Well, this Physicist (KMB here) breathes a sigh of relief! Buzz can give up one watch, and I will cheer (YaY!) this test forward for accuracy.
Why couldn’t they say this before? Well, maybe NASA didn’t want the Russians to know. It is an Air Force package, only their Interplanetary Navigator Seubert. Good on you, Seubert for keeping it real!
BY MARIA TEMMING 7:00AM, JUNE 21, 2019
“Traveling the solar system could one day be as easy as taking a bus to work….”
(KMB: which, btw, taking a bus isn’t that “easy” unless you work for Microsoft or Amazon. The Japanese hit TV show “I will NOT work Overtime,” based on a young professional woman trying to get home from work on time for “Happy Hour” at her favorite local bar.)
(KMB: wait – What scientists? So, this is how Engineers deflect responsibility!)
“…Scientists envision self-driving spaceships ferrying astronauts through deep space, and GPS-like systems guiding visitors across the terrains of other planets and moons. But for those futuristic navigation schemes, spacecraft and satellites would need to be equipped with clocks that keep time with extreme precision — more precise than any timepiece ever sent to space.
“A prototype of that clock is scheduled to launch on June 24 for a test flight.
“NASA’s Deep Space Atomic Clock, or DSAC for short, counts off the seconds with ticks that are about 50 times more uniform than those of atomic clocks onboard GPS satellites. That’s on par with the ground-based atomic clocks used for the agency’s Deep Space Network — the cadre of earthbound facilities that use radio antennas to communicate with missions throughout the solar system. But unlike those refrigerator-sized timepieces, the toaster-sized DSAC is small enough to carry aboard a spacecraft.
Outfitted on future spaceships or satellites, this mini atomic clock could “completely change the way we navigate spacecraft through deep space,” Jill Seubert, deputy principal investigator for the project, said June 10 in a news conference.
After the prototype launches from NASA’s Kennedy Space Center at Cape Canaveral, Fla., researchers will monitor its performance in low-Earth orbit for one year. Here’s a preview of what the clock could mean for future spacefaring.
How would the clock change space navigation?
“Every single spacecraft (that NASA flies; not so the PRC-China) exploring deep space today relies on navigation that’s performed back here at Earth,” said Seubert, who’s based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Earth-based antennas send signals to spacecraft, which the spacecraft echo back. By measuring a signal’s round-trip time within a billionth of a second, ground-based atomic clocks in the Deep Space Network help pinpoint the spacecraft’s location.
“With the new Deep Space Atomic Clock, “we can transition to what we call one-way tracking,” Seubert said. A spaceship would use such a clock onboard to measure the time it takes for a tracking signal to arrive from Earth, without having to send that signal back for measurement with ground-based atomic clocks. That would allow a spacecraft to judge its own trajectory.
“But that’s not all that makes the Deep Space Atomic Clock special. This clock doesn’t just use mercury atoms, it also uses charged mercury ions.
“Because ions are atoms that have electric charge, they can be contained in an electromagnetic “trap.” This keeps the atoms from interacting with the walls of a vacuum chamber, a common problem with the neutral atoms used in regular atomic clocks. When they interact with the vacuum walls, environmental changes such as temperature can cause changes in the atoms themselves, and lead to frequency errors.
“The Deep Space Atomic Clock won’t be subject to such environmental changes, according to NASA, and so will be 50 times more stable than the clocks used on GPS satellites. After the clock launches Monday, scientists will be able to begin testing the clock’s precision as it spends days, then months in orbit.”
(KMB: NOT IN DEEP SPACE)
So, Local Time is what NASA is going for in the prototype, to be used as a standard timepiece in Planetary and Lunar GPS-like systems. 🙂