When the equipment encounters a fault, the maintenance can be completed by observing, analyzing the problem performance and confirming the cause, disassembling and replacing parts. But for NASA engineers, this is often unrealistic. When a spacecraft, satellite or space probe fails, they have to find out the cause of the problem and tell these high-tech precision instruments how to do to return to normal, which is undoubtedly a very difficult process. But fortunately, NASA has accumulated rich experience.
The Voyager 2 probe has been roaming in space for more than 40 years and has begun to present problems with aging. NASA reports that engineers are working to get the probe back to normal and that the current malfunction has caused the ship to lock itself in safe mode.
Voyager 2 failed to perform its intended manoeuvre on Saturday, January 25, when it was scheduled to rotate 360 degrees to calibrate its magnetic instruments, but the operation was delayed for some reason. In this way, it means that two special power consuming systems will run at the same time, and the available power will be exhausted.
Since it is not possible to accurately send 11.5 billion miles (18.5 billion kilometers) of signals to the detector, Voyager 2 is designed to automatically respond to these conditions by entering a low power consumption mode, thereby preventing any permanent damage. Engineers at NASA headquarters can then communicate with the spacecraft to try to solve the problem.
The power supply of Voyager comes from the radioisotope thermoelectric generator (RTG), which transforms the heat from the decay of radioactive materials into electrical energy, and provides power for the spacecraft. Due to the natural decay of the materials inside the RTG, traveller 2's power budget is reduced by about 4 watts per year. Last year, engineers shut down the main heater of the Voyager 2 cosmic ray subsystem instrument to compensate for this loss of power, and the instrument continued to operate.
In addition to managing each traveler's power supply, mission operators must also manage the temperature of certain systems on the spacecraft. For example, if the spacecraft's fuel line freezes and breaks, Voyager will no longer be able to point its antenna to earth to send data and receive commands. The temperature of the spacecraft is maintained by the use of heaters or by the use of excess heat generated by other onboard instruments and systems.
The team spent several days assessing the current situation, largely because of Voyager 2's distance from Earth (about 11.5 billion miles (18.5 billion kilometers)). Communication at the speed of light takes about 17 hours to reach the spacecraft, while the response of the space shuttle takes another 17 hours to return to earth. As a result, mission engineers had to wait about 34 hours to determine if their orders had the desired effect on the spacecraft.
In the February 5 updateNASA says:
This is obviously good news, but it also reminds traveller 2 how incredible the technology is. What we're talking about is a machine that started in the 1970s and is still running today, returning valuable data as it escapes from the solar system and into the unknown.