The vehicle was designed for easy and rapid deployment and retrieval, as well as payload
carrying capability, cross-country speed, and horizontal point-to-point transport efficiency
which is better than existing gliders. Liberdade XRay’s first major ocean test was performed
in August 2006 in Monterey Bay, California, where it reported real-time via an 3.0 to 8.5 kHz
underwater acoustic modem as well as with an Iridium satellite system while on the surface.
The vehicle had an array of 10 kHz bandwidth hydrophones located in the SONAR dome
and across the leading edge of the wing. The XRay exceeded a 10 to 1 glide slope ratio
(D’Spain et al., 2007). Later deployments were in the Philippine Sea, near Hawaii, and in
Monterey Bay using the hydrophone array “to detect low frequency source signals, marine
mammals (blue and humpback whales), and ambient ocean noise” (APL, 2007). The XRay
glider is hoped to achieve 1–3 knot cruise speeds, have a 1200–1500 km range, and be able to
remain on-station up to 6 months in partial buoyant glides.