First to the Bottom: The *Trieste* and the Conquest of Challenger Deep

January 23, 1960. **Jacques Piccard** (Swiss oceanographer) and **Don Walsh** (US Navy lieutenant) descend in the **bathyscaphe *Trieste*** to **10,916 meters**—the bottom of the **Challenger Deep**, Mariana Trench. They remain the **first humans** to reach Earth's deepest point.

The Vehicle: *Trieste* (Bathyscaphe, Not Submarine)

• Designer: **Auguste Piccard** (Jacques's father) — balloonist turned deep-sea pioneer
• Principle: **Floatation tank** (gasoline, lighter than water) + **pressure sphere** (crew compartment)
• Sphere: 2.16m diameter, **12.7cm steel walls** — 13 tonnes, 2-person
• Ballast: 9 tonnes iron shot (electromagnet release)
• Built: Italy (1953), purchased by US Navy (1958)

The Dive

• Descent: 4h 47min (0.9 m/s)
• Bottom time: 20 minutes
• Observation: "Flatfish" sighted (likely sea cucumber); **diatomaceous ooze** bottom
• Communication: Acoustic (hydrophone) — 7-second delay each way
• Ascent: 3h 17min (shot dropped)
• Support: USS *Lewis* (mother ship), *Wandank* (tug)

Why It Mattered

• Proved life exists at hadal depths (settled scientific debate)
• Validated bathyscaphe design — free-diving, no tether
• Set record unbroken for 52 years (until Cameron 2012)
• Piccard & Walsh: Only duo to reach bottom **together** (Cameron solo; Vescovo repeated)

Legacy

• *Trieste* preserved: National Museum of the US Navy, Washington Navy Yard
• Piccard/Walsh: Both lived to see later dives (Piccard d. 2008, Walsh d. 2023)
• Inspired: *Deepsea Challenger*, *Limiting Factor*, *Fendouzhe* — all owe design DNA to *Trieste*

They didn't plant a flag. They **turned on a light** in the darkest place on Earth. That light is still on.