Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Human-rating is a critical certification process that validates the safety, reliability, and suitability of space systems—including orbiters, launch vehicles, rovers, spacesuits, habitats, and other crewed elements—for human use and interaction. This process ensures that systems are designed not only to protect human life but also to accommodate human needs and effectively integrate human capabilities. Human-rating requires that systems can tolerate failures, provide life-sustaining environments, and offer the crew sufficient control and situational awareness. NASA’s standards, such as a maximum allowable probability of loss of crew of 1 in 500 for ascent or descent, reflect the agency’s commitment to minimizing risk in human spaceflight.
Over the decades, the concept of human-rating has evolved significantly. Early efforts focused primarily on basic crew survival and redundancy in critical systems. However, as missions became more complex and extended in duration, the scope of human-rating expanded to include human performance, health management, and the psychological and physiological demands of space travel. Today, human-rating is a multidisciplinary effort that integrates engineering, medical, and operational expertise to ensure that systems are not only survivable but also support optimal human function in extreme environments.
Modern human-rating standards—such as NASA Procedural Requirements (NPR) 8705.2C, NASA-STD-8719.29 (Technical Requirements for Human-Rating), and NASA-STD-3001 (Human System Standards)—form the foundation of NASA’s approach. These documents emphasize risk-informed design, fault tolerance, human factors engineering, and the ability to recover from hazardous situations. They also provide detailed guidance on system safety, crew control interfaces, abort capabilities, and environmental health requirements. Together, they ensure that human spaceflight systems are designed to accommodate, utilize, and protect the crew throughout all mission phases.
The human-rating certification process is rigorous and iterative. It involves extensive testing, validation, and verification of system performance, including simulations, flight tests, and integrated safety analyses. Certification also requires continuous monitoring, configuration control, and maintenance to ensure that systems remain in their certified state throughout their operational life. Importantly, human-rating is not just a checklist of technical requirements—it represents a cultural commitment to crew safety. It fosters a mindset in which every team member, from design engineers to mission operators, shares responsibility for protecting human life.
To support program and project teams in applying these standards, NASA has conducted cross-reviews of documents like NASA-STD-3001 in relation to NASA-STD-8719.29. These assessments help identify relevant human health and performance requirements that should be considered during system design and development. While not a substitute for detailed applicability assessments, such reviews provide valuable guidance for integrating human-rating principles into mission planning and vehicle architecture.
NASA/Sydney Bergen-Hill Read More About Human Rating Share
Details
Last Updated Aug 15, 2025 Related Terms
General Artemis Commercial Space Humans in Space International Space Station (ISS) Office of the Chief Health and Medical Officer (OCHMO) Spacesuits Keep Exploring Discover Related Topics
Human Spaceflight Standards
The Human Spaceflight & Aviation Standards Team continually works with programs to provide the best standards and implementation documentation to…
Technical Briefs
Technical Briefs are available for standards that offer technical data, background, and application notes for vehicle developers and medical professionals.…
Aerospace Medical Certification Standard
This NASA Technical Standard provides medical requirements and clinical procedures designed to ensure crew health and safety and occupational longevity…
Human Integration Design Handbook
A companion document to NASA-STD-3001 Volume 2 is the Human Integration Design Handbook (HIDH). The HIDH is a compendium of…
View the full article
-
By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA now is accepting proposals from student teams for a contest to design, build, and test rovers for Moon and Mars exploration through Sept. 15.
Known as the Human Exploration Rover Challenge, student rovers should be capable of traversing a course while completing mission tasks. The challenge handbook has guidelines for remote-controlled and human-powered divisions.
The cover of the HERC 2026 handbook, which is now available online. “Last year, we saw a lot of success with the debut of our remote-controlled division and the addition of middle school teams,” said Vemitra Alexander, the activity lead for the challenge at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “We’re looking forward to building on both our remote-controlled and human-powered divisions with new challenges for the students, including rover automation.”
This year’s mission mimics future Artemis missions to the lunar surface. Teams are challenged to test samples of soil, water, and air from sites along a half-mile course that includes a simulated field of asteroid debris, boulders, erosion ruts, crevasses, and an ancient streambed. Human-powered rover teams will play the role of two astronauts in a lunar terrain vehicle and must use a custom-built task tool to manually collect samples needed for testing. Remote-controlled rover teams will act as a pressurized rover, and the rover itself will contain the tools necessary to collect and test samples onboard.
