Daily Operations of Landsat 7

Video Transcript
Download Video
Right-click and save to download

Detailed Description

What it takes each day to keep Landsat 7 operating smoothly. Hear the stories from inside the L7 Mission Operation Center.


Date Taken:

Length: 00:04:35

Location Taken: Sioux Falls, SD, US


Hi, my name is Tom Cooke. Iím the Landsat 7 Lead Ops Engineer.

My nameís Tammy Vajo. I work for Landsat 7; Iím a flight ops engineer.

TAMMY: Weíre responsible for the health and safety of the spacecraft. We monitor the data that the spacecraft sends down on itself. We look for anomalous trends. If thereís an anomaly, if the spacecraft does something itís not supposed to, we look into what it did, and why, and how can we fix that, or can we live with that. Mission planners build the command loads that get sent up to the spacecraft. Flight dynamics keeps us in orbit where weíre supposed to be.

TOM: Weíre basically running an incredibly complicated machine thatís moving at tens of thousands miles an hour. And, you have to fix it on the fly.

TAMMY: Itís a big asset to USGS and the United States. And for us to command a spacecraft, and to take care of it and make sure nothing happens to it, and to do that for almost 5Ω years without us making a mistake, I think is a huge accomplishment for us.

TOM: The whole point of us being here is to collect that science data and get it into the U.S. archive, and into the archives of our international cooperators.

TAMMY: Weíre not in contact with the spacecraft 24 hours a day. The spacecraft flies over a ground station, and we have a roughly 12-minute view of the spacecraft when it flies over that site. And then it goes away for an hour, an hour and a half, and then we get another view of it. Our MOC is manned from about 8 in the morning til 4 in the afternoon. And then after that we have automation that takes the passes just like we would Ö but it monitors, and if thereís a problem, then it sends us a text message, and we come into the control center and respond to it.

TOM: Iíll get a call in the middle of the night. And you look at it, Iíve never seen this before. And you got to rush in and try to figure out whatís happening. 

TAMMY: Usually things are green. If theyíre a little bad, they go yellow. If theyíre really bad, it goes red. 

TOM: Thereís hundreds of thousands of things that could go wrong at any time. Weíve been operating Landsat 7 now for over 18 years, and we still come across problems and issues that weíve never seen before. 

TAMMY: Any time we have a question, we can go to the simulator. We can send commands to it. We can Ö since itís just a simulator, you can kind of do whatever you want to it and see how the spacecraft would react.

TOM: And then there are things like this choke anomaly, as we call it. This last time that it happened was a little bit different than the previous times.

TAMMY: Weíre in a 12-to-15-minute pass, and weíre commanding the spacecraft, and itís not responding in a way we thought it should. And at that point,  you just kind of step back and say, OK, this isnít going the way we think it should, so weíre not going to try to do anything that weíre not comfortable with or that we havenít tested before. 

TOM: So an instance like this, we sat around the table and said, OK, our normal response didnít work. Why do we think it didnít work, and what are our options? In this case, the options were fairly limited because it wasnít really letting us command it. So we responded to that literally like you would on your computer when it freezes up. We turned the recorder off and turned it back on. When youíve had a box thatís been powered up and running for 18 years, and itís only been power cycled once or twice ever in those 18 years, you have to be really really careful about turning it off and turning it back on because thereís a very real chance that itís not going to come back on. 

TAMMY: Immediately when it came back on, that was good. And then after we turned it on, we powered up the different boards on this particular box, and they all came back on. And we recovered in a day. It took a full 12-14 hours, but we were able to do it.

TOM: In a way youíre playing with house money. Ö that this spacecraft was built for a five year mission, and weíre on year 19 now.

TAMMY: Anything could happen at any time, but itís really been a good solid spacecraft. We watch the data. We look at short term and long term trends, but thereís nothing that really has us concerned. And no reason to think that itís not going to make it until 2020 or 2021.

TOM: Itís a very interesting and very unusual career to be sure. And itís not the most stable career because youíre working on very complicated machines really far away. And if you canít fix ëem, you have to find a new job.