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Just hours before the Orion spacecraft crossed the skies on April 1 on its way to the Moon, mechatronics engineer Rodrigo Trevisan Okamoto received confirmation he had been awaiting since the Artemis II mission was announced in 2023. An e-mail from NASA (the United States federal government agency responsible for space exploration programs) informed him that the team of the first crewed flight around the satellite in half a century would carry with them a device developed by him and his team at the São Paulo-based startup Condor Instruments, with initial support from the Innovative Research in Small Businesses Program (Pipe) of the São Paulo Research Foundation (Fapesp).
“NASA’s communication was sudden and caught us by surprise. And only after the mission was completed did we learn that the astronauts had already been using the equipment in tests over the past two years”, Okamoto told Agência Fapesp. Called an actigraph, the device resembles a wristwatch and integrates accelerometers, light, and temperature sensors to accurately map the user’s sleep and wakefulness patterns over days or weeks.
Its operation is based on an activity sensor that monitors the frequency and intensity of arm movements. Through the analysis of these data, it is possible to infer periods of rest (absence of movement) and readiness (presence of movement), accurately recording the individual’s circadian behavior. This approximately 24-hour “biological clock”, which regulates the physical and behavioral functions of most living beings, is primarily influenced by light exposure.
To monitor it, the device features ten embedded sensors that detect exposure to light across different spectral ranges. These data are crucial because they make it possible to characterize not only light intensity, but also its spectral composition throughout the light-dark cycle, the main external regulator responsible for synchronizing the internal biological clock with the environment.
“The light-dark cycle is defined by the Earth’s rotation, and it is from this cycle that the brain anticipates sleep timing. In space, this reference is lost because astronauts may remain under constant light or darkness, depending on their position relative to the Sun”, explained Mario Pedrazzoli Neto, professor at the School of Arts, Sciences and Humanities (EACH) at USP. A specialist in chronobiology, the science that studies biological rhythms and the internal biological clock of living beings, Pedrazzoli coordinated studies that supported the development of the Brazilian actigraph.
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Sleep dysregulation
At the International Space Station (ISS), astronauts witness 16 sunrises and sunsets per day, phenomena that can severely disrupt the sleep-wake cycle. To mitigate this stress, light-emitting diode (LED) systems simulating the terrestrial cycle were installed at the station, helping maintain the crew’s sleep hygiene.
“Due to these factors and others still under investigation, such as the effect of gravity, astronauts tend to experience sleep deprivation. In space, rest is inherently dysregulated”, Pedrazzoli stated.
Because sleep deprivation generates cognitive and motor deficits that may compromise long-duration missions, agencies such as NASA commonly conduct studies to evaluate how irregular light cycles and sleep disorders impact the human body, posing health risks in both the short and long term, the researcher explained.
Researchers linked to the agency are investigating, for example, how factors such as light exposure and caffeine consumption affect crew members’ biological clocks and influence sleep quality. “Chronobiology was born through NASA funding, precisely because of the need to understand how astronauts sleep in space”, Pedrazzoli emphasized.
For the Artemis campaign, the North American space agency launched, in 2023, a study to monitor astronauts’ well-being, activity levels, sleep patterns and interactions. The motivation behind the Archer project (Artemis Research for Crew Health and Readiness) lies in the critical environment of the Orion capsule: a confined and restricted space where the crew faces prolonged biological and psychological challenges, including isolation and radiation during deep-space missions.
To make the study viable, NASA engineers searched the global market for actigraph options capable of monitoring the crew in real time. Condor Instruments’ device attracted the agency’s attention after startup representatives participated in international scientific congresses on chronobiology, sleep and light.
“In 2023, they contacted us in search of a new supplier. Initially, they made a small purchase for the science and engineering sectors. Since then, we have participated in several meetings as the project evolved. The device underwent rigorous testing to assess whether the data met mission requirements and whether it was safe and reliable for flight”, Okamoto recalled.
Although there had been indications of use in Artemis II since the end of 2025, official confirmation came only on launch day. “Only when the spacecraft took off did we know the device was actually onboard”, the engineer said.
Technological differentials
According to Okamoto, the Brazilian actigraph stands out from international competitors by integrating monitoring of motor activity, light exposure and body temperature. The latter parameter is crucial because human body temperature drops between 1°C and 2°C during sleep, a physiological circadian-cycle process that promotes relaxation and energy conservation.
Another distinguishing feature is the measurement of melanopic light — the blue-cyan light spectrum (approximately 490 nanometers) that impacts the human non-visual system. This light activates photosensitive ganglion cells in the retina, inhibiting melatonin and signaling to the brain that it is daytime, thereby increasing alertness and suppressing sleep.
“Cell phones emit light precisely at this wavelength. That is why using these devices at night radically alters the brain’s sleep regulation”, Pedrazzoli stated.
The device also includes an event button, activated synchronously by the astronauts during historic moments, such as on April 6, when Orion reached 406,777 km from Earth – the farthest point ever reached by humans. During the post-mission press conference, commander Reid Wiseman highlighted another use for the device: “Using this device over the past two years allowed us to regain focus whenever we became distracted.”
According to NASA, the actigraph data collected during the flight will be compared with motor coordination tests and pre- and post-launch questionnaires. The goal is to optimize the design of future spacecraft to ensure safety during long-duration missions. “What we learn will help us understand how astronauts can survive and thrive farther from Earth”, the agency states.
Check out the video about the actigraph in the player below:
Journey into space
The actigraph’s trajectory began from a need identified by Pedrazzoli while conducting studies within the Center for Sleep Studies — a Research, Innovation and Dissemination Center (Cepid) funded by Fapesp and linked to the Federal University of São Paulo (Unifesp). The first prototypes were used to evaluate the impact of daylight saving time on the population.
“We realized it was necessary to scale up production to support our research and obtain specialized technical support”, the professor explains. Following a recommendation from Arturo Forner-Cordero, professor at the USP School of Engineering, Pedrazzoli met Okamoto and Luis Filipe Rossi, then master’s students at Poli-USP interested in opening a technology startup. With support from the Pipe-Fapesp program, the engineers transformed the prototype into a high-precision commercial product.
“After the first prototypes with machined parts, we sought Pipe funding from Fapesp to make the business viable”, Okamoto said. Today, the startup exports 80% of its production — from 200 to 300 devices per month — to more than 40 countries, serving major universities and research centers. The device is used in studies ranging from the myopia epidemic in Asia to the recovery of premature babies in neonatal intensive care units.
The current goal is to maintain the partnership with NASA for the next stages of the Artemis campaign, including the landing at the Moon’s south pole scheduled for 2028. “We will do everything we can to continue as suppliers to the agency”, Okamoto concluded.
Written by Elton Alisson, from Agência Fapesp
English version: Nexus Traduções, edited by Denis Pacheco
