Hi, my name is Tom Cooke.
I'm the Landsat 7 Lead Ops Engineer.
My name's Tammy Vajo.
I work for Landsat 7; I'm a flight ops engineer.
TAMMY: We're 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 there's an anomaly, if the spacecraft does something it's 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 we're supposed to be.
TOM: We're basically running an incredibly complicated machine
that's moving at tens of thousands miles an hour.
And, you have to fix it on the fly.
TAMMY: It's 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 five and a half 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: We're 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 -
but it monitors, and if there's a problem, then it sends us a text message,
and we come into the control center and respond to it.
TOM: I'll get a call in the middle of the night.
And you look at it, I've never seen this before.
And you got to rush in and try to figure out what's happening.
TAMMY: Usually things are green.
If they're a little bad, they go yellow.
If they're really bad, it goes red.
TOM: There's hundreds of thousands of things that could go wrong at any time.
We've been operating Landsat 7 now for over 18 years, and
we still come across problems and issues that we've never seen before.
TAMMY: Any time we have a question, we can go to the simulator.
We can send commands to it.
We can - since it's 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: We-re in a 12-to-15-minute pass, and we're commanding the spacecraft,
and it's not responding in a way we thought it should.
And at that point, you just kind of step back and say, OK,
this isn't going the way we think it should,
so we're not going to try to do anything that we're not comfortable with
or that we haven't tested before.
TOM: So an instance like this, we sat around the table
and said, OK, our normal response didn't work.
Why do we think it didn't work, and what are our options?
Well, in this case, the options were fairly limited because it wasn't 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 you've had a box that's been powered up and running for 18 years,
and it's 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 there's a very real chance
that it's not going to come back on.
[old computer start-up sounds]
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 you're playing with house money.
- that this spacecraft was built for a five year mission, and we're on year 19 now.
TAMMY: Anything could happen at any time,
but it's really been a good solid spacecraft.
We watch the data. We look at short term and long term trends,
but there's nothing that really has us concerned.
And no reason to think that it's not going to make it until 2020 or 2021.
TOM: It's a very interesting and very unusual career to be sure.
And it's not the most stable career
because you're working on very complicated machines really far away.
And if you can't fix 'em, you have to find a new job.