SpaceX's third contracted cargo run was supposed to launch on Monday--a Dragon capsule ferrying 2.5 tons of supplies to the International Space Station. But a helium leak in the first stage of SpaceX's Falcon 9 rocket has delayed that launch until the end of this week. Among the tools, equipment, and food supplies being sent to the ISS are a new batch of experiments to join the over 100 already being conducted at any time on board the station. One notable new experiment is Veggie, NASA's prototype of an expandable plant chamber to grow lettuce seedlings in space. These plants will be grown on "pillows" in the device, which expands to 12x15-inches, the largest plant growth chamber yet sent to space. Astronauts will test the culinary and health potential of the space lettuce, and NASA also expects the experiment to have psychological benefits. Space gardening could be a legitimate pastime for astronauts.