This animation portrays the unfolding of all three booms making up the antenna for the radar instrument on the European Space Agency's Mars Express orbiter. The first boom was deployed in May 2005. The other two were deployed in June 2005. The animation is based on calculated simulations of how each boom could have extended itself from the folded position in which it had been stored. Now the instrument is ready to begin its work of looking below Mars's surface for buried features, possibly including water-bearing layers, and examining the ionized layer at the top of Mars' atmosphere. The instrument, Mars Advanced Radar for Subsurface and Ionosphere Sounding, was jointly funded by NASA and the Italian Space Agency. It was developed by the University of Rome, Italy, in partnership with NASA's Jet Propulsion Laboratory, Pasadena, Calif. The University of Iowa, Iowa City, built the transmitter for the instrument, JPL built the receiver, and Astro Aerospace, Carpinteria, Calif., built the antenna.