The Kepler Spacecraft is part of NASA’s Discovery Program (which is marked by having lower cost, but more focused missions). Kepler is the 10th stand alone mission of the program (the first was the Mars Pathfinder). Kepler’s purpose was to find exoplanets (with an emphasis on Earth-sized ones) and learn about their structures. Kepler was launched on March 7, 2009 and has lead to the discovery of 1,013 confirmed exoplanets and another 3,199 candidates. The most exiting ones being of course the “Earth-like” ones.
Earth-likeness is measured using the Earth Similarity Index (or ESI), the highest ESI discovered to date is 0.88 and that belongs to Kepler-438b (which is sadly 470 light years away in the constellation Lyra).
Kepler has had it’s share of problems though, originally it looked like it was “toast” back in 2013 when two of its reaction wheels stopped working (meaning it couldn’t stabilize/keep itself in one place)-however, engineers were able to use the pressure of sunlight to stabilize. However, crisis is not completely avoided, during the last scheduled contact (on April 7th) it was found that Kepler is in emergency mode (which despite being the lowest operational mode, also consumes the most fuel)-and has been since April 4th. Kepler is currently 75 million miles from Earth!
Further Reading:
- Wikipedia- Discovery Program
- Wikipedia- Earth Similarity Index
- Wikipedia- Kepler 438b
- Wikipedia- Kepler
- NASA- Kepler Homepage
- NASA-K2 Mission
