I think the current time is very critical.

About the SSP, it seems congress is sort of
considering it as an option, but more of a 40-50 year,
launched completely from Earth deal. Where is
everybody's vision? How cliche can humanity's state
of mind about space get? I would hope for a 10 year
moon-base-aseroid-SPS as a viable solution (O'Niell's
statement about how determination and human vision can
accomplish extraordinary things in extraordinary
amounts of time is not necessarily true, but I
consiider it my guiding light).

About the SSP, it seems congress is sort of
considering it as an option, but more of a 40-50 year,
launched completely from Earth deal. Where is
everybody's vision? How cliche can humanity's state
of mind about space get? I would hope for a 10 year
moon-base-aseroid-SPS as a viable solution

What was the estimated mass of the island one colony? It must be remembered that
even if launch costs from the moon + manufacturing & assembly costs for an
O'neill colony, are $10/Kg (1/1000th current earth launch costs, not including
the cost of assembly in orbit) a Billion tonne colony would still cost $10
trillion. This is equal to the GDP of the United States at present levels.

Including shielding Island one was to weigh between 9 and 10 million
tonnes - that would represent $100 million launch costs at $10/KG.

Given that NASA is supplying the bulk of the coverage as free media & that
Dan Goldin's NASA ranks Mars, Mars, Mars, Europa & Mars as the five leading
targets for space exploration, what's the big surprise?

I think you are very correct here - that is why a lot of less well
publicised scaled down studies were performed by O'Neill himself. In
his book 'The High Frontier' he admitted himself that no-one would be
more surprised than himself if the final Island One implementation
turned out to be anything like the one he proposed.

What was the estimated mass of the island one colony? ABernal Sphere would come in at under 4 million tons, and a simple Space Manufacturing Facility could mass much less still It must be remembered that
even if launch costs from the moon + manufacturing & assembly costs for an
O'neill colony, are $10/Kg (1/1000th current earth launch costs, not including
the cost of assembly in orbit) a Billion tonne colony would still cost $10
trillion. This is equal to the GDP of the United States at present levels. Yes, we all recognize this argument. It's Bob Zubrin's, and he used in in "Entering Space" to convince everybody that those Gerry O'Neill ideas are crazy, so why don't we all ignore them and come back to these marvelous Mars ideas. Lift costs 1/1000th current ones certainly sounds like a generous assumption. But why should electromagnetic launch from the moon have any basis for comparison with launch via chemical rocket? The MIT study concluded lunar mass-drivers could lift lunar material for a cost of around 10 cents/kilogram. For Zubrin to successfully dispute this, he must identify the calculation errors in these previous studies, and not merely throw out a number of his own, no matter how generous-sounding.

Including shielding Island one was to weigh between 9 and 10 million
tonnes - that would represent $100 million launch costs at $10/KG. According to my sources it was the Stanford Torus which weighed 10 millions tons. If we understand "Island One" to mean the Bernal Sphere design, that was less than 4 million, largely owing to its shape which was more efficient of shielding mass. But your other points are applicable to both, and well worth making.

At the risk of
getting lynched, nothing dates faster than futurism; & the massive
construction vision of the classical O'Neill colony is so much a part of the
postApollo bigger is brighter school that returning to the concept in 2000
as we did seemed strangely quaint. There's so much construction &
transportation required for even a small colony to be established - & no way
for the colony to achieve even nominal self sufficiency in the short term -
that with current & nearterm technologies, the concept simply isn't a viable
alternative. Your points are good ones, but in all fairness to O'Neill, he recognized this fact well before his death, and began promoting a program of SPS construction at relatively modest Space Manufacturing Facilities, with large, Earthlike space habitats coming only much later in the program.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Lift costs 1/1000th current ones certainly sounds like a generous
assumption. But why should electromagnetic launch from the moon have any
basis for comparison with launch via chemical rocket? The MIT study
concluded lunar mass-drivers could lift lunar material for a cost of around
10 cents/kilogram. For Zubrin to successfully dispute this, he must identify
the calculation errors in these previous studies, and not merely throw out a
number of his own, no matter how generous-sounding.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

In a message dated 4/3/01 10:01:15 AM Eastern Daylight Time,
markac_99@... writes:

Mark Collins wrote

> With
> abundant and cheap lunar
> materials, available in high earth orbit, entire
> fleets of ion-driven Mars bound
> ships, could be constructed.

