Science to Enable Space Exploration

How will the United States direct finite resources to make the most impactful advances of knowledge in the complex laboratory of the space among Earth, the Moon, and Mars?

The next decade will provide unparalleled prospects for BPS in space to advance fundamental science and technologies to benefit humankind. The extraterrestrial environment—with its widely varied temperatures, pressures, toxicities, gravitational forces, cosmic radiation, and vast distances—will also present extraordinary challenges for exploration.

Addressing Key Scientific Questions

The decadal survey uses a thematic and integrative framework that builds on the BPS research gained over the previous decade. This framework is organized around three major

themes of research in the space environment that address key scientific questions to help drive solutions and achieve impactful societal milestones within the next decade. A focus on this set of questions will help the United States establish leadership in knowledge across three themes: adapting to space during the travel phase, living in space for extended durations, and leveraging space to reveal phenomena that are otherwise obscured by features of Earth’s environment, including its gravitational forces.

NASA should direct its research resources toward the key scientific questions identified in this decadal survey and work with other U.S. government agencies and other nations’ space agencies to coordinate research resources toward the key scientific questions, as relevant to multiple-agency missions. As activity in LEO expands, and lunar and martian missions become realities, NASA should increase resources dedicated to understanding the answers to these key scientific themes.

ADAPTING TO SPACE

From the earliest days of the human exploration of space, there have been questions about whether terrestrial biology is capable of functioning in space. What happens to an organism as it leaves Earth and enters the space environment?

Life in space operates differently than life on Earth. Each organism goes through some physiological adaptation. While initial studies focused on the impact of spaceflight on human beings, studies have expanded to explore fundamental questions regarding the entire range of biological processes that can be affected by going into space, including the plants and microbes that will be a part of habitation systems.

Research on the space shuttle and the ISS have increased our understanding of what happens to organisms that go to space, at the physiological, cellular, and molecular levels. The decadal survey theme Adapting to Space focuses on how the fundamental physics of space environments impacts the ability of living systems to survive transition to and extended stays in space. Three key scientific questions in this theme for the next decade remain or have arisen from those gains:

• How does the space environment influence biological mechanisms required for organisms to survive the transitions to and from space, and thrive while off Earth?
• How do genetic diversity and life history influence physiological adaptation to the space environment?
• How does the space environment alter interactions between organisms?

LIVING AND TRAVELING IN SPACE

In the next decades, more humans will be traveling regularly to and from space, while also living longer in LEO for science, exploratory, and recreational purposes. They will be traveling to the Moon and living for at least short periods on the lunar surface and preparing for long-duration exploration missions to Mars. To enable this scale of humans living in and traveling into deep space, along with the vehicles and habitats and machines that must operate in those same harsh environments, we must not only understand how to survive and adapt to the space environment but also establish how we can create and maintain safe, sustainable environments and build a stable human presence.

The ISS has allowed us to observe BPS over weeks, months, and even years. The decadal survey theme Living and Traveling in Space explores longer-term interactions between biology and hardware systems, as well as the fundamental physical processes needed to sustainably explore new space locations. There are four key scientific questions, spanning a range of investigations from biology through physical sciences, to meet these requirements:

• What are the important multi-generational effects of the space environment on growth, development, and reproduction?
• What principles guide the integration of biological and abiotic systems to create sustainable and functional extraterrestrial habitats?
• What principles enable identification, extraction, processing, and use of materials found in extraterrestrial environments to enable long-term, sustained human and robotic space exploration?
• What are the relevant chemical and physical properties and phenomena that govern the behavior of fluids in space environments?

PROBING PHENOMENA HIDDEN BY GRAVITY OR TERRESTRIAL LIMITATIONS

There are scientific insights that can be found only in space. Science from the space shuttle and ISS eras has clearly demonstrated that when gravity is removed from the equations, there are processes and phenomena not observable on Earth due to variations in gravity, radiation exposure, temperature, atmospheric pressure, atmospheric and surface compositions, magnetic fields, and the effects of extremely large distances. Things can get weird in space.

Many of these features have very complex properties and unknown interactions, creating remarkable opportunities for scientific discovery regarding the effects of these novel environments on animals, plants, microbes, materials, and physical laws of space, time, and matter. These same features also create complications and hazards that need to be considered not only when conducting research in space, but also when sending equipment and living organisms to explore space.

