During the Galactic Civil War, a galaxy-wide conflict between the Galactic Empire and the splinter political faction known as the Alliance to Restore the Republic, the Inner Rim world Onderon was strategically significant to the Empire. The planet was the site of Jyrenne Base, the most important Imperial military ordnance center in the Japrael sector; the base was situated near the walled city of Iziz.
Sasha, the sole survivor of her unit
Sometime during the galactic war, the Alliance decided to conduct a reconnaissance mission on Onderon, sending a Rebel cell to gather information on the Empire's presence on the planet. During the operation, the Rebel unit accidentally gave away its position to Imperial forces while its members defended themselves with blasterfire against Onderon's dangerous native wildlife. The Imperials, now aware of the Rebel presence on the planet, responded with heavy artillery and sent a strike force of All Terrain Scout Transports to the intruders' last known position. The recon team's misstep was critical, as it led to the Rebel command's decision to leave the reconnaissance detachment on its own without any further support. Of those in the unit under fire, only a scout named Sasha survived.
The mission was first mentioned in Sasha Character Folio, a freely downloadable character sheet for The Long Arm of the Hutt, a bonus adventure for the roleplaying game Star Wars: Edge of the Empire Beginner Game. The game was published by Fantasy Flight Games as part of the Edge of the Empire RPG series. The supplement material was made available by Fantasy Flight as a free PDF eBook from its website in December 2012. The last page of the Character Folio elaborates on Sasha's backstory, as well as her participation during the reconnaissance mission to Onderon.