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Beta and Higher Patron Notice for 06/25/2021

🕑 Added 2021-06-25 22:29:55 +0000 UTC

Comments

Nyrath

Thank you! With your permission I'd like to add your correction

SSailor67

The wiki math for http://www.projectrho.com/public_html/rocket/enginelist2.php#pulsentr that estimates ~13k seconds Isp as the maximum is wrong. The math assumes cylindrical fuel geometry like a standard NERVA, but the paper's abstract says it has to be thin sheets. Money quote: "In addition, thin geometries of the fuel are mandatory to keep intimate content with the quenching coolant." If pulsing a cylindrical fuel element can get ~10,000s Isp, thin linear sheets probably can get 100x better due to more neutron contact, which would validate the "better Isp than a fission fragment" claim. Plugging that into the rocket equation, you get ~6,800km/s delta-V with a mass ratio of 2, and the possibility of high thrust, which is definitely a torch ship, albeit not one that can do a 1G brachistochrone to Pluto.

Nyrath

All true. I should add a note emphasizing that the article was written in 1979. Good for the time, but a bit dated now

Nyrath

Ooops! Sorry about that. I fixed it

John

I love how all the arguments for war in space are based on the idea that "We fight wars on Earth, we will in space!" Well, not so much. When Every Gram Counts, it's hard to get warship up into space that has any form of armament or armor worth the cost. Especially if it's manned. Unmanned ships can always Kamikaze into other ships, but not ships carrying humans. In fact putting humans at the controls of a space warship just guarantee it will be the most vulnerable ship in a space battle. Building ships in space will get you more armor, but at the cost of dV of the ship. And what kind of realistic weapons will the ship carry? Kinetic Kill systems? Frick'n laser beams? All of which have their benefits and problems. And you really can't compare battles in space with battles on a planet. They are completely different environments and have unique issues inherent with both. Having said that, it won't stop someone from trying. And the resulting Kessler Syndrome will demonstrate the futility of fighting wars In SPAAAAAaaaace!