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Wilson, J. J.

Publications and source records attributed to Wilson, J. J..

3 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

The Phoenix Mars Lander Robotic Arm

The Phoenix Mars Lander Robotic Arm (RA) has operated for over 150 sols since the Lander touched down on the north polar region of Mars on May 25, 2008. During its mission it has dug numerous trenches in the Martian regolith, acquired samples of Martian dry and icy soil, and delivered them to the Thermal Evolved Gas Analyzer (TEGA) and the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The RA inserted the Thermal and Electrical Conductivity Probe (TECP) into the Martian regolith and positioned it at various heights above the surface for relative humidity measurements. The RA was used to point the Robotic Arm Camera to take images of the surface, trenches, samples within the scoop, and other objects of scientific interest within its workspace. Data from the RA sensors during trenching, scraping, and trench cave-in experiments have been used to infer mechanical properties of the Martian soil. This paper describes the design and operations of the RA as a critical component of the Phoenix Mars Lander necessary to achieve the scientific goals of the mission.

Bonitz, Robert↗
NASA NTRS1972

OMEGA timing receiver, design and system test

The design of a two frequency OMEGA Timing Receiver is discussed. The receiver tracks the arrival time of the signals by precise phase matching at the receiving antenna. Provision is made for inserting a propagation delay correction for each signal path. Time is measured as the difference between the zero crossing coincidence of the corrected signals and the local time. This number is displayed on the front panel in microseconds. The receiver can also function as a precise phase tracking receiver for collection of propagation data essential to augmenting the propagation corrections. All phase and time information is made available in a BCD format for flexibility in interfacing with other equipment. Results of preliminary tests using experimental transmissions are given. Preliminary results indicate time may be transferred by this technique to an accuracy of a few microseconds.

Wilson, J. J.↗