Pentaborane

[menistvo]

I have occasionally read of American and Soviet attempts to utilize a pentaborane-burning engine. For the experts out there, I wonder what such an engine might look like in Traveller. Does anyone have any details on these engines?

I am aware that both nations eventually dropped the fuel, as pentaborane is very dangerous. But if someone pushed this, or if some planet (perhaps lower tech) is currently working on such an engine, I think this could be an exotic and interesting little addition.
Any version of Traveller is fine - my preference is TNE but anyone interested could speculate for any system, or theoretically.

 

[parmasson]

Honestly I had ever heard of it before I read this.
I guess they tried it back in the 60s. From what I have gleaned it offered no advantages that would offset its toxic nature and instability. Again, the amount I don’t know about rockets could fill volumes.

Found this tho’
http://rocketsciencebooks.home.att.net/liquids.html

If you are mathematically inclined it looks like a good price.

[edit] If you are looking for a relatively low price in a TL-7-8 rocket might I recommend a Soyuz booster. Liquid oxygen and low tech kerosene provide the oomph. Cool retro styling plus reliable design and easy to procure fuel. OK you only get 4000kg of cargo space but where are you going anyway? Whatever the rebellion did not wipe out the Virus did so orbit is as far as you need to go anyway.

http://www.interspacenews.com/sections/feature%20stories/russia's%20soyuz%20booster.htm

 

[menistvo]

Thank you Parmasson! That does look like an excellent book, and the Soyuz link is particularly useful for low-T spacefaring worlds (a ref could use color diagrams like those). I imagine rockets like those would be very common on lower-tech worlds on the fringes of empires.

 

[parmasson]

In a non-thruster plate world they could be quite useful. Perhaps as a LEPLAR drive if you are in TNE. New engines in an old case?

 

[menistvo]

TNE is my Traveller of choice, largely thanks to FFS; I was just toying with the MHD turbine for a grav truck design.

I came across a bit of info on pentaborane, BTW,

from a Wikipedia entry:

http://en.wikipedia.org/wiki/Pentaborane

From this website:
http://www.chem.ucla.edu/dept/Faculty/hawthorne/lecture/lecture2.htm

... The heat of combustion of boron hydrides is typically about 30,000 BTUs per pound, while a hydrocarbon fuel, such as JP4 or kerosene, was about 18,000 BTUs...The problem was that the solid boron oxides present in the combustion products of the rocket motor, interfered with the expected thermodynamics. So boranes were not super fuels for rockets and that program was dropped...

I wonder if there might be a way to limit such interference...although I'd imagine not.

Whether or not, at some point in the near future it may be worthwhile for myself to invest in that book that you linked Parmasson - did you read the list of investigated chemicals? Fascinating! - could really add tremendous color and detail to add a whole series of lower-tech liquid fuels (in addition to being one hell of a good read).
As for B5H9, pentaborane was called the "Green Dragon" because it burns with a green flame. Just maybe some world (Gollere?), a regressed colony just returning to space, might dance with that devil.

 

[parmasson]

I dunno, Liquid hydrogen/oxygen would seem to be the mix of choice to me. I was surprised to find the Soyuz used Kerosene and liquid O2.

Personally I can just see some of the old SDBs as defensive space stations. The locals you describe could use these boosters to supply and staff their “fleet”. It must have been a bad time for them if they got knocked back to TL-7/8

Here is an idea, I have not read much TNE but they use a plasma drive instead of thruster plates IIRC. You could make it a reusable booster that uses some large parachute system to return to the surface. Just make it a low efficiency drive cobbled together from some museum pieces or a book.

Rocketry is cool but my knowledge of real science is limited.

 

[Anthony]

Liquid hydrogen is an extremely obnoxious fuel (it's bulky and hard to handle), and LOX/LHd rockets have relative low thrust -- that's why LOX/kerosene is common (it was also used as the stage 1 on the saturn V).

 

[Uncle Bob]

A bigger problem is tankage. LH2 is so bulky it is difficult to get the mass of the insulated tank below 10% of the mass of fuel. Kerosine is more than ten times denser then Hydrogen and is fine at room temperature, so the tank can be 1-2% of the contents.

This is one reason the ROTON SSTO vehicle was designed to use kerosine instead of LH2.

 

[parmasson]

That makes sense. Having to store one substance at extremely low temperatures is better than having to store two.
It just seemed strange that the rocket was fueled by lamp oil.

 

[parmasson]

I wonder if they would ship? Since the costs seem to be lower and I hear NASA can be expensive I think we need a launch pad here in Chicago. Old Migs Field on the lakefront has been closed so it would make a cozy little launch site. The people in Michigan might have to watch out for falling booster parts but who cares if you have your own rocket.

 

[menistvo]

I'm pleased that this little oddity (pentaborane fuel) has spawned a discussion of liquid fuels. Perhaps that would be a better title of this thread...

Oh yes I just might manage to grab that book on liquid rocket propellants. If so, I'll post any Traveller-pertinent info I come across.