Hybrid ULA ACES/SEP stage for a Pluto Orbiter & possible ICE-E-P Next stage

Hybrid ULA ACES/SEP stage for a Pluto Orbiter

Hypothetical conops; (1)Utilizing the ULA proposed distributed launch we have a fully fueled ACES on orbit(2)ACES has a cryogenic tank of 3 metric tons of Xenon cooled by the LH2/LO2 propellants for a SEP system.The ACES/SEP hybrid carries an Imaging system for Pluto and is Docked to the Pluto orbiter with its RTG power systems.After orbit insertion, the stack undocks and the ACES stage continues on as long as propellants last with its science payload and the RTG orbiter continues on its Pluto mission.

ULA ACES ICE internal combustion engine as power source for a ACES/SEP hybrid stage  for outer planet missions

This idea might be the most innovative we might have come up with and involves its own set of complex trades.

We think the LH2/LO2 boil-off could power the ICE engine for electrical power that powers the SEP engine and this might reduce the mass of the SEP solar array or eliminate it.The spacecraft RTG still supplements this power source through the docking mechanism and use of boil-off might ironically reduce mass to orbit insertion

LH2/LO2 ACES with a 2 metric ton LXE2 tank

With ICE GH2/GO2 engine to power SEP engines

spacecraft, RTG power supplements SEP powered engines by hibernating power

SEP stage might be a ICE-P stage without solar arrays, this might be possible with distributed launch with a full propellant load on the hybrid ACES/ICE-P stage at planetary transfer from LEO or cislunar.The trades here like above would be enough Xenon & LH2/LO2 to power the NEXT engines and to not have to much mass to orbit insertion.

The goal is to place in ice giant orbit insertion both the ICE-P and spacecraft into science orbits with 150 Kg each and descope from that point.

The secondary goal is to do this at both Uranus and Neptune and to serially produce the ICE-P and ACE/SEP hybrid stage for Mars MRO follow on as well as other missions and it’s this that has a commercial procurement possibility.It’s important for the next decadal study to identify other goals that could be met by serially produced by ACES ICE-P as spacecraft main bus & payload.

Gear ratios for ACES ICE-E-P Cryogenic chemical & Noble 

Model the required GH2/GO2 to power ion engines with the ICE engine for the electrical source.Model this without the mass of solar arrays at outer planets.Model with a reduced mass solar array.Model a cislunar ACES/SEP tug with solar arrays that is a stage for the ACES ICE-E-P that stages past Saturn and the stage returns to cislunar space.