View this page "Present Plan"

[Richard...@gmail.com]

Click on http://groups.google.com/group/daedalus-space/web/present-plan?hl=en
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[JKnoll]

I have a few questions about the plan, but the biggest is verifying
the orbits. I think this is something not only are the teams in the N-
prize competition are overlooking, but the actual prize organizers as
well. Personally, I think it's nearly criminal to not have an
independent verification of orbit. Monroe's team is planning on
visually observing the re-entry plume from an object that weights from
9-19 grams. With no guidance and no idea where the satellite is,
where it entered space, how fast it is going, or the exact trajectory
- they can do no better than guess what hemisphere the satelite is.
Even then, they will probably be wrong. Even if they guessed the exact
position in the sky, what is the likelihood that you would be able to
even see a 9 gram object burn up? How long would that plume be
visible for? Less than a second?

To me here is a list of the most difficult parts of this competition:
1 Orbital velocity (energy)
Creating enough energy to put something in orbital velocity is a
daunting task. Most teams I've seen are using a very exotic or
unproven method (which I'm not saying could never work, I'm just
trying to explain how hard a thing this really is.) and are making
very large assumptions based on them working flawlessly.

2 Orbital trajectory
Even if your orbital insertion mechanism works, you will need to make
sure your burn hits an extremely small target trajectory. How do you
change the attitude of your craft to ensure the correct orbital
trajectory, i.e. how do you "steer"?

3 Orbital tracking and trajectory
Before I continue to say visual confirmation isn't possible, I think
talking with some astronomers would be a good idea. My point is, I
guess I don't see why you wouldn't try and either make or buy a very
very small transponder that could beep at a certain frequency. Used
in conjunction with visual confirmation, you might be able to get a
somewhat accurate position on the satellite.

4 Launch vehicle recovery
Launch vehicle recovery is hard. Reliability in the systems is a
tough thing to achieve in small model rockets, let alone large- space
faring bodies. The higher they go, the more difficult they are to
recover.

5 Funding
How do we find an entity that is excited enough about this contest to
sponsor us?

I don't mean to crash the party, but I think it's important to embrace
the roadblocks instead of make assumptions about them and ignore
them. Test your technology- prove you can overcome them.
Hypothesize, research, and plan for them. Is this N-prize possible?
I honestly don't know. I think it would be fun trying to prove one
way or the other. :)

On Nov 16, 1:58 pm, Richardjhau...@gmail.com wrote:
> Click onhttp://groups.google.com/group/daedalus-space/web/present-plan?hl=en

[Richard...@gmail.com]

First, from what Steve says Monroe doesn't have a team. His idea for
re-entry verification of orbit was moronic and I all but told him so.
We are not on that path. I guess I can't categorical say we will not
do anything, as this is not Team QED, but that was dumb and my vote
will never go that way. My proposal is for a passive visible light
radiating satellite. I think I mentioned the idea in the Everest
piece, and Peter did a knowledgeable write up of the math on his site:
http://www.nebula-aerospace.com/design/satellite_a.asp
As for the difficult parts:
1. Orbital energy: I agree, this plan is all about light weight and
high energy. Each piece can fill in partially for the others. Each
piece is important but none is a deal breaker, even guidance has built
in redundancy.
2. Orbital trajectory: By shooting for a 150km altitude we allow for a
highly elliptical orbit that is still legal. The key piece is final
velocity which sets the average orbital altitude. If the insertion
angle is off, then it will just be an elliptical orbit instead of a
circular one. If we use the CLGG then there is no way to steer. If
we use stages then we will pivot the motor to correct course. I am
not against a tiny Sputnik but the power levels available at this
weight range are very low. Low power is not an issue if you have
powerful receptors. The optical system solves both issues by using
reflected power from the sun. The receptors are also significantly
better in the visible ranges. A pair of binoculars has more effective
gain than even an old 8’ satellite dish in microwave bands because of
the comparable differences in wavelengths.
3. See #2, but as I said, if you can figure out a better satellite,
then tell me about it. Smaller satellites have less drag, so they
could allow a lower orbit and less total power requirements for launch
and transmission. The closest I came was a camera flash chip and a
Xenon strobe triggered every 10-15 minutes.
4. //Launch vehicle recovery is hard.// Yes, if we switch to reusable
then I suggest adding in GPS and GSM modules that will call us to
guide recovery from nearly any place on Earth.
5. Funding – I think this is possible using only personal funding,
like a couple of hundred $ from each person, but if the pump works,
DARPA will probably “sponsor” us as they have for similar projects:
https://www.llnl.gov/etr/pdfs/07_94.2.pdf . Also if the pump works,
we can either compete or sell engines to LLC competitors. In any case
if we can make a better liquid fueled rocket, funding will not be an
issue.
// I don't mean to crash the party//
You can’t crash a party you were invited too.
// I think it's important to embrace the roadblocks instead of make
assumptions about them and ignore them.//
Well, embrace is too strong a word, but I understand your point. We
need to move forward with our eyes wide open to the good and the bad
and embrace reality whether we like it or not.

MisterQED