08-05-2020, 09:53 AM | #1 |
Join Date: Aug 2010
Location: The Land of Enchantment
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[Spaceships] Can't find the right propulsion system
Hi, all. I'm trying to find an appropriate propulsion system for little work pods and inter-ship lighters, for in the space near stations, in work areas, etc. These are not long-range vehicles so they don't need massive delta-V. But they probably do need acceleration measured in something larger than milligees, if only for time management concerns, so Ion and VASMIR drives are out.
In this setting (TL10) there is a limited superscience switch that makes antimatter extremely cheap and things like the antimatter plasma torch possible. But for small craft like this such systems wouldn't be used since every Tom, Dick, and Harry welder or taxi pilot can't be trusted with a drive that spews radioactive death. So for the life of me the only option I seem to be able to find is a chemical rocket. But this seems like overkill at 3G acceleration. What I really need is just some sort of OMS, y'know? Have I missed some other option?
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08-05-2020, 10:02 AM | #2 | ||
Join Date: Jan 2014
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Re: [Spaceships] Can't find the right propulsion system
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-- More seriously, is Antimatter Thermal not acceptable for a lower power system? |
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08-05-2020, 10:39 AM | #3 | |
Join Date: Aug 2007
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Re: [Spaceships] Can't find the right propulsion system
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The OMS were a small pair of engines compared to the SSMEs and you could use a smaller than the normal SM chemical rocket for your workpod. That would cut accelration down to 1 G.
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Fred Brackin |
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08-05-2020, 11:03 AM | #4 | |
Join Date: May 2010
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Re: [Spaceships] Can't find the right propulsion system
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08-05-2020, 12:01 PM | #6 |
Join Date: Feb 2016
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Re: [Spaceships] Can't find the right propulsion system
Yes, smaller systems would be a good idea. For example, a -1 SM HEDM rocket would provide 0.67g of acceleration and two -1 SM fuel tanks with HEDM reaction mass would provide 0.33 mps of delta-v (it actually has better performance than antimatter catalyzed water, which would end up being 0.2g/0.4 mps of delta-v).
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08-05-2020, 12:26 PM | #7 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Can't find the right propulsion system
I would avoid HEDM if not needed, seeing as it tends to be explosive. Systems with low delta-V requirements are typically willing to trade performance for safety.
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08-05-2020, 12:44 PM | #8 |
Night Watchman
Join Date: Oct 2010
Location: Cambridge, UK
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Re: [Spaceships] Can't find the right propulsion system
They were, in fact, the basic same engine as used in the the Apollo Service Module, which is definitely smaller than the Shuttle. A later version is being used in the Orion spacecraft's service module: good rocket engine designs can stay around a long time.
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08-05-2020, 01:08 PM | #9 |
Join Date: Aug 2005
Location: Cowtown, Canada
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Re: [Spaceships] Can't find the right propulsion system
You can use Smaller Systems to convert a single system into three systems of one size (SM) smaller: You can replace a 3G chemical rocket with a 1G rocket and two small fuel tanks, all one SM smaller than the ship. This gives 2/3rds the capacity of a full SM sized fuel tank. If you want to go really small, you can convert down by two SM levels and get 10 systems at SM-2 for a single full sized slot. Each rocket would provide 0.3G of thrust at that level.
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FYI: Laser burns HURT! |
08-05-2020, 01:22 PM | #10 |
Join Date: Feb 2016
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Re: [Spaceships] Can't find the right propulsion system
Antimatter also tends to explode, and it seems to be ubiquitous in the setting. If you do not want HEDM, you can do chemical rockets for 1g and 0.1 mps.
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Tags |
rockets, spaceships |
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