Hod Lipson

The next episode of 3D printing will involve printing entirely new kinds of materials. Eventually we will print complete products - circuits, motors, and batteries already included. At that point, all bets are off.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.

While the agreement provides a level of constraint on Iran's nuclear weapons program, it confers legitimacy on their nuclear threshold status, an unprecedented shift for a country with so many entanglements.