Combined Decadal Survey goals
In an earlier post we suggested mission designs that incorporate orbital missions about 2 or more planets in order to combine both budgetary limits with Decadal survey desires.This idea was inspired by the Okutso Cassini end of mission paper that demonstrates that Titan flybys can send Saturn orbiting spacecraft to Jupiter and Uranus
Such a mission that combines multiple decadal survey requirements would have to be a flagship mission in costs.Here we propose yet another alternative inspired by the suggestion from NASA HQ that the next flagship to the outer planets could be two spacecraft.We propose that 1 spacecraft be an orbital mission around Uranus and the other would be a flyby of Neptune followed by a Centaur and interstellar probe.
The Neptune flyby mission would require an RTG powered SEP stage! and that requirement involves a very generous supply of RTG radionuclides and the SLS launch vehicle and an ULA ACES stage.After RSEP shut down the power of the RTG’s should keep the spacecraft alive for decades as suggested here 6-UranusTrajStudy_Hughes_et_al (1) for the interstellar follow on mission that is described here,McNutt et al Acta Astronaut. 68 (2011) 790-8011
Both spacecraft would carry atmosphere probes for Jupiter(flyby) and the target planet for a total of 4 probes The RSEP for the Uranus orbiter mission could make up in maneuverability for the small flyby mass of the moons of Uranus.
Drew Lepage writes about the next windows for flights to Uranus and Neptune here; http://www.thespacereview.com/article/2787/1
I am unable to see any practical way to enable Okutsu’s dual planetary missions that would involve Uranus and Neptune without SEP stage.
Who really invented multiple planet gravity assist?