Rank 93 documents the Rossi X-ray Timing Explorer (RXTE) — the Goddard Explorers mission that launched 30 December 1995 on a Delta II 7920 and monitored the X-ray sky for sixteen years with microsecond timing resolution across 2–250 keV. Jean Swank and Tod Strohmayer led teams operating the Proportional Counter Array (PCA), High Energy X-ray Timing Experiment (HEXTE), and All-Sky Monitor (ASM) that studied more than one hundred black-hole binary systems and helped prove event-horizon physics through X-ray variability. Named for MIT pioneer Bruno Rossi, RXTE weighed 3,200 kg yet specialised in time-domain astrophysics rather than imaging — a discipline that turned flickering X-ray sources into laboratories for extreme gravity. The spacecraft deorbited 30 April 2018 over the Pacific after a controlled reentry. Wallimilist renders the PCA collimator box with accretion disk stipple, EXPLORERS gold-star kicker, and Explorer program seal exactly as the master PNG dictates.