Welcome to Star Trek Simulation Forum

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

Sign in to follow this  
Followers 0
Guest Laarell

Ringed Earth

Oh my god! That is amazing! Man is ruining space before we can master it! So not only is Global Warming ruining Earth, but our pollution is ruining our atmosphere! Way to go Humanity!

 

Thanks for that reality check, Laarell. NO one thinks about it until they see the truth. Nice job!

Share this post


Link to post
Share on other sites

Of course, in that particular picture those satellites have been exaggerated thousands of times to be many miles across just so they can be seen, but it does illustrate the daily tracking problem NORAD has. If you look at the Earth below for scale, each of those satellites would have to be bigger than entire cities. The largest thing up there, the International Space Station, is only about the size of a football field. They actually move the ISS a mile laterally when just one of the object tracks falls within its multi-mile "collision spheroid". But this hardly ever happens. But it's still wise. I've handled some of the Shuttle tiles and a window surface that were impinged by paint flecks. It actually vaporizes little spherical sections an inch or two in diameter - which is still better than the bullet through hot butter image. The real danger is to spacewalking astronauts.

 

As the picture shows, the biggest risk of collision is in Low Earth Orbit (LEO) - within a few hundred miles of the surface. At that level, what's going for us is that atmospheric drag extends quite a ways. Uncontrolled satellites come down on their own, actually pretty quickly. The vast majority are small enough to be incinerated during re-entry. As for ground collision, you worry about really large bus-sized stuff like Mir or Skylab. And there was that incident last year where a big frozen hunk of hydrazine was a concern - if you accept that as the real rationale for why we shot down that satellite. Earth gets hit more by falling, expended rocket stages and tanks that never make it to orbit.

 

Up at higher ranges, there are Mid-Earth Orbits (MEO), Geosynchronous Elliptical Orbits (GEO), and other specialized ones (like polar, sun-synchronous, and Molniya). MEO is about half-way to GEO and has 12-hour orbits. This is mostly the realm of navigational satellites like GPS and GLONASS (the Russian version). GEO is the most famous, because of its unique property of allowing a satellite to remain above the same longitude as the Earth turns below it. Notice in the second picture how those are all in a flat ring. GEO satellites can't hover above the same spot on the Earth (like New York), they can only hover above the equator. That's what makes it valuable real-estate - countries actually sell the GEO spots they own under international treaty. If you put a satellite there, you have requirements to retire it into a "disposal orbit" so the spot opens up later.

 

It is interesting to note that in the entire Space Era, there has never been a single satellite collision, other than at the paint fleck / micrometeriod size. (This was less of a problem until the Chinese fiasco, which added thousands of debris bits right where we operate most.) At low orbit, this is because the earth tends to clean up the larger bits. At higher orbits, most of these satellites are no longer operational and thus not controllable. So it's because basically - orbital space is really big.

 

As for reality check, the problem of space debris is not trivial to aerospace engineers, but it's not even on the top-1000 list of "things that could go wrong on Earth". When you design a satellite, you include enough fuel to avoid collision with anything you plot might hit you (and I've never seen one of these corrections made outside the ISS or Shuttle) and to dispose properly. Interestingly, disposal at LEO means sending it DOWN to burn up in the atmosphere like a shooting star. At MEO and GEO, you just park it out of the way.

 

That's not to say people aren't working on solutions. The Orbital Express program, built as a means of resupplying fuel and expendables to satellites could be conceivably adapted to bring in debris. But that there's no economic market for that mission, even among deep-pocket government agencies, is one sign of how small a problem the aerospace community thinks it is.

 

But ruining space before we master it? Remember, it's satellites that enabled global communication, track weather, guide ships, watch out for bad guys looking to make war, and beam us Star Trek re-runs. If we've got to get off the planet to master space, it's hard to see how satellites aren't things we'll need to get there.

Edited by Sorehl

Share this post


Link to post
Share on other sites
Oh my god! That is amazing! Man is ruining space before we can master it! So not only is Global Warming ruining Earth, but our pollution is ruining our atmosphere! Way to go Humanity!

