10-21-2013, 12:32 PM | #41 | |
GURPS FAQ Keeper
Join Date: Mar 2006
Location: Kyïv, Ukraine
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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10-21-2013, 12:48 PM | #42 | |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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We have exactly one example of a craft that can do this (the Space Shuttle), and it flies like a brick -- glide ratio at hypersonic speed is 1:1 (i.e. drag == lift), which is totally useless for flying into orbit (as in, it would take less fuel to not use the wings). |
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10-21-2013, 01:04 PM | #43 | |
GURPS FAQ Keeper
Join Date: Mar 2006
Location: Kyïv, Ukraine
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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The uniqueness of the shuttle though is indeed a problem. As in, we're basically TL6 in the TAV tech path: in the 'spacecraft’s acceleration must also exceed gravity (...), or it must be winged' choice, we are very firmly in the first tech path camp. And yes, I know that SS glosses over the TL of aerodynamics most of the time; due to this, stuff that's probably plausible for 2100-era Responsive hulls isn't any more difficult (system-wise) with TL7 hulls. I suppose it could be seen both as a bug ('hey, humans cannot build TAVs at TL7!') or a feature ('no reason to push a TL6+1 design up to TL9!'). (Come to think of it, having more retro-research into divergent tech paths would be nice. Some of the stuff there might be worthwhile.) |
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01-21-2014, 03:03 AM | #44 |
Join Date: Aug 2007
Location: Vermont, USA
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
Minor necro:
Is there a more general formula for this? I'm looking at the Storm Bird-Class Helium-3 Shuttle (SS6, p. 22) and wondering if it can actually reach orbit. Its 1G acceleration exceeds Saturn's 0.92G gravity, but it is also winged, which initially seems redundant by the Spaceships RAW (being able to take out one of the ram-rockets would drop the price a lot), but might not be enough taking realistic drag into account. |
01-21-2014, 11:12 AM | #45 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
Real accel = (base accel) - (gravity / (L/D)) = (base thrust) * (1 - (gravity / ((L/D) * base accel))
It's got an air/ram, which basically has infinite delta-V, from what I recall. |
01-21-2014, 12:22 PM | #46 | |
Join Date: Jul 2008
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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Having wings and also removes any minimum thrust requirement, by the rules, though I doubt the realism of a jet plane with an ion engine added in as an orbital launcher.
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I don't know any 3e, so there is no chance that I am talking about 3e rules by accident. |
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01-21-2014, 12:36 PM | #47 | ||
Join Date: Aug 2007
Location: Vermont, USA
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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The text seems to imply that the ramjets are only used to add the equatorial velocity to the spacecraft's velocity, though that doesn't make sense to me (even an unpowered balloon at the equator would get the eq.v. for free). |
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01-21-2014, 01:38 PM | #48 | |
Computer Scientist
Join Date: Aug 2004
Location: Dallas, Texas
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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01-21-2014, 02:43 PM | #49 | |
Join Date: Jul 2008
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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It's probably unlikely for the jets to give you a high enough trajectory that you don't reenter long before you could get near orbital velocity with an ion drive.
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I don't know any 3e, so there is no chance that I am talking about 3e rules by accident. |
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01-21-2014, 07:12 PM | #50 | |
Computer Scientist
Join Date: Aug 2004
Location: Dallas, Texas
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Re: EuroSpace E950 Minerva Executive Transatmospheric Vehicle
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spaceships, spaceships 7, ths, ths spaceship, transhuman space |
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