Phoenix Will Try New “Sprinkle” Technique

Phoenix “vibrates” to move soil through a screen.

New motto for the Phoenix spacecraft: If at first you don’t succeed, then dust yourself off and try again. Since the Martian soil is proving to be a challenge for the Mars lander, engineers will try a new technique to try delivering the frozen arctic soil into the TEGA, or the Thermal and Evolved-Gas Anaylzer, designed to bake and sniff samples to identify key ingredients in the soil. The soil is clumping together, and won’t pass through a screen that brings it to the ovens on board the spacecraft. Engineers operating the Robotic Arm on Phoenix Lander are testing a revised method they are calling the sprinkle technique.

“We’re a little surprised at how much this material is clumping together when we dig into it,” said Doug Ming a Phoenix science team member from NASA’s Johnson Space Center, Houston.

Engineers commanded the spacecraft to vibrate the screen for 20 minutes on Sunday but detected only a few particles getting through the screen, not enough to fill the tiny oven below.

“We are going to try vibrating it one more time, and if that doesn’t work, it is likely we will use our new, revised delivery method on another thermal analyzer cell,” said William Boynton of the University of Arizona, lead scientist for the instrument.

The arm delivered the first sample to TEGA on Friday by turning the scoop over to release its contents. The revised delivery method, which Phoenix is testing for the first time today, will hold the scoop at an angle above the delivery target and sprinkle out a small amount of the sample by vibrating the scoop. The vibration comes from running a motorized rasp on the bottom of the scoop.

Phoenix used the arm Sunday to collect a soil sample for the spacecraft’s Optical Microscope, so look for images of that procedure soon. Today’s plans include a practice of the sprinkle technique, using a small amount of soil from the sample collected Sunday. If that goes well, the Phoenix team assembled at the University of Arizona plans to sprinkle material from the same scoopful onto the microscope later this week.

The Phoenix team also discussed this picture, showing a spring on the ground near a footpad of the spacecraft. It came from Phoenix itself, when the biobarrier was opened to free the robotic arm back on May 30, the sixth Martian day of the mission.

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