February 20, 2008

Defense tech - on the satellites

To the poster Mr. Byron Skinner: You said: God Evening Folks, for some reason, I think a highly combustible substance that will burn up in descent is a better target than a lump of radioactive matter that will be shot into millions of pieces and land god knows where. Plus, you don't have to pay for the health insurance... NO NO NO! i tell you the evil zionist are ploting to blow up the world and we have to stop the missile launch /sarcasm Wow, I've seriously underestimated the animus toward missile defense among the ostrich-types. "No attempt was made to intercept those SPYSAT reactor sections when they plunged to earth"

Spy Satellite Not the First to Fall

aegis.jpg

As reported in the press, a Navy Aegis missile cruiser in the Pacific Ocean will try an unprecedented shoot-down of the out-of-control, school-bus-size U.S. spy satellite loaded with a toxic fuel as it begins its plunge to Earth. Marine General James E. Cartwright, the vice chairman of the Joint Chiefs of Staff, said that the Navy missile will be fired as the satellite re-enters the atmosphere and "has a reasonably high opportunity for success." The Navy has been developing -- and has successfully tested -- a ballistic missile intercept capability aboard several of its Aegis cruisers and destroyers.


Aegis is an advanced radar/fire-control system that was originally developed to destroy incoming anti-ship cruise missiles. The Navy has 22 cruisers and some 60 destroyers with the Aegis system and between 90 and 122 vertical-launch cells for surface-to-air and Tomahawk land-attack missiles. The Navy is upgrading several of these ships for the ballistic missile defense role.

The three previous spy satellites that fell to earth with nuclear reactors on board were Soviet Radar Ocean Reconnaissance Satellites (RORSAT). The RORSAT was part of the world's first satellite system orbited for ocean surveillance to detect warships on the high seas. The Soviet Union began tests of the system in 1967 and the first operational RORSATs went into orbit in 1974.

Two types of satellites were used in tandem: Electronic Intelligence (ELINT) satellites that were "passive" and sought to "lock on" to electronic signals emanating from ships, especially radar transmissions. The 18,400-pound EINT satellites became operational about 1970. Pairs of ELINT satellites were coordinated with a single RORSAT, guiding the latter to a suspected target ship. The 10,000-pound RORSAT could then use active radar to precisely locate and target Western warships. Later RORSAT satellites could send targeting data directly to missile-armed ships, surface ships, and submarines as well as to ground stations (as did the early RORSATs).

The power requirements for the RORSAT's radar was provided by a small nuclear reactor that carried some 110 pounds of enriched uranium (U235) to produce up to ten kilowatts of power for some 90 to 120 days in space. When the service life of these Kosmos-series RORSATs was complete the reactor section carrying the radioactive fuel and weighing about one ton was designed to be boosted into higher orbits -- more than 550 miles -- where they would circle the earth for more than 500 years and then cause no danger when they did come down and burn in the atmosphere. (They normally orbited at an altitude of about 130 miles.)

But three reactor sections malfunctioned and plunged into the atmosphere: Kosmos 954 in January 1978, with portions of the craft landing in Canada; Kosmos 1402 in February 1983, which fell into the Indian Ocean; and Kosmos 1990 in February 1989. Apparently no significant pieces of the last survived reentering the atmosphere.

No attempt was made to intercept those SPYSAT reactor sections when they plunged to earth.

-- Norman Polmar

Comments

No one seems to have mentioned what will happen if they miss? Does that mean the chinese with there measly defense budget are actually ahead of the US in ASAT?

Seems to me less a case of saving "2 football fields" of dangerous hydrazine vapour. Gasp - the terror! and more a case of we'll show them we can do it too!

1) "The Navy last week placed an order with Raytheon for $1.4 Billion for 75 more Standard SM-3 Block IV's and 27 for Japan

2) This will demonstrate to the Russians and Chinese that on call now we can intercept an ICBM in orbit before it re-enters and dispenses its warheads. This could put bach Russian and Chinese ICBM and SSBN missile development a generation or more."

Uh... is that so? Thanks to a mere "75 + 22 Standard SM-3 Block IV's" ?

