Developing technologies that would enable future NASA exploration missions to penetrate deeper into
the subsurface of planetary bodies for sample collection is of great importance. Performing these tasks while using
minimal mass/volume systems and with low energy consumption is another set of requirements imposed on such
technologies. A deep drill, called Auto-Gopher II, is currently being developed as a joint effort between JPL’s NDEAA
laboratory and Honeybee Robotics Corp. The Auto-Gopher II is a wireline rotary-hammer drill that combines formation
breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted auger bit. The hammering
mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed as an adaptable tool
for many drilling and coring applications. The USDC uses an intermediate free-flying mass to transform high frequency
vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The USDC concept was used in a
previous task to develop an Ultrasonic/Sonic Ice Gopher and then integrated into a rotary hammer device to develop the
Auto-Gopher-I. The lessons learned from these developments are being integrated into the development of the Auto-
Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics.
Subsystems of the wireline drill are being developed in parallel at JPL and Honeybee Robotics Ltd. This paper presents
the development efforts of the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.
The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.
The ability to penetrate subsurfaces and perform sample acquisition at depths of meters is critical for
future NASA in-situ exploration missions to bodies in the solar system, including Mars, Europa, and
Enceladus. A corer/sampler was developed with the goal of acquiring pristine samples by reaching
depths on Mars beyond the oxidized and sterilized zone. The developed rotary-hammering coring
drill, called Auto-Gopher, employs a piezoelectric actuated percussive mechanism for breaking
formations and an electric motor rotates the bit to remove the powdered cuttings. This sampler is a
wireline drill that is incorporated with an inchworm mechanism allowing thru cyclic coring and core
removal to reach great depths. The penetration rate is optimized by simultaneously activating the
percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the
Ultrasonic/Sonic Drill/Corer (USDC) mechanism, which is driven by a piezoelectric stack,
demonstrated to require low axial preload. The Auto-Gopher has been produced taking into account
the lessons learned from the development of the Ultrasonic/Sonic Gopher that was designed as a
percussive ice drill and was demonstrated in Antarctica in 2005 to reach about 2 meters deep. A field
demonstration of the Auto-Gopher is currently being planned with the objective of reaching as deep as
3 to 5 meters in tufa formation.