Rocketdyne Tripropellant (Hydrogene and Fluorine and Lithium) rocket engine

[Michel Van]

this was attempt to build most powerful chemical engine with Isp over 500 sec
it burns liquid Hydrogene and Fluorine and injects liquid Lithium into Combustion chamber as "afterburner"
This here is related to Chrysler studies for Tripropellant rocket stages:

https://www.secretprojects.co.uk/threads/chrysler-studies-for-hydrogen-fluorine-lithium-upperstage-1970.29178/#post-312793

Here Video that explain the madness:

View: https://www.youtube.com/watch?v=KX-0Xw6kkrc

 

[Archibald]

Indeed - madness it was. But there was a reason for the madness. Is that non-fluorine LH2 SSTO (think Venture Star) specific impulse 465 seconds falls very, very short from orbit. Something like 8500 m/s when SSTO requests 9200 m/s : THAT close. And since the propellant mass fraction is already perched at 0.90 or more... only specific impulse is left to make SSTO happen.

Ideally, a SSTO would work better with a specific impulse of 500 - 510 seconds.

But hydrolox will never do better than 475 seconds, and yes, the few dozen seconds make a difference.

And that's why they fought so hard for fluorine, despite its absolute madness. They needed the extra specific impulse to help the case of hydrolox SSTO. They wanted 510 seconds rather than 465 seconds.

 

[Sferrin]

Should throw a copy of that here:

https://www.secretprojects.co.uk/threads/chrysler-studies-for-hydrogen-fluorine-lithium-upperstage-1970.29178/

Saw it a couple days ago and wondered if it was discussed in "Ignition!"

 

[Nik]

What the-- Fluorine ???
Obligatory reference to Charles Stross' 'A Tall Tale'...

A Tall Tail - Reactor

This year for Tor.com's birthday, we're initiating a tradition of Rocket Stories! For this inaugural year, enjoy an exclusive read of "A Tall Tail" by Charles Stross a week before it appears on the site! (One of the perks of being a registered user on the site.)

reactormag.com

Old Tor link 404 as now 'Reactor'. Also, their new search engine is, um, 'weird'...

 

[DWG]

Eek! A friend got their doctorate using HF.

Using HF to melt volcanic basalts, that is.

 

[kqcke for you]

Sounds to me like there is still some space for improvements like another propellent xD

 

[Michel Van]

I found even more Insane Concept for Tripropellant

TOXMAX​

It burn Liquid Fluorine with liquid Lithium mixed with 10% RADIOACTIVE CESIUM-137 !
This Is no joke, the proposal use Cesium-137 to keep Lithium at +200°C

Source X

https://twitter.com/x/status/1769958999279927787

View: https://twitter.com/ToughSf/status/1769958999279927787

 

[Yellow Palace]

This Is no joke

I think it probably is a joke, just one with some calculations behind it!

 

[Archibald]

Plus the specific impulse is, what, 475 seconds ? not enough gain compared to RL-10B-2 467 seconds, or a NASA 1978 476 seconds (ground tested).

 

[Michel Van]

Plus the specific impulse is, what, 475 seconds ?

That so low, because burn Lithium with Fluorine direct, produce heavy molecule in exhaust
if you put hydrogen in mix, it take heat from this combustion and produce fast light molecule in exhaust.

 

[Orionblamblam]

I think it probably is a joke, just one with some calculations behind it!

Best kind of joke.

 

[Scott Kenny]

Should throw a copy of that here:

https://www.secretprojects.co.uk/threads/chrysler-studies-for-hydrogen-fluorine-lithium-upperstage-1970.29178/

Saw it a couple days ago and wondered if it was discussed in "Ignition!"

Page 189 of the PDF I have.