In late April, NASA’s radiation researchers at Johnson began a multi-month BEAM radiation experiment by installing a .04 inch (1.1 mm) thick shield onto one of the two REM sensors in the BEAM expandable space habitat produced by Bigelow Aerospace. The station crew produced a hemispherical shield using the 3D printer from Made in Space’s Additive Manufacturing Facility (AMF) on the Space Station.
In the next few months this first shield will be replaced by two successively thicker shields, also 3D printed, with thicknesses of about .13 inches (3.3mm) and .4 inches (10mm), respectively. The difference in measurements from the two REMs—one with a shield and one without—will help better resolve the energy spectra of the trapped radiation particles, particularly those coming from the South Atlantic Anomaly.
Halfway into its planned two-year demonstration attached to the International Space Station, the Bigelow Expandable Activity Module, or BEAM, is thus showing that soft materials can perform as well as rigid materials for habitation volumes in space. The BEAM was launched and attached to station through a partnership between NASA’s Advanced Exploration Systems Division (AES) and Bigelow Aerospace, headquartered in North Las Vegas, Nevada.
NASA and Bigelow are primarily evaluating characteristics directly related to the module’s ability to protect humans from the harsh space environment. Astronauts aboard station work with researchers on the ground to monitor the module’s structural integrity, thermal stability, and resistance to space debris, radiation, and microbial growth.
Researchers at NASA’s Langley Research Center in Hampton, Virginia, continually analyze data from internal sensors designed to monitor and locate external impacts by orbital debris, and, as expected, have recorded a few probable micrometeoroid debris impacts so far. BEAM has performed as designed in preventing debris penetration with multiple outer protective layers exceeding space station shielding requirements.
Over the next several months, NASA and Bigelow will focus on measuring radiation dosage inside the BEAM. Using two active Radiation Environment Monitors (REM) inside the module, researchers at NASA’s Johnson Space Center in Houston are able to take real-time measurements of radiation levels. They have found that Galactic Cosmic Radiation (GCR) dose rates inside the BEAM are similar to other space station modules, and continue to analyze contributions to the daily dose from the Earth’s trapped radiation belts to better understand the shielding properties of the module for application to long-term missions. The space station and the BEAM enjoy a significant amount of protection from Earth’s magnetosphere. Future deep space missions will be far more exposed to energized radiation particles speeding through the solar system, so NASA is actively working on ways to mitigate the effects of radiation events.
Space station crew members have entered the BEAM nine times since its expansion in May 2016. In addition to the REM shielding experiment activities, the crew has swapped out passive radiation badges called Radiation Area Monitors and they routinely collect microbial air and surface samples. These badges and samples are sent back to Earth for standard microbial and radiation analysis at Johnson.
The BEAM technology demonstration is helping NASA to advance and learn about expandable space habitat technology in low-Earth orbit for application toward future human exploration missions. The partnership between NASA and Bigelow supports NASA’s objective to develop a deep space habitat for human missions beyond Earth orbit while fostering commercial capabilities for non-government applications.