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twohedwlf t1_jd10pr5 wrote

Yes, it would work, and you'd only need to flip once at the midpoint of the trip. But we don't have the technology now to maintain that kind of acceleration.

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twohedwlf t1_jd18c5k wrote

To give some idea of the amount of fuel needed. Say we wanted to JUST send a SpaceX raptor a 2 day burn(About the 1g time to Mars from u/trogon link) about 230,000,000 lbs of fuel and would start off at about 1/460th of a G acceleration. (Ignoring tanks, structural supports etc.) That gives an average acceleration over 2 days of 1/230th of a G.

So, you could never achieve it with combustion rocket engines.

Nuclear engines have much higher ISP, but only in the region of 2-3 times so they'd use roughly 1/3rd the fuel.

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Triabolical_ t1_jd1e0k4 wrote

Nuclear engines tend to be both heavy and have low thrust, which mostly cancels out the Isp advantage.

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dasBergen t1_jd1fadc wrote

Wasn't project Orion a really bad idea version of this? But I think the fuel scoop was the only missing technology?

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BrentRedinger t1_jd1lye7 wrote

I think it was Daedalus that used the scoop. Orion used the pusher plate nukes.

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Bipogram t1_jd1np17 wrote

Daedalus was still an Orion-esque engine, but with thermonuclear (not fission) 'devices'.

Bussard ramjets are out of favour as nobody is sure that they make nett thrust.

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