Going to the moon...again?

I lied about so much nowadays not being rocket science anymore, as
this part is serious "Rocket Science", though it's still not for
mankind, at least not until we actually learn about the conditions on
the moon.

Though instead of our flushing hundreds of billions and decades into
the frozen and thoroughly irradiated to death Mars space toilet, then
having to continually dodge them meteorites, I do believe this lunar
goal is worth supporting, even if it's via our resident "so what's the
difference" WMD warlord. Though as for starters, we may need some
actual lunar science data that's of "real time".

If we're not there first, it'll either be China or perhaps Russia, or
even the ESA group that certainly has nothing to lose.

"Deploying dozens of small javelin lunar probes on the cheap"

As just an example;
I'm thinking that of a modern day probe with a suitable battery and
compact PV cell array that's either tightly integral and/or
subsequently deploy able upon impact, that perhaps this form of micro
instrument and of it's data/transponder could be comprised of as
little as 1 kg. Of course, of your vastly superior "all-knowing" probe
can become whatever, 10 kg 1 t.

As for my initial delivery scheme, I'm thinking of involving hydrogen
or whatever gas filled balloons, actually quite a good number of
balloons within one another, and obviously not the least bit for their
buoyancy, but as for spreading out the impact to a rather sizable zone
of perhaps as much as 10 m2, as opposed to the instrument probe impact
zone representing as little as a mere 0.001 m2 (25 mm upper body with
a tapered 25 mm 5 mm spike end), and of what this relatively small
instrument/probe may be looking somewhat like a miniture spear or half
javelin.

1/2*M*V2 = impact energy or equivlent mass, whereas the V = 1.6 m/s/s

In other words, I'm suggesting that the initial impact of this small
probe can be spread conservatively by at least 1000:1, therefore if
the raw velocity at impact were to become 5 km/s, thus a 1 kg/probe
that was surrounded by another kg worth of balloons and sub/micro
balloons that would impact at an overall worth of 25,000 tonnes,
though this energy is subsequently being spread over the 10 m2, thus
the actual javelin probe body of 0.001 m2 should become merely 2.5
tonnes, though applying another 10X fudge factor makes for 25 t.

Any way you'd care to slice it, 25 tonnes worth of probe impact is
still one hell of an impact, though I tend to believe this could be
survivable, especially since the notion of delivering any decent probe
will ideally need to be firmly implanted into lunar soil and rock, the
deeper the better, as long as the upper protion remains exposed for
receiving and transmitting data.

Obviously, if this turned out being the 25 tonnes worth of impact
survival, as representing too much to ask for, then enlarging the
balloon and of increasing the numbers of the smaller balloons within
should further spread this impact, thus decelerating and taking the
brunt of the probe delivery impact. Another avenue is to lengthen upon
the spike end, at the risk of increasing the mass, as the compression
of this semi-hallow javelin will also absorb energy. Obviously the
deployment and desired free-fall vertical positioning will need to be
gyroscopic, though the probe itself could be initially set spinning at
100,000 rpm, adding somewhat a friction drilling attribute to the
probe impact.

The lunar soil (supposedly 11% reflective index and of clumping moon
dirt) should account for another degree of impact deceleration, then
of the penetrated rock and I'll assume some degree of compression of
the javelin probe tip itself should absorb whatever remains. At least
if all fails, the value per micro-probe isn't going to bust the world
bank, nor stress the technology expertise to any breaking point, as if
need be a dozen of every required instrument function can be deployed,
so that if only one survives the delivery, we've accomplished the
task.

Unlike those Apollo landers, every facet of these probe deployments
can be fully tested and confirmed on Earth prior to accomplishing the
real thing.

