Won't they get pelted by microastroids, molecularly pulped with ionizing radiation, cooked by various sources of heat? Popsicles usually don't last very long outside a freezer
If you send them away from the sun or otherwise shield them (dark side of a planet, out past Pluto) they’ll be pretty cold and stable. You’d leave them in the rocket of course.
The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins (−270 °C; −455 °F). Probably too cold.
Once we can successfully Futurama the bodies we will easily be able to retrieve the frozen capsules.