Spring has arrived, which means it's time to plant your space garden. These tomato seeds have flown to the edge of space onboard an Earth to Sky Calculus cosmic ray research balloon. During the flight, they spent more than 3 hours floating through the stratosphere, exposed to temperatures as low as -62 C and cosmic ray fluxes 100x Earth-normal.
 
These seeds make a great DIY science project. Each space-flown packet of seeds comes with an identical control packet, which remained on Earth during the flight. Plant them side by side to discover the difference space travel makes.