ARCHIMEDES---Direct Laser Penetration of Ice for Ocean Worlds, Martian
Polar Caps, and Terrestrial Ices
Abstract
Over the past three years Stone Aerospace has developed a novel ice
penetrating technology known as a Direct Laser Penetration (DLP). DLP
uses laser light carried by an optical fiber to a vertically descending
ice penetrator and emitted from the nose to melt the ice in front of it
at extremely high power levels and melt rates. A penetrator can be made
with an onboard fiber spool connected to a surface-based laser, allowing
the hole to re-freeze behind, drastically increasing efficiency and
providing isolation from the surface. A parallel spool can pay out a
communications fiber to carry information from imagers, fiber-based
sensors (e.g. temperature, pressure, seismic), and other optical sensors
(e.g. fluorescence or Raman). Laser power levels of up to 100 kW
(continuous) at 1070 nm wavelength are now available and can be coupled
to these probes. Successful laboratory test results at Antarctic ice
temperatures show that this approach could lead to the fastest ice
penetration rate available to terrestrial targets, with access to any
Antarctic sub-glacial lake in under 16 hours. In this way, DLP offers an
alternative to traditional, logistically intense ice drilling: a small
footprint system that is fast and can deploy sensor strings through the
deepest ice in a short period of time. DLP also shows promise in
addressing the ‘starting problem’ for extraterrestrial targets such as
Europa or Mars where low pressures prevent the formation of water at the
surface and thus heat transfer for traditional melt probe architectures.
In order to test the effectiveness of this concept, a Europa environment
‘cryovac’ test facility has been built at Stone Aerospace in Austin,
Texas. We will discuss quantitative results from initial lab and chamber
tests of the DLP concept, including in an ice column at 100 K
temperature subjected to vacuum.