Agree acetylene has challenges.
I never said acetylene was a good propellant.
I was intrigued by Rocket Lab's high density (1.78 g/cc) monopropellant.
[MEDIA=youtube]gB8LEHwfXPc[/MEDIA]
View: https://youtu.be/gB8LEHwfXPc
Rocket Lab's monopropellant consists of carbon nano particles mixed with hydrogen peroxide that got reasonable isp at high density which translates to low structure fractions. DARPA usually throws out massive fails to cause folks to come to wrong conclusions, which is appropriate for strategic technology.
Now, when a fuel and oxidizer come together, unless they're hypergolic, they do not react unless there is an activation energy applied. So, pure carbon nanoparticles extracted from pyrolysis of methane, and chilled high test hydrogen peroxide are quite stable! Yet are easily detonated with a small amount of silver nitrate injected into the combustion chamber. Hydrogen peroxide puts out high temperature oxygen which ignites the carbon.
Nano particles of lithium suspended in hydrogen burned with oxygen has higher Isp than lox lh2 alone.
Hydrogen peroxide mixed with kerosene has relatively high density and is somewhat stable.
Nanoparticles of solid hydrogen peroxide with liquid methane is another variant.
BP of O2 is same ss MP of methane so a colloidal suspension of solid methane in a lox tank is another high performing monooropellant.
Frozen oxygen in a liquid hydrogen suspension is yet another mix.
Solid flourine particles and lithium particles floating in a liquid hydrogen suspension gets 5.5 km/sec Isp and are easier to manage than liquid or gaseous flourine.
Dr vonEschen taught me propulsion physics and chemistry at OSU. Von Eschen worked on this in the 50s and 60s.
Dr Gregorek worked on SR 71 and Have Blue back in the day and taught me aerodynamics.
With low structure fraction and high Isp you can have substantial ssto capability.
[URL unfurl="true"]https://www.researchgate.net/publication/305632794_Investigation_on_Tri-propellant_Hybrid_Rocket_Performance[/URL]
[URL unfurl="true"]https://link.springer.com/chapter/10.1007%2F978-94-011-7551-7_12[/URL]
https://link.springer.com/chapter/10.1007/978-94-010-0017-8_49
[MEDIA=youtube]KqZDHBe2KlE[/MEDIA]
View: https://www.youtube.com/watch?v=KqZDHBe2KlE
Basically a flying wing no body that has air augmented tri propellant rocket that takes off from a runway accelerates as it flies ever more obliquely and ends up flying one wing tip forward one aft as SSTO.
1-1/exp(9.4/5.5) = 0.819 propellant
0.031 - structure (2010)
0.150 - payload !!!
Or
0.081 - structure (1980)
0.100 - payload !!
Or
0.121 - structure (1950)
0.060 - payload !
Good as any tsto rlv even with 1950 hardware and structure fraction.
Crazy propellant though!
*****
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My friend Jordin Kare worked at LLNL back in the 1980s and 90s and project Mockingbird use H2O2 oxidizer with RP1 fuel. Rocket Lab's VLM is very much like this imho.
Putting up a nano satellite quickly from anywhere in an uncharted orbit to surpise an enemy, stay up one orbit and land at the launch site, with surveillance data that is never radioed anywhere, provides a substantial covert capability.
A vehicle large enough to launch a pilot, say a 3 ton system that masses 30 tons at lift off with high density propellant, and HTOL capability so you can operate from a runway. With only a 2 meter diameter fuselage with high density propellant.
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A tinier more capable version of Philip Bono's Space Marine Carrier -- again Ideal for Covert Operations
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Of course Bono's ICARUS project could propel a battle group to any point on Earth, and return the empty after the payload was discharged. A tanker rocket flying back to the battle field with a cargo rocket could pull troops and equipment out equally rapidly.
A smaller 30 ton system that carried 3 tons payload -- the same as a DC 3 -- or a 0.9 tonne payload the same as a Honda Jet you cna fly 745 nm and back 12 minutes each way. This range is extended if you drop off a payload and fly back empty. You can also develop a tanker versiion that refills and lets you extend range that way.
So a high performan monopropellant provides a vehicle to launch 3 ton payload up to 745 nautical miles away from a submarine missile launcher and fly to a spot, land drop off agents and/or supplies, and extracts agents and/or supplies, and flies back and land back as the sub, or onward to another sub or aircraft carrier and then withdraw.
Flights of about 12 minutes each way.
Relevant data to calculate this here;
[URL unfurl="true"]https://www.rand.org/content/dam/rand/pubs/monograph_reports/2006/MR737.pdf[/URL]
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theta is the angle between the take off point and the landing point of a ballistic vehicle with zero lift. sqrt(2gR) = 11.18 km/sec escape velocity.
So, with a 9.4 km/sec delta vee you get to orbit and back with gravity drag and air drag. A 4.7 km/sec delta vee
4.7 km/sec = 11.18 km/sec * sqrt(sin(t)/(1+sin(t))) --> t=0.216353 radians (12.396 degrees)
The circumference of the Earth times 12.396/360 = 745.1 nautical miles in 12 minutes.
So a fellow can talk via Skype in the morning through a VPN from a sub off the Chinese coast, that spoofs that he's calling from DC, to a Chinese leader. Take an hour break for lunch. Fly up to 745 nmi inland, pick up agents drop off agents, pick up contraband, drop off contraband, get up to all sorts of mischief. Fly back, and have another call after lunch from the sub with the same spoof. Then, fly from the South China Sea to Mcclean Va near DC in 37 minutes. Take a car from CIA HQ to a dinner with the Chinese ambassador -- any report that he was in China stirring up various ethnic groups against the Chinese would be dismissed as impossible.
That's what this tech could do in these sorts of programs.
Of course, a ballsitc biz rocket is a dream -- and that would be awesome too! haha.
