A small team in the Mojave Desert built the first privately funded crewed spacecraft to cross the boundary of space using a rocket motor that burned synthetic rubber with nitrous oxide and a reentry system modeled on a badminton shuttlecock. This episode explores Burt Rutan and Paul Allen's Tier One program and the Ansari X Prize, which required a reusable vehicle to reach 100 kilometers twice within two weeks while replacing no more than 10 percent of its non-fuel weight. We look at why Allen spent roughly 25 million dollars chasing a 10 million dollar prize and why suborbital flight at Mach 3 demands about 60 times less energy than reaching orbit.

We break down the White Knight carrier aircraft that air-launched SpaceShipOne from 50,000 feet and doubled as an in-flight simulator, the hybrid engine that could not be throttled or steered on ...