Residual Propellant Transfer System for Upper Stage Refueling
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Solution Overview
Problem
Current launch systems do not effectively utilize residual propellant from upper stages for refueling payload propulsion systems after orbit insertion, leading to waste and increased launch weights, costs, and safety concerns due to ground handling of cryogenic propellants.
Innovation Solution
A system for transferring residual propellant from an upper stage to a payload propellant storage tank, using multilayer insulation and thermally low-conductive struts to maintain cryogenic propellant temperature and employing high-specific-impulse propulsion systems for efficient use in orbit, thereby reducing the need for ground propellant handling and increasing launch vehicle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If residual propellant is expelled through blow down to safe the stage, then safety of the upper stage is improved, but propellant waste increases and launch weight increases
Solution Approach 1:
The patent recovers residual propellant from the upper stage by transferring it to the payload's propellant storage tank instead of expelling it through blow down. This recovery process eliminates propellant waste while maintaining the safety function of the upper stage, as the residual propellant is utilized rather than discarded.
Solution Approach 2:
The payload's propulsion system serves itself by receiving and utilizing residual propellant from the upper stage. This self-service approach allows the payload to fuel its own propulsion needs using the available residual propellant, eliminating the need for additional propellant loading and reducing launch weight.
2Ease of manufacture
If cryogenic propellants are handled on the ground, then propellant transfer is simplified, but safety risks and costs increase
Solution Approach 1:
The payload's propellant storage tank is prepared in advance with insulation and thermal management systems before launch. This preliminary preparation enables the tank to maintain cryogenic temperatures during spaceflight without requiring complex ground handling procedures, thereby reducing safety risks and costs associated with ground propellant handling.
Solution Approach 2:
The insulated propellant storage tank acts as an intermediary between the upper stage and the payload's propulsion system. This intermediary component enables safe transfer and storage of cryogenic propellants in space by maintaining thermal isolation, eliminating the need for complex ground-based propellant handling infrastructure.
3Adaptability or versatility
If upper stage propellant tanks are made larger to provide sufficient propellant for deep space exploration, then mission capability is improved, but launch vehicle weight increases
Solution Approach 1:
The upper stage's propellant storage system serves multiple functions: it provides propellant for the upper stage's own propulsion mission and simultaneously serves as a source of residual propellant for the payload's propulsion system. This multi-functionality increases mission capability for deep space exploration without requiring additional propellant capacity, thereby avoiding increased launch vehicle weight.
Solution Approach 2:
Instead of discarding residual propellant after the upper stage's primary mission, the system recovers and transfers it to the payload. This recovery process enables the upper stage's propellant to serve dual purposes, increasing mission capability without requiring additional propellant capacity that would increase launch vehicle weight.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient use of residual propellant for payload propulsion and cooling, reducing launch costs, enhancing safety by minimizing ground handling risks, and providing affordable space access for multiple purposes, including covert missions.
Implementation Method 1
using multilayer insulation and thermally low-conductive struts to maintain cryogenic propellant temperature
Data Source
AI summary
A launch system is provided which includes a secondary payload. The secondary payload includes a propellant tank and at least one module that is supported by an adapter ring that is commonly used to secure an upper stage to a primary payload. The propellant tank is launched empty and subsequently filled with residual propellant from the upper stage.