Samizdata

I write this as I am flying at some 36,000 feet over the midwest on my way to Los Angeles and the 25th annual International Space Development Conference (ISDC). I chair the committee which overseas the local conference teams so I will be busy with that and other National Space Society (NSS) management duties. But despite much work ahead, I will try to do an occassional live blog.

This is quite an event we of NSS (along with our major co-sponsor this year, The Planetary Society) have going this week. Pretty much everyone who matters in the space world will be there. If you are interested in space tourism or commercial space, this is the place to be.

I hope to see some of you!

It is now the next afternoon. When I went to file the story I got drafted into making the conference wifi network and router work so that I could use it.

Israel has a new defensive system for vehicles called ‘Trophy’, now under evaluation by the US military. I first heard of it yesterday when I came across a demo video on Fox News under the category ‘Nation’ (hurry and see it before it goes away!)

I did not uncover anything else about it until this afternoon. It appears the system is a tiny version of an anti-ballistic missile missile. The incoming RPG (or whatever) is tracked by radar and knocked out of action by what looks to me to be a kinetic energy impact kill to the head of the incoming round by a very fast little short range rocket.

What I find interesting in the Fox News video is the way the explosion plume spreads out as if the incoming hit a non-physical wall.

Also see this General Dynamics report.

Many thanks to one of our commentariat for figuring a way to link to the Fox News video!

This statement was released last night:

Falcon 1 Maiden Flight Update: Posted March 22, 2006
No major issues were discovered following the static fire, but, as a cautionary measure, we are going to take one more day to review data and verify system functionality. Launch is now scheduled for Friday at 1 p.m. California time.

Elon Musk

Ed: While you wait… Watch the engine test video.

According to Elon Musk:

“Falcon 1 has been removed from its hangar and erected on the launch pad. All systems are currently go for a static fire on March 17 or 18, followed by a launch between March 20 and 25.”

My fingers are crossed as a successful first launch would be a wonderful thing… but then, how often does that happen in rocketry?

PS: You can see Elon at the 25th International Space Development Conference and offer him your congrats or condolences, depending…

Sometimes there are unexpected side effects of Samizdata posts. My discussion of the Blackstar project last week had that in spades. When Mike Lorrey posted some technical information defending the possibility such a vehicle might be real, I sat up and took notice. Amongst things I knew about he described something I was completely unaware of. There is a safe Boron gel fuel. This led to an exchange of emails and Mike kindly produced a paper on that and several other important technologies and basic concepts of spaceplane design.

NASA got the spaceplane design so badly wrong on the Space Shuttle one hardly knows where to start. Mike shows the science behind some of those truly awful design choices. First off is wing loading. Virtually everyone in the business knows high wing loading on a manned re-entry vehicle is not just a bad idea, it is almost criminally insane. Once you go down that route you are forced into ever more dangerous and ever more marginal design decisions. High wing loading means there is a lot of vehicle weight per square foot of wing. It means more kinetic energy has to be dissipated over a smaller area. It means the re-entry interface happens much deeper into the atmosphere. It means you cannot skip and bleed off heat. It means you need heavy thermal protection systems… and on and on.

The key bit in his paper though is the Boron Gel. I must say this mythical substance was one I knew very little about and what I had heard was it is more closely allied to a chemical weapon in toxicity than a rocket fuel! But according to Mark there is more than one way to gel a boron, and this one is a boron/keresene slurry.

Why does this get me excited? Another factor pretty much everyone knows is liquid hydrogen is a really bad fuel. Yeah, it has a high ISP (a measure of how good a fuel/oxidizer combination is) when used with oxygen, but the problem is density. It is horrible for density. You need gigantic tanks to carry a reasonable amount and the tankage and associated structures weight eats up all the gain from using the stuff in the first place. On top of which, it bleeds off. You can not make hydrogen stay put. It is useless for long voyages or for a long stay in orbit. That is why upper stages use really nasty, evil and deadly fuels that happen to be liquid at room temperatue and are hypergolic (ignite when mixed).

Even if your fuel is not as ‘good’ as hydrogen in absolute terms, it can be better in practical ones. A very dense fuel means smaller structures to hold it and that means less weight to orbit which means less fuel to carry the fuel… you win points in your rocket equation. Dense fuel is a big win. Dense fuel that also has a very good ISP is a very big win. The Boron/Kerosene mix appears to be just what we need.

What I look forward to finding out now is: what is required to handle the stuff safely? Is it truly not in the high danger category of the other Boron Gel technologies?

If you feel yourself called to the label ‘rocket scientist’, go read Mike Lurrey’s paper. I await your comments.

SpaceX has been working towards the first launch of its Falcon since late last summer. First they were delayed by a blacksat launch window which caused them to shift operations from Vandenberg to Kwajalein Island. This winter they had the pressurization test accident that caused a fuel tank to crumple.

Everything I have been hearing says this month could finally be it. Best wishes and godspeed to Elon and his crew.

You can download their information pack (just published yesterday) on the upcoming maiden flight from here.