...debris from a satellite that the U.S. Military is going to destroy just to prove that the U.S. has bigger balls than China!

Sorry, Canadians!

Remember when the Chinese were shooting down that satellite and the big argument was over whether they were polluting the earth's orbit with dangerous space junk? I wonder why we're not hearing the same argument here.

Because this one is already on its way down, and so the debris is unlikely to remain in orbit.

They want to shoot it for two reasons that I can see:
1) to prevent China/Russia/anyone from getting their hands on sensitive technology that might be onboard, and
2) to make it more likely to just burn up on reentry, rather than poke a hole in the roof of the White House.

Cheers

To expand somewhat on what Mark is saying:

The altitude is the biggest difference between the two shots. There was an article somewhere yesterday (it was in the consolidated group of 'you might be interested in' articles I get at work) that compared the altitudes of the two satellites. The Chinese one was at a high altitude (537 mi) orbit, while US-193 is already in a degrading orbit between 160-167 mi. They expect most of the pieces to enter the atmosphere (and burn up rather than strike the ground) within five days.

Some people are concerned about the sensitive technology. This was a NRO satellite, so there is some ridiculously classified equipment on it. Any time you start dealing with sensors or communications, countries will go through a lot of trouble to protect that technology.

The other concern is hydrazine. The tanks are big and bulky and may survive re-entry. The stuff is nasty. If it doesn't kill you, it can still cause seizures and comas and damage your liver, kidneys and nervous system. Destroying those tanks greatly increases the chances that the pieces will burn up on re-entry and not pose a threat to anybody.

That one always just sounded like a PR excuse to me. If there was any significant amount of hydrazine left on the satellite, then it would have been burned to help it maintain orbit longer. After all, that's what it was put up there for.

So the tanks are pretty much empty, but possibly still hazardous if they survive reentry intact. But I wouldn't really expect them to -- big, thin walled thingies.. no way.

Cheers

I'm not sure I'm convinced the debris is all gonna drop. Sure, the thing is in a slowly decaying orbit right now, so the idea is that the debris will decay too. But think about it. You blow it to smithereens, each smithereen is going to go flying off in a random direction at a wildly unpredictable velocity. I say there's a good chance some of those individual smithereens will end up in stable orbits.

Oh, wait. If we believe the original press release (why not?), then the tanks probably are full after all:

And are there any West Wing fans having Deja Vu right now?

(One of the episodes had one of the characters overseeing an orbital missile-intercept test in the situation room, and the test miseed by like 100 miles or something.)

Plus, the flash point of hydrazine is <40C. There's no way any of that is surviving re-entry.

Peter

I'm unable thus far to find out that information. The press releases imply that the shoot-down is planned for just a few days before the satellite is due to enter the atmosphere, which would indicate a rapidly decaying orbit by some definitions.



But real information on spy satellites is somewhat tricky to come by.

Cheers

Rather randomly, Claire saw this one launch at Vandenburg... and I was in China so I missed it. Turns out her american cousin works there as a rocket/payload person which means he can get people really fairly close to the launchpad which makes for great viewing.

Here's hoping that she doesn't get to see it come down...

Hugo

Its been roughly 10 years since my last thermodynamics course, but doesn't pressure have a large part to do with flash point? The normal way it is calculated is with an open cup, but I would expect pressurized vessels behave quite a bit differently.

Yes, I suppose I'm also assuming that the pressurised vessel wouldn't survive uncontrolled re-entry unpunctured. Unless the vessel is glider-shaped and made of space-shuttle tiles, that's probably a fair assumption.

Peter

This particular launch was important to a lot of people. It was the first launch from United Launch Alliance (ULA) which was a team of Lockheed-Martin and Boeing that was formed in the wake of the EELV fiasco. People were interested in seeing if the two could play nice together after all the litigation that occured because of the way Boeing won the contract.

The other part that got a lot of attention was that this satellite was viewed as an emergency capability gap filler. The Boeing Future Imagery Architecture (FIA) satellelites were suppose to be launched in 2005. People were suprised Boeing won the contract because their experience with satellites was limited to communications and launch vehicles. This launch was seen as validation that the FIA program was unsustainable and vindication for everybody that was saying that Lockheed-Martin should have received the contract from the start.

It raised a lot of eyebrows when communication with the satellite was never achieved. The only thing known about it was that it reached the intended orbit successfully (the first successful launch by ULA). In the commercial world, satellites are tested by the builders before the controls are handed over to the owner. In this case, that step would never have happened if it wasn't an USG satellite.

The visibility on this launch is pretty extraordinary for a Classified launch. Because of all the people interested, I would be surprised if anything they said about the satellite failing wasn't completely true.

According to the BBC, the fuel is now frozen solid as the heating systems have failed. A pretty good chance that it would survive re-entry. This missile pretty much has to rupture the tank then, right? Thats a tough shot!

From the Wikipedia write up of the anti-missile-missile that they used it appears it does indeed have the capability of hitting a selected part of its target.

So out of laziness to look it up and burning curiosity...

How do they do this? What tech is the missle using to track and hit it's target with such precision? Any ideas or links?

All my information comes from wikipedia, according to which the ship's radar tracks the target and guides the missile to the target. It also says the warhead has some sort of sensor for identifying the right place to hit the target (sounds like a video camera and image recognition).

http://en.wikipedia.org/wiki/RIM-161_Standard_missile_3

There is some more information being released about how the shoot-down happened and what occured to make it happen. I'm not sure how long that link will be good for, it might change if another article is released. The title of that article is 'Little Time, Lots of Effort Led To Successful Satellite Shoot-Down'.

There is also an article in Space and Missile examining the potential political fallout from the shot. I can't find an online presence for the article, but it states that based on the shot, full funding for the next fiscal year ($1.2B) is expected. The article is based on a paper by Victoria Sampson. She is an analyst with the Center for Defense Information (aka a beltway bandit), but I won't go into my thoughts on any of those think tanks.

"The page you tried to access is only available to paid subscribers."

"Single-user subscriptions are available at the following rates:

* 6 months, $3,200
* 12 months, $5,900"

Ooph, sorry about that. We have site licenses to a ton of sites, and wasn't aware that was one of them.

Well, it was interesting reading.