International Space Exploration Coordination Group Assessment of Technology Gaps for LOx/Methane Propulsion Systems for the Global Exploration Roadmap

Abstract

As part of the Global Exploration Roadmap (GER), the International Space ExplorationCoordination Group (ISECG) formed two technology gap assessment teams to evaluate topic discipline areas that had not been worked at an international level to date. The participating agencies were ASI, CNES, DLR, ESA, JAXA, and NASA. Accordingly, the ISECG Technology Working Group (TWG) recommended two discipline areas based on Critical Technology Needs reflected within the GER Technology Development Map (GTDM): Dust Mitigation and LOX/Methane Propulsion. LOx/Methane propulsion systems are enabling for future human missions Mars by significantly reducing the landed mass of the Mars ascent stage through the use of in-situ propellant production, for improving common fluids for life support, power and propulsion thus allowing for diverse redundancy, for eliminating the corrosive and toxic propellants thereby improving surface operations and reusability, and for increasing the performance of propulsion systems. The goals and objectives of the international team are to determine the gaps in technology that must be closed for LOx/Methane to be used in human exploration missions in cis-lunar, lunar, and Mars mission applications. An emphasis is placed on near term lunar lander applications with extensibility to Mars. Each agency provided a status of the substantial amount of Lox/Methane propulsion system development to date and their inputs on the gaps in the technology that are remaining. The gaps, which are now opportunities for collaboration, are then discussed.

Fill-In and Boiling Transition Characteristics during the Liquid Oxygen Chill-Down Process in a Vertical Exit-Contracted Pipe

“…Liquid oxygen (LO 2 ) and liquid methane (LCH 4 ) are characterized by low-cost, nontoxic, high performance compared to hypergolic propellants, and both of them could be produced on Mars [1,2]. In this way, a number of projects have been put forward to support future exploration missions using this cryogenic propellant combination [3].…”

Pipeline fault simulation and control of a liquid rocket engine

“…With the increasing demand for cryogenic, nontoxic, and low-carbon propellants, LOX/LCH4 propellants become preferable for a biopropellant propulsion system due to their favorable characteristics for long life and reusability. 1,2 Liquid methane presents several opportunities for launchers, such as less-constrained design thanks to the soft-cryo temperature, easier safety conditions for reusable trajectories, and better operability. 3 The electric pump gained more attention in recent years with the development of batteries and electric motors, 4,5 especially after the launch of the Electron rocket with the Rutherford engine pressurized by an electric pump.…”

“…With the increasing demand for cryogenic, nontoxic, and low-carbon propellants, LOX/LCH4 propellants become preferable for a biopropellant propulsion system due to their favorable characteristics for long life and reusability. 1,2 Liquid methane presents several opportunities for launchers, such as less-constrained design thanks to the soft-cryo temperature, easier safety conditions for reusable trajectories, and better operability. 3…”

Characteristics of Flow Development and Boiling Transitions in the Liquid Oxygen Chill-Down Process in a Straight Horizontal Exit-Contracted Pipe

“…Cryogenic nontoxic liquid rocket engine is a hot spot in aerospace power development, such as liquid oxygen/kerosene and liquid oxygen/methane engine [1,2]. A cryogenic propellant has the characteristics of a low boiling point and low latent heat of evaporation, so it is easy to boil into a two-phase flow, resulting in an uncontrollable flow process.…”