Spaceship propulsion

[elte]

http://newatlas.com/orion-project-atom-b...d-91806145

Something that I found interesting is that max rocket exhaust velocity was given as 6000mph in the article.  I recall that escape velocity is 7500mph.  I was imagining the rocket having to fly up to higher altitude and then fall back with rocket engines  still flaring, down to slingshot its speed up to escape velocity.   Slingshot is a word I seem to recall hearing NASA use.  I also seem to recall the analogy of the swinger being pushed from behind on a swing.

[Secular Sanity]

From your article...

"It's been sixty years since the Orion project began in the wake of Sputnik. Today, it's seen as a bizarre dream – as fantastic as Cyrano de Bergerac flying to the Moon in a chair with sky rockets strapped to it. But this fantasy was very much a thing of reality that died more from politics than engineering. It is also one that may well play a key role in the future of the human race as it expands its horizons to the stars."

Looks like there is current ongoing research.

https://en.wikipedia.org/wiki/Nuclear_th...t_research

http://www.space-travel.com/reports/NASA...s_999.html

[C C]

In the 1970s, the British Interplanetary Society took Dyson's idea and refined it for Project Daedalus [...] unmanned probe that could reach a maximum velocity of 12 percent of speed of light. This would allow it to reach Barnard's Star, 5.6 light years away, in about 46 years. In 1989, the US Naval Academy and NASA unveiled Project Longshot [...] 4.5 percent of the speed of light on a 100-year mission to Alpha Centauri.

The vast amount of antimatter places Project Valkyrie in fantasy land. 92% the speed of light would more than recruit the effects of relativity for the crew. But being behind the engine and relying on that tungsten shield the entire journey would really stretch confidence.

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[RainbowUnicorn]

http://newatlas.com/orion-project-atom-b...d-91806145

Something that I found interesting is that max rocket exhaust velocity was given as 6000mph in the article.  I recall that escape velocity is 7500mph.  I was imagining the rocket having to fly up to higher altitude and then fall back with rocket engines  still flaring, down to slingshot its speed up to escape velocity.   Slingshot is a word I seem to recall hearing NASA use.  I also seem to recall the analogy of the swinger being pushed from behind on a swing.

mass exchange point is probably more technically important.
the "burn speed" of the burning chemicals defines the propulsion speed very basically speaking.
atmospheric density & gravity also effect that.
as the rocket gets further from the surface of th eearth gravity gets less, atmosphere gets less & momentum is sustained as kenetic energy making accelration easier.
the rocket exhaust is a fairly loose term.

http://www.dictionary.com/browse/exhaust-velocity

https://en.wikipedia.org/wiki/Rocket_engine_nozzle

https://en.wikipedia.org/wiki/Rocket_engine#Net_thrust
(way too much math for my brain)


Thus when talking of Exhaust speed it is purely relative to the type of fuel/rocket/nozel lift to flow rate etc etc etc....

burn rates do not deliver direct thrust speed because of all the other things that get in the way.
as technology gets better the better the ability to utilise the actual burn rate as a thrust speed.
efficiency
directional combustion
weights of materials
ability to counteract gravity
ability to counteract atmosphere
etc etc

"sling-shot" is the use of innertial energy gain by using the gravitational field of a mass/body with gravity.

the gravitational pull of a mass/body/moon/planet pulls the object with its gravitational speed/energy which is a force rather than a actual speed.
by making the angle of touching the gravity field at a specific angle it allows the greater collection of innertial collection/kinetic build up
because of E=MC2 obviousely the object relatavistically stays in orbit of the body/mass/moon/planet at its terminal gravitational effect due to its relative variants. by then thrusting off to push away it then leave the gravitational field having gained a lot of speed/energy