If you've actually run the numbers, I'm happy to concede the point. but I think it's still an open possibility. And I think the larger point stands: This is all about convenience and flexibility, the ability to get eyes and/or ordnance onto any specific target on the globe in under an hour. If you have a different explanation, please share.

It all depends on how much delta-V you can impart to your projectile, and by what means (and on what vector). Yes, it's a big push, but you've got 80lbs of reaction mass to work with (at least). It's not hard to imagine making this work with a very simple mechanical device. In particular, if you launch a spotter/sniper pair of satellites, they can both be optimized for their particular jobs.

For example, the spotter-sat could eject a small "hummingbird" reentry vehicle shortly after reaching orbit, in order to descend over the target area, and still be hovering on station a half-hour later when then "sniper-sat" comes into range.

IOW, yes that IS how orbital mechanics work, if you can generate enough delta-v, pointed in the right direction. Once you make interface with the upper atmosphere, you've got the ability to "steer" toward your target.

Of course this isn't a cost-saving approach, it's real goal is maximum convenience and flexibility. Let's say I want "eyes" on a particular location ASAP, but I don't have any "birds" on a good trajectory for several hours to come. This would allow me to put a satellite precisely on target in under an hour.

And if they can add a miniature projectile launcher into the same 100lb package, they've basically got a global "kill switch" for a limited range of targets. You wouldn't need more than a few pounds of depleted uranium, shaped into a steerable "bolt" and packed with some high explosive, and the necessary thrust could probably be provided by a simple spring mechanism, just like a crossbow.

With a 100lb mass budget, you could probably even allow enough propellant to get the bird back over the same spot (or near enough to shoot at it) on the very next orbit. Say the satellite costs a $mil, plus another $mil for the launch... that's cheaper, per shot, than some of the ordnance already in service. Or, if you don't mind launching two in rapid succession, you can use the first one as spotter and the second one as sniper.

I wonder how long it will take for the magnitude of that achievement to be noticed, let alone to sink in with T.C. Mits. I have a feeling that it will get mentioned, and Bill Nye will share a few words on CNN, but that it won't get much play in the mainstream press. We'll find out soon enough, I guess.

Keeping fingers crossed... ;-)

How can you claim to have any knowledge of the degree to which Iran is enriching its uranium? Citation please! What we've heard from international inspectors seems to indicate that they are playing above board, just as it seemed in the run-up to the Iraq war... Pardon me if some of us get a sense of "deja-vu" in this situation.

Ok, sure. But given the prevailing wind patterns, wiping out Israel with nukes would not have favorable "fallout" for Iran. Therefore, why would they do it? I still don't see it.

It's the same MAD conundrum that kept the USA and USSR from wiping each other out a few decades ago. We survived that threat ok, and the USSR was a much worse threat than puny Iran ever was or will be.

Ditto!

You're right. A nuclear "terrorist" attack is not impossible in the next 10 years, esp. the "dirty bomb" variety. But I don't think even the the "loonies" in Iran would launch a first strike. What possible benefit could be gained? At what cost? The entire proposition is ludicrous. Please explain.

No, I didn't forget about it, I never heard of it before. That is sad. Citation....??

Ahmedinijad is out of power and the tales of Iran's nuclear program (from what I can see) appear to be mostly overblown propaganda. I'll grant that this is a "legitimate" issue among "experts" in diplomacy, but I'm not buying it. YMMV...

Whatever you think of their politics, I'm sorry to see them leave the club, even if it's only temporarily. Spaceflight is one of the few remaining areas of "friendly rivalry" where everybody still cheers for the other teams' success, even as we hope to best them. Nobody ever watches a launch and thinks "I hope it explodes! I hope it explodes!" No... you always think "Go, baby, go!"

It will be interesting to see how "bad" this landing was... Was it a total, catastrophic loss, or did it just break a leg on landing and fall over onto the barge platform? The engines are the most expensive part of the "stack", and there are nine of them on the F9 booster stage. If they can salvage six or seven of these Merlin engines from this booster, even that will be a major victory.

Given the rate of innovation and development we've seen from SpaceX in the last few years, I suspect we'll see them nail the landing within the next couple of launches.

I can hardly wait! ;-)

The announcer said they might try again as early as Friday, just before SpaceX live stream was terminated.