Cryogenic propellant management in space: open challenges and perspectives.

Area of Science:

• Aerospace Engineering
• Cryogenic Fluid Management
• Deep Space Exploration

Background:

• Crewed deep space missions require long-term propellant storage and on-orbit refueling capabilities.
• Liquid hydrogen, liquid methane, and liquid oxygen are key propellants, necessitating cryogenic conditions (below 120 K).
• Current technologies face challenges in sustaining cryogenic propellants for extended mission durations.

Purpose of the Study:

• To outline open challenges and perspectives in propellant management for crewed deep space exploration.
• To review existing reference missions, architectures, and technology demonstrators for cryogenic fluid management.
• To identify critical knowledge gaps in cryogenic storage and transfer operations.

Main Methods:

• Review of scientific literature and technical reports on propellant management.
• Analysis of reference missions and architectures for deep space exploration.
• Evaluation of technology demonstrators for cryogenic storage and transfer.
• Synthesis of findings based on ESA's SciSpacE strategy white paper.

Main Results:

• Identified liquid hydrogen, liquid methane, and liquid oxygen as primary propellants requiring cryogenic management.
• Highlighted the necessity of on-orbit cryogenic depots for mission extension.
• Summarized the state-of-the-art in cryogenic storage and transfer, revealing numerous unresolved physical knowledge gaps.

Conclusions:

• Significant advancements in understanding and managing cryogenic propellants are required for successful crewed deep space missions.
• Further research is essential to fill identified gaps in physical knowledge for reliable cryogenic storage and transfer.
• Addressing these challenges is critical for enabling extended duration space exploration and on-orbit servicing.