“NASA’s Human Exploration Rover Challenge creates opportunities for students to develop the skills they need to be successful STEM professionals,” said Alexander. “This challenge will help students see themselves in the mission and give them the hands-on experience needed to advance technology and become the workforce of tomorrow.”
Seventy-five teams comprised of more than 500 students participated in the agency’s 31st rover challenge in 2025. Participants represented 35 colleges and universities, 38 high schools, and two middle schools, across 20 states, Puerto Rico, and 16 nations around the world.
The 32nd annual competition will culminate with an in-person event April 9-11, 2026, at the U.S. Space & Rocket Center near NASA Marshall.
The rover challenge is one of NASA’s Artemis Student Challenges, reflecting the goals of the Artemis campaign, which seeks to explore the Moon for scientific discovery, technology advancement, and to learn how to live and work on another world as we prepare for human missions to Mars. NASA uses such challenges to encourage students to pursue degrees and careers in the fields of science, technology, engineering, and mathematics.
Since its inception in 1994, more than 15,000 students have participated in the rover challenge – with many former students now working at NASA or within the aerospace industry.
To learn more about HERC, visit:
https://www.nasa.gov/roverchallenge/
Share
Details
Last Updated Aug 15, 2025 EditorBeth RidgewayLocationMarshall Space Flight Center Related Terms
Marshall Space Flight Center Explore More
4 min read NASA IXPE’s ‘Heartbeat Black Hole’ Measurements Challenge Current Theories
Article 3 days ago 6 min read NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star
NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory have teamed up to identify a…
Article 3 weeks ago 4 min read Stay Cool: NASA Tests Innovative Technique for Super Cold Fuel Storage
Article 4 weeks ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
Roscosmos cosmonaut Kirill Peskov, left, NASA astronauts Nichole Ayers and Anne McClain, and JAXA (Japan Aerospace Exploration Agency) astronaut Takuya Onishi are seen inside the SpaceX Dragon spacecraft on the company’s recovery ship shortly after splashdown in the Pacific Ocean off the coast of San Diego, California, on Aug. 9, 2025.Credit: NASA/Keegan Barber After spending almost five months in space, NASA’s SpaceX Crew-10 astronauts will discuss their science mission aboard the International Space Station during a news conference at 4:15 p.m. EDT, Wednesday, Aug. 20, from the agency’s Johnson Space Center in Houston.
NASA astronauts Anne McClain and Nichole Ayers, and JAXA (Japan Aerospace Exploration Agency) astronaut Takuya Onishi will answer questions about their mission. The crew returned to Earth on Aug. 9.
Live coverage of the news conference will stream on the agency’s YouTube channel. Learn how to watch NASA content through a variety of additional platforms, including social media.
This event is open to media to attend in person or virtually. For in-person, media must contact the NASA Johnson newsroom no later than 12 p.m., Tuesday, Aug. 19, at: jsccommu@mail.nasa.gov or 281-483-5111. Media participating by phone must dial into the news conference no later than 10 minutes prior to the start of the event to ask questions. Questions also may be submitted on social media using #AskNASA. A copy of NASA’s media accreditation policy is available on the agency’s website.
The crew spent 146 days aboard the orbiting laboratory, traveling nearly 62,795,205 million miles and completing 2,368 orbits around Earth. While living and working aboard the station, the crew completed hundreds of science experiments and technology demonstrations. The latest NASA space station news, images, and features are available on Instagram, Facebook, and X.
NASA’s Commercial Crew Program has delivered on its goal of safe, reliable, and cost-effective transportation to and from the International Space Station from the United States through a partnership with American private industry. This partnership is opening access to low Earth orbit and the International Space Station to more people, more science, and more commercial opportunities. For almost 25 years, people have continuously lived and worked aboard the space station, advancing scientific knowledge and demonstrating new technologies that enable us to prepare for human exploration of the Moon as we prepare for Mars.
Learn more about NASA’s Commercial Crew Program at:
https://www.nasa.gov/commercialcrew
-end-
Joshua Finch
Headquarters, Washington
202-358-1100
joshua.a.finch@nasa.gov
Courtney Beasley
Johnson Space Center, Houston
281-483-5111
courtney.m.beasley@nasa.gov
Share
Details
Last Updated Aug 14, 2025 EditorJessica TaveauLocationNASA Headquarters Related Terms
Commercial Crew International Space Station (ISS) ISS Research Johnson Space Center View the full article
-
By NASA
Explore This Section Earth Earth Observer Editor’s Corner Feature Articles Meeting Summaries News Science in the News Calendars In Memoriam Announcements More Archives Conference Schedules Style Guide 19 min read
A Tapestry of Tales: 10th Anniversary Reflections from NASA’s OCO-2 Mission
When woven together, the tapestry of experiences of staff and scientists provide the complete picture of OCO-2.