> I think the current time is very critical.
>
> If we are to prevent the monopolisation of space resources by
> the 'let's get to Mars as soon as possible' we must start promoting
> the Gerard O'Neill vision now. We risk another short term mega-bucks
> blow out similar to Apollo with the delay of SPS and space
> colonisation, which are surely a more sensible course to take. This
> time there is a risk of other countries getting dragged in too.
>
A Mars project would not be as bad as you think if it is not cut abruptly as
the Apollo program. A Mars travel asks for the same delta vee as a trip to
Phobos or Deimos, both are made from common asteroid stuff. A mass driver on
one of these small world would launch at low cost the raw material for a
space settlement. In space, what count is not distance, it is energy or delta
vee. In that respect, the martian satellites are are better target than the
Moon. They are too the rearest asteroids-like object at hand.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
A Mars project would not be as bad as you think if it is not cut abruptly as
the Apollo program. A Mars travel asks for the same delta vee as a trip to
Phobos or Deimos, both are made from common asteroid stuff. A mass driver on
one of these small world would launch at low cost the raw material for a
space settlement. In space, what count is not distance, it is energy or delta
vee. In that respect, the martian satellites are are better target than the
Moon. They are too the rearest asteroids-like object at hand.

>
> Including shielding Island one was to weigh between 9 and 10
million
> tonnes - that would represent $100 million launch costs at $10/KG.
>
> According to my sources it was the Stanford Torus which weighed 10
millions
> tons. If we understand "Island One" to mean the Bernal Sphere
design, that
> was less than 4 million, largely owing to its shape which was more
efficient
> of shielding mass.
>
> But your other points are applicable to both, and well worth making.
>

>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>
> A Mars project would not be as bad as you think if it is not cut
abruptly as
> the Apollo program. A Mars travel asks for the same delta vee as a
trip to
> Phobos or Deimos, both are made from common asteroid stuff. A mass
driver on
> one of these small world would launch at low cost the raw material
for a
> space settlement. In space, what count is not distance, it is
energy or delta
> vee. In that respect, the martian satellites are are better target
than the
> Moon. They are too the rearest asteroids-like object at hand.
>

A Mars project would not be as bad as you think if it is not cut abruptly as
the Apollo program. I'd agree that a big push toward Mars would be better for High Frontier than no new projects in space at all. In space, what count is not distance, it is energy or delta
vee. In that respect, the martian satellites are are better target than the
Moon. To a certain extent. But travel times must be taken into account too, and can make a big difference wrt life-support requirements. Also, it's possible that teleoperation may become available. If so, it could be implemented on the moon, but not at the distance of Mars.

To expand on Mike's comments...

The MIT study made no attempt to factor construction & infrastructure costs
into its Lunar mass driver calculations; & so came up with a figure which is
almost ridiculously low in comparison to the real cost of such a system.

Even at the most basic space platform level, you're still talking massive
transISS construction activities at a time where mission profiles are being
simplified to the minimum just to have a ghost of a chance of viability; &
adding a solar power platform to the mix just makes things worse. The above
the line cost just to develop the technologies for such a mission concept
are frankly, appalling, with current & near term capacity; & the lack of in
situ resources (which would exist if you went Lunar, Martian or used the
interior of an Earthgrazer asteroid as an ersatz O'Neill) would leave you
incredibly vulnerable to the terrestrial zeitgeist.

> Even at the most basic space platform level, you're still talking
massive
> transISS construction activities at a time where mission profiles
are being
> simplified to the minimum just to have a ghost of a chance of
viability; &
> adding a solar power platform to the mix just makes things worse.
The above
> the line cost just to develop the technologies for such a mission
concept
> are frankly, appalling, with current & near term capacity; & the
lack of in
> situ resources (which would exist if you went Lunar, Martian or
used the
> interior of an Earthgrazer asteroid as an ersatz O'Neill) would
leave you
> incredibly vulnerable to the terrestrial zeitgeist.

The MIT study made no attempt to factor construction & infrastructure costs
into its Lunar mass driver calculations; & so came up with a figure which is
almost ridiculously low in comparison to the real cost of such a system. OK. But if a mass-driver launched sufficient mass to build 5 Island 3's over its operational lifetime, that would be around 5 billion tons. How many individual kilogram launches would that be? If we amortized construction & infrastructure costs, how finely-divided would those costs wind up being? And obviously, subsequent lunar mass-drivers will be much cheaper to construct than the first one. Construction costs will be less, and many infrastructure costs will be non-recurring. Lunar mass drivers require so much technology to be placed into space to
support the technology that it isn't hard to work the numbers to show that
it's cheaper to build most space platforms by constructing them on - &
launching them from - Earth, no matter how how terrestrial launch costs are
or how low the marginal launch costs of mass drivers are. If by "most space platforms" we mean things like ISS, the first prototype SPS, or maybe even the first half-dozen SPS, certainly right. But if talking about enough SPS to industrialize the third world, or Island One, then the lunar mass driver will most certainly pay for itself with lift costs savings.
Regards,

I think at the moment that lunar telepresence is the lowest
bar that has growth potential. However, whether it would open
space depends on what we find at the poles.