Kim: Delta-V manuveurs are changes to orbits that are already heliocentric. Since the sun is very close to the barycenter of these orbits, it can't be used for a gravity boost. Jupiter works because so many comet asteroid and spaceship orbits actually cross the jovian orbit. Close encounters will actually transfer velocity to or from Jupiter.
From the standpoint of heliocentric orbiting objects, the Sun is actually standing still.
For energy transfer between the sun and and an object from beyond the solar system in a hyperbolic orbit, the object would have to be massive enough to actually change the direction of the sun in interstellar space. Such events happen all the time in globular clusters but in the process any orbiting planets are flung into space like a stones from a slingshot. DT --- On Mon, 11/8/10, Kim <kimharch@cut.net> wrote:
From: Kim <kimharch@cut.net> Subject: [Utah-astronomy] Sci Fi Question To: "'Utah Astronomy'" <utah-astronomy@mailman.xmission.com> Date: Monday, November 8, 2010, 5:48 AM Chuck, since you're a fan of Arthur C. Clarke, maybe you can answer this one: Do you recall if Rama's rendezvous with the Sun was used for a directional, only gravity-assist maneuver, or if it was also used for a delta-v maneuver? Or, did Sir Arthur ever say in the novel?
I had a sleepless night, and I had questions come to mind about gravity-assist maneuvers, so I had to look it up this morning. I then remembered Rendezvous With Rama and the above question came to mind. However, I couldn't find an answer online; hence this post. Thought you might like to know the process that brought me to this profound question. Then again, maybe not.
Kim
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