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[Music]

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Phoenix is the first March down it's the

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first mission that's going to try to

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land near the North Pole of Mars and

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it's the first mission that's actually

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going to go try and reach out and touch

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water on the surface of another planet

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where there tends to be water at least

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on earth there tends to be life and so

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it's potentially a place where life

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could have existed on the planet in the

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main purpose of UDL is to take a

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spacecraft that is traveling at 12,500

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miles now and bring it to a screeching

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halt in a soft way in a very short

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amount we enter the Martian atmosphere

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where 70 miles above the surface of Mars

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and our Lander is safely tucked inside

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what we call an arrow show looks kind of

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like an ice-cream cone

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more or less and on the front of it is

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this heat shield this saucer looking

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thing that has about a half inch of

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essentially what's cork on the front of

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it which is our heat shield now this is

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really special cork and this clerk is

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what's going to protect us from the

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violent atmospheric entry that we're

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about to experience friction really

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starts to build up on the spacecraft and

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we use the friction when it is flying

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through the atmosphere to our advantage

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to slow us down from this point we're

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going to decelerate from 12,500 miles an

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hour down to 900 miles an hour the

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outside can get almost as hot as the

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surface of the Sun a temperature the

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heat shield to reach 2,600 degrees

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Fahrenheit but the inside doesn't get

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very hot it probably gets about room

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temperature hits this window of

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opportunity in within which we can

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deploy the parachute we fire the shoot

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to earlie the parachute itself could

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fail fabric in the stitching the cool

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that would be better in the first 15

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seconds after we deploy the parachute

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will decelerate from 900 miles an hour

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to a relatively slow 250 miles now we no

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longer need the heat shield to protect

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us from the force of atmospheric entry

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so we jettison making shield exposing

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for the first time our Lander to the

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atmosphere of Mars after the heat shield

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has been jettison and the legs are

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deployed the next step is to have the

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radar system begin to detect how far

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Phoenix really is from the ground

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we've lost 99% of our entry philosophy

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so we're 99% of the way to where we want

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to be but that last 1% as it always

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seems to be is the tricky part

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now the spacecraft actually has to

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decide when it's going to get rid of its

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parachute we separate from the lander

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going 125 miles an hour at roughly a

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kilometer above the surface of Mars 3200

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feet that's like taking two Empire State

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buildings and stacking them on top of

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one another

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that's when we separate from the

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backshell and we're now in freefall it's

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a very scary moment a lot has to happen

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in a very short amount of time so it's

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in a freefall but it's also trying to

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use all of its actuators to make sure

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that it's in the right position to land

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and then it has to light up its engines

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right itself and then stand then slowly

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slow itself down and touch down on the

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Earth and Mars are so far apart that it

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take over ten minutes for a signal from

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Mars to get to earth and EDL itself is

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all over in a matter of seven minutes so

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by the time we even hear from the lander

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that EDL is started it'll already be oh

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we have to build large amounts of

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autonomy into the spacecraft so that it

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can land itself safely EDL is this

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immense technically challenging problems

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about getting a spacecraft it's hurtling

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through deep space and using all this

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bag of tricks to somehow figure out how

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to get it down to the surface of Mars at

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zero miles now it's just immensely