The TransAstra Mini Bee concept is a small 250 kg spacecraft that would extract water from C-type asteroids. Credit: TransAstra Corporation.

TransAstra was one of two groups awarded the first ever NASA Innovative Advanced Concepts (NIAC) Phase III grant. TransAstra will use the Phase III funds to advanced its first flight demonstration mission of the Mini Bee asteroid mining concept. The Mini Bee spacecraft will be about 250 kg in size, and will test the optical mining concept in a space environment using a synthetic asteroid launched from Earth. The CI-type asteroid simulant will be made by the Florida-based company Exolith Labs using leftover materials from Deep Space Industries before they shut down. Expected to launch in the early 2020s, this will be the first time water is extracted from material similar to asteroids while in space.

The NIAC program supports groups working on early stage concepts by providing funding. The ultimate goal is to advance the concept's Technology Readiness Level (TRL), which increases confidence in the technology while decreasing risks. TransAstra has already completed Phase I and II studies for the optical mining concept. This selection was the first time a Phase III stage has ever been awarded. It provides $2 million for a two year study.

The Mini Bee concept is the smallest vehicle in TransAstra's proposed fleet, with Honey Bee and Queen Bee being the two larger asteroid mining vehicles. Mini Bee's purpose is to prove that the optical mining system can catch a hydrated asteroid and process water from it while in space.

TransAstra's optical mining technology uses concentrated sunlight to extract water from water rich asteroids. The process involves directing concentrated sunlight onto a specific area of a captured asteroid, where the intense heat causes water pockets near the exposed surface to vaporize and flake material away. This process is called spalling and is more time efficient than simply heating the entire asteroid.

After vaporizing the water trapped within the asteroid, cold traps will condense the water vapor into storage containers. Once finished processing the asteroid, the concentrated sunlight will be used to super-heat collected water in a solar thermal rocket. This complete system would enable the TransAstra spacecraft to capture, extract, store, and transport valuable water around the Solar System.

In addition to testing the optical mining technology, TransAstra may also test the asteroid capture mechanism. This would involve releasing the asteroid simulant into space and then recapturing it. The system will use an inflatable capture system to enclose the target. The asteroid will likely be rotating, so the spacecraft will have to match rotation before capture, secure the asteroid with struts, then slowly despin it. To prevent excess maneuvering, asteroids with very slow rotations are ideal.

Joel Sercel stated at the 2019 ISDC that the complete Mini Bee mission will require around $10 million. The actual launch of Mini Bee is expected to occur in the early 2020s. If TransAstra's Phase I and II reports are to be followed, we eagerly await updates on the Phase III study.