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Music and sound effects.

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atomic clocks are central to

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deep space navigation it's

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just that those clocks are

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on the ground. And so an

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atomic clock generates a signal

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and it is sent through the

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antennae on the ground to a

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spacecraft in deep space. And

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that signal is turned around

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and received back at the

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transmitting. And with that

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transmission of the signal

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we can do measurements of that

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signal. You know how the

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doppler shift on the signal

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is how we can know how fast

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the spacecraft is moving and

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how long that signal takes

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is a measure of how far that

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spacecraft is. So the deep

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space atomic clock can change

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that paradigm. It can originate

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the signal at the earth

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and it can end at the

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spacecraft. Its good enough, that

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small clock that we are

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building is as stable and

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accurate as the ground clock

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that originated the signal. We

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get to utilize some of the

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efficiencies that the deep space

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tracking network has to

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offer today. The DSN supports

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more downlink than it does

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uplink and so at places

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like Mars where  we have a

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number of spacecraft that are

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competing for two-way tracking

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time... you don't have to

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do that anymore. What does

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that do for us? well what we

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have found with a 2 times

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improvement in our tracking

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data for a Mars orbiter, the

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orbit information that we get

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is improved upon by a factor

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of five. One of the things

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we are envisioning at Mars

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is landing a pin-point lander,

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one that can land to a

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very precise location (beep

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sounds) on the surface of Mars.

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there's a lot of steps into

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making that happen. One of

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which is entering the top

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of the atmosphere and taking

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your entry state knowledge

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and onboard flying a

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trajectory with that entry state

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knowledge. We way in which we

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upload that navigation state

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today is that we do all the

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processing on the ground in about

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six or so hours and before

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entry we upload a final nav state

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to the vehicle. Well you can

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imagine after six hours of flight

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that solutions is little stale

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when you get to the top of the

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atmosphere. Well with DSAC with

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the measurement happening onboard

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you don't have to suffer that six

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hour delay. You can be computing

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onboard in real time. And what

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that does is where the six hour

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solution is in error by a few

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kilometers, this solution that's

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onboard is only off by a handful

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meters. that has a real benefit

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to decreasing the amount of

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propellant you have to carry to then

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later fly out the errors you had

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when you didn't know where you

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were at when you originally were

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at the top of the atmosphere.So

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that's gonna open up new ways,

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new science we are going to be

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able to do. In fact it's going

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to improve the gravity science

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we are going to be able to do

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at Mars today. An example of

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gravity science improvement that

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the clock enables further out is

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NASA is envisioning going to

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Europa; an moon around jupiter. And

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to be able to do the measurement,

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the gravity science measurement

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that NASA is planning. They're

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going to do it, one approach

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is a flyby mission. So they will

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fly by Europa with a four hour

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tracking pass, and then have a

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thirty day orbit around Europa,

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and then come back again for

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another flyby. And do a sequence

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of thirty or so of these flybys.

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Well if we have the atomic clock

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on a downlink signal from that

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flyby and it's received at the

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earth we can do it at Ka band.

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and the benefit of going to Ka

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band isn't so much that it has

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to deal with we can increase the

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bandwidth but what it does do

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is that it improves the accuracy

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of the measurement that we are

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taking, and it improves it by an

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order of magnitude and that is

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fundemental. Its that improvement

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in the data quality that will

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allow us to determine the gravity

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well enough. If decisions need

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to be made in real time, the