I’m sorry I haven’t had much opportunity to blog lately. The move’s going behind schedule due to me getting so sick last weekend that I could barely get out of bed for three days straight, which of course happened while Tiff was in Oregon for a week so I could pack. And of course, the day she came home, she and little Jon got sick, just as I was getting better. Add on top of that the fact that I was trying to get another iteration out on the sheetmetal and other hardware for our latest engine, trying to design and build an alignment jig, trying to help pack up the shop, etc, etc, etc.
So, apparently now that I’m no longer having sucky birthdays like I used to [long story], my bad luck has hopped over to my blogiversaries. Could be worse I suppose.
Anyhow, enough self-pity, I really did have a point I wanted to make with this post!
In a lot of the commentary to my post below about propellant depots, many people seemed to take the Henry Ford “You can have any color you want so long as it’s black” sort of attitude. Basically, there are some propellants that are harder to handle than others–the poster boy being hydrogen. Having dealt a little with hydrogen, I can understand others’ dislike for the stuff.
That said, we’re not Henry Ford. If someone wants to buy hydrogen from me on-orbit, I’m not about to tell him “Sorry pal, come back when you want a Real Man’s propellant!” The fact is that for all the extra hassles, there are plenty of benefits for using hydrogen in some systems, and having the ability to sell it to those who want it is going to be important.
I guess this all boils back down to the whole monoculture idea that I hit on in one of my very first posts. The fact is that there are likely going to be many different things done in space that demand different vehicles, made and operated by different companies, not all using the same fuels, engines, etc. There will likely be stations in equatorial orbits as well as higher inclination orbits. VTVL vehicles and HTHL vehicles will likely have niches. You’re going to see hydrogen powered vehicles as well as hydrocarbon powered ones. I think that even ELVs and RLVs will coexist for a while.
So, while some propellants can be stored using simple rubber bladders with Murphy Straps, there’s going to be someone (likely quite a few) who want to buy hydrogen from you. There are ways of solving the problems of cryogenic propellant storage for hydrogen, so we may as well investigate those technologies anyway. The good news is that once we know how to store and transfer liquid hydrogen, pretty much everything else is going to be easy.