Samizdata

I thought I would let all of you be the first to know I have won my election bid to the National Space Society Board of Directors.

The last time I served on the board it was still called the L5 Society 🙂

The C-130 based laser you have read about here seems to be doing quite well in testing, and although I have not yet read a document on the topic, there are at least some who would like it deployed to Iraq. The weapon is even better than I had thought it would be. No, let us be truthful. I am stunned at the capabilities they are demonstrating. According to a Wired article (hat tip to Glenn Reynolds):

According to the developers, the accuracy of this weapon is little short of supernatural. They claim that the pinpoint precision can make it lethal or non-lethal at will. For example, they say it can either destroy a vehicle completely, or just damage the tires to immobilize it. The illustration shows a theoretical 26-second engagement in which the beam deftly destroys “32 tires, 11 Antennae, 3 Missile Launchers, 11 EO devices, 4 Mortars, 5 Machine Guns” — while avoiding harming a truckload of refugees and the soldiers guarding them.

The author goes on at length about claims the weapon could be used for plausibly deniable standoff attacks. It is my belief he is being insufficiently creative when he imagines what such attacks would entail. One might take out a communications facility by targeting a turnbuckle on an antenna guy wire; or a power plant by blowing away a standoff and dropping a high voltage line onto others; or perhaps blowing a hole in an oil filled transformer. I can easily think of ways of disabling infrastructure with this device in ways that would leave enemy repair crews terribly puzzled.

You just have to think outside the box: new weapons imply new definitions of the possible.

Here is the official word from SpaceX on the cause of the failure last weekend:

On August 2 nd, Falcon 1 executed a picture perfect first stage flight, ultimately reaching an altitude of 217 km, but encountered a problem just after stage separation that prevented the second stage from reaching orbit. At this point, we are certain as to the origin of the problem. Four methods of analysis – vehicle inertial measurement, chamber pressure, onboard video and a simple physics free body calculation – all give the same answer.

The problem arose due to the longer thrust decay transient of our new Merlin 1C regeneratively cooled engine, as compared to the prior flight that used our old Merlin 1A ablatively cooled engine. Unlike the ablative engine, the regen engine had unburned fuel in the cooling channels and manifold that combined with a small amount of residual oxygen to produce a small thrust that was just enough to overcome the stage separation pusher impulse.

We were aware of and had allowed for a thrust transient, but did not expect it to last that long. As it turned out, a very small increase in the time between commanding main engine shutdown and stage separation would have been enough to save the mission.

The question then is why didn’t we catch this issue? Unfortunately, the engine chamber pressure is so low for this transient thrust — only about 10 psi — that it barely registered on our ground test stand in Texas where ambient pressure is 14.5 psi. However, in vacuum that 10 psi chamber pressure produced enough thrust to cause the first stage to recontact the second stage.

It looks like we may have flight four on the launch pad as soon as next month. The long gap between flight two and three was mainly due to the Merlin 1C regen engine development, but there are no technology upgrades between flight three and four.

Good Things About This Flight

* Merlin 1C and overall first stage performance was excellent
* The stage separation system worked properly, in that all bolts fired and the pneumatic pushers delivered the correct impulse
* Second stage ignited and achieved nominal chamber pressure
* Fairing separated correctly
* We discovered this transient problem on Falcon 1 rather than Falcon 9
* Rocket stages were integrated, rolled out and launched in seven days
* Neither the near miss potential failures of flight two nor any new ones were present
* The only untested portion of flight is whether or not we have solved the main problem of flight two, where the control system coupled with the slosh modes of the liquid oxygen tank. Given the addition of slosh baffles and significant improvements to the control logic, I feel confident that this will not be an issue for the upcoming flight four.”

So it looks like I may have to stay up all night for you again in September!