Magnetic catapult to space?

On Feb 18, 10:25 am, wrote:
On Feb 18, 10:12 am, tadchem wrote:



On Feb 17, 1:37 pm, Robert Clark wrote:

Magnetic Catapult a feasible advanced earth launcher.
February 11, 2008
"A 9000 meter long magnetic catapult was proposed in 2003 by Warren D
Smith, mathematician at Temple University. It was designed to launch 5
meter long, 1 meter diameter projectiles at 2250 gees of constant
acceleration with a launch velocity of 20km/s (twice earth escape
velocity, Mach 58). It would cost about $2-20 billion to build and
operating costs would be $10-100 million/year. This system is not a
railgun and is not a coilgun."http://nextbigfuture.com/2008/02/magnetic-catapult-feasible-advanced....

Bob Clark

I can already see the enviro-whiners wringing their hands and filing
their requests for restraining orders because of what they imagine it
might do to the migratory birds' navigational systems, the impacts of
the sonic booms on the local wildlife, the air pollution, the water
pollution, the local traffic patterns (more SUVs on the road carrying
technicians to work!), and so on.

Tom Davidson
Richmond, VA

Your use of the perjorative "enviro-whiners" suggests that you do not
see their concerns as valid and yet by listing a series of immenently
reasonable concerns you undercut that very notion. A good, properly
engineered, system must take into account and work with, the
environment(regulatory and ecological) in which it operates. The valid
concerns you raise are not showstoppers, nor are they unreasonable.
I would gently suggest that your complaining about "eviro-whiners" is
itself not far removed from whining.
It isn't environmentalists that have landed the space program in such
pathetic shape that an abomination such as the ARES -1 can even be
considered. It is instead a stunning "lack of imaginatin"( to quote
Wayne Hale in a recent comment) and unbeleivably poor leadership from
the White House down.
The Orbiter is a magnificent spacecraft once in space. In addition to
its payload bay and arm, it has wings that can be used for aerobraking
to LEO or LMO. The Orion is virtually just "spam-in-a-can with far
less capability for space operations of any kind beyond transporting
astronauts. The Orbiter can catch and service sattelites and carry
large payloads among many other activities.
Using the Orbiters we have, with relatively minor modifications and
additions, we can establish a self sufficient(in terms of propellant)
Earth - Mars transportation system using solar based ISRU at Phobos
and/or Deimos.
A sketch of how this can be done:
1. Replace the OMS thrusters with LOX - methane rocket engines fed
from tanks in the payload bay After the ET is dropped, these thrusters
can fire to greatly increase payload to orbit. If a way to drop the
SSME's could be worked out, the payload could increase further.
2. Add a solar concentrator based system for extended power supply
via highly efficient triple junction PV and use the same large
concentrator mirrors as solar furnaces for ISRU and 100% recycling of
consumables. In addition these mirrors can provide solar thermal and
electric propulsion and high baud communication. The mirrors must be
able to retract into the payload bay and be redeployed.
3. Launch two of these modified Orbiters. Receive additional
propellant, perhaps from the other Shuttle on orbit and use the
methane O2 rockets(restartable in space of course) to move to a highly
elliptical Earth orbit and then to a Mars bound trajectory. Rely on
solar thermal for emergency return from Mars to reduce propellant that
must be carried.
4. Tether the two Orbiters together to provide spin for "artificial
gravity" during the trip.
5. Seperate, stow mirrors and aerobrake first to a highly elliptical
and then to LMO and Phobos/Deimos rendesvous.
6. Use solar furnace to process regolith for propellant and store it.
7. Return to Earth by first acheiving HEMO and then a final thrust
for Earth bound trajectory.
8. Aerobrake at Earth to HEO with perhaps some help from the rocket
engines with enough propellant to return with additional equipment
that could include a lander.
9. Lather, Rinse, Repeat.

Or we could do what we always do: develop sytem, operate it a while -
throw it away or put in museum.

Now I know this is heresy and is absolutely impossible, etc.
I also know however that if the space community saw this as the only
way forward it would somehow magically become possible..

Steve Mickler
Solar Thermal/Electric Propulsion
First STEP

All of the above are perfectly doable as is, and the reason why they
will not be done is simply the focus or intent of those in charge of
creating as much evidence exclusion and/or banishment as they can
muster. It's what certain faith-based types do best, even if it means
puppeteering a certain warlord or two (ideally opposing one another)
into power and of sustaining their status quo until hell freezes over
and/or every other drop of bloody oil, coal and natural gas is
expended, with all profits from such going into their offshore bank
accounts.

Wouldn't to like to know or simply admit as to which faith-based group/
cult is most in charge?
.. - Brad Guth

Dear behlingjo:

wrote in message
...
....
No, they would still look for a viable way to do
it, because this concept is impossible

Clarification:
- catapults to space are impossible, or
- said catapult will destroy anything not made of solid iron due
to the g forces is impractical, or
- the environmental lawsuits and land rights make it impossible?

Just curious.

David A. Smith

On Feb 18, 12:07 pm, "N:dlzc D:aol T:com \(dlzc\)"
wrote:
Dear behlingjo:

wrote in message

...
...

No, they would still look for a viable way to do
it, because this concept is impossible

Clarification:
- catapults to space are impossible, or
- said catapult will destroy anything not made of solid iron due
to the g forces is impractical, or
- the environmental lawsuits and land rights make it impossible?

Just curious.

David A. Smith

Is this mindset of yours primarily because you can't read?
.. - Brad Guth

On Feb 18, 3:07 pm, "N:dlzc D:aol T:com \(dlzc\)"
wrote:
Dear behlingjo:

wrote in message

...
...

No, they would still look for a viable way to do
it, because this concept is impossible

Clarification:
- catapults to space are impossible, or
- said catapult will destroy anything not made of solid iron due
to the g forces is impractical, or
- the environmental lawsuits and land rights make it impossible?

Just curious.

David A. Smith

My response was to the other concept of modifying the orbiters, not
the catapults