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Rue
2007-Aug-13, 05:54 PM
As easy as shooting rocks in the sky.

NASA plans 'Armageddon' spacecraft to blast asteroid. (http://www.flightglobal.com/articles/2007/08/03/215924/nasa-plans-armageddon-spacecraft-to-blast-asteroid.html)


NASA's Marshall Space Flight Center has designed a nuclear-warhead-carrying spacecraft, to be launched by the US agency's proposed Ares V cargo launch vehicle, to deflect an asteroid that could threaten all life on Earth.

Is this an ace in the hole for dealing with the next Administration's (possible) budget concerns? "Keep funding Constellation or we all go Dino."

Or is it good to see the issue of NEOs finally addressed seriously?

01101001
2007-Aug-13, 06:04 PM
Yeah, I'm sure the budget decision-makers can be swayed by powerful persuasion such as:


For the study, however, its orbit was changed to bring it into a "dead-centre" collision course with Earth and its mass was assumed to be 1,000,000kg.

Edit: I'm having trouble finding the so-called study. It's big talk on abovetopsecret and godlikeproductions, but nobody seems to cough up a citation. Is this real at all? The article didn't give names beyond Marshall. Who wrote it? when? Title?

Edit: Maybe it's this old thing: 2006 Near-Earth Object Survey and Deflection Study (http://www.hq.nasa.gov/office/pao/FOIA/NEO_Analysis_Doc.pdf) (PDF 15 megabytes), but I can't see the whole thing because my connection is squirrley. Probably not. This looks more serious than the purported Marshall report.

Edit: Maybe. A little more trickled in. There is some Apophis stuff:


6.13. Possible Scenarios Application of the Alternatives
This section provides several illustrations of how the alternatives might be applied to
hypothetical deflection scenarios drawn primarily from Reference [31]. The inclusion of
actual objects in these scenarios does not indicate any increase or decrease in the
understanding of the hazard they pose; instead they were chosen both because they are
publicly known and are representative of classes of potential threats.
The scenarios include missions to deflect:
A. The 330-meter asteroid, Apophis, before its close approach to Earth in 2029 (a
possible keyhole, see Section 5.2.3).
This scenario was divided into two design points:[...]

Edit: Got it all. 275 pages. No mention of Marshall, and I don't see the language from the report as quoted, for instance, "Hollywood scenario". I suppose the newer Marshall report, if it exists, could be a continuation of this major NEO Analysis report (by the way, a "pre-decisonal draft"), taking Ares as a given, and speculating about designs. Anyone able to find it?

Rue
2007-Aug-13, 06:12 PM
Exactly! It's gangster diplomacy.

01101001
2007-Aug-13, 06:22 PM
Exactly! It's gangster diplomacy.

Effective until a decision-maker says, "Why don't you go back and redo the study using the actual known orbit parameters instead of assuming a dead-center strike, and get back to us? Thanks."

mugaliens
2007-Aug-13, 07:25 PM
Effective until a decision-maker says, "Why don't you go back and redo the study using the actual known orbit parameters instead of assuming a dead-center strike, and get back to us? Thanks."

Because a dead-center strike is worst-case (requires the most deflection)?

Seriously, if you can design to deflect a dead-center strike, anything less than dead-center is easier, not harder.

01101001
2007-Aug-13, 08:19 PM
Because a dead-center strike is worst-case (requires the most deflection)?

Because?

I don't know in what context you were reading, but I was writing in the context of the report suspected of being an offer-you-can't-refuse for Ares V.

In that context, the text that indicates the report is covering purely hypothetical situations instead of actual, makes it an offer one can refuse.

Yes, they reported correctly on the physics. They're good engineers and scientists. But, alas, they're poor gangsters, as indicated by their inept use of threat.

01101001
2007-Aug-14, 01:16 AM
Anyone able to find it?

I found something out of Marshall, more a presentation than a report. It's got some of the quoted text (but not the key "Hollywood scenario") and at least similar terminology and illustrations.

Near Earth Object (NEO) Mitigation Options Using Exploration Technologies (http://www.aero.org/conferences/planetarydefense/2007papers/S3-8--Adams-Brief.pdf) (PDF 2.5 megabytes) Presentation to 2007 Planetary Defense Conference


Baseline NEO was assumed to have an orbit similar to Apophis
Orbit was modified to cause Apophis to impact Earth on April 22, 2029 12:10:10.73

Rue
2007-Aug-14, 05:45 PM
01101001: very good reverse journalism you've done!