Breathe in… Breathe out.
This simple rhythm sets the foundation of life on Earth – and it’s a pattern that a NASA satellite has been watching from space for over a decade.
On July 2, 2024, NASA’s Orbiting Carbon Observatory-2 (OCO-2) celebrated 10 years since its launch. Built by NASA/Jet Propulsion Laboratory (NASA/JPL), OCO-2 is now viewed as the gold standard for carbon dioxide (CO2) measurements from space and has quietly become a powerful driver of technological, ecological and even economic progress – including providing unexpected insights into plant health, crop-yield forecasting, drought early warning systems, and forest and rangeland management.
While the mission can point to many scientific achievements – some of which will be highlighted in the pages that follow – these accomplishments have occurred in the context of a larger human story. Scientists from around the world have come together to bring the important data from this satellite to the broader community, making OCO-2 the success that it is today.
This article provides readers an introduction to several transformative characters in this carbon story. The text peers behind the scenes to reveal the circuitous path that scientists and engineers must navigate to take a brilliant scientific concept and turn it into flight hardware that can be launched into space to make beneficial observations. The article depicts milestones that mark the mission’s successes, but also the failures, dead ends, long nights, and discouragements that make up the complexity of any science story.
2003: The First OCO Science Team Meeting
Measuring CO2 from space: Great idea but can it really be done?
When the idea for OCO was first proposed, it wasn’t universally embraced. At the time, more than a few experts scoffed at the idea that CO2 could be measured from space. Unlike nitrogen and oxygen, which are the dominant components of Earth’s atmosphere, CO2 is a trace gas, often no more than a few hundred parts per million. Miniscule, elusive, and nomadic, these measurements, though challenging, are crucial because of the important role CO2 plays in global climate.
In April 2003, a handful of hopeful scientists gathered at the California Institute for Technology (Caltech) for the first OCO Science Team meeting. To mark the occasion, they took a break during the meetings and lined up for a group photo – see Photo 1. Upon returning to work, they took up the arduous task of determining how to measure CO2 from space with a satellite and instrument hardware that simply did not exist.
OCO-2 was developed as part of NASA’s Earth System Science Pathfinder program, which supports small, low-cost missions that can still provide tremendous value for high-impact goals. The satellite carries a high-resolution spectrometer that collects data in three, narrow spectral bands. These spectral bands follow a divide and conquer strategy – two measure the clear “fingerprint” that CO2 leaves when it absorbs sunlight, and one takes the same measurement for oxygen (O2). The satellite is able to estimate CO2 concentrations by comparing the CO2 and O2 measurements.
Photo 1. A photo of participants during the original OCO Science Team meeting in 2003 at the California Institute of Technology. Photo credit: NASA/Jet Propulsion Laboratory OCO-2 2014: A Night at Vandenberg Air Force Base – To Launch or Not to Launch
A Mother and daughter await the midnight launch.
On a warm July evening in 2014, Vivienne Payne [JPL—current OCO-2 Project Scientist] would normally have tucked her four-year-old daughter into bed. But this night was special. They were lined up in a crowd waiting for a bus to take them to Vandenberg Air Force Base (now Space Force Base) in California. The group huddled in the chill night air awaiting the launch of the OCO satellite into the cosmos.
Shortly after midnight, hundreds of guests spread blankets across the gravelly ground to make their wait more comfortable. The air was charged with excitement. The participants waited quietly, murmuring to one another while the soft slosh of the Pacific Ocean offered a steady pendulum counting down to the impending launch. Like most people there that night, Vivienne felt upbeat and excited, but she also understood the gravity of the moment – a lot was riding on this launch.
While Vivienne had not been part of OCO since inception – having joined the project in 2012 – she knew OCO’s story. The first launch in 2009 ended in failure – when a faulty launch vehicle doomed the first OCO to a watery grave just moments after launch. In the aftermath, the OCO community were left in limbo, unsure if the project would survive. All was not lost. The Japan Aerospace Exploration Agency (JAXA) had successfully launched the Greenhouse-gas Observing satellite (GOSAT or IBUKI, Japanese for “breath”) that same year. This launch gave the OCO team an opportunity to test and refine their methods and algorithms using data from GOSAT.
