Parking Orbit

"Will McLean" wrote in
ps.com:


Rand Simberg wrote:
On 17 Feb 2006 12:17:26 -0800, in a place far, far away, "Will
McLean" made the phosphor on my monitor glow in
such a way as to indicate that:

How practical is it to tailor a parking orbit for lunar missions
that is reasonably efficent to reach from KSC and precesses at
180 degrees a lunar month?

What's wrong with 360?


Nothing. Any multiple of 180 will do. 180 seemed more doable, based
on the orbits I've been able to find information on.

Oh, I misunderstood. You're looking for an actual precession in an
inertial frame? I thought you meant an apparent precession from the
viewpoint of the earth. How does 180 help you? I would think that
360 would be the only one that would give you constant angle with
respect to the earth.


D'oh!. I meant to say 180 degrees in half a lunar month, or 360 a
month. Or any multiple of that, since I don't require a constant angle
with respect to to the system. I want to arrange the precession so
that every time the lauch window opens to a particular lunar orbit,
the moon is in the plane of the parking orbit.

Then I'm afraid you're out of luck. Regression for a 100 nmi equatorial
orbit is nine degrees per solar day (less than 270 degrees per lunar
month), and the effect decreases with both altitude and inclination.


--
JRF

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On 17 Feb 2006 13:29:33 -0800, in a place far, far away, "Will McLean"
made the phosphor on my monitor glow in such a
way as to indicate that:

D'oh!. I meant to say 180 degrees in half a lunar month, or 360 a
month. Or any multiple of that, since I don't require a constant angle
with respect to to the system. I want to arrange the precession so that
every time the lauch window opens to a particular lunar orbit, the moon
is in the plane of the parking orbit.

That makes more sense. But I'm not aware of any way to get a lunar
(and I assume that you want it to be a lunar polar) orbit to do that,
absent continuous thrusting (you could do it with an ion drive, or
perhaps a sail). Of course, if you are aligning it with a bimonthly
launch window, 180 actually would work--it would just be a matter of
entering from above versus entering from below.

Anyway, what's wrong with L1, other than the performance hit (a
penalty I think well worth paying)?


Performance hit, the travel time,

Only an extra day or so, I believe. What's the big deal?

and L1 is no longer an option with the current plan.

Ah, but other people can make better plans.

On Fri, 17 Feb 2006 21:37:37 GMT, in a place far, far away, Orval
Fairbairn made the phosphor on my monitor
glow in such a way as to indicate that:

Why would anybody *want* such a long-duration parking orbit? The craft
could go stale if it is kept in orbit that long -- besides, the only
reason for an earth parking orbit is to extend the launch window from
some 3 minutes to several hours. It costs propellant to insert into park
and then inject into translunar.

Presumably to establish a propellant depot, which could pay for itself
in terms of the extra propellant for the insertion.

Will McLean, "finite systems", "Rand Simberg" and to all other
dumbfounded souls,
What is it that's so gosh darn taboo/nondisclosure (aka need-to-know)
about our utilizing the efficient though somewhat interactive
LL-1/ME-L1 as per station-keeping a significant platform and best ever
mission refueling depot, that's supposedly within a fairly regulated
location situated at roughly 60,000 km away from the otherwise
extremely nasty and by way of raw sunlight being reactive as
contributing those hard-X-rays that'll be coming off the dark and nasty
lunar deck, and for otherwise being roughly 316,500 km from the surface
and relative sanctuary of mother Earth?

Isn't that good, or what?

At least it's sharing in a touch of benefit from what our Van Allen
expanse has to offer, and the required push-off energy that's necessary
in order to go towards the moon or Earth can be accommodated by as
little as a what good release of flatulence might generate.

Seems the amount of required auxiliary ion thrust or even conventional
reaction thruster energy as per interactively station-keeping within a
somewhat tidal-halo-orbit would be the least energy intensive of all
the alternatives. It also seems that robotic resupply missions of beer
and pizza that could be subcontracted out to HOOTERS should be the best
part, and you'd certainly never be out of our sight nor out of
terrestrial communications.

Efficiently deploying of whatever to/from the moon or Earth is simply
why LL-1 is still the one and only best ever sweet-spot for
accomplishing such efforts. Extremely accommodating as for countless
Earth-science, moon-science and just good old astronomy
whatever-science are but a few of the obvious and potentially
significant advantages to behold.

You can start off robotically small and grow out to as much as you can
imagine (for example; the sky's the limit). Oops, I bet that I've used
too many of those fancy words.
-
Brad Guth

Life upon Venus, a township w/Bridge & ET/UFO Park-n-Ride Tarmac:
http://guthvenus.tripod.com/gv-town.htm
The Russian/China LSE-CM/ISS (Lunar Space Elevator)
http://guthvenus.tripod.com/lunar-space-elevator.htm
Venus ETs, plus the updated sub-topics; Brad Guth / GASA-IEIS
http://guthvenus.tripod.com/gv-topics.htm

"Will McLean" wrote in message
oups.com...
How practical is it to tailor a parking orbit for lunar missions that
is reasonably efficent to reach from KSC and precesses at 180 degrees a
lunar month?

