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we're setting up for testing an rs.25

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engine which is similar to the previous

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space shuttle main engine that was used

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in the space shuttle program and so

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we're going to be testing this engine to

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cover the new areas for how this engine

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would operate under this new system

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called SLS the overall test objective

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for engine zero five to five as it's

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currently on the stand is to take it

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from the the original ssme test profile

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up to the profile that's intended to be

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used on the SLS vehicle and so in order

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to do that instead of making that change

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all at once which increase the overall

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risk level of the testing we are

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gradually stepping through the changes

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to the start profile as well as the main

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steady state testing profile so some of

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the two main changes from a hardware

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perspective on the engine are the

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controller and then some of the nozzle

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insulation so the old controller was out

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of date and you can't even make it

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anymore plus it wouldn't talk well with

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the other SLS computers so we developed

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a new controller that can actually

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control the engines that it stays on

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thrust and mixture ratio one of our

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other key performance parameters is one

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of the main things we're doing in the

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test program when you are running a hot

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fire test on an engine there's more that

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goes into it that might meet the eye at

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first glance it's not only the engine

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and the engine control software that has

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to be ready for test there's facility

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software and data recording systems and

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all of the control systems have to

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properly talk to each other which means

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they have to be speaking each other's

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language at the same time and that's

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usually a difficult endeavor intakes

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takes a few tries to get right usually

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doesn't happen on the first try so we

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spent some months and some weeks putting

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some significant effort in and making

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sure that that all ran seamlessly as it

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did on test 1008 for the artist

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the first hot fire test followed the

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ssme test profile exactly so that we

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could establish that we could still run

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the engine in the same way that we did

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under the shuttle program the second

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test program begins stepping us into the

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rs.25 program objectives to be able to