A Neptune Orbiter & Tritan Lander enabled by a Cryogenic Neon “battery”

Neptune orbiter and lander augmented by a cryogenic Neon expansion gas battery generator

The battery is powered by ground launch electrical power and replenishment and LH2/LO2 or LCH4 boil off. During cruise to Uranus &/or Neptune ZBO and/or boil off keeps the cryogenic Neon in liquid form. This mission design mostly closely follows the TOP mission proposal 1 (Mustafi). The TOP mission design has an ambitious goal of ZBO for LH2 and LO2 for 81/2 years to Saturn/Titan polar orbit insertion.Its interesting Mustafi does not cite Bennard Kutter or any of the ULA XBO papers.

Many Triton lander studies postulate that there may not be enough power or delta-v for a long-lived lander.

Many Triton lander studies postulate that there may not be enough power or delta-v for a long-lived lander(Campagnola)or any lander at all. Recent studies by the OPAG & Ice Giant Science Definition Team and JPL Ice Giant Study Teams suggest Neptune orbiters with gravity assist Triton flybys (Mark Hofstadter) I disagree with the team over the following remarks; “Dual-planet mission of interest because of its high science value, but not considered for next study due to expected high cost”. This statement would not make sense if NASA HQ has announced that a flagship Ice Giants mission might involve two spacecraft. Another short sightedness by the Ice Giant Science Definition Team and JPL Ice Giant Study Teams is that TOF from Saturn to Uranus for purely ballistic missions using Titan gravity assist is 23 years as shown by Okutsu and The Europeans have suggested a Saturn Probe with flyby to Uranus with the carrier spacecraft. These types of studies or options are lacking in the Hofstadter report. It should be pointed out that the Saturn Atmosphere probe is on the decadal survey priority list for new frontiers missions. Having said that a Saturn Probe with a Uranus flyby or an orbiter are most likely beyond the cost caps of the New frontiers program. This gap needs explaining and brigading.

RTG’s and solar power may be in short supply this far out, Solar arrays inwards of 5 AU or more have made a contribution to ZBO of our LH2 or LCH4 in the SEP/Chemical stage. We have modified the TOPS proposal to extend out to Uranus and Neptune. RTG’s being in short supply could make for a trade with our proposed cryogenic Neon Battery as a last minute power source for what may be a short-lived lander.Decadal survey science goals for the Neptune system are stated here (Marley)

 We propose to study the mass and physics of a cryogenic tank under pressure of Neon and to utilize its gas expansion ratio to power a turbine or sterling engine. The energy potential has been stored since launch by ground power and replenishment and by ZBO and LH2 or LCH4 boil off since launch. The battery depletes itself once the power source is shut off from keeping the pressure and temps down. If the mission design calls for a lightweight short-lived lander the Neon potential energy could be transfer to the lander or trades could have the Neon onboard the lander. How much thrust would a Neon expansion ratio provide to a cold gas thruster after running an electrical power system?  Without the cold gas thruster system how much power can be generated out at Neptune by a fresnal lens and a Neon or noble gas sterling motor system? So many trades! We have attempted to find the citation for the Triton Hopper without success.

Campagnola, Stefano, et al. “Mission design for the exploration of Neptune and Triton.” IEEE Aerospace and Electronic Systems Magazine (2015): 6-17. <http://issfd.org/ISSFD_2014/ISSFD24_Paper_S6-1_campagnola.pdf>.

Mark Hofstadter, Amy Simon, Kim Reh, John Elliott. “Ice Giant Mission Study Status Briefing to OPAG.” LPI,USRA.EDU, 2016. 14 Sept 2016. <http://www.lpi.usra.edu/opag/meetings/aug2016/presentations/day-2/Hofstadter.pdf>.

Marley, M., et al. “Planetary Science Decadal Survey JPL Rapid Mission Architecture Neptune-Triton-KBO Study Final Report.” NASA Mission Concept Study Report.” 2010. <http://www.lpi.usra.edu/icegiants/documents_presentations/App%20G%2024_Neptune-Triton-KBO.pdf>.

Mustafi, S., et al. “Cryogenic propulsion for the Titan Orbiter Polar Surveyor (TOPS) mission.” Cryogenics 74 (2016): 81-87. (2016): 81-87. <http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150018322.pdf>.

1 Mustafi, S., et al. “Cryogenic propulsion for the Titan Orbiter Polar Surveyor (TOPS) mission.” Cryogenics 74 (2016): 81-87.