A plane has been in space for 500 days

Sure they do. But the world population in general does not and that is the bulk of the people exposed to this behaviour. In essence it looks as though the US reneges on its obligations and what the underlying cause is does not really matter. The usual attitude towards signatures is that they are somehow binding, signing something and then not abiding by it is very bad PR, it makes you look dishonest.

Given that the two times the world arguably came closest to nuclear wars (Cuban Missile Crisis and Able Archer 83) were, at least in part, caused by the deployment of weapons that looked like they were intended for decapitation strikes I suspect having such a weapon whirling about above our heads would do no good to overall world security.

Also, it's fairly easy to work around a possible decapitation strike - have the political leaders tell the military what to do in the event they are killed:

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

I considered that option when I wrote my comment. There are only a few countries with the resources to detect an ICBM launch. These are also countries which can detect orbiting satellites and determine their orbit. For that matter, there are amateur organizations which track satellite orbits, and are usually the first ones to report when the US has put up a new spy satellite; doing so within a few days.

Yes, it's possible to shift the plane of the orbit when over, say, the South Pacific, and get an element of surprise. "Just enough" is still quite a bit. The Shuttle and Soyuz use air breaking, and take about an hour from the deorbit burn to landing.

Any country that can detect an ICBM launch, with 30 minutes of warning, can likely also detect the ionization trail of a craft/vehicle/weapon going through reentry. Also, said craft won't be able to use any external targeting guidance like GPL until after getting through the blackout.

If I read http://www.spaceflight101.com/soyuz-tma-10m-mission-updates.... right, there's at least 10 and more likely 15 minutes of warning from ionization trail detection to hitting the ground. By comparison, https://www.princeton.edu/sgs/publications/sgs/pdf/3_1-2gron... lists a sub-launched Trident as being able to hit a target 3,000 km away in 9.8 minutes.

Also, it's easier to launch a missile from a sub, and easier to test sub launches than it is to test satellite-based attack deorbits.

Although wikipedia isn't tremendously reliable :

"In the case of the system mentioned in the 2003 USAF report above, a 6.1 m × 0.3 m tungsten cylinder impacting at Mach 10 has a kinetic energy equivalent to approximately 11.5 tons of TNT (or 7.2 tons of dynamite). The mass of such a cylinder is itself greater than 9 tons, so it is clear that the practical applications of such a system are limited to those situations where its other characteristics provide a decisive advantage - a conventional bomb/warhead of similar weight to the tungsten rod, delivered by conventional means, provides similar destructive capability and is a far more practical method. Some other sources suggest a speed of 36,000 ft/s (11,000 m/s),[8] which for the aforementioned rod would amount to a kinetic energy equivalent to 120 tons of TNT or 0.12 kt. With 6-8 satellites on a given orbit, a target could be hit within 12–15 minutes from any given time, less than half the time taken by an ICBM and without the warning. Such a system could also be equipped with sensors to detect incoming anti-ballistic missile-type threats and relatively light protective measures to use against them (e.g. Hit-To-Kill Missiles or megawatt-class chemical laser)

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

It's not the idea to have one single bombardment weapon, but many in an orbit. That's what makes it a quick reaction. A single unit could likely be a testing platform for such a system.

Slower for a retaliatory strike, yes.

But if you are hitting first and by surprise, you might be able to coordinate around this limitation. Once the object is in the right place it has the delivery speed advantage.

Slower than ICBM if the target is Earth, but if the target is massive satellite damage by spewing orbital debris then it's probably in the right place.

far range space combat perhaps, otherwise the launch should be pretty detectable as the propulsion would need to be provided by the launcher, rather than the mechanics of the orbit (unless , perhaps, a slingshot maneuver was used to propel the mass through the enemy via an indirect route)

You're being downvoted because you're bringing irrelevant fanboyism into the thread.

If you think a project aimed at (in relation to the current space industries) mass-produced cost-effective commercial launch vehicles is a threat to small-production-run projects aimed at defense missions, I think you have some horizon-broadening to do.

SpaceX is, for the most part, just taking well-trod ground and trying to make it more efficient. Classified defense stuff, on the other hand, tends to break a lot of new ground and do exotic things the civilian market hasn't even considered enough to debate whether they're possible.

It'd be kind of like someone working on a cheaper, more efficient jet airliner, and you coming in and saying "see, this is a threat to stuff like the SR-71 because it's so much cheaper than all the bloated contractors!"