Date of Award
2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Mechanical and Aerospace Engineering
Committee Chair
Jason T. Cassibry
Committee Member
Robert Frederick
Committee Member
Matthew Turner
Committee Member
Gabriel Xu
Research Advisor
L. Dale Thomas
Subject(s)
Nuclear propulsion, Outer planets, Systems engineering--Mathematical models, Space flight to Jupiter
Abstract
Nuclear Thermal Propulsion (NTP) provides the compelling alternative between the chemical and electric propulsion systems for outer planet robotic missions. High-thrust and high-specific impulse (over twice the best chemical propulsion engine) NTP systems can enable outer planet missions that have been limited due to the large ΔV requirements. This dissertation identifies an enabling mission architecture and NTP engine thrust class for rendezvous missions to the Gas giant and Ice giant systems. The work presented in the dissertation demonstrates the performance impact of the NTP system and its feasibility for robotic missions using a systems engineering model driven by the model based systems engineering (MBSE) which is coupled with the domain engineering analysis models and systems engineering architectural models. The performance metrics are chosen based on the finite maneuver analysis and design reference mission trade tree to determine the solution space of NTP for high energy missions. The developed spacecraft integrated system model allows rapid mission analysis for engine thrust class ranging from 5 klbf to 30 klbf and Isp from 850 s to 900 s for expendable and non-expendable architectures. The direct spacecraft injection analysis showed payload delivery of over 12% to Jupiter and over 30% to Saturn for NTP system on a commercial heavy lift launch vehicle when compared with standalone super heavy-lift launch vehicles. The point design studies demonstrated the enhanced capability of NTP system by reducing the trip times to Gas giant missions by a factor of two or more. Engine trade analysis shows 12.5 to 15 klbf NTP engines are optimum for rendezvous missions to the outer planets using expendable configuration, which consists of a spacecraft and NTP injection stage with injection stage being used for trans-planetary injection and plane change maneuver only and spacecraft’s storable propellant to be used for planetary orbit insertion. Payload mass delivery using an expendable configuration for a Jupiter rendezvous mission is shown to outperform non-expendable configuration (NTP system to be used for both trans-planetary injection and planetary orbit insertion) by 5.67% for Hohmann transfers. However, non-expendable configurations have shown similar payload delivery for high energy Type-I trajectory missions with trip times of 1.49 years.
Recommended Citation
Kumar, Saroj, "Enabling outer planet exploration : performance and feasibility of nuclear thermal propulsion for rendezvous missions" (2024). Dissertations. 397.
https://louis.uah.edu/uah-dissertations/397