07-26-2021, 01:58 PM | #1 |
Banned
Join Date: Aug 2020
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Spaceships: How to take off?
Most systems have horrendous acceleration in G. In addition, decent acceleration systems have an awful delta-V in mps. What system is the best to take off from Earth without dropping nuclear bombs on the task (Orion Drives)?
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07-26-2021, 02:05 PM | #2 | |
Join Date: Aug 2007
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Re: Spaceships: How to take off?
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Oh, there was an lmplied bias against Superscience! drives in your post (also one about takign off from Earth) so I assumed you didn't want those. Reactionless Thrusters (above Rotary) are usable if Superscience! is allowed and Contragravity makes lift-off with almost anything possible.
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Fred Brackin |
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07-26-2021, 02:13 PM | #3 | |
Banned
Join Date: Aug 2020
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Re: Spaceships: How to take off?
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However HEDM is 0.5 mps while the required mps is 5.6 mps for Earth orbit, while Antimatter Thermal Rocket is 0.1G by TL9, 0.2G by TL10, etc. with a delta- V of 1.8 mps, which is lower than the 1G and the 5.6 mps implied to be necessary to take off from Earth... I guess that I don't get this. |
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07-26-2021, 02:19 PM | #4 |
Join Date: Oct 2004
Location: Pennsylvania (roaming charges may apply)
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Re: Spaceships: How to take off?
You need to use multiple engine systems to get the required acceleration and many fuel tanks to get the total delta-v. Consider building a very large multi-stage design.
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07-26-2021, 02:24 PM | #5 | |
Join Date: Jun 2013
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Re: Spaceships: How to take off?
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GURPS Overhaul Last edited by Varyon; 07-26-2021 at 02:28 PM. |
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07-26-2021, 02:38 PM | #6 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Spaceships: How to take off?
There's no options for taking off easily that don't involve low-end WMD, because even the lowest-energy option for getting into orbit (ISp = orbital velocity) generally require somewhat upwards of 20x the payload weight in TNT.
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07-26-2021, 03:17 PM | #7 |
Join Date: May 2021
Location: Eastern Kentucky
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Re: Spaceships: How to take off?
I’d go for a g-drive and set it for 1.1 so you can gently glide up into space with no fuss and no muss.
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07-26-2021, 03:29 PM | #8 |
Join Date: Aug 2004
Location: Binghamton, NY, USA. Near the river Styx in the 5th Circle.
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Re: Spaceships: How to take off?
Realistically, using non-superscience drives, a ship is going to need most of it's mass to be fuel or be the upper-stage of a multi-stage rocket where the lower stage is all fuel and rocket engine. Even the higher TL realistic rockets don't get much better, because gravity wells suck. See the Midnight Sun-Class Orbital Shuttle on p. 7 of Spaceships. The Fuel Tank system on p. 17 explains how you get extra Delta-V (mps) when you have many Fuel Tank systems; this is the "Rocket Equation" bump that was mentioned above.
If you want to have spaceships routinely landing on and taking off from planets you basically need some form of Superscience drive - either straight Reactionless drives or otherwise standard drives with Superscience level of thrust of fuel economy.
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Eric B. Smith GURPS Data File Coordinator GURPSLand I shall pull the pin from this healing grenade and... Kaboom-baya. |
07-26-2021, 04:04 PM | #9 |
Join Date: Mar 2008
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Re: Spaceships: How to take off?
Or a ground based launch system like a mass driver, Lofstrom loop, laser launch or such.
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07-26-2021, 07:06 PM | #10 | ||
Join Date: May 2010
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Re: Spaceships: How to take off?
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