The atomic clock in deep space is moving toward increasing the range of spacecraft

Spacecraft venturing out of our moon rely on communicating with ground stations on Earth to know where they are and where they are heading. NASA’s Deep Space Atomic Clock gives these distant explorers greater independence when navigating. In a new article published today in the magazine nature, the mission notes the progress made in its work to improve the ability of atomic clocks in space to continuously measure time over long periods.

known as MoreThis feature also affects the work of the 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 vice versa. They use atomic clocks the size of a refrigerator on Earth to record the times of those signals needed to accurately measure the spacecraft’s position. But for robots on Mars or in distant 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 hours in space.

Operated by NASA’s Jet Propulsion Laboratory in Southern California, the Deep Space Atomic Clock has been operating aboard the General Atomic Orbital Test spacecraft since June 2019. The new study indicates that the mission team has set a new record for long-term stability. A clock in space achieves more than 10 times the stability of atomic clocks found in space, including those on GPS satellites.

When every nanosecond counts

All atomic clocks You have a certain degree of instability that results in a deviation of hourly time compared to actual time. If not corrected, the displacement, no matter how small, increases rapidly, and with astronautics, 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 ever longer periods, to see how it changes over time. In the new paper, 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.

“As a general rule, an uncertainty of a nanosecond in time corresponds to an uncertain distance of about a foot,” said Eric Burt, atomic clock physicist for the mission at JPL and co-author of the new research paper. “Some GPS clocks need to be refreshed several times a day to maintain this level of stability, which means that GPS is highly dependent on contact with the Earth. An atomic clock in deep space pushes it a week or more, so it is likely to offer an application like GPS Global (GPS) most independent.

stability and more time The delay reported in the new document is about five times better than that reported by the team in Spring 2020. This is not an improvement to the clock itself, but rather to a measure of the team clock stability. Longer run times and nearly a full year of additional data improved measurement accuracy.

The Deep Space Atomic Clock mission will end in August, but NASA has announced that work on the technology is ongoing: The Deep Space Atomic Clock-2, an improved version of the latest timing instrument, will fly to VERITAS (short for Venus Emissivity, Radio Science, Insar), topography, spectroscopy) Task to Venus. Like its predecessor, the new Space Clock is a technology show, which means that its goal is to develop capabilities in space by developing tools, hardware, software, or the like that do not currently exist. The ultra-accurate clock signal generated by this technology was created by the Jet Propulsion Laboratory and funded by NASA’s Space Technology Mission Directorate (STMD), which could help enable autonomous operation. space ship Navigation and enhancement of radio scientific observations on future missions.

“NASA’s selection of the Deep Space Atomic Clock-2 over Veritas speaks volumes about the promise of this technology,” said Todd Ely, principal investigator for the Deep Space Atomic Clock and project manager at JPL. “At VERITAS, we aim to test the next generation of space clocks and demonstrate their capabilities in depth space Navigation and science.