Of course, having a fully fly-by-wire robotic lander certainly would
be nice, though a wee bit spendy, and I'll suppose that of some day
our crack NASA teams will actually obtain that degree of purely rocket
powered controlled flight capability, as otherwise the next best
technology is obviously what the recent Mars probes utilized in order
to decelerate their impact. Since there's so little difference between
the thin Mars atmosphere and that of the moon, where actually the
lesser gravity of the moon should almost offset this disadvantage, so
that such a well proven method of essentially dropping objects safely
onto such a foreign surface seems almost like way-overkill for the
task of delivering such small (1 kg) probes onto and preferably as
partially impaled into the moon, though dozens of such probes might be
safely deployed by one such velocity breaking maneuver, such as
bringing everything to a vertical velocity of zero at the elevation of
1 km would certainly do wonders for alleviating the horrific impact
that's otherwise faced with the 1.6 m/s/s influence of lunar gravity.

A raw javelin probe of 1 kg, as dropped from 1 km, should impact at
roughly 0.8 t (800 kg), well within survival specifications of even
toys-R-us, which might not even represent sufficient impact for
implanting these lightweight probes.

Keeping in mind that shape and/or size is not a velocity factor, other
than spreading the impact energy over a greater or lesser zone,
whereas the Hindenburg of 242 metric tons and of representing more
than 210,000 m3 will obtain the exact same impact velocity as a
bowling ball or that of a dust-bunny, identical velocity as long as
each were introduced from the same altitude.

Of course, this is all purely "one-way", and never given a second
thought of our retrieving anything but measured data, nor of having to
sustain human or other life by shielding them from the truly horrific
elements of various lunar exposures.

I believe such small/compact probes can be engineered to survive these
sorts of deployment impacts, as well as sufficiently immune to such
horrific radiation, and of their avoiding meteorite impact, as their
odds are greatly improved upon by the sheer fact that these compact
probes represent such a small target, though eventually they'll each
be pulverised by something.

Regards. Brad Guth / IEIS~GASA

On Mon, 16 Feb 2004 08:37:47 +1100, Sylvia Else
wrote:

Charles Buckley wrote:

NASA has a good rundown of the whole decision process at:

http://history.nasa.gov/SP-4221/sp4221.htm


Thanks for the link, Charles.

I've taken a look at that.

There are dangers in comparing the real shuttle hardware that's in place
with hypothetical other approaches. Still, I found the idea of a
titanium stubby winged orbiter quite compelling.

The objections to this seem to have been:

a) Not so much knowledge in the industry of titanium manufacture. Well,
how many of these things did they intend to build anyway?

My understanding was that the USAF wasn't too keen on NASA going with
a Titanium shuttle due to supply concerns. This was at a time when the
USAF was planning thousands of F-15's and hundreds of B-1's which were
expected to put large demands on the nations production of Titanium.
Sharing it with a Shuttle program was a concern and the situation that
NASA was in to get the shuttle funded meant that they were over a
barrel when it came to USAF demands. (The Shuttle needed the USAF, but
the USAF didn't need the Shuttle)

b) Cross range limits. Could have been lived with.

c) Transition from deep stall descent into normal flight. Aviation has
rightly been concerned with deep stalls, and it has caused a few
crashes, but these were aircraft that were never intended to operate in
that region. There was also concern that you have a craft that is
presumably travelling in a fairly steep path at the point where it has
to start flying, so it will accelerate, downward, quite quickly. But
this is just physics, and should be manageable.

On the plus side, you have a much smaller area to protect from heating.
More energy is dumped into the shock wave, and less has to be lost from
heating. Lower structural weight. And the aerodynamics are of a craft
operating in the subsonic region - not even transsonic. You don't have
to build a hypersonic glider with acceptable subsonic characteristics.

Will this be revisited now? Or will the next shuttle also be a delta wing?

I doubt there will be a next shuttle for a while. Although wings are
sexy they are pretty much dead weight for %95 of the flight. The
Shuttle system launches as much payload into orbit as the Saturn V,
its just that most of it is the shuttle itself, the wings of which are
only good for the last 10 minutes of flight.


Kelly McDonald

Sylvia.