see if you can get the money somehow. Go for it! And hurry up! Hey I'll help ya any way I can, you just have to ask the right questions.

Monroe

Or you can join our team and help us! So we can move on to the X-Prize!

A light weight passive "corner" radar reflector could be easily tracked. The following page has a diagram and description of just such a reflector:

http://wiki.ukhas.org.uk/ideas:flight_support

Very Good! I wonder if we could fire one like that from our gas gun and have it open up in the vacuum of space? Can you design one to do that and survive 250 thousand G's or even 500 thou? With a 72" gun you would have to take 1 mil to get obital velosity from a stand still in space. And you would have to fire in both directions to counter the recoil! It would turn the reflector into powder. Just thinking out loud.

Monroe

It looks like some origami lessons are required

Would you need such a large G-Force to reach orbital velocity from space? Most modern launch systems use a solid propellant for the final stage. I would have thought that a gas gun would be useful for the inititial launch stage.

Here is how I would picture using a gas gun:
1. Launch small rocket with payload from the ground using a gas gun to around 30-40km.
2. 2nd stage solid fuelled rocket.
3. Once space is reached, use a smaller rocket to insert payload into orbit using origami to open the satellite.

(A liquid fuelled motor may not survive the high G forces).

i don't think you understand how large the g-forces actually involved are. we're talking about a 7km/s more or less change in velocity, essentially instantaneously. the force is more or less just a delta function. you need some really special materials to be able to survive that with any more structure than atoms/molecules shooting out. it's possible for a payload to use these, it isn't possible for a solid rocket to use these.