[ExI] De-Orbiting Gold
kellycoinguy at gmail.com
Wed May 30 01:37:03 UTC 2012
On Mon, May 21, 2012 at 4:48 PM, spike <spike66 at att.net> wrote:
>>...So you're saying that I couldn't predict where it would come down
> without rapid deceleration? That seems a little hard to believe...Spike, I
> have tremendous respect for your knowledge in this area...-Kelly
> Thanks Kelly, I didn't explain that very well. If we go for aerobraking, we
> are talking about very shallow reentry angles. That means high uncertainty
> on the reentry path. Small uncertainties in atmospheric density mean large
> uncertainties in landing spot.
Ok, that makes more sense. It seems to me that there are two ways to
get down... One, which is what everything I am aware of is to fire the
rocket straight ahead which slows your speed and you drop to earth.
Another, which probably isn't used, is to fire the rocket straight up
into space pushing you down but not slowing you. I figure that with
monkeys in the can, you want to be going as slow as possible, is that
right? So would firing the rocket straight up give you more
predictability, but a hotter entry?
> Recall the event burning into my brain from
> my childhood, the reentry of the ill-fated Apollo 13. That was a case where
> one of the biggest dangers was avoided when mission control realized the
> reentry vehicle was about 300 pounds light, since it was not carrying the
> moon rocks it had planned to return. Had that not been found
> (understandable under the circumstances) that alone would have caused the
> landing site to be off far enough the astronauts would likely have perished
> out at sea before they were found.
Yes, that would be very bad.
> The reason is that the density of the upper atmosphere is difficult to
> predict with the precision that we know the density of the air down here: it
> varies by time of day, by F10.7 radiation from the sun up to a factor of 3
> at very high altitude, by position of the moon (the atmosphere has tides way
> bigger than the seas), by geomagnetic index and a handful of smaller
> effects. Add to all this the fact that the upper atmosphere has waves and
> surges, like the ocean only thousands of times bigger.
But would it not also be true that the bigger the variability, the
less it would actually impact the orbiting object? If it's thinner, it
seems that it would affect it less, and also be more exposed to solar
wind effects, etc.
> If the reentry angle is too shallow, the reentry body (RB) might actually
> start to go back out, a skip-off event a little like a flat stone skipping
> off the surface of a lake.
I've heard of that. I always figured you had to be going faster than
orbital speed to get this effect...
> Even a small event like that has enormous
> consequences when you realize an RB has a velocity of 11 km per second. You
> can have a piece break off, which changes the ballistic coefficient, which
> again adds to unpredictability of the landing spot.
And again, if you have a transponder in the object, does it matter, so
long as it lands SOMEWHERE in the Pacific ocean?
> So in a very shallow reentry event is difficult to predict exactly where a
> payload will reenter. So back in the Mercury days when we were trying to
> work out atmospheric reentry, the trick was to have the RB come in as
> steeply as practical (steeper means higher G decelerations, which means
> greater heat load and structural load on the shield as well as more
> discomfort for the apes aboard) for if they went for shallower angles (less
> delta V needed) there was increased risk of losing the capsule to some
> unknown location never to be found.
Ok, so there is a balance that has to be reached. What I'm asking is
would that balance be significantly different if apes and fragile
equipment were not on the list of concerns?
> All that being said, there probably is some way to reenter high value
> payloads without the shuttle, but all I have seen so far is a number of
> approaches which will not work for known reasons or are very high risk.
High risk? Really, what's the risk? I mean risking a big ball of gold
is clearly a risk, but you would practice with copper or something to
get it right, no?
> ps Since I am running over the five a day posting limit, do let me make a
> short comment with respect to Brent's commentary on the immorality of
> hoarding gold. On the contrary sir, gold hoarders do a service: they keep
> governments honest. We are a planet awash in fiat currencies that various
> governments claim have value. The test of these claims is in how much gold
> (or other predicable-supply substance) the market will give for that
> currency. This is how we know that Monopoly money and anything minted by
> the government of Zimbabwe is worthless: no one will give you gold for it.
> But they will cheerfully trade you these currencies for gold, plenty of it.
> Any fiat currency can be converted to gold if it has actual value. So gold
> hoarding is not immoral, gold traders keep governments honest.
And my idea about an orbiting currency would keep governments even
more honest because the gold would not be physically present in any
country, and thus not as susceptible to government confiscation. The
thing that would REALLY keep such a thing safe is if every despotic
leader had a significant amount of the currency in their private
account... It has worked for Switzerland for a long time.
More information about the extropy-chat