Water Water Everywhere Part 2

So I wrote myself into a corner. I was seeking better ways to transport hydrogen and looked into water and methane. They didn't need cryo tech, but weren't any great shakes at shipping the stuff. Now water is quite useful: for drinking, bathing, maintaining humidity. But we need something more efficient for our fuel needs.

My friend Ray McVay at Blue Max Studios is of the opinion space opera vessels have fuel as dense as dwarf star matter. He likes figuring out stuff like that. 

It makes you look at those TIE fighters and X-Wings in a different light. No wonder they're so 'splodey.

However I have two forms of unobtainium that may be obtainium one day. I wrote about one in my Zaonia posts under the brand name Metasol. The plucky Zaonians were TL5-6. they had access to an old junked ship and discovered they could use its reactor to compress hydrogen into its metallic state. Now this mH2 has some very interesting properties. 

For one thing, if you achieve the pressures required to condense it, the stuff is (probably) stable at room temperatures. It is lovely dense stuff, about as dense as water. All of it is hydrogen, unlike water. 

The downside is it turns into regular H2 at a temperature around 1,000 degrees Centigrade. The flash from a firearm firing could detonate it. And when I say detonate, I mean detonate! I quote the learned writing of... well the writing anyway of me:

Now you can smack, it shoot it. Bite it. You can toss it in a campfire and nothing will happen. Bring it to 1000 Centigrade and brother, stuff happens! Metallic hydrogen heated to 1000 Kelvin becomes plain old gaseous hydrogen and goes on to occupy a much greater volume very quickly. It explodes with fifty times the force of TNT, a whopping 216 megajoules per kilogram. Let's go to the Boom Table. (I highly recommend the Atomic Rockets site Winchell Chung is great tech support for research impaired people like me in particular and the Boom table alone is worth the price of admission.)

Two kilos of the stuff has the explosive force of one of the USS Iowa's 16" shells. One kilo has the force of 36 120 mm tank gun rounds. A gram of the stuff has a quarter mega joule of wallop. Twenty grams gives you the bang of a kilo of C-4. Obviously the stuff has dozens of peaceful uses. Wait what? (12 grams will disintegrate a human completely, and far more messily than a phaser.)

Imagine a small piece of jewelry with the explosive force of a couple of hand grenades.

It's so brutal as a rocket fuel it outperforms nuclear thermal rockets and doesn't turn your bones to aluminum. It has an Isp of 1700 compared to 1400 for a Nerva. Unfortunately it also has a combustion temperature of 7000 Kelvin which is star hot. It'd make an awesome welding fuel if you could keep the torch from exploding (and those goggles wouldn't help the welder much if it did). If you diluted it, cut it with liquid hydrogen to bring the temperature down, you could get the combustion chamber down to 3700 Kelvin which is barely doable with current technology. the alternative is having a combustion chamber 30+ meters across which is not good for lift offs. this brings the Isp down to 1000. 

Note that chemical fuels usually have a specific impulse (Isp)  of 200-300. Lame. 

For our purposes, you can make a slush of powdered metallic hydrogen and add it to your liquid hydrogen. that will keep it far from that nasty combustion temperature, which is a good thing. I'd allow 50% more fuel to be carried. Cost is up to the referee, make it as steep as you want. Any ship with Jump 2 will get at least another J-1 out of it. At least double normal fuel costs (Cr 1,000). At the very least a full hit will result in a hull hit as well. 

If you get a captain who wants to use just metallic hydrogen... let 'em. The Universe knows what to do -or you do.