[Forgiven_Sinner]

"slingshot" orbital speedups are gained by having the spacecraft fly by a planet or moon starting at exactly the right place that the planet gives up energy from its forward orbital motion to the spacecraft. What this means is that every time we use Jupiter to speed up a probe, the planet slows down slightly. if we sent a really, really large number of probes by Jupiter this way, we could get it to fall into the Sun."

"Hmmm... Actually, as an orbiting body is slowed, it gains in altitude, not the other way round. :-)"

Not quite. Slower moving bodies are further away, but they have more potential and more total energy. If you slow a planet by slingshot method, it actually reduces the orbital size and speeds up as it falls toward the sun. This is called "orbital decay" and it happens all the time.

[RadioAstronomer]

I understand this stuff very well. Read my later post. I worked as an orbit analyst with NASA and still "do" orbit design work as required. I was trying to be funny, but obviously I fell flat on my face.

Sigh.