|
NASA Activates Deep Space Atomic Clock An atomic clock
that could pave the way for autonomous deep space travel was successfully activated
last week and is ready to begin its year-long tech demo, the mission team
confirmed on Friday, Aug. 23, 2019. Launched in June, NASA's Deep Space Atomic Clock is a critical step toward enabling spacecraft
to safely navigate themselves in deep space rather than rely on the
time-consuming process of receiving directions from Earth.
Developed at
NASA's Jet Propulsion Laboratory in Pasadena, California, the clock is the
first timekeeper stable enough to map a spacecraft's trajectory in deep space while
being small enough to fly onboard the spacecraft. A more stable clock can
operate farther from Earth, where it needs to work well for longer periods than
satellites closer to home.
Atomic clocks,
like those used in GPS satellites, are used to measure the distance between
objects by timing how long it takes a signal to travel from Point A to Point B.
For space exploration, atomic clocks must be extremely precise: an error of
even one second means the difference between landing on a planet like Mars or
missing it by hundreds of thousands of miles. Up to 50 times more stable than
the atomic clocks on GPS satellites, the mercury-ion Deep Space Atomic Clock loses one second
every 10 million years, as proven in controlled tests on Earth. Now it will
test that accuracy in space.
Navigators
currently use refrigerator-size atomic clocks on Earth to pinpoint a spacecraft's
location. Minutes to hours can go by as a signal is sent from Earth to the
spacecraft before being returned to Earth, where it is used to create
instructions that are then sent back to the spacecraft. A clock aboard a
spacecraft would allow the spacecraft to calculate its own trajectory, instead
of waiting for navigators on Earth to send that information. This advancement would
free missions to travel farther and, eventually, carry humans safely 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," said navigator Todd Ely, principal investigator
of the project at JPL.
In coming
months, the team will measure how well the clock keeps time down to the
nanosecond. The results begin the countdown to a day when technology can safely
help astronauts navigate themselves to other worlds.
The Deep Space Atomic Clock is hosted on a spacecraft
provided by General Atomics Electromagnetic Systems of Englewood, Colorado. It
is sponsored by the Technology
Demonstration Missions program within NASA's Space Technology Mission
Directorate and the Space
Communications and Navigations program within NASA's Human Exploration and Operations
Mission Directorate. JPL manages the project.
|
