Old Boom Boom

It's time this blog constrained the Orion. This rocket was pretty much done in the late 1950s but, alongside the NERVA thermal project, kept floating across various Presidents' desks. Until it didn't.

What the Orion proposed was to go find some place nobody lived, line the ground with Plumbago, set up a honkin' big rocket and, er, set off uranium fission bombs. Or plutonium, whatever. There's something about pressure-plates that I didn't pay much heed to. Anyway if it doesn't scatter bright blue fallout all over Nevada then this would push sufficient delta-V to raise bell-bottoms and bongs off the gravity-well. A lot of them.

Later the Orion (and NERVA) madlads learnt that over magnetic 80° Arctic / Antarctic would be best for not interfering with Van Allen and/or our satellites. This angles away from the solar ecliptic and the lunar orbit. If we're not aiming for Luna, peak blastoff times are the twin solstices; but I think we will be aiming for Luna (see below).

One in space, you do need to pivot it for one more burn (rather, blast) to approach the ecliptic, which is where everything is. There are additional limits as to what it can do next: Solar-well Oberth maybe? In particular, like Air Qaeda, it can't land. But you're in space. You should be assembling new rockets out there. Some Earth-Luna Libration halo is best for that.

As a result, for Orion engineers, your job is to load up as much mass as you can and say, "nevermind" to anyone whining about ISP. You care about one thing: thrust. So on the Orion chart, as Project Rho had it, we want the full Interplanetary package but only so much as to get us to ELL1. It takes 9.3 km/s for LEO and, from LEO, 3.7; but since we are shooting past LEO, I expect a Pythagorean solution for total delta-V. Our escape velocity is 11.186 km/s; nudging into ELL1 halo or even L4/5 is trivial compared to that. So: we'll be shifting cargo from the polar capture-orbit to ELLx somewhere in the 5700-6000 ton range. I think those are metric, so mega-grams.

As to what you send up there: people. And life-support. The awesome thing about Orion is that we're not forced to squeeze astronauts into pressurised Dr Pepper cans with big ring-target signs on the side saying "SPACE JUNK AIM HERE". We can even line the hab and electronics with lead against the EM pulse from the rocket's own radiation. Which shields we can reuse outside Van Allen.

Although we assemble the various spacefaring ships at ELLx, where Earth can see it, some of those ships might be some other sort of atomic torchship... where Earth can see it. Those, we don't launch from ELLx. We launch those from ELL2.

Ultimately we want to be mining thorium in the Moon and Mars, so in future, we don't fire old boom-boom from Earth excepting for biology. The Moon and Mars fire boom-boom because they don't have environmentalists. Although I'm unsure where they find the graphite. Maybe there's Martian cliftonite? Or do we soak the Martian ice-caps with boron...

UPDATE 1/4/2021: Mot-O-Rion! 2/20: Let's distinguish from NERVA.

OBERTH 3/13: Something to do up there.