NASA will pay you $160 per day to lie in bed — and they've got plenty of takers.

Lying on your stomach at a slight downward angle for months on end used to stand in for the effects of nearly no gravity. Now, the scientists at NASA's Human Test Subject Facility in Galveston, Texas, are trying a new type of bed rest to simulate the moon's gravitational field. They put you, face up, on a bed tilted up at exactly 9.5 degrees with your feet planted on a panel. Do the trigonometry, and the experiment places just about the same amount of gravity on your feet as the moon would.

"Obviously, there's no magic switch to turn off gravity," said Ronita Cromwell, senior research scientist heading up the project. "What we're doing is removing some of the effects of 1 G and achieving one-sixth G along the long axis of the body."

While previous bed-rest studies have required a commitment to lying in bed for 90 days, the feasibility studies for the lunar analog study only require six days in bed. If the test subjects can handle it, which they appear to be doing, it will be extended to much longer periods of time. It's a novel analog, though, so the team is taking it slow

"Not many people have done it before, and no one has done it in the way that we're doing it," Cromwell said.

The effects of lying in bed for months on end aren't pretty. Our bodies are used to being used. Astronauts and "pillownauts" as some study participants call themselves, experience muscle atrophy and even some mild bone-density loss. They also can experience headaches, nausea and a host of other unpleasant symptoms. It can take astronauts weeks or months to readjust to the Earth’s gravitational force.

In fact, that's exactly why NASA runs these bed-rest studies. They help them to understand the physiological changes that the body undergoes when it's not being used like a normal human body. They can try out ways to mitigate the problems that arise.

Cromwell answered most of our functional questions — conjugal visits, food, bone loss — about the bed-rest studies last year, but we've always wondered what it* feels like* on the NASA bed-rest ward. Do people have fun? Is it boring? We spoke with Heather Archuletta, IT specialist, sometime pillownaut, and ardent blogger about her experiences.

Archuletta just completed the lunar bed-rest feasibility study after being chased out of Galveston by Hurricane Ike last year after 50 days of the down-tilted bed-rest study. Her photos and blog provide a fascinating peak into a community of people united by their duty to stay in bed, tilted in one direction or another.

They do crafts, keep fish, watch movies, read books, sing each other Happy Birthday and, in some cases, form a cohesive community. It sounds like camp, but just, you know, always lying down and using a bed pan.

"We had this joke that we were all dating," said Archuletta. "By the end when we got to know each other, we were doing dinner and a movie."

That is to say, the nurses would wheel the residents' prone bodies into the common social area and array them in rows in front of a television for some camaraderie. Archuletta organized a library of books and DVDs. And the activities' coordinator would make sure that they could order new movies from the communal NetFlix account.

While looking for a new job, Archuletta found the bed-rest studies through your favorite science blog, Wired Science.

"If I hadn't done it, I would have just gotten another IT job, probably," Archuletta said.

But she's a space lover and wanted to contribute to humanity's return to the moon and Mars. And maybe do a little something different.

"Something unique, something not in an office environment," she said. "It was a chance to confront stillness in a way."

As it was, Archuletta, who usually works out avidly, subjected her body to intense discomfort, particularly in the first week.

"When they first put me head down that first day — part of it is mental — I had a little bit of a moment right before they put the head at minus six degrees. I thought, 'Oh my god, my feet aren't going to touch the floor for 90 days,'" she said. "But I had committed to it. Once I was head down, what's immediate is the blood rush. All the blood rushes up to your face and you get a little headachey, nauseous."

After a week, she'd adjusted and didn't experience much pain. The nasty surprise came at the end of 50 days of the study, when Ike forced the premature end of her experiment and a readjustment process that had to occur in hours instead of the normal days.

"We all of a sudden got this evacuation order that we had to outrun a storm. Here's a storm literally the size of Texas. We got up in three hours," she said. "They monitored our blood pressure and I never lost consciousness, but I did fall twice. The pain in my feet was so bad. You don't realize what your feet feel like after two months off of them."

After that, you'd think she wouldn't have gone back. But she did, easily completing the much shorter lunar-analog study in May.

"It was absolutely, totally worth it," she said.

WiSci 2.0: Alexis Madrigal's Twitter, Google Reader feed, and book site for The History of Our Future; Wired Science on Facebook.