Moonshots: Inside the UC Davis Center for Spaceflight Research

A couple of miles east of the University of California, Davis, campus, there is an unassuming building down the street from a Chinese restaurant and across from a foot and ankle clinic. It's a military olive green and has few windows. A passerby would do just that — pass by — and think nothing of it.  

They would never guess that inside the building, a wide spectrum of spaceflight research projects is underway: Robotic limbs are being taught to find and pick up a dropped wire, hard disc drives are being converted into reaction wheels for satellites the size of a tissue box and a prototype of an astronaut-powered laundry machine is being developed and tested.  

Housed under the UC Davis Office of Research, the Center for Spaceflight Research, or CSFR, where this research takes place, comprises four laboratories that take a transdisciplinary approach to investigate all aspects of human spaceflight from multiple viewpoints, from engineering to computer science to chemistry.  

Stephen Robinson, professor of mechanical and aerospace engineering and director of the CSFR, along with his three collaborators, Professors Zhaodan Kong and Sanjay Joshi and Assistant Professor Rich Whittle, aim to establish the center as the preeminent human spaceflight research laboratory in the U.S.  

"The vision [of the center] is enabling human exploration and utilization of space through research and development," said Robinson. "The core is this concept of predicting the behavior of complex engineering systems that are integrated with human beings who have complex bodies and complex brains."  

Preparing for Life in Space 

Living in space will likely not be as simple as portrayed in TV shows like For All Mankind, which depicts a present where humans have colonized the moon and Mars. Systems, Robinson explains, degrade and break down, and if you are millions of miles from Earth, communication can be delayed, leaving problem-solving to the humans and autonomous robots in deep space.  

"You have to have a spacecraft that is fully capable of supporting human life, which is a very difficult thing to do in space, especially reliably because some of these systems are so complex, fragile and brittle," he said. "And when people aren't there, the whole spacecraft has to be able to know itself and take care of itself." 

One of the ways researchers in Robinson's Humans/Robotics/Vehicle Integration and Performance, or HRVIP, Lab, are tackling this issue is by working with autonomous robots, particularly in handling flexible objects like fabrics and plants. A current project has a robot arm training to help with the maintenance of life support systems by learning to autonomously turn locks, open drawers and retrieve certain tools. Another pair of robot arms is learning to communicate with each other to find a lost object — in this case, a dropped electrical wire — that is behind a barrier, retrieve it and put it back.  

Elsewhere in the center, a maze of pipes, valves and gauges is monitored by chemical engineers. The contraption mimics a life-support system that captures carbon dioxide on a spacecraft to investigate when the filter starts to break down, which is critical knowledge for deep space habitats, where a life-support system will be running continuously for years.   

Laundry is another aspect of living in space the HRVIP Lab is addressing. Mechanical and aerospace engineering Ph.D. student Andrew Arends is leading the design of a standalone laundry machine with a closed-loop water filtration system using a bicycle as the mechanism for the power source. This project aims to make in-space laundry a reality, reducing the amount of textile waste generated by spaceflight, as clothing is typically worn until it can't be worn anymore and then thrown away.  

Building Helping Hands 

There is also the exterior of the habitat or spacecraft to think about. Assessment of damage and subsequent repairs are often needed, but spacewalks are dangerous and time-consuming, so the labs are investigating ways to help with these issues.  

In the Satellite Lab, a branch of the HRVIP Lab managed by mechanical and aerospace engineering Ph.D. student Adam Zufall, small satellites, called CubeSats for their shape, are being designed and tested. These tissue-box-size satellites will be deployed from spacecraft to conduct external inspections for damage in lieu of sending out an astronaut for a spacewalk.  

"It's dangerous to send humans out, and it takes days to plan out an extravehicular activity [or EVA]," said Zufall, using astronaut-speak for a spacewalk. "If we could get satellites to do the job and immediately get data on the problem, [it would help with] safety, health and risk management."  

The cube-shaped satellites being designed at UC Davis feature the novel idea of using hard disc drives as reaction wheels, which control a spacecraft's orientation. Zufall and his fellow researchers are developing algorithms and techniques to teach the satellites to visually recognize the handrails on the exterior of the International Space Station, or ISS, so the handrails can be used as navigational landmarks during spaceflight. The team has worked with the UC Davis Department of Theatre and Dance to test a 1/5 scale model handrail, using the stage lighting in Wright Hall to simulate the lighting conditions in space.  

Janine Moses, a master's student in mechanical and aerospace engineering and manager of the HRVIP Lab, is working on keeping those CubeSats and other electronics cool in the vacuum of space where there is no airflow. She is investigating sublimation phase-change heat transfer, which is inspired by how spacesuits keep astronauts cool.  

"With astronauts, you basically gather all the heat they're generating as they're sweating inside their spacesuits and that gets transferred to a piece of hardware called the sublimator," she said. "All this thermal energy goes into ice, and that ice becomes water vapor, [which dissipates into space] transferring heat away from the astronauts."  

Keeping small tech cool could be especially helpful with inspection satellites armed with infrared cameras and other imaging technology like remote sensors that need to be kept cold, but could offer key insights for spacecraft inspection, climate change and celestial phenomena.  

