NASA

If you just can't get out of bed, NASA might have a mission for you.

A NASA study is recruiting volunteers to to lie in a bed that's tilted downward at a 6-degree angle for 70 days. Subjects who complete the entire bed rest project can earn up to $18,000.

The study is meant to test the conditions astronauts might experience while traveling in space. NASA hopes to find out what physical changes occur to scientists on these missions and how much body function is required for a person to complete a specific task. The information will be used to develop methods that make it easier for astronauts to physically acclimate to daily life following space exploration.

Since there is no gravity in space, astronauts don't exert as much effort and might not get the exercise they need to stay in shape.

Researchers are requiring participants to stay on a slight tilt, which is intended to allow fluids to move toward the upper part of the body. That would allow researchers to study cardiovascular symptoms similar to what might be experienced during a space expedition.

The volunteers will be required to live in a bed rest facility located in NASA's Flight Analogs Research Unit (FARU) at the University of Texas Medical branch in Galveston. The subjects will be split into two groups. Some will be required to spend 105 days living in the facility and go through a variety of resistance and aerobic exercises while remaining on bed rest. The others will spend 97 days at the research unite, and will not be required to do the exercises.

Data about the subjects' bones, muscles, heart and circulatory systems, nervous systems, nutritional conditions, and their ability to fight off infections will be recorded.

If they need to shower or use the bathroom, NASA has a modified shower device so the subjects will not need to stand.

Both groups will have a few days of regular, mobile living inside the facility, as well as a two-week recovery period after their 70 days of bed rest during which they will be reconditioned back to normal physical activity.

NASA will pay $1,200 a week for the study which can last up to 15 weeks. The study was vetted and deemed safe by the Institutional Review Board of the University of Texas Medical Branch at Galveston, a committee which looks at the safety and ethics of medical research studies with human subjects.

Still interested? You must be in shape -- another requirement is that participants have to be non-smokers in healthy physical condition who pass the Modified Air Force Class III physical.

"We don't want couch potatoes for this study," Dr. Roni Cromwell, a senior scientist on the study, said to the Houston Chronicle.

The project does come with potential health risks. Dr. Adam Stein, chairman of the dept. of physical medicine and rehabilitation at the North Shore-LIJ Health System in Great Neck, N.Y., told CBSNews.com that he typically sees loss of muscle strength, bone density and respiratory capacity in patients who have extended periods of bed rest. There's also the danger for developing urinary and constipation problems.

"I would expect after 70 days there would be changes that can't be made up for and recovered from (right away)," he said, adding that healthy people should be able to recover to their pre-experiment function eventually.

Immobile persons chance getting skin issues like bed sores and pressure sores, especially because many patients lose sensation. But, Stein, who is not involved in the NASA study, said that since these volunteers will be in good health, the risk of getting these particular problems is low.

What he's most concerned about are the psychological issues that may develop. People can become distressed or anxious from being stuck in bed for so long.

"I read a lot of studies where I thought people were lunatics to do it," Stein said. "I would really worry about the psychological effects of this particular study almost more than the physical."

Still, Cromwell told Forbes that "not every type of person" is able to 70 days at a time.

'A way to help'

"Subjects in the study look at it as a way to help, in that what we eventually do will help astronauts maintain their health while in space," Cromwell explained.

Heather Archuletta, a NASA contractor for the studies program, previously volunteered for a bed rest study for the space agency in 2008.

"Even when it was sometimes challenging, I tried to remember I was doing this for astronauts, so that we can keep them more healthy in space," she said to Forbes. "The day I got up, after being in bed for 54 days, my feet hurt like crazy walking for the first time! But, I reminded myself, this is what astronauts go through, too. Being a ground analog tester for astronauts is exciting, because you get to experience a lot of the things they do."

She added to CBSNews.com by email that she never had any long-term side effects and recovered 100 percent. She doesn't regret joining the project, and knew when she was approved for the study that it would be difficult. However, the fact that she was able to provide valuable information for NASA and the U.S. made everything worth it.

After the micro-gravity study, she went back for two additional studies.

Archuletta emphasized that the screening process for these NASA programs is rigorous and only those who have the right personality and physical traits are invited to participate.

"No one in the program is crazy, crippled, or in the least unaware of what we are doing. The briefings and preparations are weeks long, and THOROUGH. We are willing to do this to help find ways to keep astronauts healthier in orbit, and when they return to Earth gravity," she wrote.

NASA

This story originally appeared on CBSNews.com.