Changing velocity only

Kriss

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Consider chasing ISS in orbit, having RInc 0, and PeR, and ApR equal to ISS.
Is there a way to calculate a angle that i could thrust toward where only the velocity would change, and all the other variables above would be the same?
 

Jarvitä

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Nope, changing your velocity will inevitably change at least one of those variables. You might want to read up on orbital dynamics.
 

garyw

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constant thrust will still change something.

thrust prograde = orbit height increases
retrograde = orbit height decreases

You can't chase the ISS if all the parameters are the same. instead you'll loiter at a distance from it
 

tori

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It's doable, but very expensive with current technology: (see attachment)

EDIT: It's noteworthy that this approach does modify the real orbital parameters as well, but the virtual orbit (i.e. the trajectory actually travelled by the spacecraft under the effect of the constant thrust) matches the initial orbit (as if only the velocity changed).
 

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Eagle

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If you want to learn how to orbit very fast read this thread: KSC to Ascension


Assuming you want to keep the same altitude and plane as ISS and want to approach it you have one FUEL INTENSIVE option:
1: Thrust Prograde to increase your tangential velocity. Cut engines.
2: Thrust straight down continuously to keep your altitude from increasing(rolling upside down and using hovers works well).
3: Thrust Retrograde when you get close to ISS to mach velocity.

Oh, and fly the KSC to Ascension time trial. :)
 

RisingFury

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You can stay in the same orbit after increasing your velocity, but you'll have to thrust straight down, in the same direction as gravity.

It's theoretically doable, a MFD could probably be able to do that.


Someone here claimed to have orbited the Moon at beyond 2 km/s, at very low orbit, in the range of 10 meters or so, upside down in a DG, with hover thrusters pushing down...
 

Calsir

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Someone here claimed to have orbited the Moon at beyond 2 km/s, at very low orbit, in the range of 10 meters or so, upside down in a DG, with hover thrusters pushing down...

It is also the way by which agentgonzo reaches his insane velocities (10km/s +) in high earth atmosphere for his KSC-ascension flight. In this case, the downward force is given by aerodynamic lift (which is more or less free), rather than thrust.
 

Sky Captain

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It`s doable with futuristic spacecraft like DGIV and XR series. I once set XR2 hover thrust to very high value and accelerated to 40 km/s while keeping constant 120 km altitude by flying upside down with hovers burning at max.
 
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