Will McLean

I'm not sure what you're planning to park there, but I'll throw out a
scenario. With Apollo, the command module was left in orbit around the
moon. If you were planning a 2 year mission, you could park the command
module in low Earth orbit, high, Earth orbit, or lunar orbit. Lunar orbit
is unstable. When comparing high to low Earth orbits, you can expend fuel
now or later. I would favor leaving it in low Earth orbit and expending
fuel to reach the moon when you need to reach the moon. In low Earth orbit,
it is easier to do maintenance on it. If it rusts out, you can recover the
fuel.

Michael Rhino,
In addition to or perhaps in place of sharing something in regard to
the Usenet topic taboo/nondisclosure as related to LL-1, how about our
sharing upon a little honest respect to the energy polarity or whatever
basis you'd care to impose of what mother Earth represents, whereas it
seems that in spite of your pagan NASA/Apollo fiasco we still don't
know squat as to what's the energy polarity and/or of what voltage and
amperage (aka mega, giga or perhaps terajoule) potential of what our
nearby moon represents.

What's the voltage polarity of our moon?

How many joules does our moon represent?

It seems that we don't even know the average drag coefficient of our
salty moon, and there's next to nothing that's formalized as to the
tidal energy that's also having to take into consideration for the
required 3.8 cm/year recession worth of applied energy, of what's
obviously pushing (aka accelerating) our extremely salty and once upon
a time icy proto-moon along, that's transpiring in spite of the drag
coefficient and continual pull of gravity.

Do you or by way of anyone that you know of have a clue?

If so, might you care as to share that knowledge?
-
Brad Guth

h (Rand Simberg) wrote in
:

On Fri, 17 Feb 2006 18:12:56 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:

D'oh!. I meant to say 180 degrees in half a lunar month, or 360 a
month. Or any multiple of that, since I don't require a constant angle
with respect to to the system. I want to arrange the precession so
that every time the lauch window opens to a particular lunar orbit,
the moon is in the plane of the parking orbit.

Then I'm afraid you're out of luck. Regression for a 100 nmi equatorial
orbit is nine degrees per solar day (less than 270 degrees per lunar
month), and the effect decreases with both altitude and inclination.

I thought he was referring to a lunar orbit, not an earth orbit.

Ah. If so, mea culpa.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
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h (Rand Simberg) wrote in
:

On Fri, 17 Feb 2006 20:26:20 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:

I thought he was referring to a lunar orbit, not an earth orbit.

Ah. If so, mea culpa.

I should add, that I'm guessing that this question arose in the
context of a recent discussion at my blog, which may (or may not)
clarify things:

http://www.transterrestrial.com/archives/006473.html

Context is everything.

If we're talking about a lunar orbit, I agree L1 beats low lunar orbit, not
least because of the instability of LLO.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
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on Fri, 17 Feb 2006 23:49:03 GMT, Rand Simberg
sez:

` On Fri, 17 Feb 2006 20:34:15 GMT, in a place far, far away, "finite
` systems" made the phosphor on my monitor glow
` in such a way as to indicate that:

`
` Hello - I am new to this Group - but I do have some insight to this
` astonishing Question?
`
` 180 Degrees Being the infra-spectrum in which we can see and operate in that
` the temperature is fine for working in? - not too much?
`
` Also the indexing of the interior is a advantage in that the interior is
` really the importance of the overall in that the indexed interior is a
` fundamental in that the overall importance in that the overall input pattern
` is a fundamental?
`
` Question though? With the Moon so interconnected and seemingly ineventfully
` - connected to the Tide Lines on the planet - could the Moon be a poor
` destination in that I believe that the Solar Winds (Geo-magnetical forces)
` are the
` willing and given in that the overall is very efficient as is!? Very light
` craft as landed
` before - (as with more propulsion) are event
` full enough!?
`
` I hope this answers your Question? I also as my Web Space below serves -
` answer Questions about almost anything?
`
` Here is my Web Space Address?
`
` http://www.members.shaw.ca/finitesystems/index.html
`
` Another thing - as I am an experienced Networking Cohesive newsgroup
` person? - as I may have Just witnessed a simple thing as I Just read 1
` Posting - please do not do that to Me if you did what you did or you will
` surely see the other side?
`
` Casper

` Boy, that wasn't just out of left field. It was out of a completely
` different ballpark, in a different county.

It's either a work-in-progress AI bot tech expert (at pre-alpha stage)
or it's passed through several layers of babelfish... or perhaps both!


--
================================================== ========================
Pete Vincent
Disclaimer: all I know I learned from reading Usenet.

h (Rand Simberg) wrote in
:

On Fri, 17 Feb 2006 20:26:20 -0600, in a place far, far away, "Jorge
R. Frank" made the phosphor on my monitor glow
in such a way as to indicate that:

I thought he was referring to a lunar orbit, not an earth orbit.

Ah. If so, mea culpa.

I should add, that I'm guessing that this question arose in the
context of a recent discussion at my blog, which may (or may not)
clarify things:

http://www.transterrestrial.com/archives/006473.html

I should add that the only reason I interpreted Will's question to be about
LEO rather than LLO was because he specified "reasonably efficent to reach
from KSC". That makes a big difference for LEO, not so much for LLO.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
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