In the Robotics, Autonomous Systems and Controls Lab, co-PI for the CSFR Sanjay Joshi and his team are looking at how robots and astronauts might work together to mitigate the risk of spacewalks using supernumerary robots, or machines that work like an extra appendage for the human body.  

"Steve walked into my lab one day and said, 'Astronauts could really use something like this on spacewalks,'" said Joshi, referring to prosthetics control systems he was working on. "That got us thinking about how we could combine the stuff Steve was working on for astronauts and space professionals doing complex tasks and the stuff I was working on in control of robots and prosthetics."  

Joshi and his collaborators are currently working on a prototype for a leg muscle control system that detects movement using electrical signals at the leg. The signals then correspondingly move cursors and robots on a computer screen. Joshi is collaborating with neuroscientists to research how the brain and body change to accommodate learning how to control an external limb.  

Trusting Your Machine Coworkers 

Kong and his Cyber-Human-Physical Systems Lab are also investigating how humans and autonomous robots work together, specifically the issue of trust between humans and machines for a future that will rely heavily on human-machine collaboration.  

"Currently, the way that it works is the astronauts at the ISS are supported by mission controllers in Houston," said Kong. "But if we're going to send humans to Mars, this would not be the case. There would be a communication delay of up to 20 minutes. Astronauts will have to work with robots or AI."  

While a researcher is working on a task with AI — like reclassifying images of satellites — they are hooked up to EEG sensors to measure electrical pulses in the brain, ECG sensors to measure heartbeat and skin conductors to detect sweat, all of which can indicate anxiety or a critical human state, like whether they are tired or confused, and whether they trust a robot to continue doing its part of the job.   

Kong's team is taking the data from those physiological signals and aiming to model the trust dynamic based on those signals and adjust and calibrate the trust based on the abilities of the robot.  

"If you know the capability of the robot and the trust of the human, you can adjust it to experiment with," said Kong. "You can have the robot saying, 'I'm not good at doing this, maybe you should not trust me that much.' If the system isn't working, you shouldn't trust it, but if you don't trust it enough, you'll underutilize it."  

Coming Home Healthy 

Elsewhere in the CSFR, a mannequin lies in a 29-foot-long tube, a mock-up of a space ambulance made of polycarbonate, acrylic and wood. The small vehicle would transport an injured astronaut and an emergency medical crewmember from the ISS to an airport on the ground within 90 minutes to get them to a hospital for medical treatment.  

However, one of the barriers the lab is researching is how to safely reenter Earth's atmosphere without causing more damage to the injured person. The team models the ambulance after the X-37B space plane, an unmanned spacecraft designed to operate in low orbit and shuttle experiments down to Earth, rather than the commonly used capsule. The wings of the plane can reduce the forces of atmospheric entry on the astronauts, particularly the patient.  

"Upon reentry into Earth's atmosphere [in a capsule], a person can experience up to nine G's of force," said Zufall. "If you weren't having a medical emergency before, you might be afterward."  

This project is particularly exciting for Whittle, who joined UC Davis last summer and whose expertise is in what happens to the body while in space. He is currently leading a project doing cardiovascular modeling on the effects of reentry trajectory on the cardiovascular system in his Bioastronautics and eXploration Systems Lab.  

"By looking at the reentry effects on a healthy person, you can then look at it for an injured subject or someone with acute blood loss," he said. "You can use that data to determine the key times during reentry that a medical professional might need to be aware of. It's not going to be the same at the beginning than at the end."  

Whittle is also beginning research into metabolic performance while in a spacesuit or on the space station where the concentration of carbon dioxide is higher than on Earth. He'll have testing participants walk on a treadmill wearing a mask; he will then increase the CO2 in small (read: not dangerous) amounts and measure the energy expenditure, applying the data to create planning algorithms and tools for predictive modeling on how different individuals' bodies might react in space.  

Working Together to Go Above and Beyond 

Cristina Davis, a professor of mechanical and aerospace engineering and the Associate Vice Chancellor of Research for the UC Davis Office of Research, says the multidisciplinary approach of CSFR, coupled with its partnerships — the center is involved with multiple NASA projects, including Habitats Optimized for Missions of Exploration, or HOME, and is a new member of the U.S. Space Command Academic Engagement Enterprise — place the center in a strategic position to be a trailblazing resource now and in the future for spaceflight research.  

"UC Davis is emerging as a national leader in spaceflight research," she said. "Our interdisciplinary, collaborative strengths set us apart from other groups across the nation that are also pursuing this goal. Steve has done a fantastic job assembling team members from a variety of research areas, including engineering, medicine, neuroscience, psychology and plant sciences, among many others, to solve spaceflight problems."  

The research does not only benefit astronauts and future generations of space explorers, Davis points out. The research CSFR is pursuing has the potential to impact the planet and its current inhabitants: us.  

"Learning how to live in space can teach us how to live more sustainably on Earth," she said. "It is perfectly aligned with our efforts toward sustainability, which is a major theme of research here at UC Davis."