 

Thanks for that reality check, Laarell. NO one thinks about it until they see the truth. Nice job!

I know! God if anyone can look at this and think of a way to brush it off I am going to give them an award/scream in anger. I really want to live on pluto.

Planetoid here I come!

Ali

Share this post


Link to post
Share on other sites
God if anyone can look at this and think of a way to brush it off I am going to give them an award/scream in anger.

I'd prefer an award. Screaming is so... emotional.

Edited by Sorehl

Share this post


Link to post
Share on other sites
I'd prefer an award. Screaming is so... emotional.

What about punching the wall but showing no emotions as you do it?

~Ali

Share this post


Link to post
Share on other sites
What about punching the wall but showing no emotions as you do it?

~Ali

 

That tends to lead to bodily damage.

Share this post


Link to post
Share on other sites

I classify that picture as art. And I classify art as A.R.T. = Altering Reality to Taste.

 

Beyond that, listen to Sorehl cause he knows what he's talking about. He won't toot his own horn but he's living most of our dreams working in the space industry. And while he may have moved on to other projects his first job was with satellites.

Share this post


Link to post
Share on other sites

LoL. Yes. Sorry to alarm people if I didn't slap a huge ARTIST RENDITION, CONTENTS ENLARGED TO SHOW TEXTURE label on the link.

Share this post


Link to post
Share on other sites
LoL. Yes. Sorry to alarm people if I didn't slap a huge ARTIST RENDITION, CONTENTS ENLARGED TO SHOW TEXTURE label on the link.

 

Not your fault. Here, for those who are interested, is the original source of those images in the blog post:

http://www.esa.int/SPECIALS/ESOC/SEMN2VM5NDF_mg_1.html

 

There are many, many more images there, by the way, and they show some of the things Sorehl was talking about re: orbit management.

Share this post


Link to post
Share on other sites

This is a job for Captain Planet.

Share this post


Link to post
Share on other sites

Why isn't the ring situated around the equator?

Share this post


Link to post
Share on other sites
Why isn't the ring situated around the equator?

It is. The various pictures show it from different angles, but if you extend the plane of the GEO ring down to the Earth, it intersects at the equator. In the first link, you'll see it lies just above the horn of Africa. In the images on the ESA site, it's the same or through the top of South America.

 

What I find interesting is the sort-of "echo ring" above and below it. I think that's the disposal orbit for GEO satellites, but I'll have to do more investigating to confirm.

 

Don't let the yellow rings in some of the close-up images fool you - those are just "probability clouds" representing the altitudes of typical satellites. LEO, MEO, and elliptical satellites aren't restricted to the equator, so they're all over. One of the favorite s is the polar orbit which runs - you guessed it - pole to pole. The Earth turns underneath it, so if you've balanced your altitude and swath (the area your camera, antenna, or sensor can see), you can take images of the entire planet in half a day. Weather satellites are fond of this orbit, as are satellites in a "constellation" known as Iridium. There's almost 70 active satellites in Iridium at one time, providing global satellite phone coverage. If you pick some close-up images from the ESA site, Iridium sats are the ones that look like a capital T with a wide crossbar. In the artwork, they're about the size of New Jersey - in reality, I think they're 10-12 feet long.

 

If anyone cares, you can actually see the sun reflecting off the flat lower antenna of these satellites on many nights. It's called an Iridium flare. I find this one of the coolest things to show people, but you have to know your location fairly well (GPS coordinates are best) to find out what time one will be in your part of the world. The website www.heavens-above.com can help you plot them, as well as ISS and Shuttle (when it's up) overpasses.

 

I'd be interested to know if anyone goes out and sees one.

Edited by Sorehl

Share this post


Link to post
Share on other sites

I actually used the site to watch the ISS fly over head on Wednesday night. I had planned to take a picture to prove it but...alas.

