As NASA prepares for missions to Mars and places in our galaxy far, far away, researchers are working to understand how humans behave in confinement and isolation over extended periods of time. In 2014, NASA launched its Human Exploration Research Analog (HERA) project, a three-story habitat at Johnson Space Center that allows researchers to study subjects while participating in mission-like scenarios. UH alumna Patrice O. Yarbough, Ph.D. (Biochemistry ’80, ’85), principal investigator for the project, gives some insight into the HERA missions and what we’re learning from them.
Q. What is the purpose of HERA?
A. HERA is one of NASA’s ground analogs funded by the NASA Human Research Program. It’s a controlled study environment that allows us to understand how people respond to the stress of being in confinement. NASA is preparing for some very long missions – and we don’t quite know how being confined or isolated for extended periods of time will affect our astronauts. So we create missions for our HERA habitat to explore the various physiological and psychological stressors that develop during the mission and we use this data to inform our astronaut corps. Because the subjects inside HERA perform operational tasks similar to what the astronauts do on the International Space Station, this allows us to monitor and collect data that is directly applicable to our astronauts. Doing studies in a ground-based analog is cost and time efficient.
Q. How does a study work?
A. Every complete study is called a campaign. Since the project’s launch in 2014, we have completed three campaigns and are currently in our fourth. Each campaign consists of four missions with four subjects each, giving our investigators 16 data sets that are needed for statistical significance. So far, we’ve completed a 7-day, 14-day and 30-day campaign. We are now doing a 45-day study.
The campaign is named for the duration inside the HERA; the mission duration includes transit to target, days on target and return transit. That means our subjects will be inside the HERA habitat for 45 days participating in a pre-planned spaceflight mission. While they are in the habitat, our HERA team and researchers monitor them from the outside. We collect an array of data on the physiological and psychological effects of isolation and confinement.
As we prepare for an upcoming HERA mission, we put out a call for subjects to find the right people for the study. We look for subjects who are U.S. citizens, 30 to 55 years old, have work experience or a master’s degree in a STEM field, and are in excellent health. Nobody really knows the makeup of the perfect astronaut. They can be from any culture, background, gender, educational background and life experience. So we’re really looking for someone who meets these general requirements who can complete the study.
Candidates that meet these requirements will then undergo a medical examination and a battery of lab tests to confirm health status. We need really healthy subjects for the study because our astronauts are very healthy. Even though it is a controlled research study, everything we do is designed to have as much mission fidelity as possible, so finding people who reflect our astronaut corps is critical.
After candidates pass the medical exam, they come to NASA for additional screenings and an informed consent briefing. Since we are doing a virtual reality study, we screen for tolerance to the virtual reality simulations. All of our subjects are also screened by a clinical psychologist, who looks for emotional stability and indicators that the subject can complete an isolation and confinement study.
After we select our four subjects, we prepare them for their upcoming mission. Our subjects arrive at JSC two weeks before mission start for training. The mission will include outbound transit, on location at an asteroid and return transit phases, so they learn the details of the flight simulation and communication delays, they are trained on equipment, and they provide the baseline data for the various physiological measurements that will be monitored for the duration of the study. Each subject will be randomly assigned their role in the mission as commander, flight engineer, mission specialist 1 or mission specialist 2.
We do some ice breaker activities that allow the subjects to interact with each other and begin the process of teamwork. Our subjects come from a small community of people who have been committed to the mission of NASA. Some of them find us through some social communities online, while others wanted to be an astronaut in the past or are hoping to become an astronaut in the future. Some subjects come to us very prepared and committed to carrying out the HERA mission in order to provide the data that will inform the best practices for the health of the future astronauts. Once the pre-mission training period is completed, the subjects are briefed for the mission, and we host a ceremony to kick off the start of the mission. Then they enter the habitat and the door is closed for 45 days.