No more all-out launches then?


Great: We're safe!

Posted by: freefallingbomb

Whats so hard to understand here it called follow the money. The Navy last week place an order with Raytheon for $1.4 Billion for 75 more Standard SM-3 Block IV's and 27 for Japan.

The Navy is asking for 19 CG(N)2000's, Missile Defense is the largest single item in the budget.

This will demonstrate to the Russians and Chinese that on call now we can intercept an ICBM in orbit before it re-enters and dispenses its warheads. This could put bach Russian and Chinese ICBM and SSBN misslile development a generation or more.

ALLONS,
Byron Skinner


I miss some details in this article:


1) U.S. officials announced plans to use a single modified "S.M.-3 Standard Missile" launched from a group of three ships in the North Pacific to shoot down the failed re-entering U.S. American satellite "U.S.A. 193". They stated that their intention was to "reduce the danger to human beings" due to the possible release of the toxic hydrazine fuel carried onboard that satellite. But what spot on the globe exactly is threatened by this entering satellite, to justify such a Space-War-like measure? Without ANY concrete names of places, this whole thing sounds to me just as more unbearable "me too" whining from the U.S. Americans, because the Chinese recently and successfully shot down an obsolete satellite of their own (= U.S. American superiority complexes).


2) If the "S.M.-3 Standard Missile" is going to be used, then according to this Web-site here

http://www.designation-systems.net/dusrm/m-161.html

the "S.M.-3 Standard Missile" has a speed of 9.600 kilometers / hour (6.000 miles / hour), but according to Wikipedia

http://en.wikipedia.org/wiki/Atmospheric_reentry

the typical re-entry speed of spacecraft (at 60 kilometers altitude) is of 7,8 kilometers / second (= 28.080 kilometers / hour). But that alone is 2,925 times (= almost three times) faster than the "S.M.-3 Standard Missile" chosen to intercept it, and that doomed satellite is even to be shot down at 240 kilometres altitude = out there in Space, where it surely flies even faster than that! (The typical re-entry speed for example of large = non-evaporating meteorites is ~ of 50 kilometers / second, that's 180.000 kilometers / hour. I'll take my hat off to any country's Armed Forces who manage to hit those somehow directly, tip to tip - anyhow - and on very short notice too!)

Empirically, that almost begs the next question...: How does a turtle catch a rabbit? By accurately predicting its more or less linear flight path and putting itself in the hyperbolic target's way, although with scant hopes for a final precision approach? Could even work, but then how comes that a few days ago I still read in the news that it would take even MONTHS before the precise impact point of this uncontrolled satellite on the Earth's surface became predictable? How many "S.M.-3 Standard Missiles" exactly do the U.S.A. want to spend on this experiment? Or is this whole thing nothing but a validation of the anti-missile-missile concept, one of many different "Star Wars" weapon technologies?

3) For the Trekkie-minded poster "Nessuno": 3 arguments AGAINST plinking at satellites just for da kicks, unless it's absolutely imperative:

a) It contravenes the "Outer Space Treaty" (not that U.S. American politicians give a wet damn about any "treaties"...),
b) the debris from successful hits spreads out and becomes harder to track, while also presenting a hazard to other satellites and spacecraft,
and
c) the net result of a hit would be that you still had the same amount of mass at exactly the same speed going in roughly the same direction, but after one or two (or centuries of...) orbits it would all be coming down in lots of different places, depending on the drag coefficient of each fragment.

Don't you remember any caricatures about the constant rain of "Mir" space station parts here on the ground while it was STILL IN ORBIT ?

Posted by: freefallingbomb at February 19, 2008 10:43 PM


Let's also make clear that the satellite target is NOT nuclear powered. The danger is posed by a tank full of frozen rocket fuel which might survive reentry. As for the implied logic of "we didn't shoot down falling Soviet satellites during the Cold War, so we shouldn't shoot down our own satellite when it poses a danger now" well...wow. There are reasons not to think this is a good idea or warranted by the risk, but this version is weak.

Posted by: lucabrazi





No comments:

ShareThis