NASA's Kepler spacecraft, that hunts for Earth-like planets orbiting other stars, has gone into emergency mode some 75 million miles from Earth, the US space agency said.

During a scheduled contact on April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM). EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team's priority at this time, NASA said.

Initial indications are that Kepler entered EM before mission operations began the manoeuvre to orient the spacecraft to point towards the centre of the Milky Way for the K2 mission's microlensing observing campaign, officials said. The spacecraft is nearly 75 million miles from Earth, making the communication slow, they said. Even at the speed of light, it takes 13 minutes for a signal to travel to the spacecraft and back. The last regular contact with the spacecraft was on April 4. The spacecraft was operating as expected.

Also read NASA's Kepler spacecraft finds 100 new alien planets orbiting other stars

Kepler completed its prime mission in 2012, detecting nearly 5,000 exoplanets, of which, more than 1,000 have been confirmed. In 2014 the Kepler spacecraft began a new mission called K2. In this extended mission, K2 continues the search for exoplanets while introducing new research opportunities to study young stars, supernovae and many other astronomical objects.

Credit: NASA