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C. Newman

Publications and source records attributed to C. Newman.

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Results from InSight Robotic Arm Activities

The InSight lander carried an Instrument Deployment System (IDS) that included an Instrument Deployment Arm (IDA), scoop, five finger “claw” grapple, forearm-mounted Instrument Deployment Camera (IDC) requiring arm motion to image a target, and landermounted Instrument Context Camera (ICC), designed to image the workspace, and to place the instruments onto the surface. As originally proposed, the IDS included a previously built arm and flight spare black and white cameras and had no science objectives or requirements, or expectation to be used after instrument deployment (90 sols). During project development the detectors were upgraded to color, and it was recognized that the arm could be used to carry out a wide variety of activities that would enable both geology and physical properties investigations. During surface operations for two martian years, the IDA was used during major campaigns to image the surface around the lander, to deploy the instruments, to assist the mole in penetrating beneath the surface, to bury a portion of the seismometer tether, to clean dust from the solar arrays to increase power, and to conduct a surface geology investigation including soil mechanics and physical properties experiments. No other surface mission has engaged in such a sustained and varied campaign of arm and scoop activities directed at such a diverse suite of objectives. Images close to the surface and continuous meteorology measurements provided important constraints on the threshold friction wind speed needed to initiate aeolian saltation and surface creep. The IDA was used extensively for almost 22 months to assist the mole in penetrating into the subsurface. Soil was scraped into piles and dumped onto the seismometer tether six times in an attempt to bury the tether and ∼ 30% was entrained in the wind and dispersed downwind 1-2 m, darkening the surface. Seven solar array cleaning experiments were conducted by dumping scoops of soil from 35 cm above the lander deck during periods of high wind that dispersed the sand onto the panels that kicked dust off of the panels into suspension in the atmosphere, thereby increasing the power by ∼15% during this period. Final IDA activities included an indentation experiment that used the IDA scoop to push on the ground to measure the plastic deformation of the soil that complemented soil mechanics measurements from scoop interactions with the surface, and two experiments in which SEIS measured the tilt from the arm pressing on the ground to derive near surface elastic properties.

Mars↗
NASA NTRS2022

Mars 2020 Perseverance Rover Studies of the Martian Atmosphere Over Jezero From Pressure Measurements

The pressure sensors on Mars rover Perseverance measure the pressure field in the Jezero crater on regular hourly basis starting in sol 15 after landing. The present study extends up to sol 460 encompassing the range of solar longitudes from Ls ∼ 13°–241° (Martian Year (MY) 36). The data show the changing daily pressure cycle, the sol-to-sol seasonal evolution of the mean pressure field driven by the CO2 sublimation and deposition cycle at the poles, the characterization of up to six components of the atmospheric tides and their relationship to dust content in the atmosphere. They also show the presence of wave disturbances with periods 2–5 sols, exploring their baroclinic nature, short period oscillations (mainly at night-time) in the range 8–24 min that we interpret as internal gravity waves, transient pressure drops with duration ∼1–150 s produced by vortices, and rapid turbulent fluctuations. We also analyze the effects on pressure measurements produced by a regional dust storm over Jezero at Ls ∼ 155°.

A. Sánchez-Lavega↗