{"id":320749,"date":"2025-11-22T01:35:25","date_gmt":"2025-11-21T15:35:25","guid":{"rendered":"https:\/\/www.nasa.gov\/?migration=converted-node-437890"},"modified":"2025-11-22T01:35:25","modified_gmt":"2025-11-21T15:35:25","slug":"what-is-biosentinel","status":"publish","type":"post","link":"https:\/\/www.vibewire.com.au\/?p=320749","title":{"rendered":"What is BioSentinel?"},"content":{"rendered":"
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\"Illustration<\/a><\/figure>
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llustration of BioSentinel\u2019s\u00a0spacecraft flying past the Moon.<\/div>\n
NASA\/Daniel Rutter<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

Editor\u2019s Note: This article was updated Nov. 21, 2025 shortly after BioSentinel’s mission marked three years of operation in deep space<\/em><\/strong>.<\/p>\n

Astronauts live in a pretty extreme environment aboard the International Space Station<\/a>. Orbiting about 250 miles above the Earth in the weightlessness of microgravity, they rely on commercial cargo missions<\/a> about every two months to deliver new supplies and experiments. And yet, this place is relatively protected in terms of space radiation<\/a>. The Earth\u2019s magnetic field shields space station crew from much of the radiation that can damage the DNA in our cells and lead to serious health problems. When future astronauts set off on long journeys deeper into space, they will be venturing into more perilous radiation environments and will need substantial protection. With the help of a biology experiment within a small satellite called BioSentinel, scientists at NASA\u2019s Ames Research Center, in California\u2019s Silicon Valley, are taking an early step toward finding solutions.<\/p>\n

To learn the basics of what happens to life in space, researchers often use \u201cmodel organisms\u201d that we understand relatively well. This helps show the differences between what happens in space and on Earth more clearly. For BioSentinel, NASA is using yeast \u2013 the very same yeast that makes bread rise and beer brew. In both our cells and yeast cells, the type of high-energy radiation encountered in deep space can cause breaks in the two entwined strands of DNA that carry genetic information. Often, DNA damage can be repaired by cells in a process that is very similar between yeast and humans.                             <\/p>\n

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\"Conceptual<\/a><\/figure>
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Conceptual graphic of a radiation particle causing a double-stranded DNA break.<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

BioSentinel set out to be<\/a> the first long-duration biology experiment to take place beyond where the space station orbits near Earth. BioSentinel\u2019s spacecraft is one of 10 CubeSats that launched aboard Artemis I<\/a>, the first flight of the Artemis<\/a> program\u2019s Space Launch System, NASA\u2019s powerful new rocket. The cereal box-sized satellite traveled to deep space on the rocket then flew past the Moon<\/a> in a direction to orbit the Sun.  Once the satellite was in position beyond our planet\u2019s protective magnetic field, the BioSentinel team triggered a series of experiments remotely, activating two strains of the yeast Saccharomyces cerevisiae to grow in the presence of space radiation. Samples of yeast were activated at different time points throughout the six- to twelve-month mission.<\/p>\n

One strain is the yeast commonly found in nature, while the other was selected because it has trouble repairing its DNA. By comparing how the two strains respond to the deep space radiation environment, researchers will learn more about the health risks posed to humans during long-term exploration and be able to develop informed strategies for reducing potential damage.<\/p>\n

During the initial phase of the mission, which began in December 2022 and completed in April 2023, the BioSentinel team successfully operated BioSentinel\u2019s BioSensor hardware \u2013 a miniature biotechnology laboratory designed to measure how living yeast cells respond to long-term exposure to space radiation \u2013 in deep space. The team completed four experiments lasting two-weeks each but did not observe any yeast cell growth. They determined that deep space radiation was not the cause of the inactive yeast cells, but that their lack of growth was likely due to the yeast expiring after extended storage time of the spacecraft ahead of launch.\u00a0<\/p>\n

Although the yeast did not activate as intended to gather observations on the impact of radiation on living yeast cells, BioSentinel\u2019s onboard radiation detector \u2013 that measures the type and dose of radiation hitting the spacecraft \u2013 continues to collect data in deep space.<\/p>\n

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\"Two<\/a><\/figure>
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Jesse Fusco, left, and James Milsk, right, at the BioSentinel command console at the Multi-Mission Operations Center at NASA\u2019s Ames Research Center in Silicon Valley. The team is receiving spacecraft telemetry at the three-year timepoint since the mission launched on Artemis I. BioSentinel continues to fly in its heliocentric orbit, now more than 48 million miles from Earth. <\/div>\n
NASA\/Don Richey<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

NASA\u00a0has extended BioSentinel\u2019s mission to continue collecting valuable deep space radiation data in the unique, high-radiation environment beyond low Earth orbit.<\/p>\n

The Sun has an 11-year cycle,\u00a0in which solar activity rises and falls in the form of powerful solar flares and\u00a0giant eruptions called\u00a0coronal mass ejections<\/a>. As the solar cycle progresses from maximum to a declining phase, scientists expect strong solar activity to continue through 2026, with some of the strongest storms seen during this declining phase. These events send powerful bursts of energy, magnetic fields, and plasma into space which causes the aurora and can interfere with satellite signals.\u00a0Solar radiation events from particles accelerated to high speeds can also pose a threat to astronauts in space.<\/p>\n

Built on a history of small-satellite biology<\/h2>\n

The BioSentinel project builds on Ames\u2019 history of carrying out biology studies in space using CubeSats \u2013 small satellites built from individual units each about four inches cubed. BioSentinel is a six-unit spacecraft weighing about 30 pounds. It houses the yeast cells in tiny compartments inside microfluidic cards \u2013 custom hardware that allows for the controlled flow of extremely small volumes of liquids that will activate and sustain the yeast. Data about radiation levels and the yeast\u2019s growth and metabolism will be collected and stored aboard the spacecraft and then transmitted to the science team back on Earth.<\/p>\n

A reserve set of microfluidic cards containing yeast samples will be activated if the satellite encounters a solar particle event, a radiation storm coming from the Sun that is a particularly severe health risk for future deep space explorers. <\/p>\n

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\"BioSentinel<\/a><\/figure>
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BioSentinel\u2019s microfluidics card, designed at NASA\u2019s Ames Research Center in Silicon Valley, California, will be used to study the impact of interplanetary space radiation on yeast. Once in orbit, the growth and metabolic activity of the yeast will be measured using a three-color LED detection system and a dye that provides a readout of yeast cell activity. Here, pink wells contain actively growing yeast cells that have turned the dye from blue to pink color.<\/div>\n
NASA\/Dominic Hart<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

Multiple BioSentinels will compare various gravity and radiation environments<\/h2>\n

In addition to the pioneering BioSentinel mission that will traverse the deep space environment, identical experiments take place under different radiation and gravity conditions. One ran on the space station, in microgravity that is similar to deep space, but with comparatively less radiation. Other experiments took place on the ground, for comparison with Earth\u2019s gravity and radiation levels. These additional versions show scientists how to compare Earth and space station-based science experiments \u2013 which can be conducted much more readily \u2013 to the fierce radiation that future astronauts will encounter in space.<\/p>\n

Taken together, the BioSentinel data will be critical for interpreting the effects of space radiation exposure, reducing the risks associated with long-term human exploration, and confirming existing models of the effects of space radiation on living organisms. <\/p>\n

Milestones<\/h2>\n