On Oct 25, 8:10 am, Hop David wrote:
Quadibloc wrote:
On Oct 23, 12:02 pm, "Mike Combs"
wrote:

There seems to be an assumption that overland travel on Mars has got to be
easier than moving between asteroids because the latter is space travel and
the former isn't, and as everybody knows, space travel is difficult,
dangerous, and hideously expensive. I think this notion overlooks two
points:

1. Overland travel on Mars, unlike same on Earth, will have pressurization
and other life-support requirements little different from space travel.

2. Our notions of space travel are influenced by our most common experience
of it, which is to say, travel from the surface of the Earth into orbit.
Such travel requires large amounts of thrust (greatly in excess of vehicle
weight in 1-G) quickly achieved, and an aerodynamic shape. None of these
will be requirements for systems traveling from one asteroid to another.

These are legitimate points. If one is _in_ space, one doesn't need an
awful lot of thrust to go places.

However, while a Mars buggy needs to be pressurized, a voyage from one
asteroid to another, if it is to have modest fuel requirements, will
take a while. Trips between the Kuiper Belt for biomass and the
Asteroid Belt for metals will take many years.

Trips to the Kuiper belt for biomass are unnecessary, in my opinion.http://clowder.net/hop/railroad/asteroidresources.html

Nor are trips to the asteroid belt. I suspect both metallic asteroids
and asteroids with ice interiors exist among the NEOs.



So, while you are right that the commonplace view based on past
experience of an Apollo moon mission versus a drive to the country in
one's car exaggerates the situation, Mars is a single body that has
both metals and carbon, hydrogen, oxygen, and nitrogen available. So I
think it is still favored for lower start-up costs despite the fact
that the disparity can be exaggerated.

And what would the return on investment for martian start up costs be? I
can imagine profitable exports from the Moon, Phobos, Deimos or NEOs to
near earth space. These may be unlikely but profitable Martian exports
are far more unlikely.

Hop- Hide quoted text -

- Show quoted text -

Yes, this reminds me of the premise for a novel I outlined for a
former member of the Mars Society: in some decade late in this
century, there is a space-faring society including tourism operations
in LEO, colonies on the moon and mining outposts on asteroids and the
Martian moons, with a tiny fringe activist group scattered among them
that never seems to get any political traction or private financing
for its agenda of colonizing Mars.

This activist group's last, best hope in the opening pages of this
never-to-be-written SF non-classic: a passel of lawsuits wending their
way through appeals courts in various jurisdictions on and off Earth,
based on stretching the letter and spirit of deep-space claims law to
make Mars their property. In one suit they seek reparations from past
and present users of the Martian atmosphere (for aerobraking) and the
Martian gravity well (for momentum exchange), for having provided
"propulsion services". In another, they want to impose fines for
littering, since aerobrakes inevitably deposit some debris in the
Martian atmosphere and in orbit. They are also suing for rent in
arears, from the corporations mining Phobos and Deimos. In support of
these suits, they cite a passage granting the right to exploit the
main bodies and any satellites of properly claimed asteroids, and the
considered opinion of an obscure member of the International
Astronomical Union (Luna Branch) that all objects orbiting the sun
should be called "asteroids" (a guy who -- surprise -- happens to be a
member of their society.) And what about the longstanding legal
requirement that a living human being be present on the surface of an
asteroid to establish a claim? Decades before, much to the
consternation of exobiologists *still* concerned about forward
contamination of Mars, this group carried out a mission to drop a
package containing a frozen fertilized human ovum into a polar region
of Mars, with most of the money coming from a pro-life PAC with whom
they otherwise have rather testy relations (politics making, as
always, for strange bedfellows.) The little guy's name is Bob,
though there's a splinter faction that prefers the name "Mike". Bob's
shelf-life is soon to expire, unfortunately, assuming he was ever
viable at all after the cosmic ray exposure suffered on the trip to
Mars in an undershielded vehicle thrown together on the cheap.

In that notional future, this pro-Mars-colonization group is,
naturally enough, called The Mars Society. Because that's the kind of
mean, sarcastic guy I am. ;-)

-michael turner