 

::Gives Sorehl a cookie, or whatever is logical::

Share this post


Link to post
Share on other sites
It is interesting to note that in the entire Space Era, there has never been a single satellite collision, other than at the paint fleck / micrometeriod size.

Until now.

 

One of the Iridium satellites I mentioned in previous remarks got mowed down by a 2000-lb discarded Russian satellite. One of the reasons this has never happened before is that the Pentagon (specifically NORAD) tracks all these items and is supposed to advise a working satellite to nudge itself out of the way - why it didn't happen for an object that was well above the tracking threshold size will be a source of investigation.

Share this post


Link to post
Share on other sites

All I can say is... holy crap. Gene Roddenberry didn't provide for this in his universe...

Share this post


Link to post
Share on other sites

I may be breaking "thread resurrection" protocol, but after the Iridium/Russian satellite collision in February, I think this is still topical. In a previous post (above), I mentioned there are a number of orbital waste management schemes, but no one felt there was a good business model for it and no government felt the risk outweighed the tremendous cost. The topic comes up again in today's news: http://www.foxnews.com/story/0,2933,512766,00.html

 

First, warning: Objects in image may be larger than they appear.

 

The artist's renderings of orbital debris exaggerate the size of satellites by factors larger than I want to compute. A typical satellite may be 3m in length. In the picture, they're the size of New Jersey. If we had hundreds of New Jersey's orbitting Earth - well, we have unfathomable problems on so many levels. The article cites the need for a civil agency to track all the objects, but this is routinely done by NORAD. Problem is: if two objects are heading toward the same point, who's job is it to move? After the Iridium collision, the Russians blamed the US for not getting out of the way. They assumed no responsibility for tracking their own device, alerting others, or trying to move. It's the classic parking lot collision extended into space.

 

Second, this article focuses mainly on Low Earth Orbit (LEO) objects, which is where most of the crowding is, but isn't where the most expensive and valuable satellites (namely, communications, GPS, and remote sensing) are. The guidelines suggested by the UN are already standard features on American launches, especially because of the liability issues. The article mentions several countries that seem to just not care. Mir used to dump garbage bags out the airlock. China intentionally took out one of its LEO satellites - generating thousands more tiny pieces in the worst possibe place. Deorbiting objects from Mid-Earth Orbit and Geo-sync is not as simple as using a laser, a fire hose, or creating drag. These orbits are thousands of miles away from the Earth, far beyond its atmosphere. It can take a hundred pounds of thruster fuel to change an orbit by just 50 miles. And every pound you send up can take a thousand pounds of rocket fuel to lift off the Earth in the first place. And Superman charges too much to toss junk into the Sun.

Share this post


Link to post
Share on other sites

One day, preferably soon, I would hope that some country would assemble an orbiting smelting factory so that fabricating a large space station would be more practical. If / when that happens, it is good to see that said factory should have a reasonably large pool of raw materials.

Share this post


Link to post
Share on other sites

What I might start to question and be really concerned is when a Independent Nation takes it upon it self the responsibility to remove/ launch from their "Satellite's" projected path...with zero communication with the other powers that have been in place for years...especially if the ones monitoring,and allowing the vehicle to be involved in an orbital non corrected path. I certainly deem that as an certain aggressive move/attack on our own defense systems. :D

Share this post


Link to post
Share on other sites

The "Next Frontier" or "Final Frontier" may sound romantic but with every frontier there has come a battle over that territory when resources or space becomes limited. I think we've always had it in our mind outer space would be free of such trends becomes there is so much space that there would be plenty to share. While nowhere near overcrowded yet we may be edging towards the first orbital boarder skirmishes.

 

The idea of an orbital smelting plant sounds brilliant. It costs millions of dollars to get objects in orbit... why not make use of what's already up there. The main hurtle would be finding a cost effective way of altering orbits so it's worth gathering up loose objects. Then I guess there's salvage rights to deal with. May take another 50-100 years for there to be enough raw material up there to make a buck at this anyways.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0