For those inerested in such things, David Porttree posted on his blog a
discussion of my old paper "Footsteps to Mars," suggesting how to do a
Mars mission in incremental stages; on which I’ve been adding some
comments and responses.

Link is:
http://altairvi.blogspot.com/2007/01/integrated-incremental.html

(the original paper was first presented at the Case for Mars Conference
[http://www.amazings.com/sbb/reviews/review0395.html ], and reprinted
in the Journal of the British Interplanetary Society, Vol. 48,
September 1995).

In response to a question (from another mailing list) "But isn’t the
Mars Direct approach still the most viable?", I replied:

I have no qualms with Mars Direct, if we could get it funded and
moving!  However, the "footsteps to Mars" approach allows you to start
missions before you have developed and tested and human-rated a Mars
lander, allows you to start missions before you have developed and
tested an ISRU plant to convert hydrogen to Methane, and allows you to
start missions before you have developed and tested technology to ship
liquid hydrogen to Mars.  Basically, with the originally proposed Mars
Direct concept, you don’t do anything until you have all the pieces put
together and ready.  The footsteps to Mars approach puts the pieces
together one at a time.

Let me emphasize, the human lander is by far the hardest part of the
Mars mission.  A vehicle for getting down to the surface and back up
again is the one piece that we have to develop from scratch.
Everything else is,  more or less, stuff we can put together from
pieces that already have been developed.

Do keep in mind that the footsteps approach does incorporate the
essential element of Mars Direct, namely the use of Martian fuel for
the return to Earth.  So you can think of the footsteps to Mars
approach as a phased version of Mars Direct, if you like, and you can
incorporate the three-vehicle approach that Zubrin proposes.

–
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis

At first I thought that globular clusters would be a good place to look
for ET but soon found that most such clusters are metal poor although
some are just slightly metal poor.  However, the lifetimes of planets
in clusters can be expected to be low due to numerous stellar
interactions.  But, there would be some survivors and you would expect
for some of these planets to have civilizations.
So,  What would be the perspective of such a civilization?  Their sky
would be an awesome sight but probably nearly devoid of other planets.
Eventually, they might develop space travel.  Travel times to other
stars would be fairly low for them and if there were many planets it
wouldnt take long for such a civilaztion to cover the entire cluster.
They probably would not find any other civilizations in their cluster
because planetary lifetimes are too low so theirs would be very
unusual.  They would find themselves alone.
What then?  They would look out to the rest of the galaxy and the
closest other stars would be very far away, in some cases approaching
intergalactic distances.  Travel out of their cluster would be
impossible for all practical purposes.  They might surmise that other
civilizations exist "out there" but would conclude that the probability
of any "visits" would be too low to think about.  Even communication
with any other civilizations would be nearly impossible as round trip
travel time for a signal might be longer than the age of their
civilization.  How would this cetainty of being alone affect them and
their philosophy?
Contrast this with our civilization where the closest stars are very
far away but we can at least consider the possibility of visiting them
using multi-generational ships in a reasonable length of time.  We can
even consider sending probes that will send back signals in a single
human lifetime.  There is enough variation in stellar type that we
conclude that the nearest civilization might not be too far away.  We
can even consider the possibility of communicating with them although
this will involve multi-generation lag times.  Even if somehow we
explore out to 100 light yearswithout finding anyone else we would
still not conclude that we are essentially alone because other stars
are still close enough to either visit or communicate with.  Our view
of the civilization possibilities is basically "open" whereas the view
of those in the cluster would be "closed".

I’d like to remind folks that the National Space Society’s Space
Settlement Calendar Art Contest is still open until the end of the
month.  For details, see:

  <http://www.nss.org/settlement/calendar/>

If any of you have both reasonable artistic skill, and any interest in
humanity’s future in space, I encourage you to give it your best shot.  
If they get twelve good pictures, it will be something to inspire a new
generation of people to look upward and think ahead.

Best,
– Joe

http://news.bbc.co.uk/2/hi/science/nature/6246513.stm
The search for purple-haired ladies begins!

Pat

For anybody who’s interested in SF set in space habitats, I just wanted to
mention that I’ve added a new short story to my Space Settlement site. It’s
called "Improbable Events".

http://members.aol.com/oscarcombs/shortstories.htm

Direct link: http://members.aol.com/howiecombs/improbable_events.htm

Regards,
Mike Combs

When, and I assume there will be a when. When 1/2 Doz people set off for
Mars, long dangerous flight, unless some leap in propulsion technology comes
along, at least 2years befor return maybe much longer. What would you take?
This is for you, not a tool, just for you. A little bit of earth (maybe just
that). I would take, perhaps a persion rug, or a Tang Horse, some grape
seeds, in fact seeds of all type including acorns etc. Maybe the guy with
the collection of kitchen knives should be looked at again.

Just my thought

I read a suggestion to use the sun as a gravitational lens to directly
image extra-solar planets.  However, the discussion said that the focal
point would be about 600 million miles from the sun which is beyond the
orbit of Jupiter and not readily accessible.
SO……..what about a smaller diameter gravity lens like
say………..our moon?
Unfortunately, I can find no reference to the focal distance in terms
of the lens mass and diameter.  Can anyone help?
Of course, the effective aperture might be small but the resolution
would be equal to a lunar diameter lens…….

I make x-ray optics for a living but my optics are very small with
apertures on the order of a cm or so.  On the other end of the size
scale is the Chandra x-ray telescope.  Can we make a REALLY BIG x-ray
telescope?  Maybe we can if optical quality is not an issue and what we
want is a "x-ray bucket".

Take a very large inflatable mylar sphere, say 1 km diameter.  Put a
ring of gold about 400nm thick around a circumference.  The width of
the ring would determine the maximum grazing angle.  Inflate said ring
in space to form a sphere.  The object being imaged lies at infinity
along a line perpendicular to the gold ring and the focal point
(region) lies in the opposite direction along said line.  The thin
mylar and low density gas in the sphere would be essentially
transparent to the higher energy x-rays while the gold would refelct
them at grazing incidence.

1965 scientist-astronaut recruitment brochure quotation

I’m looking for the wording on NASA’s recruitment brochure
on the 1965 (first-ever) scientist-astronaut cadre, specifically
the language of seeking ‘perspicacity’ and its definition as a trait
that leads one to keep one’s eyes open and notice unusual
phenomena — or something like that. Can anyone help?
And I’m seeking examples where space travelers later exhibited
exactly this trait — spotting something weird that wasn’t part of
pre-flight programs, that turned out to have scientific value —
such as Buzz Aldrin’s ‘light flashes’ on the way to the Moon,
or Georgiy Grechko’s unauthorized sleep-period sketches of
noctilucent clouds…

Thanks!

Jim O
www.jamesoberg.com

The next Mars lander, Phoenix, will be landing in
the north arctic area of Mars, in an area where
the ice has just retreated. Exposing ice rich
soil for sampling to look for organic material.

So far, those hematite concretions on Mars
have been found at both Rover landing sites.
And the poor images from Sojourner also
show what appear to be the very same
blueberries.

Question. Should inorganic mineral concretions
also form in areas that are perpetually frozen?
Isn’t it true the formation of mineral concretions
require liquid water?

What if the blueberries are found there also?

Mars Phoenix Lander
http://phoenix.lpl.arizona.edu/

s