The New Horizons spacecraft, built and operated by the Applied Physics Laboratory, is now midway between the orbits of Saturn and Uranus on its way to Pluto. For much of the 10-year voyage, as a means of saving wear on the spacecraft and also saving money, New Horizons will hibernate, with most of its instruments powered down. Approximately once a year, though, APL engineers wake it up and have it run self-diagnostic tests to make sure all of its scientific instruments will operate when it encounters Pluto in 2015. New Horizons was 1.19 billion miles from Earth when, on July 7, APL ground controllers initiated the process of “ACO-3,” the craft’s third annual checkout. Here are simple instructions for making sure your spacecraft is fit and functional:

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