LIT TC Project (fwd)

[Kevin C Houston <hous0042@maroon.tc.umn.edu>]

recieved and fwd. please add this person to your LIT mail list.  he seems 
sincere.

---------- Forwarded message ----------
Date: Sun, 11 Feb 1996 17:57:41 -0600
From: L. Parker <lparker@destin.gulfnet.com>
To: Tex Houston <hous0042@maroon.tc.umn.edu>
Subject: LIT TC Project

Hi Kevin,
I am a little new here and have been reading through older postings as fast
as I can. So if I duplicate an issue or repeat a question that has already
been answered please excuse me. Is there an updated version of Kelly Starks'
proposed configuration for Asimov? It seems some major profile changes have
been made since he posted it in '94.

Have you compared simple solar pumped mechanical lasers to the microwave
generators? They would not transmit power as effectively, but it seems to me
that they could be massed produced in HUGE numbers to provide more than
enough power and remove the need for quite so much magnetic shielding.

BTW, I am not sure depending on shielding generated by an external wire mesh
dish is such a good idea. As Kelly pointed out in his early design proposal,
we don't really know what the composition of interstellar space is. Suppose
that just occasionally we run into something bigger than the shield can
deflect, or a pocket of denser media which imparts more kinetic energy to
the structure than it is capable of abosrbing...might be a good idea to
combine both shielding ideas (mass/magnetic) as well as any other built in
redundancy we can come up with.

Matter of fact, I am not too fond of the idea of the mesh period, too many
things can/might/will go wrong with it. Sure would be nice if we could focus
magnetic fields over a long (1000 km) distance. That might even allow us to
resuscitate the idea of using a RAM scoop.

Most of the postings I have read seem to assume a period of coasting in all
configurations, why? It would be far simpler to design for continuous 1 G
acceleration for the duration of the mission. It might even be agood idea to
DESIGN for operation at up to 3 or 4 G for extended periods (Emergency
Contingency Planning).

Okay, now for some REALLY strange questions... 

1) Has anyone calculated the mass density of matter impacting the ship at
..99 c and computed how much and what kinds of primary, secondary, and
Cherenkov radiation would be generated? CAN we provide that much shielding?
How about blue shifted free radiation? Wouldn't there be a great deal of
radiation in the x-ray and gamma ray bands? Can we shield against it? Also
remember that at relativistic velocities the event horizon contracts for and
aft, concentrating the radiation exposure there.

2) What is the particle density in the various speed regimes? Is there a
minimum speed at which the density would become great enough to initiate an
EXTERNAL fusion reaction similar to a QED-electric REB plasma rocket (page
11 of Kelly's paper)? Now wouldn't that be neat? An air breathing spaceship!

3) Generally, what is the MAXIMUM particle density we could safely use for
acceleration?

4) Generally, what is the maximum particle density we could safely navigate?

5) Can we detect increased particle density ahead of our course by any
means, and at sufficient range to allow us to generate enough delta v to
avoid it? Twould be a shame to lose the first interstellar mission to a
cloud of water vapor!

Well, enough for now, I have lots more questions, many of which, like some
of these, may not be germane, but what the heck, someone has to ask them! :-}

Lee Parker

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+                                                                             +
+  Weave a circle 'round him thrice, and close your eyes with holy dread...   +
+                                                                             +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++