In-Situ Resource Utilization
Martian exploration and settlement at any meaningful scale will depend on materials found on Mars. This is enabled by a technology known as in-situ resource utilization (ISRU). ISRU circumvents the limits of the rocket equation — that every 10 pounds of rocket need 90 pounds of propellant. Without ISRU, the cost of importing materials from Earth renders the project impossible.
Second, habitats should be completed with life-support systems in place before humans arrive. NASA plans to send machines in advance to harvest the Martian landscape, extracting materials for robotic printers to build our first homes on Mars in anticipation of our arrival.
MARSHA marks a radical departure from previous Martian designs typified by low-lying domes or buried structures. Where structures on earth are designed primarily for gravity and wind, special conditions on Mars point to a structure optimized to handle internal atmospheric pressure and structural stresses: a vertical container with a minimal footprint. MARSHA’s vertical orientation and small footprint also alleviate the need for a construction rover moving on the unfamiliar ground.
Instead, MARSHA is constructed with a vertically telescoping arm attached to a stationary rover throughout the 3D printing process. These innovations challenge the conventional image of “space age” domes by focusing on the creation of vertically oriented, human-centric habitats tuned to the demands of a Mars mission.
After NASA landed astronauts on the Moon, most people assumed we would be well on our way to Mars. Concept art depicting visions of vast orbital and Martian settlements, often depicted as suburban utopias, were everywhere. This never panned out as depicted, of course, but with an uncertain future for the aging International Space Station (ISS) and with the powerful surge of private sector Space companies, we are as a species once again on the precipice of a future that includes a sustained human presence on Mars. This time, the project is happening.
This incredible challenge can be divided into three:
- getting to Mars
- living on Mars
- returning to Earth
In the current paradigm of Space missions, the possible is entirely governed by something known as the rocket equation which relates energy expenditure against gravity, energy available in your fuel and how much propellant you need compared to the total rocket mass. As NASA astronaut and engineer Don Petit says, “The rocket equation contains three variables. Given any two of these, the third becomes cast in stone”. Having already reached the limits of chemical energy, getting into Space requires a rocket with on the order of 90% fuel by mass (compared with the average family sedan which is 3% fuel by mass). This ratio has made robustness, risk reduction, and lightness all keystones of aerospace engineering. As Petit sums up, “When making a rocket that is near 90% propellant (which means it is only 10% rocket), small gains through engineering are literally worth more than their equivalent weight in gold”. This is the reason we have space capsules, rather than spaceships.
The tyranny of the rocket equation, however, will soon be relaxed by the advent of a family of technologies that enable ISRU – in-situ resource utilization. ISRU is just a technical term for “living off of the land” and is the benchmark that separates a simple outpost or camp from a settlement or village. Rather than depending on a distant motherland for material goods, one creates artifacts by processing local material resources. Crossing this developmental threshold is a prerequisite for self-sufficiency. Because the rocket equation governs the economics of launching and landing goods, the heavier and larger the artifact, the stronger the forcing function for its local manufacture and the spaces we live out our lives in are, of course, the largest, most complex and heaviest.
In this context, NASA has created the 3D-Printed Habitat Challenge. This visionary challenge, now in its third phase hosted by Bradley University, is intended to advance the state of the art in autonomous 3D-printing construction methods, materials technology and architectural design for humans. It pushes design and engineering teams to develop beautiful habitats that can be constructed in-situ before the arrival of humans.
thumbnail courtesy of aispacefactory.com