Will aerocapture work for a Jupiter orbiter/moon lander? Options

[Guest_Zvezdichko_*]

This is something interesting. But knowing the harsh radiation environment of the giant, I don't know whether it could be used at all. I suppose that a plunge into the atmosphere then achieving a trajectory which leads to a direct encounter with a moon could be used for a lander... Or for a long-living orbiter.

[JRehling]

This is something interesting. But knowing the harsh radiation environment of the giant, I don't know whether it could be used at all. I suppose that a plunge into the atmosphere then achieving a trajectory which leads to a direct encounter with a moon could be used for a lander... Or for a long-living orbiter.

Radiation should not be a problem: The harm that radiation does is integrated over time, and a quick pass through Jupiter's radiation belts on a single pass would only accumulate a small fraction of the radiation damage that Galileo encountered. The Galileo Entry Probe passed, obviously, through all of Jupiter's radiation belts once with no harmful effects. An aerocapture craft would simply do so twice. The question would be how much more radiation it had to absorb during the rest of its mission. The first few hours wouldn't be the concern.

The idea of a lander for Io or Europa that utilized aerobraking is quite interesting. Ideally, the craft would leave Jupiter's atmosphere with just enough velocity to kiss the orbit of the target moon. Then a powered descent would have similar delta-v requirements to that for a lander headed towards Earth's Moon. Some combination between powered descent and a penetrator could also be apt. In one ideal design, you could have a craft ride ballistically all the way from launch to penetration into the surface of Europa -- I wonder if the specs would work out on that?

Note that the minimum-energy departure from Jupiter would mean a slower pass through the radiation belts, and then the accumulated radiation exposure could be significant. A trajectory to "kiss" Europa's orbit would take a significant amount of radiation on the way out, versus a lot less on the speedy path in. Europa might even be, unluckily, at about the worst-case-scenario distance for radiation exposure on the post-aerobraking trajectory.

You'd definitely hope to get two-for-one value out of the radiation and entry shields. I don't know about the engineering constraints there, but if you could have a heavy metal providing heat shielding as well as protection against charged particles, that would leave a lot more mass for payload.