Of course there's the other issue of putting nuclear warheads in space. (if used)

Someones is bound to claim this as an example of the weaponization of space.

novaderrik
2007-Aug-14, 07:34 PM
i wonder if the study took into consideration what Bruce Willis and Aerosmith are doing on that fateful day?

01101001
2007-Aug-14, 08:01 PM
Near Earth Object (NEO) Mitigation Options Using Exploration Technologies (http://www.aero.org/conferences/planetarydefense/2007papers/S3-8--Adams-Brief.pdf) (PDF 2.5 megabytes) Presentation to 2007 Planetary Defense Conference

With a clearer mind I mounted another run. I checked the conference materials (http://www.aero.org/conferences/planetarydefense/2007papers.html), and found the paper to go with the presentation:

Near Earth Object (NEO) Mitigation Options Using Exploration Technologies (Adams, Campbell, Hopkins, Smith) (http://www.aero.org/conferences/planetarydefense/2007papers/S3-8--Adams-Paper.doc) (Word .doc, 4.3 Mb)

Yay. It almost uses the article-quoted phrase "Hollywood scenario":


In the event of a last minute scenario, the Hollywood solution of shooting several ICBMs at the incoming rock is fraught with danger.

Since the article reporter didn't quote it right, I might wonder what the reporter read. Oh, someone did a rewrite. Great. Flightglobal.com article (http://www.flightglobal.com/articles/2007/08/03/215924/nasa-plans-armageddon-spacecraft-to-blast-asteroid.html):


"The Hollywood scenario solution of shooting several intercontinental ballistic missiles at the incoming rock is fraught with danger. [...]" says the report.

No wonder I couldn't lift good search-fodder quoted text from the article and use it to find the report on the Web.

mugaliens
2007-Aug-14, 08:07 PM
Because?

I don't know in what context you were reading, but I was writing in the context of the report suspected of being an offer-you-can't-refuse for Ares V.

In that context, the text that indicates the report is covering purely hypothetical situations instead of actual...

Actually, the report specifically mentions, "A close approach by Apophis is reported as 2022 on page 30, it should be 2021."

This is a correction to the information given on page 30 of the report, which mentions, "The highly publicized asteroid, Apophis, which currently passes by
Earth about every 7 years but is not resonant [13], offers an example of orbit resonance. It
will make close approaches to Earth in 2013, 2022, 2029, and 2036."

It also mentions, "For the 2029 encounter, Apophis must pass through a keyhole that measures 600 meters
wide, an occurrence that cannot be confirmed or eliminated by current observations.
However, as additional measurements are made on each successive close approach, there is a 95% probability that the 2036 impact will be ruled out after 2013 and a 99.8%
probability that it will be ruled out in 2022."

However, it also mentions, "While additional information
gained by each pass usually will confirm whether the object will miss Earth, if an object
becomes resonant by passing through a keyhole, very little time (6 years in the case of
Apophis) will usually be available to mitigate the threat..."

Bottom line, despite the 5% and 0.2% chance of a collision, Apophis is but one of many potential NEOs.

I'd sure hate to have to explain to my kids that they're going to die in six years because Daddy was too stupid to begin simple but effective program waaaayyyy back in 2007 that could have saved our entire race.

01101001
2007-Aug-14, 08:31 PM
Bottom line, despite the 5% and 0.2% chance of a collision, Apophis is but one of many potential NEOs.

So... returning to the topic, I might take it you agree that the report is not a gangsterish strongarm-threat demand for the Constellation program. Or do you? Is the report, or its message, gangster diplomacy?

publiusr
2007-Aug-18, 07:37 PM
Some of you may remember the Giant Comet special showing a collision with the Earth. One of the experts was an individual named Melosh who hates the nuclear option--even though a warhead is about the only thing with enough mass energy that can fit into a Delta II shroud, though it cannot reach its target as quickly as this concept very like what we saw in the movie METEOR.


But the nuclear option isn't all we saw in the article--look again:


"The Marshall study also has a solar collector option that has a very different vehicle design to the warhead and kinetic vehicles. The collector, which is more like an orbiter probe, would maintain station near the NEO and use a 100m-diameter inflatable parabolic collector membrane to focus sunlight into a "thruster" that directs that energy on to the NEO's surface. The heating of surface material evaporates it generating thrust and deflection."

This would also require a larger vehicle, like Ares V, as would a fully fueled gravity tractor, as opposed to an empty Centaur husk that has depleted its propellants in simply getting to the asteroid.

It all comes back to the need for heavy lift.