[ RadSafe ] space elevator

Brennan, Mike (DOH) Mike.Brennan at DOH.WA.GOV
Tue Aug 18 13:06:35 CDT 2015 

The nice things about building elevators for the Moon and Mars are that the gravity well isn't as deep as for Earth, and you start from the top.

In its simplest form the downside station can be the lander that takes the ribbon to the surface.  You would want to be able to steer it and anchor it when it was down, but it wouldn't be as difficult as a lander that had to do the whole thing with rockets.

Of course, to get to the top of the Moon's or Mars' gravity wells you first have to climb out of ours, and take everything you will need with you.  Yet another one of those exercises.

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of KARAM, PHILIP
Sent: Tuesday, August 18, 2015 10:27 AM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] space elevator

Of course, first we have to get back to the Moon and to Mars to build the things - and at the rate we're going I'm not sure it will happen within my lifetime. Or that of my kids. Who'd ever have believed that, over 40 years after reaching the Moon, the US would lack the ability to get a person even into Earth orbit, let alone to the Moon?


P. Andrew Karam, PhD, CHP
NYPD Counterterrorism
One Police Plaza, Room 1109
New York, NY 10038
(718) 615-7055 (desk)
(646) 879-5268 (mobile)


-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Brennan, Mike (DOH)
Sent: Tuesday, August 18, 2015 12:14 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] space elevator

I think that a space elevator is not yet technically viable, but the millennium is young.

I think the material/engineering for a Moon-to-space elevator is within our grasp, and this would provide a way to get material to and from the Moon's surface with economic operating costs (up-front capital costs will be large, but probably both doable and worthwhile).  I would not be surprised if we have the material for an Earth-to-space elevator in my lifetime, though I'd be surprised to see it actually built.  

There has been talk (quiet and wistful) about a Mars-to-space elevator, perhaps attached to Olympus Mons.  I understand we probably have the material to handle it, if someone will pay for shipping and handling.  It would make a colony a much more viable enterprise, as it would remove the need to ship huge amounts of fuel to Mars and put it on the surface, just to be used to get things back off the surface.

One of the aspects of a space elevator that is interesting from a rad point of view is the effect of radiation on long chain polymers.  As all plans for an elevator call for long strands of polymer, or carbon filaments in a polymer matrix, radiation, especially high-Z particles, breaking the chains is a problem.  It simply does not do to have your ribbon get stiff and crack, or weaken because or broken chains.  The solution, again, is left as an exercise to the reader.  

I believe the research on space elevator technology is worthwhile, and deserving to be paid for, at least in part, from the public purse.  But I don't think it is yet time to fire up the reservation system. 

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Joseph Preisig
Sent: Monday, August 17, 2015 5:39 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] space elevator

Hmmmmm,

       I posted the space elevator news because it was news.  Don't think it is viable???

       Clearly, a TR3B or some other flying saucer could be built in the public domain with enriched uranium or plutonium reactor power.
The TR3B is faster than modern jets, due to its levitation ability.
Heck, German Haunebu's have been around for more than 70 years???  We continue to fund public domain and black project flight systems --- it is expensive.  A mothership could have more than one reactor, and could have shuttlecraft flying saucers coming from it.

      Joe Preisig



On 8/17/15, Brennan, Mike  (DOH) <Mike.Brennan at doh.wa.gov> wrote:
> I've been following Liftport, one of the leaders in the space elevator 
> quest for some time, and it is a very interesting proposition.  We now 
> have materials that could be used for a Moon-to-space elevator, though 
> we do not have materials that can be used for an Earth-to-space 
> elevator (but there is good reason to believe we will be there soon).
>
> The Earth-to-space elevator proposed by Liftport would have a station 
> in geosynchronous orbit (about 42,000 km), with a ribbon continuing 
> out another
> 90,000 km (give or take) to act as a counterbalance.  Cars climbing 
> the ribbon from the ground would take one to two weeks to reach the 
> station (cars going to Low Earth Orbit to release satellites would get 
> there in a couple of days).  The counter balance ribbon could be used 
> as a launch system, letting probes free-wheel down the ribbon, using 
> centrifugal force to sling (literally) the package out of the 
> Earth-Moon system (targeting left as an exercise for the reader).
>
> Shielding will be a non-trivial issue, as the station at geosync will 
> be in the Van Allen Belt, rather than below it like the ISS.  It may 
> be that a lot of the work at the station will be done via telepresence.
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of ROY HERREN
> Sent: Monday, August 17, 2015 3:35 PM
> To: The International Radiation Protection (Health Physics) Mailing 
> List; The International Radiation Protection (Health Physics) Mailing 
> List
> Subject: Re: [ RadSafe ] space elevator
>
> An operable space elevator would be a wonderful step towards 
> humanities reaching out and inhabiting space.  The financial cost per 
> kilogram of material currently launched into space is a limiting 
> factor that is holding back greater exploration of space.  It's 
> hard to imagine though how any one company or even country could 
> afford to build such a complicated and large of a structure.  If this 
> is to happen, it will likely require an international consortium for financing and construction.
> Question, where in space would such an elevator terminate, i.e. a 
> space port, a space dock for assembling space ships, etc.?
> Just to rope this discussion into the mailing list topic of concern, 
> would deep-space manned space ships assembled in a space dock 
> initially have fission reactors?  What would propel such ship, ion 
> propulsion? Could deep-space space ships harvest enough interstellar 
> gas to provide propulsion, or would they have to bring all the 
> material with them from earth?
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