Space-enabled fundamental science represents the opportunity to understand fundamental biological and physical mechanisms that can only be understood by access to the space environment beyond Earth. Such knowledge helps society not only better understand our place in the universe but also take major technological leaps forward on Earth. Space-based laboratories can expand our knowledge about many topics including how materials form and change when temperature or other physical conditions change suddenly, and better understand how fluids flow differently in space conditions. This allows us to better understand how to sanitize water, store propellants, or even how to measure time more precisely.

The decadal survey theme Probing Phenomena Hidden by Gravity or Terrestrial Limitations integrates the many areas of science needed to enable spaceflight successfully and responsibly while also benefiting life on Earth. It can be prioritized by these key scientific questions.

• What are the mechanisms by which organisms sense and respond to physical properties of surroundings and to applied mechanical forces, including gravitational force?
• What are the fundamental principles that organize the structure and functionality of materials, including but not limited to soft and active matter?
• What are the fundamental laws that govern the behavior of systems that are far from equilibrium?
• What new physics, including particle physics, general relativity, and quantum mechanics, can be discovered with experiments that can only be carried out in space?

Research Campaigns

Through the coming decade, NASA should pursue dedicated research campaigns that will drive solutions to specific groups of the key scientific questions. The concept of research campaigns is a new one for the BPS community. The purpose of these campaigns is to unite and focus researchers on specific goals. These highly directed efforts were developed by the decadal survey by prioritizing significance, feasibility of scientific goals, and potential for capability building, and should be pursued only when specific campaign-level investments above the current operating budget are available for the BPS Division.

Two research campaigns—Bioregenerative Life Support Systems (BLiSS) and Manufacturing Materials and Processes for Sustainability in Space (MATRICES)—are coupled tightly to the key scientific questions and directly target mission needs for future space exploration and habitations. The decadal survey recommends coordination should be considered beyond NASA, including other federal agencies and the private sector, as well as public–private partnerships to support these research campaigns.

BLISS

Sustainable bioregenerative life support is crucial for sustaining life and mitigating negative physiological effects on long-duration missions. The BLiSS campaign is targeted to build and understand the systems that would provide high-quality food, refresh air and water, process wastes, and enable the creation of space environments sustainable for long periods of time independent of Earth.

BLiSS would enable understanding of the multiple biological phenomena at play while providing a distinct technology gain for space exploration and presenting high return-on-investment for development of sustainable technologies for Earth.

MATRICES

Advances in materials science and manufacturing via in-space research can drive fundamental knowledge of physical principles enabled by space and create approaches that will enable future human space exploration in sustainably built environments.

The MATRICES campaign addresses two challenges in the journey and destination of space travel and habitation: the limited mass of resources launched from Earth for long journeys, and limited knowledge of how to repeatably use resources from both Earth and space to manufacture and repair the world around us, with minimal impact to that world. This campaign envisions the types of materials science, complex fluid dynamics, and

manufacturing, near and far from equilibrium conditions, that will be enabled over the next decade in an expected ecosystem that includes the ISS, commercial space destinations in LEO, and planetary space experimental platforms.

Other Research Opportunities

In addition to the two research campaigns, the decadal survey also outlines a multi-agency opportunity and one research infrastructure concept.

Probing the Fabric of Space-Time (PFaST) is envisioned as a campaign-style, multi-agency opportunity centered on deploying an advanced quantum sensing network, enabled by recent scientific discoveries that will be continuously refined throughout the decades to come. PFaST would use recent advances in atomic and optical clocks, and spaceflight’s ability to span large distances and large variations in gravitational fields to seek both validation of purely theoretical models as well as previously unobserved features of spacetime. This extremely large-scale research and technology effort scales well beyond the sole domain of NASA. This opportunity should be actively pursued only as a multi-agency effort where a substantial majority of the funding is provided by non-NASA sources.

Polar Radiation of Model Organisms (PRoMO) is a notional concept of future research infrastructure that describes an opportunity for using a space vehicle not currently available to science, an uncrewed, freeflyer spacecraft that would fly over Earth’s poles. This would allow a unique spaceflight experience that combines the effects of radiation and microgravity on mammals, plants, and cellular systems, thus underpinning the health-risk-based decision process that is inherent in exploration beyond LEO. The PRoMO concept could potentially enable crewless research investigations of physical systems, as well as on organisms including mammals, for extended exposure durations of interest to several key scientific questions.

“The proposed research campaigns, multi-agency opportunity, and notional concept for BPS research platforms offer transformative opportunities for sustained, coordinated science that advance the knowledge needed for extended space missions and return benefits to society.”