After a brief glitch last week, the European Space Agency's Mars Express spacecraft has successfully deployed the first of its MARSIS booms to its full length. The 20 metre (66 foot) boom is composed of 13 segments, but one joint didn't fully lock into place. Controllers turned the cold side of the boom into the Sun, which heated it up, and forced it into place. With the first boom complete, controllers will extend its two additional booms within a few weeks, so Mars Express can begin searching for underground sources of water.