[Steely Tom]

Bit hard to see where they’ll put the fuel on a chip-sized space probe.

Maybe they’re betting on the EmDrive.

[Hot Tabasco]

Just our luck it lands on an inhabited planet and because it’s so small, someone or something unknowingly steps on it......

[Rebel_Ace]

"Very nice, but no mention of a means of propulsion..."
"Bit hard to see where they’ll put the fuel on a chip-sized space probe."

Don't think, "rocket", think "shotgun".

The pellets in a shotgun shell don't have propellant, they are ballistic, given an initial "shove" from the gunpowder explosion behind them.

Objects in space COAST for the most part. So, imagine a rocket with a payload of a hundred of these "miniaturized" space probes. It launches, leaves Earth orbit, then with one big SHOVE, it expels the probes like a dandelion blowing off seeds.

Hit or miss, coasting various gravity wells, to report back 100 years or more later, if they survive.

Now, in reality, they won't be "nano sized", but some of their individual components might be. Imagine if a space probe could be shrunk down to the size of say, a typical flashlight. We have the means now to accelerate a flashlight sized mass to very, very high velocities. If it could take images in a variety of spectrums (IR, VL and UV), and make some magnetic measurements, with the rest of the space devoted to the energy and communication requirements to "phone home", it might be practical.

That's what I think they are shooting for.

[alexander_busek]

Bit hard to see where they’ll put the fuel on a chip-sized space probe.

It wouldn't be fuelled.

Rather, it would be propelled, e.g., by an Earth-based (or space station-based) laser cannon.

Regards,