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Mode Identification and Recovery

              <img src="/m/project/remote-agent/images/psbig.png" alt="Cartoon" style="float: left;" height="172" width="200">
              <p>
                A spacecraft consists of many complex devices and systems which are necessary for the 
                spacecraft to function properly.  Often, the more complex a device or system is, the 
                greater the chance that something will go wrong.  Many failures, if not fixed, can cause 
                an entire mission to fail.  It is important that any failure that exists is identified 
                and corrected as quickly as possible; this is the job of the Mode Identification and 
                Recovery (MIR) piece of Remote Agent.
              </p>
              <p>
                MIR acts like a doctor for a spacecraft.  Although a doctor just gives annual check-ups, 
                while MIR is constantly monitoring the health of the spacecraft, there are many 
                similarities between the two.  Just as a doctor knows what a healthy person looks like, 
                MIR knows what a healthy spacecraft looks like.  A doctor examines a patient and then 
                comes up with a diagnosis if something unexpected is seen. If MIR senses something 
                unusual, it will also come up with the most likely diagnosis of the problem.  Once a 
                problem is diagnosed, the doctor will try to treat the problem; for example, by 
                administering medication.  When MIR diagnoses a problem, it will also, upon request from 
                the Smart Executive (EXEC) suggest an action to correct the problem.  Finally, if a 
                patient's problem cannot be fixed, a doctor will notify the patient or their family and 
                might recommend that the person change their future lifestyle.  For example, a doctor 
                may recommend that a heart attack victim stick to a low fat diet.  MIR also reports 
                permanent failures to EXEC, so EXEC and Planner/Scheduler (PS) can alter the plans and 
                strategies for carrying out those plans accordingly.
              </p>
              <h2>Benefits of Remote Agent's Mode Identification and Recovery</h2>
              <p>
                MIR greatly <strong>increases mission reliability</strong>. There is always a possibility 
                that an unexpected problem could occur deep in space during a crucial part of a mission.
                It is also very possible that communicating with earth in order to solve the problem 
                would take too long, resulting in the failure of a costly mission.  MIR is on board the 
                spacecraft and autonomous, in other words, able to work without help from Earth. MIR can 
                fix many problems immediately, without any communication delay, increasing the chance 
                that the problem will be fixed in time to save the mission.
              </p>
              <p>
                MIR is programmed using models of the spacecraft; each spacecraft part, how it should 
                behave, and how it might fail is programmed in separately and the model describes how 
                the parts work together.  This model-based program makes MIR easy to change to adapt to 
                new plans or even to adapt to a completely different spacecraft.  In the long run, this 
                technology will save NASA engineers much time and effort, thereby decreasing costs.
              </p>
              <h2>How MIR Works</h2>

Many of you have heard of Apollo 13 and are aware of the complex, serious problems that the ground controllers were trying to solve in a short amount of time. The future goal is for MIR to be able to do that on its own, with no help from ground control! The technology is not quite that advanced yet, but MIR can still monitor the state of the spacecraft and detect and correct many types of failures. In order to accomplish this task MIR:

  • receives information about the behavior of various components on the spacecraft from sensors strategically placed throughout the spacecraft.
  • compares the sensor data with its model of what the components should be doing given the spacecraft's current activities.
  • sends confirmation to EXEC that everything is going as planned if sensor data matches the model describing what should be happening.
  • diagnoses the most likely cause of any inconsistencies between the sensor data and the model's description, and reports the failure to EXEC.
  • sends a recovery action to EXEC to correct the failure.
More details about MIR in action

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