Purpose

Perform risk reduction research on several of the innovative system components of the Mars Hopper concept to increase the foundation of the concept and prepare for a potential flight experiment effort

Figure 1. Artist's conception of Mars Hopper ( Click on the above picture for an enlarged image )

Figure 2. Hopper Propulsion system includeing engine in thrust cradle
( Click on the above picture for an enlarged image )

Background

Today the concept of surface mobility on Mars is defined by the use of surface rovers. The Mars Pathfinder and MER missions have convincingly demonstrated the value of mobility on a planetary surface. Even though the total distance traveled by the rovers is only kilometers from the landers, the scientific (and public outreach) value of these successful missions is incalculable. However, surface rovers are limited by terrain, and cannot explore much of the most interesting territory on Mars. A hopper vehicle, able to rise above the surface, can traverse “impassible” chasms and hop over “uncrossable” cli

In-situ resource utilization, a technology that has been espoused for two decades as a means to enhance and even enable long-term exploration and sustained human presence, is now receiving high profile attention in NASA’s new exploration vision. One ubiquitous resource on Mars is the carbon dioxide in the atmosphere. One option for utilizing this resource is to use a thermal-electro-catalytic process to dissociate the CO2 and separate it into oxygen and carbon monoxide.

Approach

For the Mars hopper propulsion system, oxygen and carbon monoxide propellants will be produced from the carbon dioxide in the Mars atmosphere. The baseline engine system assumes that the propellants produced as gases will be liquefied and stored as cryogenic liquids. In this system, a small amount of propellants will be tapped into pressurant bottles and allowed to warm up to Mars ambient temperature before each hop, thereby increasing pressure to a preset value. Calculations for various size tanks indicate that approximately 10 percent of the propellant mass will be required to pressurize the tanks.

A small propellant system has been constructed of the appropriate size for a 500 meter hop on Mars to test the pressurization and ignition systems. The objective is to develop a light-weight, close-coupled system that will utilize the precious propellant most efficiently. In addition, it is envisioned that the hopper will perform a semi-soft landing by allowing the engine to naturally “throttle-down” as the propellants are expended. Although considered a high-risk concept, this is an attractive landing method if the operation of the engine is sufficiently reproducible. This will also be tested in this task.

Accomplishments

The self-pressurization system has been successfully demonstrated, and the data is being used to redesign and modify the original concept.

Status of Research

Funding renewed under IR&D to complete propulsion systems tests and perform detailed preliminary design of hopper concept to enable accurate estimates of size, mass, and cost.

Researchers

Diane Linne