[ Music ] My name is Stephen Merkowitz, I am a scientist at NASA Goddard, and I am the project manager for the space geodesy project. Space geodesy is simply the science of where things are either on Earth or in space, and we use a number of different techniques for determining that, including what's very familiar to most people, GPS, along with Very Long Baseline Interferometry, Satellite Laser Ranging, and also a French system called DORIS. One of the best experiences I've had is to go out to the optical site here at Goddard at night, when they are laser ranging to either the satellites or to the Moon, and as you're looking out at the telescope, you can see a laser coming out and you can see it moving across the sky as it tracks a satellite. And just the knowledge that this laser is going up to some satellite way above us, bouncing off of it and returning light to us, and we're detecting where that satellite is to millimeters is really an incredible experience. Well if you have an altimetry satellite that's trying to measure the height of the different objects on the Earth, it needs to know its height very precisely in order to measure the Earth, so that's information that we feed back to the satellites. In addition, by understanding the precise orbits of the satellite, we can get a measure of where the station is on the Earth, and where the Earth is within space. Space geodesy is one of these projects that is like basic infrastructure. The current network is aging, it's thirty, forty years old, and it's really time to develop a new network, and that's one of the things that our project is striving for. The most exciting part about my job is thinking about a lot of the societal impacts that our work has, that it's not just abstracted, it affects people's everyday lives. [ Music fades ] [ Sound effect]