I think the suggestion was to send the data after impact. I guess the idea is to basically fire a shock-absorbing crate full of scientific instruments, let the impact destroy the crate, and hope the instruments survive and get to work.

Yup, that was my idea. Or to have NH itself fire off some very tiny instruments that might weight little enough to not go off like an atom bomb when hitting the ground. A GoPro, for example. (I KNOW: NOT AN ACTUAL GOPRO. A small armored camera.) Or a thermometer.

The constraint there, though, might be designing equipment that is both very low mass and also capable of talking back to either Earth or the rest of NH as it zips away.

I fear that won't work. The speed relative to Pluto during closest approach was 13.78 meters every millisecond, I can't imagine that anything larger than a grain of sand will not behave like a liquid upon impact.

Even a grain of sand will go boom. Here's what a particle of similar size did to the space shuttle windshield, traveling at half the speed of New Horizons. https://commons.wikimedia.org/wiki/File:Space_debris_impact_...

How does new horizons survive? Space must be pretty empty.

That's why they call it space!

More seriously, there's a dust counter on the probe whose entire job is to be hit with stuff. But it's much tinier than a sand grain.

wow.

You would put something else in orbit and have high bandwidth communication to it and relay from there.

A few million miles prior to arrival, jettison a 'probe from the probe', control this separately, beginning the negative acceleration of the mini-probe. This mini probe could enter a controlled orbit, and then launch a mini landing probe of even smaller size...etc.

Getting something to slow down enough to orbit is still a huge change in velocity. And even if it did, exactly how much bigger a transmitter could it carry considering it has to be hurled out to Pluto. At least with direct to Earth transmissions we can aim enormous[1] dishes at the signal source.

[1] http://deepspace.jpl.nasa.gov/about/DSNComplexes/70meter/

Putting something else in orbit is the hard part.

The relay doesn't have to be in orbit around Pluto, it could be trailing the impacter and fly by. Deep Impact did something like this with a comet.

Ahhhh you said probe.