Earth to Orbit

--- "Tom Tucker (Olympia)"
> Marcel,
>
> IMO, the earth's gravity well is too deep for a
> single plane or stage to orbit (i.e. STO) vehicle to
> work unless we somehow discover anti-gravity :-).

MW: That's why I advocate a two stage horizontal take
off and horizontal landing vehicle capable of placing
10 to 20 people into orbit. The first stage could also
be used as an intercontinental suborbital passenger
plane that could carry a hundred plus passengers to
any point on the planet within one or two hours. This
first stage could also be used as a hypersonic bomber
that could attack any point on Earth within 2 hours.

> Tom Tucker: This is why I am examining the tether
approach. You
> see, what is the tether could build-up speed in LEO
> using nuclear or solar power, and then dip down to
> pick-up the payload from a Boeing space plane at say
> 100KM? Why go all the way to orbit when something
> in orbit could work as a team and meet you half-way,
> so to speak? Lets think outside of the box and not
> be tied to the notion that we have to have a single
> vehicle that can independently go from earth to LEO
> un-assisted.

MW: Again, a two stage aerospace plane would not only
give private companies easy access to orbit but the
first stage would revolutionize international air
travel.

> Tom Tucker: For further background on this question,
I recommend
> Dr. Zubrin's book Entering Space, chapter 3 "The New
> Space Race" where he review various space plane
> options and current projects. The bottom line is
> that STO will work on Mars and the Moon, but not on
> earth; too much gravity.

MW: Aerospace planes will never be practical as heavy
lift vehicles. That's why they should be limited to
human transport. The average human weighs less than
100 kg. But even if you allowed 500 kg for seating,
air, water, luggage, space suit, and body mass, you
could still launch as little of ten tonnes of payload
(20 people into orbit). Most of the cost of launching
mass into orbit is not fuel cost, but the capital cost
of the vehicle and the cost of labor. The mass
production of the first stage as an international
suborbital space plane and launching the two stage
vehicle like an airplane could reduce cost
significantly, IMO. And since these two stage
aerospace planes could take off from any international
airport, cost could be further reduced by taking off
from international airports located on, or near, the
equator.

Single stage to orbit vertical take off, and vertical
landing, heavy lift vehicles, of course, would be
significantly lighter than winged vehicles-- with
structural weights less than three times that of a two
staged winged vehicle. And such heavy lift vehicles
capable of putting 100 to 200 tonnes into orbit would
be far too potentially explosive to be launched from
any airport and will probably continue to be launched
from special launch facilities run by NASA.

>
>Tom Tucker: Zubrin also points out that the major
rocket
> manufacturers have absolutely no incentive to reduce
> the cost to LEO since they feel that they would be
> cutting their own financial throat.

MW: That's certainly not true since their is
international competion in the satellite launching
business.
Independent
> efforts are indicated and, IMO, the winner may not
> be flown from US soil at the rate we are going now.
>
> Cheers,
>
> Tom

MW: The US simply needs to invest money into simple
reusable Earth to orbit vehicles that have been on
the drawing boards for more than 30 years. And this
money should come from the military budget, IMO. One
satellite manufacturing factories are on the Moon, the
moon will dominate the satellite manufacturing and
launching business until we begin to exploit the
asteroids which could make satellite manufacturing and
launching as cheap as as building a Mercedes Benz.

Marcel F. Williams
12/10/00