Madrid, 1 (European Press)
The deep space atomic clock that NASA has tested since 2019 has reached record levels of stability and accuracy, an essential advance for travel beyond the moon.
Currently, interplanetary spacecraft rely on communicating with ground stations on Earth to find out where they are and where they are heading.
NASA’s Deep Space Atomic Clock is giving these distant explorers more independence when navigating. In a new research paper published in Nature, the mission reports progress in its work to improve the ability of atomic clocks located in space to consistently measure time over long periods, NASA reports.
This feature known as stability also affects the operation of GPS satellites that help people navigate the Earth, so this work also has the potential to increase the independence of the next generation of GPS spacecraft.
To calculate the trajectory of a distant spacecraft, engineers send signals from the spacecraft to Earth and back. They use atomic clocks the size of a refrigerator on Earth to record the timing of those signals, which is necessary to accurately measure the spacecraft’s position. But for robots on Mars or far-flung destinations, waiting for signals to make the trip can take tens of minutes or even hours.
If those spacecraft carried atomic clocks, they could calculate their position and direction, but the clocks would have to be very stable. GPS satellites carry atomic clocks to help us reach our destinations on Earth, but those clocks require updates several times a day to maintain the necessary level of stability. Deep space missions require more stable space clocks.
10 times more stable
Managed by NASA’s Jet Propulsion Laboratory, the deep space atomic clock has been operating aboard the General Atomics Orbital Test Bed spacecraft since June 2019. The new study indicates that the mission team has set a new record for the long-term stability of the atomic clock in space, reaching up to More than 10 times as stable as current atomic clocks in space, including GPS satellites.
All atomic clocks have a degree of instability that causes the clock to shift from real time. Left uncorrected, the displacement, although small, increases rapidly, and with spacecraft navigation, even a small displacement can have drastic effects.
One of the main goals of the Deep Space Atomic Clock mission was to measure the clock’s stability over increasingly long periods, to see how it changes over time. In the new document, the team reports a level of stability that results in a time deviation of less than four nanoseconds after more than 20 days of operation.