NASA | Birth of a Space Laser Instrument

Uploaded by NASAexplorer on 30.08.2012

The ASCENDS acronym
is the name of this mission for measuring carbon dioxide.
One of the exciting things about this project is that you can actually
watch trees eat and breathe.
Of course, trees are breathing all the time, but they are only eating, meaning,
performing photosynthesis when the sun is out. The main science
is to measure how much carbon dioxide there is in the atmosphere,
at this particular time on the Earth, how much is there total
and where is it located. Turns out that when you burn
materials, then a lot of carbon dioxide comes off. If you could see it,
it would look like smoke and it stays, it is also a little heavier than the air,
it stays in the lower part of the atmosphere. And that carbon dioxide
has been tied into warming of the atmosphere.
That is key interest to us on the planet.
The great thing about a laser instrument is that is can make the measurement both
in the daytime and the nighttime, because it is its own light source.
It doesn't count on the sun being out to make these measurements.
The way that we evolve the carbon dioxide instrument is we use a small gas cylinder.
By doing that we can put a controlled amount of
carbon dioxide in there, basically 100%, and it allows
us to make that measurement, which we are ultimately going to measure
from space. It allows us to make it in a controlled way not using air,
but with a big absorption in a very small,
physical footprint. So we can do the measurement on our lab bench.
Then, the next step is we make measurements across the parking lot.
We hang the target on the cell phone tower and then we direct our
laser beam to that tower, the light hits the target, comes back to us,
now we can measure all of the light in the column of air between our
laboratory and the cell phone tower. The amount of data
coming down from the carbon dioxide sounder is not an unwieldy amount.
Again, we're interested in measuring ten-kilometer
squares on the Earth averaged over a month, and then measuring how much
carbon dioxide is there. So, typically our job here is to
look at what is happening in the commercial field, what is happening
elsewhere in the government, and try to leverage that to build a science
instrument. You know, we are doing our best to make use of the resources
that are there, but also we want to see what technologies are going to evolve
without a lot of additional funding so that we can take advantage of its evolution.
But now, we are talking about maybe making that measurement from Mars as well.
The carbon dioxide instrument, you know, is probably one of the most exciting things
that anybody could be working on at this time in history.
We have this new technology, the fiber lasers to work on it.
We have this incredible need to measure the health
of the Earth over time. We have this great place NASA
that is set up to bring the scientists and the technologists
together to do that. It really just does not get much better than that.
I mean everything has come together. There is great synergy there.
Beep, Beep, Beep
Beep, Beep, Beep

without a lot of additional funding so that we can take advantage of its evolution.