Looking for Earths Far From Home - by Tracy Drain

What is Kepler?
photometer lowered into spacecraft
The photometer is lowered into the spacecraft in this picture. › Larger image

Kepler is a mission that is designed to find Earth-sized planets outside our solar system. Specifically, it will look for these rocky planets in the “habitable zone” near their stars — meaning at a distance where liquid water could exist on the surface.

Kepler will accomplish this by monitoring a large set of stars (approximately 100,000) and looking for the signature dip in brightness that indicates that a planet has crossed between the spacecraft and the star. The instrument that detects this dip is called a photometer — literally, a “light meter.” It is basically a large telescope that funnels the light from the stars onto a CCD array (similar to the ones used in digital cameras).

By surveying such a large number of stars using this “transit” method, Kepler will be able to determine the frequency of Earth-sized (and larger) planets around a wide variety of stars.

What do I think is cool about this mission?

I love the fact that the Kepler approach - looking for the dips in stellar brightness that occur when a planet passes between the photometer and a star - is so straightforward. It is such a wonderfully simple way to look for planets! Of course in practice, there are plenty of complicating factors that make this a challenging mission to execute. The change in brightness that we are looking for is very small (on the order of 0.01 percent). To make sure we can detect that, we have to carefully control noise in the system - things like electronic noise from reading out the CCDs, smear from tiny motions of the spacecraft, etc. These and other aspects of the mission have provided plenty of challenges to keep things interesting for the design team.

One of my favorite things about the Kepler mission is that the patch of sky we will be surveying is near a particular group of highly recognizable constellations. The stars Kepler will look at are in the area of what is known as the Summer Triangle, a group of constellations - Aquila, Cygnus and Lyra - that are overhead at midnight when viewed from northern latitudes in the summer months. When the scientist team starts identifying planets in our field of view, anyone will be able to go outside, point towards the Summer Triangle and say “they’ve just discovered a planet over there.” To me, there is something about that which will make the discoveries that much more personal.

photometer lowered into spacecraft
This image shows the Milky Way region of the sky where the Kepler photometer will be pointing. Image credit: Carter Roberts, Eastbay Astronomical Society, Oakland, Calif. › Larger image

I am also a huge sci-fi fan and I have always been particularly fascinated by books and movies about how humans might some day colonize other worlds in the galaxy. I think it is fantastic to get to work on a mission that will be looking for planets outside our solar system that are Earth-sized and in a range around their stars that could be habitable; places where such colonization could one day take place… I can’t wait to see what we find!

What do I do?

I am a member of the Project System Engineering Team at JPL. This team is responsible for a wide variety of tasks on Kepler, aimed at ensuring the project meets the driving scientific and technological objectives. This often involves checking that the interfaces between the different elements of the project work smoothly. For example, one of our responsibilities is to conduct end-to-end tests of the mission’s information system. In this test, we check to make sure that the right commands are being generated to collect data, data is collected using spacecraft hardware, and then the data flows correctly through the ground data system. This lets us verify that the entire data flow chain functions as it should before we launch.

My particular focus has been ensuring that we work out all of the details associated with executing each of the mission phases (the launch phase, the on-orbit checkout period that we call the commissioning phase, and the main data-gathering portion of the mission, which is the science phase). I work closely with my colleagues at NASA Ames, Ball Aerospace and JPL to identify and resolve open issues associated with planning for, testing and eventually executing the activities associated with these phases.

What is happening on the project right now?

This animation shows how Kepler will work.

The project is in what is known as the Assembly, Test and Launch Operations phase. Right now, the assembled spacecraft and instrument (known collectively as the flight system) is in the middle of the environmental testing campaign at Ball. This involves many hours of running the flight system and monitoring its performance while exposing it to the types of temperatures, pressures and other conditions that it will see in space. The system that will collect and distribute the data is undergoing integrated testing as well, with teams of people working to push test data through all of the various ground interfaces. The operations team — the people who will be responsible for generating and testing commands, monitoring the health and safety of the spacecraft and ensuring that data is collected from it by the Deep Space Network — are undergoing training and getting ready for upcoming mission phase rehearsals that we call “operational readiness tests.” Even though we are still several months away from launch, it is a very busy time on the project!

Who is involved?

The principle investigator and the science office that will lead the scientific data analysis are at the NASA Ames Research Center in Mountain View, Calif. The spacecraft and photometer were built at Ball Aerospace & Technologies Corporation in Boulder, Colo. The mission operations center is located at the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder. The mission is managed here at the Jet Propulsion Laboratory in Pasadena, Calif.

    8 Responses to “Looking for Earths Far From Home - by Tracy Drain”

  1. Jie Zhou Says:
    August 5th, 2008 at 8:52 pm

    I love this program ,though the possibility to find E.T is very small.

  2. Mark Says:
    August 6th, 2008 at 10:46 am

    While finding some form of extra terrestrial life or eco system would change our self image of the universe; We will be still left with the realization that space, to quote the Hitchhikers guide to the galaxy, “is big, really big…” and that for the forseeable future we would be left observing planets from a great distance and many years into the past.

  3. Derek Says:
    August 13th, 2008 at 12:27 am

    I would like to think that this mission would be a stepping stone to the Terrestrial Planet Finder but I am sure that mission has went down the drain. I do not understand why we could not just cooperate with the European Space Agency for a collaborative mission as they have a similar concept–Darwin–that has the same goals. Besides, the discovery of extrasolar Earth-like planets is not an event that a single nation should enjoy, but the entire world. That’s how it will be anyways, so we might as well take their money while we’re building it. In the mean time, I might as well start looking forward to the James Webb Space Telescope and hopefully a future launched coronagraph (i.e.: New Worlds Discoverer “starshade”).

    Anyways, I think you guys have a good chance of detecting Earth-like planets with Kepler than the Europeans have with their wildly unsuccessful COROT. I hope that within a few years time, man will know that the Earth is not as unique as it seems right now. Hey, if we can get that far, then we can extrapolate that into far more interesting possibilities. Good luck!

  4. John DuCrest Says:
    August 27th, 2008 at 2:49 pm

    I understand the basis of our search for Extra-Terrestrial Life is the existence of a planet with earthlike qualities. This method however seems to limit our search for life because our search is based on how life was created here. I am curious to know if there are other scientific methods (or theories of how life can exist without earthlike conditions) to detect life beyond our planet.

  5. johnny Says:
    February 4th, 2009 at 9:26 am

    what is the possibility that another earth is observing us from afar? what would they in us and what does it all mean in terms of philosophy? this is a strange question but will we be considered brothers/sisters ultimately, from the same star stuff?

  6. UFC betting Says:
    March 30th, 2009 at 2:06 pm

    Interesting blog, nice design, i have bookmarked it for the future referrence

  7. Stacey Says:
    January 31st, 2010 at 9:31 pm

    i really want to become an astronaut!

  8. snehal odedra Says:
    March 24th, 2010 at 12:55 am

    According to me after 2015 something very dangerious happens with earth.because ozone depletion is not stop and now a days weather is also going change so i think that we must think about other planet where we can live and make settlements on moon or mars as soon as possible.m working for design settlements contest of NASA.so i need ur help if possible.and also want to know that which type of system is useful for space settlement?plz.

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