Closing a complex spacecraft like Kepler requires not only sending a "close" command. According to NASA, space telescopes have a range of security modes that can be reopened if they accidentally shut down or lose communication with the Earth, so each must be disabled. To make matters worse, the spacecraft is spinning slowly, so when the fixed radio antenna points to the Earth, the command sent to it must be accurate.
The most important of these commands is to turn off Kepler's radio transmitter. Although it is about 94 million miles (151 million kilometers) from Earth, it is still in a safe orbit, but it is still vulnerable to navigation - not because it may collide with another spacecraft, but because its radio beam may Unexpectedly causing another detector to lose contact.
To ensure that Kepler has closed, NASA says it will continue to monitor the spacecraft to ensure it has complied with the order.
The Kepler Telescope was launched at the 17B Space Launch Complex at Cape Canaveral Air Force Base, Florida on March 6, 2009 at 7:49 pm PST, when it was carrying the Alliance Delta II rocket. The Puller mission was originally scheduled to last only 3-5 years but has more than doubled. Throughout his career, it has found 2,723 planets orbiting other stars and has detected thousands of other potential candidates.
The decision to close Kepler was announced on October 30, when it was determined that the ship no longer had enough propellant to operate its attitude thrusters. Coincidentally, the closure came on the 388th anniversary of the death of his namesake German astronomer Johnannes Kepler.