Number 3 is BS. That is just "chicken little" syndrome. It just depends on the orbit. SPS would be in GSO. O'Neil at L2. which are nowhere near 800 km to 1000 km
A TV and comms satellite, Express-AM11, was sent spinning out of control by a chunk of cosmic crud in March 2006 in a special orbit that is becoming the Piccadilly Circus of the space lanes.That is because its height of 22,240 miles means satellites will remain above a fixed point on the ground, allowing our TV dishes to stay pointed at them. The satellites that bring us satellite TV all orbit at the same altitude making it a relatively crowded patch of space.
I found this new paper by Donald J. Kessler himself that he put out on his website less than a week ago that includes his thoughts on the Cosmos 2251 - Iridium 33 collision. Some highlights:"We are entering a new era of debris control….an era that will be dominated by a slowly increasing number of random catastrophic collisions. These collisions will continue in the 800 km to 1000 km altitude regions, but will eventually spread to other regions. . . .Think about what this means:1. The Kessler syndrome is not something abstract that might or might not happen in the future. It's happening now. The early phases of exponential growth always happen so slowly that they're hardly noticeable. 2. Consider the part about large constellations--like GPS constellations. The US built the first, now the Russians and Europeans each have their own. Whose next? Such triple redundancy is not only unnecessary, it endangers the space environment for everybody. One world government, anybody? 3. Consider the part about large structures. The risk of collision for anything in orbit is proportional to its cross-section area. We can start to forget about space solar power for Earth, space elevators, and big O'Neil-style colonies in Earth orbit. Only small, comparatively maneuverable, manned space stations situated in what is basically Earth's upper atmosphere will be practicable. They will never get much bigger than the ISS. 4. Rogue nations and NGO's could wreck a lot of asymmetrical havoc if they wanted.5. The Moon all of a sudden looks pretty good.
2. Consider the part about large constellations--like GPS constellations. The US built the first, now the Russians and Europeans each have their own. Whose next? Such triple redundancy is not only unnecessary, it endangers the space environment for everybody. One world government, anybody?
Quote from: Warren Platts on 03/14/2009 01:38 pm2. Consider the part about large constellations--like GPS constellations. The US built the first, now the Russians and Europeans each have their own. Whose next? Such triple redundancy is not only unnecessary, it endangers the space environment for everybody. One world government, anybody? Whilst American's regard their GPS as a military asset and denied at will ...it is wise to have your own backup. Galileo constellation not in place yet apart from the legal minimum. Echo Jim re: O'Neill Except to *cough* note in passing that the Mass Catcher was to be at EML2. http://www.nss.org/settlement/ColoniesInSpace/colonies_chap08.html with colonies initially at L5. Hence the <a href="http://en.wikipedia.org/wiki/L5_Society>Society[/url].One of the nice things about the SPS program of yesteryear was the bonus of really large communication platforms with the various hardware all attached to a singular power and service structure thus avoiding the current GSO 'clutter'.And the Moon has always looked good!
Think about what this means:1. The Kessler syndrome is not something abstract that might or might not happen in the future. It's happening now. The early phases of exponential growth always happen so slowly that they're hardly noticeable. 2. Consider the part about large constellations--like GPS constellations. The US built the first, now the Russians and Europeans each have their own. Whose next? Such triple redundancy is not only unnecessary, it endangers the space environment for everybody. One world government, anybody? 3. Consider the part about large structures. The risk of collision for anything in orbit is proportional to its cross-section area. We can start to forget about space solar power for Earth, space elevators, and big O'Neil-style colonies in Earth orbit. Only small, comparatively maneuverable, manned space stations situated in what is basically Earth's upper atmosphere will be practicable. They will never get much bigger than the ISS. 4. Rogue nations and NGO's could wreck a lot of asymmetrical havoc if they wanted.5. The Moon all of a sudden looks pretty good.
Quote from: Warren Platts on 03/14/2009 01:38 pm2. Consider the part about large constellations--like GPS constellations. The US built the first, now the Russians and Europeans each have their own. Whose next? Such triple redundancy is not only unnecessary, it endangers the space environment for everybody. One world government, anybody? Whilst American's regard their GPS as a military asset and denied at will ...it is wise to have your own backup. Galileo constellation not in place yet apart from the legal minimum.
But guess what: studies show you don't have to wait on SPS to clean out space. For the price of one shuttle launch we could build an aiming turret for some of the national ignition source lasers that already exist and start de-orbiting space junk today. The invested money would also yield advances in power beaming technologies and open up really effective space weapon/ satellite killer opportunities. So while it would mean "open season" on space weapons and destroying working satellites up there, the space junk laser could clean up after it self just as easily.
1. Exponential growth cannot happen in the absence of exponentially growing resources.
This seems to be a bit of bloviation by Kessler, plus there is a lack of logic here.a) a few large orbiting structures is less risky than a lot of small ones. space structures will be modular. SPS' have never been considered for use in LEO, btw, so chicken littling about them is unsupported. One incident does not a trend make.
b) It is unfortunate that some folks want their own navigation constellations, logically everybody using the same one puts everybody on the same tactical level playing field. Using separate ones implies that those developing new systems are intent on jamming the US' GPS system and they consider the US a threat to their own military expeditions in the future. Thats a much bigger problem than whether more satellites collide, it implies an intentional stance for war.
c) Rogue nations and NGO's will need their own space programs to put anything in orbit, and would need to do so illicitly, or somehow hijack existing satellites.
5. The Moon looks good for what?
Quote from: LegendCJS on 03/15/2009 03:27 amBut guess what: studies show you don't have to wait on SPS to clean out space. For the price of one shuttle launch we could build an aiming turret for some of the national ignition source lasers that already exist and start de-orbiting space junk today. The invested money would also yield advances in power beaming technologies and open up really effective space weapon/ satellite killer opportunities. So while it would mean "open season" on space weapons and destroying working satellites up there, the space junk laser could clean up after it self just as easily.There is a whole lot of bunk in that statement1. Cost is based on what2. ignition source lasers have limited number of firings. Less than the number of human digits3. It can't deorbit HEO junk
For the price of one shuttle launch we could build an
Quote from: LegendCJS on 03/15/2009 02:26 pm For the price of one shuttle launch we could build an When using the shuttle as comparison, it insinuates a orbital vehicle. Additionally you reference the ABL, a flight experiment A ground based laser is discussed on other threads
Actually they can't deny GPS at will, the best they can do is detune the accuracy for anybody who doesnt have a military chipset to about 35 meters, which is still good enough for most military applications, and that detuning also impacts civillian uses globally, not just in a specific theater.
The US military can turn off the civilian component of the GPS signal completely in whatever conflict zone they choose.
Quote from: LegendCJS on 03/16/2009 11:23 amThe US military can turn off the civilian component of the GPS signal completely in whatever conflict zone they choose. That is not true. It is always on.