Pluto Hop, Skip, and Jump NIAC Phase II Final Report

New Horizons (NH) was traveling at 14 km/s when it flew past Pluto. If it had been desired to land a payload on the surface using propulsion, it would have needed a three-stage retrorocket. This would have required almost all its mass to be converted to propellant. It could have landed perhaps 1 kg of payload. It is expensive to slow down that much propulsively. A future Pluto lander mission would need a very large propulsion system at Pluto and, as a result, a much larger, more expensive launcher at Earth. Alternatively, a spacecraft could include a nuclear, low-thrust propulsion system to get to Pluto quickly and slow down to make the landing propulsion system practical; however, this would be very expensive and beyond the cost bounds of a NASA New Frontiers mission.
The key challenge of the Pluto Hop, Skip and Jump mission is slowing down from a fast interplanetary approach speed and landing on a planet with very little atmosphere and doing so with a low-cost system. For a short flight to Pluto (11 years) the approach speed is about 14 km/s, about twice as fast as low Earth orbit speed. To make matters worse, the Pluto atmosphere is only about 1/100,000th of Earth surface pressure. So, how can we land given these conditions with a
low-mass, low-cost project? If we meet this challenge, we could do a Pluto lander mission with a similar budget to NASA’s NH Mission. A key solution to meeting this challenge is Enveloping Aerodynamic Decelerator (EAD) technology.
In the initial phase of the Phase II effort, we reestablished the importance of the Pluto mission in relationship to the key New Horizon’s mission findings and the 2013-2022 Decadal Survey themes. In addition, we began to address the three main system challenges, which are the Pluto landing uncertainty using EAD technology; the EAD envelope packing, deployment, and inflation; and the strength of the envelope given the Pluto entry thermal and loads environment.