The Importance of Planetary Sample Returns
Dr. Mary Sue Bell of NASA's Astromaterials Research and Exploration Science Directorate explains why it's important to help astronauts develop sample collection techniques during NASA's analog missions.
Why are planetary sample returns so important?
Planetary science has seen a tremendous growth in new knowledge as a result of recent NASA robotic missions that have detected deposits of water-ice at the moon's poles and potential conditions under which life could have flourished on Mars.
While some sophisticated data can be derived from "in situ" measurements taken by rovers and satellites, returned planetary samples allow scientists on Earth to use latest technologies available to maximize the scientific return. The science community has recently seen compelling sample returns, including solar wind particles (NASA's Genesis), comet particles (NASA's Stardust) asteroid particles (JAXA's Hayabusa) and Antarctic meteorites, which scientists collect each Austral summer.
The National Research Council Decadal Study of 2011 recommended that NASA's chief scientific goal should be to return samples from Mars by 2023. Measurements taken by the MER rovers Spirit and Opportunity indicate that Mars had a warmer and wetter climate early in Mars history – conditions in which scientists believe life could have formed on early Mars. But chemical evidence of life in materials like the rocky regolith of Mars can be quite small and difficult for robotic geologists to detect and measure.
The Astromaterials Research and Exploration Science (ARES) directorate at NASA's Johnson Space Center curates all of NASA's "extraterrestrial" samples. The ARES directorate mission is to protect, preserve, and distribute samples for study from the Moon, Mars, and interplanetary space in support of solar system exploration. These sample collections include lunar rocks and regolith returned by the Apollo missions.
Samples from Mars will require special handling protocols from the time the sample collection site is chosen through documentation, encapsulation, and transport to Earth and to NASA's curation facility for allocation to scientist for analysis and study. Because scientists don't yet know how to differentiate an Earth-derived sample of life from a Mars-derived sample of life, scientists are eager to develop protocols that will protect Mars samples from Earth contamination. Landers, collection tools and sample containers could all carry trace amounts of Earthly biology, so must be equipped with decontamination materials and procedures to protect the precious samples.[image-78]
How do NASA's analog missions, like NEEMO, help scientists develop special sample handling techniques for their exploration programs?
Planetary environments are considered extreme for both robotic and human exploration. Apollo astronauts experienced lower gravity on the moon than on Earth and a very thin atmosphere that required them to wear a space suit with life protection and support systems. When they collected moon rocks, the astronauts didn't know if they were exposing themselves to health hazards, so they wore large bulky gloves and used special sample collection tools and containers. These protective materials and special sample devices were developed in laboratories at Johnson Space Center and then tested in the field by geologists. After the sampling tools and techniques were sufficiently refined, Apollo astronauts were trained to use the techniques developed by the scientists.
Today, ARES scientists are developing tools and techniques for use on planetary surfaces with the same life support requirements and gravity conditions for human exploration as on the moon or Mars but lower gravity environments like near-Earth asteroids as well. Low gravity environments present special obstacles for collecting and containing geologic materials because loose material can drift away and an astronaut can be propelled away from a planetary surface just by hitting a rock with a hammer. NASA's Extreme Environment Mission Operations (NEEMO) is an undersea research facility that allows humans to experience reduced gravity due to the buoyancy provided by water in an environment requiring life support for breathing air. During NEEMO 16, NASA can refine sample collection techniques in an extreme environment and train astronauts to use tools and procedures developed for those unique conditions.
NASA develops tools and techniques during analog missions to ensure the scientific integrity of samples returned from a variety of planetary surfaces both by robots and by human explorers. NASA's returned samples will help scientists understand the formation and evolution of the solar system and determine if life or the conditions for life existed on other plantary bodies. These returned samples will be curated for future generations and allow them to employ advanced techniques not yet available to scientific researchers.
How does this Analog activity fit with NASA's current mission plans?
[image-94]NASA is actively planning to expand the horizons of human space exploration, and with the Space Launch System and the Orion crew vehicle, humans will soon have the ability to travel beyond low Earth orbit. That opens up a solar system of possibilities, and NASA's goal is to send humans to explore an asteroid by 2025. Other destinations may include the moon or Mars and its moons.
Regardless of the destination, the work must start now. NASA is developing the technologies and systems to transport explorers to multiple destinations, each with its own unique – and extreme – space environment. Because sample return requirements are mission specific, the handling protocols are designed specifically for the types of questions the scientific community hopes to answer using samples from a particular planetary destination. ARES curation scientists are in collaboration with the mission architecture engineers to develop mission goals that are aligned with the science goals. ARES scientist participate in analog missions for protocol development and science operations development from mission conception to execution and sample return to ensure that the requirements of the scientific community will be met and the scientific return to the public will be maximized.