Rank 36 documents MESSENGER — MErcury Surface, Space ENvironment, GEochemistry, and Ranging — the Discovery Program mission that became the first spacecraft to orbit the innermost planet. Launched 3 August 2004 aboard Delta II from Cape Canaveral, MESSENGER endured a 6.6-year cruise with six planetary gravity assists before entering orbit 18 March 2011 under principal investigator Sean Solomon at Johns Hopkins APL. The 507 kg spacecraft carried a ceramic-coated sunshade, MDIS cameras, magnetometer, and gamma-ray/neutron spectrometer through an eccentric 200 × 15,193 km orbit for four years. MESSENGER mapped Mercury's entire surface, confirmed water ice in permanently shadowed polar craters, and rewrote volcanic history textbooks. Deliberate impact 30 April 2015 ended the mission on the planet it had studied. Wallimilist renders MESSENGER diagonal with sunshade and solar arrays against cratered Mercury limb, vertical title spine, and Discovery Program patch exactly as the master PNG dictates — 2011 orbit kicker, cream-navy palette, and curator copy on polar ice and global mapping heritage.