Q. What is a HERA mission like?
A. HERA missions are like real-life NASA missions, except that you on are Earth and onsite at JSC. Every mission is tediously planned, including what our subjects will do every hour of the day for 45 days. Everything is scheduled, from the time they wake up in the morning – including how much time they get for general hygiene, all of their housekeeping duties, all of their mission duties such as testing hardware and each of their science experiments – to the time they go to sleep at night. During the mission, the crew only have routine contact with each other and the HERA Mission Control.
Because these studies are like real missions, we want our subjects to enter the habitat and carry out the flight simulation as if they are really in outer space. To do that, our subjects have to mentally prepare for confined habitation, which means getting into the mindset of being on an actual mission. That means ‘staying in the moment’ and getting beyond the fact that they are in a chamber in a hanger at JSC with a team of people monitoring their activities right outside the door. Our subjects follow a timeline like the International Space Station crew and they’re engaged in meaningful work.
The crew wear devices that capture data such as voice recorders, actigraphy watches and heart rate sensors. There are eight cameras in the habitat, giving our team the ability to monitor and record every interaction from HERA mission control. Our study investigators rely on our science and operational teams to record everything that happens. Because the HERA Campaign 4 is a behavioral study, our investigators need to know if the subject had a toothache or a headache that affected their behavior that particular day. Ultimately all this data will be used to develop countermeasures to the human response to stress often faced on NASA long duration missions.
Q. How many teams are involved in each study?
A. We have three teams that manage and monitor every detail of the mission: an operations team, a medical team and a science team. Our operations team designs the mission and all activities for our subjects during the 45-day study. If something goes wrong inside the habitat (real or simulated), our operations team troubleshoots and coaches our subjects to mitigate the situation, as mission control would do for NASA missions.
Our medical team meets weekly with each subject during a private health video conference to observe their mental and physical health. We have three NASA physicians who do the medical monitoring of our subjects and one clinical psychologist who monitors behavior. Although we are committed to capturing all the data needed to complete the study, we are first dedicated to our subjects and their safety, so we take monitoring very seriously. For overall well-being and for mission fidelity to International Space Station, our HERA subjects have one private family video conference weekly.
Our science team ensures that a reasonable amount of science is performed during the study. This is the team I am on as the the HERA Campaign Complement Scientist. We not only assess the feasibility of the science, but we work with the operations team to make sure that each of the ongoing investigations do not interfere with other investigations. There are 18 investigators in our current study, so that’s a daunting task. If we can’t integrate a study on a non-interfering basis, then it will not be part of the mission. As the principal investigator for the collective group of studies, I routinely interface with the investigators to ensure study compliance. Each investigation has to go through IRB approval, so I work to ensure those studies meet our compliance requirements for human subjects research.
Q. What are you hoping to learn from these studies?
A. One of the goals for the astronaut corps is to be part of a strong and sustainable team, so our investigators are interested in how individuals morph into stronger team members over time. Our subjects only have two weeks to interact with each other before going inside HERA, so even though the preparation for the mission is much more condensed than what astronauts experience, it allows us to see what the adaptation process is. We are asking the big question of ‘what influences team function? Much of the research is studying teamwork and team cohesion and the impact of sleep reduction, on overall physical fitness and performance.
At this point, we don’t know what discrete changes happen over time in confinement because we haven’t done a lot of confinement studies. Traveling outside of low Earth orbit will take a long time, so investigators want to know how soon they can detect psychological changes that may impact behavioral performance. They want to know how well subjects will perform when they’re tired and stressed, and how that impacts the duties they would have to perform as an astronaut under those conditions.
Q. What is your favorite part of the job?
A. The subjects. I’ve been a research scientist for almost 30 years and I’ve been involved in many studies on the molecular level to understand human immune systems and viral infections. But here, I’m working directly with people as test subjects in studies on the human response to stress.
When I was in graduate school, I knew I wanted to be involved in translational research. In my opinion, the NASA Human Research Program HERA project is one of the best examples of translational research. Everything we learn in HERA will be directly applied to the astronaut corps for the purpose of sustaining astronaut health and performance on long duration space explorations. This is very important work and I feel very fortunate to be involved in it!