Total cost of planned human exploration missions is strongly driven by the need to launch large quantities of rocket propellant, drinking water, oxygen, and radiation shielding. If plentifully-available in cis-lunar space, water could be used directly as propellant in Solar Thermal Rockets (STRs) to provide inexpensive transportation. The lunar surface has been proposed as a source of such water, but independent analysis of Lunar ISRU suggests that it would not be cost effective due to the Size, Weight, Power, and Cost (SWAP-C) of ISRU equipment, the large round trip #V to get to the lunar surface, and the logistical issues of working there. Likewise, a technical publication regardingn asteroid mining by a NIAC-funded team recently concluded that they “could not find any scenario for a realistic commercial economic return from such a mission.”
We understand why past attempts have failed and we offer an innovative new mission concept called Apis. Apis harvests and returns up to 100 tonnes of water from a near Earth asteroid using only a single Falcon 9 v1.1 launch. Apis is based on a major new innovation called “Optical Mining” that we are proposing here for the first time. Optical mining is a novel approach to excavating and processing asteroid materials in which highly concentrated sunlight is used to drill holes, excavate, disrupt, and shape an asteroid while the asteroid is inclosed in a continent bag. Optical mining is enabled by advanced anidolic optics that have thus far not been considered for ISRU applications. Apis further combines the mid-TRL technologies of thin-film inflatable structures and water solar thermal propulsion with an innovative new TRL-1 solar thermal oven technology to extract water from a volatile-rich asteroid.
APIS mission operations start with a Falcon 9 V1.1 or equivalent launch to a low C3 ARM-like but volatile-rich NEO. Once at the target, APIS uses an inflatable capture system similar to that proposed for ARM, but fabricated from high temperature material and designed to fully enclose the target. After the asteroid has been encapsulated and the system de-spun, an inflatable solar concentrator in an advanced non-imaging configuration, provides direct solar-thermal energy through Winston Cones and light tubes to the asteroid surface. This heat is used to excavate the asteroid and force the water to outgas into the enclosing bag at a low pressure of 10^-4 to 10^-5 Atm. The outgassing water is cryopumped at modest temperature into a passively-cooled water storage bag and stored as solid ice. After several months of collection, up to 120MT of water are stored. Using solar thermal propulsion with some of the water as the propellant, the APIS system returns the harvested water to Lunar Distant Retrograde Orbit (LDRO) where it can support a far more affordable program of human exploration of cis-lunar space. The presence of large quantities of water in cis-lunar space cost-effectively supplied from asteroids will profoundly benefit HEOMD missions.
This SBIR Phase-1 project will demonstrate the feasibility of an innovative breakthrough in ISRU methods that we call “Optical Mining”. Optical mining is an approach to simultaneously excavating carbonaceous chondrite asteroid surfaces and driving water and other volatiles out of the excavated material and into an enclosing inflatable bag without the need for complex or impractical robotics. In optical mining, highly concentrated sunlight is delivered to the surface of the asteroid through a mechanically simple but optically sophisticated system of reflective non-imaging optics. The highly concentrated optical energy ablates the surface in a controlled way analogous to how intense lasers can ablate surfaces constantly exposing new material and forcing water out of the ablated material. Optical mining is part of a mission concept that ICS Associates has developed called Apis (Asteroid Provided In-Situ Systems). Apis is a commercially viable approach to the extraction, processing, and delivery of water from asteroids to in-space assets. Mission system studies show that Apis can extract up to 100MT of water from an accessible near Earth asteroid and deliver it to Lunar Distant Retrograde Orbit (LDRO) based on the launch of just one modest sized spacecraft from a single Falcon 9 rocket. The Apis mission concept depends on the completion of the proposed SBIR work. In this Phase-1 SBIR we will develop a facility to simulate and demonstrate key aspects of optical mining to show the mission system feasibility of Apis and provide a breakthrough in ISRU and space transportation for NASA. We will do this by upgrading an existing xenon arc lamp and vacuum system and using the optical energy from the lamp to simulate optical mining on asteroid materials in vacuum. We will perform experiments to validate the process by optically ablating the surfaces of meteorite samples and asteroid simulations under carefully controlled and observed conditions.
The proposed work will support NASA’s plans for human exploration by providing mission consumables and propellant for all missions of the Evolvable Mars Campaign including: human exploration missions to Lunar Distant Retrograde Orbit (LDRO), human exploration missions to near Earth asteroids in their native orbits, exploration of the Moon, and exploration of Mars.
Completion of the proposed work demonstrating the physics and chemistry of optical mining will enable NASA to fly the extremely exciting “Apis” mission. Requiring only a modest-sized spacecraft launched to a low positive C3 compatible with a single Falcon 9 rocket, Apis is capable of providing NASA with propellant and mission consumables in cis-lunar space. The proposed SBIR work will demonstrate a key aspect of the Apis mission, namely the process of “Optical Mining” to excavate asteroid surfaces by ablation, drive water from the ablated materials, collect the evolved water as ice in cold storage bags, and return up to 100MT (metric tonnes) of water to LDRO or other depot location.
Optical mining could also be used to extract the volatile materials from the target of the Asteroid Redirect Mission (ARM) and convert that material to consumables and propellant in cis-lunar space to support human exploration.
The proposed work is designed to create an industrial revolution in space in which propellant and other consumables for commercial processes in space are supplied from near Earth asteroids instead of from the surface of the Earth. Our mission system studies show that such propellant, if minded from highly-accessible Near Earth Objects (NEOs) can be used to supply propellant for reusable solar thermal orbit transfer vehicles that fly on recirculating routes between LEO, GEO, and a propellant depot in LDRO. These reusable solar thermal OTVs, which we call Worker Bees, more than double the effective throw capability of launch vehicles by eliminating the need for high energy upper stages and allowing rockets to launch their payloads to LEO instead of to high-energy transfer orbits. The proposed Phase 1 SBIR will perform a critical proof of concept that enables this vision, creates a commercial market in space for asteroid mining products, and allows the development of commercial OTVs supplied from asteroid ISRU.