Choosing 4E Spaceship Propulsion

munin · 02-26-2012, 05:20 PM

A 1G reactionless engine will make almost all interplanetary travel measured in days (e.g., from earth to mars with multiple engines) to weeks (e.g., one side of the system to the other on a single engine). Even limiting reactionless to the TL7^ 0.1G rotary reactionless engine still gives you some interplanetary travel times measured only in days with few journeys requiring more than a couple months.

If jump gates (that jump either directly to a jump gate in another system, or into hyperspace where you can travel in parsecs per day) can only be built outside of stellar and planetary gravitational influence (e.g., past Neptune's orbit), then interplanetary travel will always be easier than interstellar travel and planets within a system will find it easier to trade and travel within the system, but interstellar travel won't be necessarily out of the question.

If reactionless engines are limited to 1G per spacecraft system (e.g., super reactionless isn't allowed or hasn't been developed), but superscience reaction engines are allowed, then interplanetary/interstellar travel will use reactionless engines but short-distance travel/combat will use reaction engines. There are a number of reaction engine choices at TL11^ -- for example, the Super Fusion Torch pulls 50G per engine and lasts 25 minutes per tank per engine, while a High-Thrust Super Antimatter Plasma Torch consuming antimatter-boosted water can pull 600G per engine but lasts only 16 seconds per tank per engine -- so there's a lot of room for design choices. Even some non-superscience engines might be advantageous over a 1G reactionless engine in a short dogfight: for example, a TL10 High-Thrust External Pulsed Plasma engine pulls 4G per engine and lasts 2.6 minutes per tank per engine.

02-26-2012, 05:20 PM	#6
munin Join Date: Aug 2007 Location: Vermont, USA	Re: Choosing 4E Spaceship Propulsion A 1G reactionless engine will make almost all interplanetary travel measured in days (e.g., from earth to mars with multiple engines) to weeks (e.g., one side of the system to the other on a single engine). Even limiting reactionless to the TL7^ 0.1G rotary reactionless engine still gives you some interplanetary travel times measured only in days with few journeys requiring more than a couple months. If jump gates (that jump either directly to a jump gate in another system, or into hyperspace where you can travel in parsecs per day) can only be built outside of stellar and planetary gravitational influence (e.g., past Neptune's orbit), then interplanetary travel will always be easier than interstellar travel and planets within a system will find it easier to trade and travel within the system, but interstellar travel won't be necessarily out of the question. If reactionless engines are limited to 1G per spacecraft system (e.g., super reactionless isn't allowed or hasn't been developed), but superscience reaction engines are allowed, then interplanetary/interstellar travel will use reactionless engines but short-distance travel/combat will use reaction engines. There are a number of reaction engine choices at TL11^ -- for example, the Super Fusion Torch pulls 50G per engine and lasts 25 minutes per tank per engine, while a High-Thrust Super Antimatter Plasma Torch consuming antimatter-boosted water can pull 600G per engine but lasts only 16 seconds per tank per engine -- so there's a lot of room for design choices. Even some non-superscience engines might be advantageous over a 1G reactionless engine in a short dogfight: for example, a TL10 High-Thrust External Pulsed Plasma engine pulls 4G per engine and lasts 2.6 minutes per tank per engine.