Gordon Cooper remembers the early, heady days of the space program. The pressurized suits were uncomfortable, the food was bland, and the capsule itself was crammed so full of circuitry, there was barely enough room for the astronaut.
"Mercury was a tiny little spacecraft, there was no room to move around," says Mr. Cooper, now the chairman of an aerospace engineering firm. "It was really a strap-it-on-and-go vehicle."
Rather than complain about it, Cooper and other astronauts took an active part in designing later-generation spacecraft, and dramatically improving their safety and comfort.
Launches have become safer and spacecraft roomier, pressurized space suits have rotating hinges at the elbows and wrists, and even everyday clothing is as comfy as a pair of old sweats.
At 340 miles above Earth, life may not be exactly like home; but it's pretty close.
"Thirty six years ago, people did not know what would happen if you launched a human into space," says David Williams, an active-duty astronaut and space and life-science director at Johnson Space Center here.
"For doctors, there was a concern whether the astronauts eyeballs would pop out in launch, or whether people would be able to eat in space," says Mr. Williams. "In the Mercury program, John Glenn certainly proved he could eat."
It wasn't much of a meal, however, and at 4 hours and 55 minutes, Glenn's mission wasn't much longer than a modern snack flight. His dinner was apple sauce from an aluminum toothpaste-tube.
Of course, NASA's primary goal has always been safety, not comfort. Glenn's historic launch in 1962 was scrubbed 10 times before engineers finally gave the go-ahead. Today, most shuttle and satellite launches occur on time, delayed more by Florida weather than by faulty wiring.
"There's no doubt the shuttle is much safer than Mercury," says Cooper, who was part of the original shuttle design team back in the late 1960s.
The shuttle is also considerably roomier than the early space modules. Mercury had only about 36 cubic feet of cabin space - just a walk-in closet, really. A fully suited astronaut took up a third of that space. Today's shuttle offers apartment-size 2,325 cubic feet, with plenty of elbow room for a crew of seven.
But sophistication begets complication. The Mercury capsule that Glenn flew in 1962 had 8 buttons to push; the shuttle has 219. Mercury had 56 toggle switches; the shuttle has 856.
Space suits also have improved dramatically. In 1962, aluminized cloth was the Calvin Klein of its day, designed to protect an astronaut from overheating during reentry. The problem was the suit trapped heat as well, making for a fairly sweaty flight.
Today's well-dressed astronaut wears a space suit only during launch and landing, and tout le monde is wearing orange these days - for visibility in the event of a rescue operation.
And the food. Cooper remembers the taste of Mercury food as "kind of blah. It was pureed stuff in an aluminum tube." He laughs, "Who knows what it was?"
Fortunately for Cooper, who spent more than a week aboard a two-man Gemini space capsule, and later astronauts, who spent months aboard Skylab, NASA made step-by-step improvements not only for safety, but for basic comfort.
TODAY'S food, while certainly nothing like the pte at New York's famous Lutce, is approaching what the astronauts are accustomed to on Earth.
In the Mercury program of 1962-63, the menu was mostly bite-size cubes of high-calorie, freeze-dried peanut butter and semi-liquid items in tubes.
And Skylab, in 1973-74, featured a 72-item menu, including filet mignon, improving further over the shrimp cocktail and butterscotch pudding of earlier Gemini missions.
Today, with 150 possible items to choose from on the shuttle menu, every astronaut has favorites. Glenn is having chocolate with nearly every meal. Pedro Duque, not even born when Glenn made his first orbit, prefers a spot of tea with lemon. Williams says he packs lots of New England maple sugar candies when he goes into space. "As a Canadian," he grins, "I'm rather partial to maple syrup products."
Given all the advances, it's not surprising that Cooper and his colleagues are starting to talk, only half-jokingly, about returning to space.
"I think it's great that John is able to go on later in his career," says Cooper, referring to his 77-year-old friend. "I'd like to do it myself, but I'm not old enough. I'm only 71. Give me another six years."