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.
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.
MIR greatly increases mission reliability. 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.
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.
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: