The American space agency, NASAsays it has again made contact with a spacecraftstudying the sun and space weather.NASA said it lost contactwith the Solar Terrestrial Relations Observatories,also known as the STEREO-B spacecraft, two years ago.Communications with the spacecraft were lostafter NASA attempted to tryto prevent overheating of the spaceship's antenna.The space agency saidcontact with STEREO-B was restored last week.NASA has another spacecraftthat is nearly identical to STEREO-B called STEREO-A.It also was launched in 2006 to study the sun and space weather.STEREO-A is working normally.NASA said it will now test STEREO-B to see ifthe spacecraft's instruments and sensors are operating correctly.Both spacecraft are located on the other side of the sun from earth.NASA says they have added to the understanding of how the sun works.The ships have studied the sun's gasses,wind, particles and its atmosphere.