Lars Siewesca was a planetologist from the planet Culat, who graduated from the Arrakis' School of Planetology, and had been assigned to Salusa Secundus by Emperor Paul Atreides to oversee the terra-forming project there.
Visit by Jessica, Chani, and Irulan
In 10200 AG, the Emperor Paul asked his mother Jessica Atreides, his concubine Chani, his wife Irulan Corrino; to visit the home of the exiled House Corrino, to report on the terra-forming of the world to livable standards. While there, the Imperial entourage' joined with the former Emperor Shaddam Corrino IV, and his advisor, the former Count Hasimir Fenring.
As the group went to a desolate region of the atomics devastated world, they met the leader of the terra-forming team, Lars Siewesca, and his aide, Qhomba. Lars was particularly interested in meeting Chani, her being the daughter of Dr Liet Kynes, the galaxies-wide famous planetologist; and somewhat ignored the rest of the dignataries. Chani warily told the group that she felt that Salusa was a world that was dead in it's soul.
Nonetheless, Siewesca led the group to a viewing platform near a deep canyon, where explosives were used to blast open an underground aquifer, which began watering the huge region. Lars and Qhomba let out a huge cheer, that part of the project being a success, and exclaimed that Salusa would become a garden world in just a few centuries.