[noduerme]

Not trying to oversimplify. But suppose 95% of the probe's mass was intended to be jettisoned ahead of it on arrival by an explosive charge, and would then serve as a reflector. That might give enough time for the probe to be captured by the star's gravity...?

[Fargren]

It seems to me that building a recording device that can survive in space, that it's very light, and that can not break apart after receiving the impact from an explosive charge strong enough to decelerate it from the speeds that would take it to Alpha Centauri is... maybe impossible.

We're talking about 0.2 light years. To reach it in 20 years, that's 1/10th of the speed of light. The forces to decelerate that are pretty high.

I did a quick napkin calculation (assuming the device weighs 1kg), that's close to 3000 kiloNewton, if it has 10 seconds to decelerate. The thrust of an F100 jet engine is around 130 kN.

IANan aerounatics engineer, so I could be totally wrong.

[lazide]

You’re just talking about a very inefficient rocket (bad ISP).

A rocket works the same way (accelerating mass to provide thrust), just far more efficiently and in a more controlled fashion.