This illustration shows NASA’s Deep Space Atomic Clock technology demonstration and the General Atomics Orbital Test Bed spacecraft that hosts it. Spacecraft could one day depend on such instruments to navigate deep space. Credit: NASA
Geared toward improving spacecraft navigation, the technology demonstration operated far longer than planned and broke the stability record for atomic clocks in space.
For more than two years,
The Deep Space Atomic Clock is about 10 inches (25 centimeters) on each side, roughly the size of a toaster. Its compact design was a key requirement, and an even smaller iteration will fly aboard NASA’s VERITAS spacecraft. Credit: NASA/JPL-Caltech
Currently, spacecraft rely on ground-based atomic clocks. To measure a spacecraft’s trajectory as it travels beyond the Moon, navigators use these timekeepers to precisely track when those signals are sent and received. Because navigators know that radio signals travel at the speed of light (about 186,000 miles per second, or 300,000 kilometers per second), they can use these time measurements to calculate the spacecraft’s exact distance, speed, and direction of travel.
But the farther a spacecraft is from Earth, the longer it takes to send and receive signals – from several minutes to a few hours – significantly delaying these calculations. With an onboard atomic clock paired with a navigation system, the spacecraft could immediately calculate where it is and where it is going.
The Deep Space Atomic Clock was launched on a SpaceX Falcon Heavy rocket as part of the Department of Defense’s Space Test Program-2 (STP-2) mission from Launch Complex 39A at NASA’s Kennedy Space Center in Florida on Tuesday, June 25, 2019. Credit: NASA/Joel Kowsky
Built by NASA’s Jet Propulsion Laboratory in Southern California, the Deep Space Atomic Clock is an ultra-precise, mercury-ion atomic clock encased in a small box that measures about 10 inches (25 centimeters) on each side – roughly the size of a toaster. Designed to survive the rigors of launch and the cold, high-radiation environment of space without its timekeeping performance degrading, the Deep Space Atomic Clock was a technology demonstration intended to carry out technological firsts and fill critical knowledge gaps.
Watch this video explainer to learn why accurate timekeeping in space is essential and how NASA’s Deep Space Atomic Clock will make future spacecraft less dependent on Earth to navigate autonomously. Credit: NASA/
Three eye-catching posters featuring the Deep Space Atomic Clock and how future versions of the tech demo may be used by spacecraft and astronauts are available for download here. Credit: NASA/JPL-Caltech
In a recent study, the Deep Space Atomic Clock team reported a deviation of less than four nanoseconds after more than 20 days of operation.
Like its predecessor, the Deep Space Atomic Clock-2 will be a tech demo, meaning that VERITAS will not depend on it to fulfill its goals. But this next iteration will be smaller, use less power, and be designed to support a multi-year mission like VERITAS.
“It is a remarkable accomplishment by the team – the technology demonstration has proven to be a robust system in orbit, and we are now looking forward to seeing an improved version go to Venus,” said Trudy Kortes, director of technology demonstrations for NASA’s Science and Technology Mission Directorate (STMD) at NASA Headquarters in Washington. “This is what NASA does – we develop new technologies and enhance existing ones to advance human and robotic spaceflight. The Deep Space Atomic Clock truly has the potential to transform how we explore deep space.”
Jason Mitchell, the director of the Advanced Communications & Navigation Technology Division of NASA’s Space Communications and Navigation (SCaN) at the agency’s headquarters agreed: “The instrument’s performance was truly exceptional and a testament to the capability of the team. Going forward, not only will the Deep Space Atomic Clock enable significant, new operational capabilities for NASA’s human and robotic exploration missions, it may also enable deeper exploration of the fundamental physics of relativity, much like the clocks supporting GPS have done.”
More About the Mission
The Deep Space Atomic Clock is hosted on a spacecraft provided by General Atomics Electromagnetic Systems of Englewood, Colorado. It is sponsored by STMD’s Technology Demonstration Missions program located at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and SCaN within NASA’s Human Exploration and Operations Mission Directorate. JPL manages the project.