The successful activation – which will be followed by a year-long tech demonstration to see if the clock performs as expected; i.e. how well the clock keeps time down to the nanosecond – was confirmed by the mission team on Friday 23 August.
Developed at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, it is the first clock allegedly stable enough to map a spacecraft’s trajectory in deep space while still small enough to fly onboard said spacecraft.
A more stable clock will be able to operate father from Earth, NASA explained, where it need to be able to work for longer periods than satellites closer to home. The agency hailed it as a “critical step” in enabling “spacecraft to safely navigate themselves in deep space rather than rely on the time-consuming process of receiving directions from Earth”.
Atomic clocks, like those used in GPS satellites, can be used to measure the distance between two objects by timing how long it takes a signal to travel from point A to point B.
For space exploration, such clocks have to be extremely precise, as even a one second error could be mean the different between landing on a planet like Mars and missing it by several miles. This new atomic clock allegedly 50 times more stable than those on GPS satellites.
In controlled tests conducted on Earth, NASA said it lost one second per ten million years – now engineers will be able to test that accuracy in space, where the clock would be most useful, replacing the larger Earth-bound clocks currently used by navigators to pinpoint a spacecraft’s location.
It can take minutes to hours from a signal to be sent from Earth to the spacecraft before returning to Earth, where it can be used to create instructions that are then sent back to the spacecraft. An onboard clock would allow it to calculate its own trajectory, instead of waiting for navigators back on Earth, allowing missions to travel farther and – eventually – safely take humans to other planets.
“The goal of the space experiment is to put the Deep Space Atomic Clock in the context of an operating spacecraft – complete with the things that affect the stability and accuracy of a clock – and see if it performs at the level we think it will: with orders of magnitude more stability than existing space clocks,” Todd Ely, navigator and principal investigator of the project at the JPL, said in a statement.
The clock is hosted on a spacecraft provided by General Atomics Electromagnetic Systems of Englewood, Colorado, and sponsored by the Technology Demonstration Missions and Space Communications and Navigations programs. The JPL manages the project.