Rank 101 documents Lunar Prospector — the 1998 Discovery mission that confirmed Clementine's polar hydrogen signal and ended with a deliberate crash into the Moon. Launched 7 January 1998 aboard Athena II from Cape Canaveral, the 295 kg Ames Research Center spacecraft entered a 100 km polar lunar orbit and operated for nineteen months with gamma-ray, neutron, and magnetometer instruments at a total mission cost of $63 million. Data confirmed strong hydrogen enrichment at both lunar poles — the strongest evidence yet for water ice in permanently shadowed regolith — and mapped magnetic anomalies across the surface. On 31 July 1999, mission controllers commanded a controlled impact into a south polar crater later named Shoemaker in honour of Eugene Shoemaker, hoping to loft a detectable water vapour plume; telescopes saw no clear plume, but the impact cemented Lunar Prospector's legacy as the mission that made polar ice a program driver. Wallimilist renders the octagonal spinner with instrument booms, polar crater cross-section with blue hydrogen crystals, vertical and horizontal LUNAR PROSPECTOR titles, and polar water ice kicker exactly as the master PNG dictates — Ames Discovery kicker, 1998 lunar palette, and curator copy on hydrogen confirmation and Shoemaker impact heritage.