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The Next Falcon Heavy Will Carry the Most Powerful Atomic Clock Ever Launched (space.com)
schwit1 shares a report from Space.com: This isn't your average timekeeper. The so-called Deep Space Atomic Clock (DSAC) is far smaller than Earth-bound atomic clocks, far more precise than the handful of other space-bound atomic clocks, and more resilient against the stresses of space travel than any clock ever made. According to a NASA statement, it's expected to lose no more than 2 nanoseconds (2 billionths of a second) over the course of a day. That comes to about 7 millionths of a second over the course of a decade. n an email to Live Science, Andrew Good, a Jet Propulsion Laboratory representative, said the first DSAC will hitch a ride on the second Falcon Heavy launch, scheduled for June.
Every deep-space mission that makes course corrections needs to send signals to ground stations on Earth. Those ground stations rely on atomic clocks to measure just how long those signals took to arrive, which allows them to locate the spacecrafts position down to the meter in the vast vacuum. They then send signals back, telling the craft where they are and where to go next. Thats a cumbersome process, and it means any given ground station can support only one spacecraft at a time. The goal of DSAC, according to a NASA fact sheet, is to allow spacecraft to make precise timing measurements onboard a spacecraft, without waiting for information from Earth. A DSAC-equipped spacecraft, according to NASAs statement, could calculate time without waiting for measurements from Earth -- allowing it to make course adjustments or perform precision science experiments without pausing to turn its antennas earthward and waiting for a reply.
Every deep-space mission that makes course corrections needs to send signals to ground stations on Earth. Those ground stations rely on atomic clocks to measure just how long those signals took to arrive, which allows them to locate the spacecrafts position down to the meter in the vast vacuum. They then send signals back, telling the craft where they are and where to go next. Thats a cumbersome process, and it means any given ground station can support only one spacecraft at a time. The goal of DSAC, according to a NASA fact sheet, is to allow spacecraft to make precise timing measurements onboard a spacecraft, without waiting for information from Earth. A DSAC-equipped spacecraft, according to NASAs statement, could calculate time without waiting for measurements from Earth -- allowing it to make course adjustments or perform precision science experiments without pausing to turn its antennas earthward and waiting for a reply.
You need to think of power like a superhero's power. From the Oxford Dictionaries website the first definition of power is: The ability or capacity to do something or act in a particular way.
Obviously, an atomic clock's power is to measure time accurately using atomic behavior. So this is indeed the most powerful atomic clock launched.
But this is actually relevant (well, almost)!
I don't know the orbital speed of this clock, but if it goes as fast as ISS, it's about 8 km/s.
The time dilation relative to an earth observer will be approximately
t/t' = 1/sqrt(1-v^2/c^2) = 1/sqrt(1-(8/300000)^2) ~ 1.000000000355
That corresponds to 0.355 ns per second, so if the expected drift is ~2 ns/s, they are actually homing in to the relativistic limit for how much two observers can agree on in this setting. I.e. it would be kind of pointless to make it 10x more accurate.
I believe this clock is accurate up to ±2ns per day, not per second. In fact I would be shocked if it were per second.
Plus, this has to be understood as a random walk of time keeping. When a clock "looses" a second, it's not necessarily slower than some other reference. It may be faster.
Now, if relativity states time dilation slows clocks (from the point of view of Earth-based observers), this is something we can agree upon and take into account. This is not clock imprecision of random loss (or gain) of time. It has in fact and must be taken into account for the GPS system to work at all.
See: https://physics.stackexchange....
You don't compensate for it. You want accurate time measurement within the orbiting clock's frame of reference. The value comes from comparing it to other clocks in their respective frames of reference. A translation between frames of reference can be done to take advantage of the accuracy of whatever is considered to be the most accurate clock.
On the subject of accuracy, about that 7 microseconds per decade -- does that assume that all errors accumulate in the same direction? Or might some oscillation errors be in different directions from other errors. (eg, an extra "tick" or a missing "tick".)
Even if all errors accumulate in the same direction, it is probably not enough for slow, inefficient, puny humans to notice. The length of sprints do not need to be adjusted to compensate, and thus no effect on the release schedule.
I'll see your senator, and I'll raise you two judges.