In December 2014, NASA's OPALS announced a breakthrough in space-to-ground laser communication, downloading at a speed of 400 megabits per second. The system is also able to re-acquire tracking after the signal is lost due to cloud cover.[25] The OPALS experiment was launched on 18 April 2014 to the ISS to further test the potential for using a laser to transmit data to Earth from space.[26]