RSS iconTwitter iconFacebook icon

The Trek BBS title image

The Trek BBS statistics

Threads: 139,691
Posts: 5,430,942
Members: 24,828
Currently online: 494
Newest member: ncc1500


Welcome! The Trek BBS is the number one place to chat about Star Trek with like-minded fans. Please login to see our full range of forums as well as the ability to send and receive private messages, track your favourite topics and of course join in the discussions.

If you are a new visitor, join us for free. If you are an existing member please login below. Note: for members who joined under our old messageboard system, please login with your display name not your login name.


Go Back   The Trek BBS > Entertainment & Interests > Science and Technology

Science and Technology "Somewhere, something incredible is waiting to be known." - Carl Sagan.

Reply
 
Thread Tools
Old July 27 2013, 03:24 PM   #31
Crazy Eddie
Rear Admiral
 
Crazy Eddie's Avatar
 
Location: I'm in your ___, ___ing your ___
Re: Satellites in Space

sojourner wrote: View Post
Crazy Eddie wrote: View Post
sojourner wrote: View Post
You would still need to target individual satellites at that radius. not very effective use of nuclear warheads...
THAT depends on where you choose to engage them.

For example, if you deliberately knock out all of America's communication satellites when they just happened to be directly over the continental United States and/or U.S. military bases, not only would you knock out the satellites, the resulting EMP would also zap half the computers in the country.
Comsats are in geosynchronous orbit. They don't wander around.
Civilian satellites, yes. A surprising number of military datalink satellites are still operating at lower altitudes (I'm not entirely sure why).

Would an EMP have the range to take out both a satellite at that altitude and whatever is on the Earth below it?
Hard to say, because the EMP is generated by the interaction of the warhead's radiation with the Earth's ionosphere and not by the bomb itself. The Starfish Prime tests demonstrated that the EMP actually gets STRONGER the higher up you go; an airburst at 100km produces an EMP that covers a smaller area and is less intense than an airburst at 500km or higher.

But nobody's ever tested a nuclear weapon at intermediate/satellite orbits above 5,000km. Could be the radiation pulse is too weak to produce a significant EMP, or it could create reactions in the Earth's magnetic field that fries all of our brains like so many eggs.
__________________
The Complete Illustrated Guide to Starfleet - Online Now!
Crazy Eddie is offline   Reply With Quote
Old July 27 2013, 08:34 PM   #32
publiusr
Commodore
 
Re: Satellites in Space

I don't think it would be that bad. I know here is this idea that early on people thought shooting off the first nuke down here would ignite the atmosphere, or something--but, as Sagan would say, we are star-stuff. There is another word for that though--stellar fallout. Once a star "burns" down to iron, that's all she wrote. It collapses. That collapse allows one final forging of elements allowing for heavier elements (that and neutron star collisions for gold it seems)

So we are nuclear ashes. Matter is tough. Now if nature allowed all these over-unity devices the conspiracy-believers think are out there--forget shooting off a nuke--I'd be scared to light a match.

In terms of satellites, it looks like they keep getting bigger:
http://www.space-travel.com/reports/...llite_999.html

http://www.aviationweek.com/Blogs.as...2-7b7fb65dee07

Optics, the size of antennas, all these limit the real utility of small sats, which just clutter up LEO.

There have been even larger concepts: http://www.astronautix.com/craft/globis.htm

The largest was the orbital antenna farm (OAF) called for by Director of COMSAT Labs, Burt Edelson:
http://www.permanent.com/space-produ...-services.html


Large antennas allow for better reception, but I think we still are addicted to the Smaller faster cheaper mantra of Goldin.

Ironically smaller circuits in some ways led to larger comsats anyway.


Early on, Clarke wanted manned communication platforms, not unlike--I hate the acronym-- OAF, thatwere large affairs. The idea is that you re-use the dish and solar power systems, but just slide in and out different breadboards.


The Soviets just used off the shelf electronics and made big pressurized, air-conditioned housings for their early systems. The electronics and early nukes were heavy, allowing their space advocates to say--don't shrink the payload--make the rocket bigger.

They still make the Vostok hull to this day, it is just used for research craft like FOTON
http://en.wikipedia.org/wiki/Foton_(space_programs)


Our warheads were small, and our sats were small. So our craft had to be space-rated...rad-hardened..vacuum proof...shock-proof...


Now simple solid state systems, while still better than room sized computers like ENIAC what with vacuum tubes, were rather hardy due to their primitive natures.

Early integrated circuit chips didn't have a lot too them, and only a hadfull of people worked with computers on the ground.


But once microchips were used in numbers down here--a funny thing happened. Computers here evolved faster than what could be put in space. By the time the 486 was space-rated, it was already obsolete. I think it takes eight transistors to hold one bit of data with authority IIRC. Now everyone down here has faster computers than many systems in space.Asia-Pacific uses who don't have fiber-optic trucks or other land-line infrastructure demand more and more data.


So comsats have gotten larger, not smaller. Since Russian rockets were already over-powered, they picked up the slack. Ariane 5 was going to launch the Hermes, and was considered overlarge. Now, it straines a bit and had to be up-dated with the ECA and other life-extensions. Musks rockets are overpowered with regards to EELVs, but that allows him more payloads.

Now some comsats have had to use electric drives since their hydrazine thrusters became stuck, so there is a trend towards all electric propulsion now, and that allows a lower "wet mass" as it were. But there are still adherants to the cubesat movement. I on the other hand think we need to embrace the gigantism, and go farther, with smaller numbers of larger, perhaps shielded systems.


One more note. I rather like primative electronics. To me, the circuits on the viking spacecraft are about what any spacecraft bus needs. Not as sensitive as some of todays circuits, but smaller than Apollos. Some happy medium needs to exist for hardy systems that can last. Voyager seems to be doing quite well after all.

Last edited by publiusr; July 27 2013 at 09:05 PM.
publiusr is offline   Reply With Quote
Old August 3 2013, 09:30 PM   #33
publiusr
Commodore
 
Re: Satellites in Space

Some other large concepts
http://arsastronautica.com/article.php?news_id=4

Dwayne Day talks about satellites that "would have 300-meter diameter dishes"
http://www.thespacereview.com/article/1691/1
publiusr is offline   Reply With Quote
Reply

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 08:39 PM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
FireFox 2+ or Internet Explorer 7+ highly recommended.