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nothing can be taken for granted when

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you get to mars there's a lot of things

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we just don't know

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space always has a way of throwing us

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curveballs and surprising us

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i mean until we get the data that says

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we're on the ground safely i'm gonna be

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worried that we're not gonna make it

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entry descent and landing is often

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referred to as the seven minutes of

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terror

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because it takes about seven minutes to

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get from the top of the atmosphere of

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mars

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to the ground safely the spacecraft has

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to do all of this

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by itself there are many things that

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have to go right to get

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perseverance onto the ground safely

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there's a lot counting on this this is

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the first leg of our sample return relay

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race there's a lot of work on the line

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starting about 10 minutes before

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atmospheric entry we

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get rid of really the spacecraft part of

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of the rover that's been supporting us

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we come screaming in to the martian

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atmosphere

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at 12 to 13 000 miles per hour

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and the heat shield is what dissipates

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all that initial energy through friction

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the vehicle will continue actually

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flying itself through the atmosphere

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it's sort of like a transforming

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vehicle that went from spacecraft and

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now it's kind of like an aircraft

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actively guiding itself

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when we're going slow enough we deploy a

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the biggest supersonic parachute we've

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ever sent to another planet

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it's critical for slowing down the

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vehicle

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perseverance entry descent and landing

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borrows heavily from that

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of curiosity but fundamentally

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perseverance is a

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different rover she's bigger she has

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different instruments

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we've added a lot of smarts on the

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inside to make it more capable

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so that it can deal with the landing

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site that we've given the science team

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identified jezreel crater as

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basically an ancient lake bed and one of

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the most promising places to look for

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evidence of ancient microbial life and

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to collect samples for future return to

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earth

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the problem is it's a much more

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hazardous place to land

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you look at jezreel all you see is

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danger how do we go to a site

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that we never thought was safe enough to

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go to before so the heat shield which

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has protected us all the way through

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entry is no longer necessary we need to

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get that off so that we can actually see

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the ground

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different ways perseverance will be

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the first mission to use terrain

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relative navigation

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so while it's descending on the

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parachute it will actually be taking

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images of the surface of mars and

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determining

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where to go based on what it sees this

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is finally like landing with your eyes

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open

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having this new technology really allows

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perseverance

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to land in much more challenging terrain

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than curiosity

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or any previous mars mission could

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amongst the rocks and the craters and

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the cliffs

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these things are hazardous to the rover

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but these are the things that are

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interesting to the scientists

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once perseverance has figured out where

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she is we jettison the back shell and

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parachute

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those rockets help us steer to a safe

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landing spot that's nearby

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that descent stage takes us all the way

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down to about 20 meters off the ground

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that's when we start the skycrane

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maneuver

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[Music]

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once the rover has hit the ground the

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descent stage will cut loose from the

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rover and fly away to a safe distance

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surviving that seven minutes is really

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just the beginning for perseverance

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its job right being the first leg of

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sample return to go look for those signs

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of past life on mars all that can't

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start

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until we get perseverant safely to the