View Full Version : Some baby steps to intersteller flight within grasp of todays technology

2006-May-01, 12:50 AM
~The question was about reactionless drives, which in theory can thrust contineously for centuries. One reactionless drive we can begin with today's technology, which takes near infinate amounts of money (An SE = space elevator would reduce the cost) is to launch several laser arays in hyperbolic orbit anually. Nuclear and solar powered. These do sling shot manuvers to gain more speed. In 1000 years, or so, these would be scattered randomly about the solar system including the Kupier belt and the Oort cloud. Solar sail craft could then be suplimented by a laser beam in the rather rare periods, when they were within a million (someone thought a billion miles may be posssible) miles of a laser array.
The cost would be partially justified by the fact that the laser arrays could minutely alter the course of asteroids and comets threatening Earth, and the beam of laser light could be tracked by telescopes to help chart tiny asteroids and tiny comets that would be 30th magnetude illuminated only by sun light. Please embellish, or refute. Neil~

Hal typed: Were you insinuating that some hypothetical, future, laser-pumped solar sail transportation system would be the financial savior for an upstart SE?

~Here are some more details. My points were: 1 we can (as soon as we get organized) launch laser arrays into solar orbit.
2 Nuclear is a practical power source, except we have not yet developed the details of light weight nuclear reactors to be launched into solar orbit. These do not need comfinement nor shielding as there will be no human crew. If we anticipate a future laser repair person, the nuclear reactor can be dragged behind the steam turbine which is dragged by the laser array by its long extension cord. We cannot repair the unshielded nuclear reactor with human technicains, but waldo type robots may be able to make the repairs. Solar mirrors can supliment the heat energy that will run the turbine which will turn the generator that supplies electricity for the laser beam. Some power will be available if the nuclear reactor fails partially or completely. A solar pumped laser may be a third back up system. If the laser array is to remain opporational continously for 1000 years, we do need back up systems.
3 sling shot manuvers = gravity assist manuvers. The laser array needs some propulsion to set up (and fine tune) the gravity assist manuvers.
4 costs are reduced when an SE can assist with the launch of improved laser arrays. Lauching several of these increasingly more massive laser arrays per year would provide revenue for SEs very long term
5 Solar sails are one of the benefactors of these laser arrays in solar orbit, as the laser beam can suppliment the sun as a propulsion energy source.
Yes I was insinuating as you said, except we need only minor advance of the details to start lanching these solar arrays. With rare exceptions the details are beyond hypothesis = theory and we should be lauching prototype laser arays before 2018 when the SE will hopefully be available to assist in the launch of laser arrays. In my opinion, it is urgent that we begin doing things like this before human civilization collapses, or a big asteroid sends human civilization back into the dark ages. Neil

Carl typed~ Given the low (or unknown) near-term probability of these events, I wonder if resources might be better spent in other areas. A recurring theme in SE literature is using the first elevator to carry up the pieces of its successors, reducing the need for further expensive rocket launches. Take this a step further and begin carrying up bootstrap manufacturing facilities. Being able to produce required components in space rather than lifting them from earth would likely lead to exponential growth, given the energy, mass and sheer space available. By the time a few of your laser arrays have barely started on their 1000 year deployment flights, factories in space could be producing much or all of the required hardware along with chemical fuels to push it around at much better speeds.

The 1000 year deployment reminds me of the sf stories about generational starships that arrive only to find faster-than-light ships had subsequently been developed and arrived much sooner. If the asteroid strikes next year, we will probably be hosed. If it comes 100 years from now, we will probably have much better tools to deal with it. I'm not sure it makes sense spending a lot of money now to cover the 1 to 100 year range.

~You are likely correct that the laser arrays are best assembled in orbit and GEO orbit will be more accessible than LEO orbit after 3 SEs are completed. That could be soon as 2021, so it is not too soon to seriously fund the first proto types to be lunched before the SE is available. We will have better tools to deal with diasters later, if we design and build prototypes during the coming decade. We need to create public enthusiasm and keep it high with ambitious projects.
Some tests have been done at the ISS = international space station to find practical methods of manufacturing and assembly in space. I definately favor following up on these. Neil~

2006-May-04, 10:11 PM
I think in space assembly should be delayed as much as possible, with modules as large and as few in number as possible. A Sea Dragon NSWR combo will get to another starsystem--but you will have to wait. In the mean time, the HLLVs can be used to ease Space Elevator construction.