MER mission

View log of the Rock Abrasion Tool (RAT) opperations on Mars.

Mission Overview

By studying the contents of martian rocks, scientists believe they will be able to determine many facts about the climate history of Mars, how life may have begun on Earth, and whether or not some form of life existed or exists on Mars today. NASA has sent two roving robotic geologists to Mars, they are known as Spirit and Opportunity.

Spirit landed in the Gusev Crater on January 3, 2004 (EST) and Opportunity touched down on the Meridiani Planum on January 25, 2004 (EST).

If a geologist were to visit Mars, he would use his eyes for surveying the territory, his brain for navigating, and his legs for traveling to an interesting rock, and then more motor skills to bend down and pick up the rock. He would then use a hammer or chisel to chip away some of the retrieved rock and then, after a short amount of time and minimal effort, he would have gathered a number of facts about the rock he chose; its interior color, its relative hardness and heft, and possibly whether the rock was sedimentary or igneous. In a one hour period the geologist could examine several rocks.

All of these tasks and movements are simple for human geologists but since we cannot yet send humans to Mars, NASA has developed a rover that can accomplish many of these tasks. By equipping the rover with spectrometers and other instruments (known collectively as the Athena (link to Cornell Athena site) Science Payload) the rover will also be able to perform complex scientific tests. That is the aim of the Mars Exploration Rover Mission. The rover has a periscoping camera (used to gather information for rock selection and rover navigation), means for navigating and traveling, the Rock Abrasion Tool (RAT) for exposing fresh Martian rock, and a battery of analytic imagers for determining rock characteristics.

RAT Job Description

The RAT will be capable of exposing a fresh surface on rocks that meet certain requirements such as height, cragginess, and whether they offer a smooth plane suitable for positioning the RAT. Once fresh rock has been exposed by the RAT, analysis by other Athena payload instruments that are mounted on the rover’s arm, known as the Instrument Deployment Device (IDD), will begin. The scientific instruments are the M-ssbauer spectrometer, the Alpha/Particle/X-ray spectrometer, and the Microscopic Imager. The rover arm moves similarly to a human arm and will position the RAT against a rock and hold it there while it operates. A combination of low force and high speed will be used as settings on the RAT to comply with limited power and stability available from the rover.