In 2014 MSNW LLC of Redmond Washington suggested that a magnetic field around ionized gas could be used to slow a spacecraft down sufficiently to eliminate the need for a thermal protection system, or as it’s more commonly known, a heat shield.
While the focus of MSNW’s proposal was on missions to Mars and Neptune, the system could also be used for any spacecraft entering any atmosphere.
MSNW applied for and received a Phase I NIAC award to design a Magnetoshell AeroCapture (MAC,) system for missions to Mars and Neptune.
NIAC is the acronym for the NASA Innovative Advanced Concept program that puts seed money into emerging technologies or ideas which have the potential to be space-exploration “game changers” if proven out. MSNW had such an idea.
Quoting David Kirtley, Principal Investigator on the project for MSNW:
“The Magnetoshell deploys a simple dipole magnetic field containing a magnetized plasma. It is interaction of the atmosphere with this magnetized plasma that supplies a significant impediment to atmospheric flow past the spacecraft, and thereby producing the desired drag for braking.”
The “interaction of the atmosphere” to which Dr. Kirtley refers is the attraction of neutral charges in the atmosphere to the ionized gas in the magnetic field. The field will swell as shown in the picture above, stripping away the
The science part of the proposal was not cutting edge but the application certainly was. To prove the application was viable MSNW built a small magnetoshell.
Quoting from MSNW’s Phase I report:
“Finally, a stationary 1.6 meter argon Magnetoshell was fully demonstrated and a 1000:1 increase in aerodynamic drag was found. This experimental program definitively demonstrated a subscale Magnetoshell by eliminating electromagnetic interference, utilizing a dielectric torsional thrust stand, and placing all key electrical components under vacuum in the plasma environment.”
MSNW had proven on a small scale that the magnetoshell worked.
The Phase I study concluded that:
“ . . . a 200 kg, 2 m magnet could generate a 9 m radius Magnetoshell for Neptune aerocapture with a 21 km/s injection at a peak force of 150 N entirely removing the need for a TPS (Thermal Protection System”.
That is a big MAC.
MSNW estimates that a 60 metric ton payload could be landed on Mars using a 2.5 m magnet to generate a MAC with a radius of 21 meters, again without the need for a thermal protection system.
Making MACs work impacts space exploration in several ways. The most important impact is of course on the money needed for a mission. Eliminating the need for the traditional thermal protection system would save $2.0 billion in the complicated process of Design Reference Architecture (DRA) for a manned mission to Mars. DRA is the term used to describe the planning process for minutest details of a mission including the sequence of events which occur during a mission..
Magnetoshell aero braking would also allow for easier entry into orbit around exploration targets.
This week NIAC awarded MSNW Phase II money which will be used to determine how to create a magnetoshell which can insert a spacecraft into orbit. MSNW will attempt to land a cube sat from low Earth orbit using this system.