Gemini 3 launched carrying astronauts John Young and Purdue Alum Gus Grissom. Part of their mission was to test out newly developed food for use in space. It was understood at that time, food developed for space was not very good. This led to Gus Grissom being the first person to be offered and eat a corned beef sandwich in space.

John Young smuggled a corned-beef sandwich into space. Young slipped the sandwich into his pocket just before launch. The corned-beef sandwich sparked a brief conversation between Young and Grissom, according to the Gemini 3 transcript.

“What is it?” Grissom asked. “Corned-beef sandwich,” Young replied. “Where did that come from?” Grissom asked. Answered Young: “I brought it with me. Let’s see how it tastes. Smells, doesn’t it?”
Grissom tasted the sandwich but quickly announced he would stick it back in his pocket because it was starting to break up and crumbs were starting to float throughout the cabin. Young suggested the sandwich was “a thought … not a very good one.” Replied Grissom: “Pretty good, though, if it would just hold together.”
But the brief incident sparked a review by the U.S. House of Representatives’ Committee on Appropriations, in which one member of Congress called it “a $30 million sandwich” and politicians cited safety concerns about crumbs interfering with spacecraft operations.

While the infamous sandwich is no longer available to historians, a similar one, preserved in acrylic, is on display at the Grissom Memorial Museum in Mitchell, Indiana.

I highly recommend stopping at the museum if you’re ever heading down to Bloomington or French Lick. It’s not a very big museum, but it’s very well done and they have the actual Gemini space capsule from this story there, along with the replica sandwich.