As the gravel poked through the thick flannel blankets, Vivienne shifted uncomfortably waiting for the interminable countdown to reach its conclusion – and then everything stopped. A technical issue was detected, triggering a command to abort the launch.
Vivienne tried to explain to her disappointed daughter that this was simply how things went with space work. Sometimes you put in 1000 work-years of labor, get up in the middle of the night, and sit on uneven ground just to have everything stopped, unceremoniously.
Fortunately, the problem was quickly resolved, and the launch was rescheduled for the very next night. The participants returned to the staging site – rinse and repeat. This time Vivienne’s daughter was decidedly more sluggish. At 3:00 AM PDT, OCO-2 launched flawlessly into space. Unfortunately, a layer of fog obscured the spectators’ view. While it could not be seen, the resounding boom of the rocket taking off could be heard for miles.
For Vivienne, the sonic boom shocked the ears and rumbled through the bodies of the assembled crowd, who erupted in cheers. Having invested a lot of her time in the OCO project during the past two years, she was thrilled to see a successful launch.
As they returned to their hotel, Vivienne’s daughter remained unimpressed. “Mummy, let’s not do that again,” she said as she splayed out on the hotel bed and soon fell fast asleep.
2014: OCO-2 Joins A Larger Earth Observing Story
Leading to surprising new insights about how we see plants – and fires.
When OCO-2 launched in 2014, it joined a tightly coordinated group of Earth-observing satellites known as the Afternoon Constellation (or the “A-Train”) – see Figure 1. Flying in formation, the satellites could combine their observations to unlock more than any one mission could reveal on its own. Around the same time, scientists discovered that OCO-2 could do more than measure CO2 – it could also detect signs of plant health.
Figure 1. As of January 2024, the international Afternoon Constellation (“A-Train”) has two missions remaining: OCO-2 and GCOM-W. While Aqua and Aura continue to collect science data, the satellites have both slowly drifted out of the constellation – and will soon be decommissioned. CALIPSO ended its scientific mission on August 1, 2023. CloudSat radar operations ceased on December 20, 2023. Figure credit: NASA This discovery opened the possibilities for many different people, including Madeleine Festin, a former wildland firefighter in Montana, to work with OCO-2 data through an internship sponsored by the DEVELOP program, under the Earth Action element (formerly known as Applied Sciences) of NASA’s Earth Science Division.
When she was on the ground battling fires, Madeleine faced the harsh reality that fire prediction is notoriously difficult. In the field, she might be surrounded by smoke with just 20 ft (6 m) of visibility and red flames tearing through dry brush. Through her internship, she’s continued to tackle fires – just from a very different vantage point.
OCO-2 can detect the faint glow given off by plants during photosynthesis. This glow, called solar-induced fluorescence (SIF), offers a fast, sensitive indicator of plant health – see Figure 2. While other satellite-based tools, such as soil moisture or vegetation indices often detect stress only after damage has already occurred, SIF values drop the moment photosynthesis slows down – even if the plant still looks green. These data open the door to new applications: monitoring crop performance, identifying flood-damaged areas, and tracking drought before it sparks wildfires. That’s exactly how Madeleine is now using the data.
Madeleine’s team, a collaboration between OCO-2 scientists and the U.S. Forest Service, is working to update fire-risk models – some of which were developed in the 1980s – by incorporating SIF data.
“It’s fulfilling to know that you’re helping people,” Madeleine says. “And it’s nice to see science and firefighting work align.”
What makes the data even more powerful is OCO-2’s synergy with its A-Train counterpart, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’S Aqua platform. MODIS contributes land-cover information that, when paired with OCO-2’s SIF measurements, creates a detailed, global dataset of plant photosynthesis far beyond what either satellite could produce on its own. This example is a perfect synergistic pairing of measurements the A-Train has made possible. This information gives Madeleine and her team a better foundation for improving fire prediction tools.
“When firefighting, I used to hear about all these fire indices and metrics, and never knew what they meant,” Madeleine says. “Now, I’m learning the science behind it. And it’s interesting to think about how to get that information to firefighters on the ground, without overburdening them. What do they really need to know, and how can we deliver it in a way that helps?”
Figure 2. OCO-2 can measure plant health and photosynthesis from space. Puente Hills in eastern Los Angeles County, CA was once one of the largest landfills in the United States. The landfill has since been closed and its surface replanted to resemble a natural hill rising above the surrounding densely populated neighborhoods. These two images show how solar induced fluorescence (SIF), or “plant glow,” measured from OCO-2 and OCO-3 can be used to study urban greenery. The satellite image of the landfill and surrounding area [left] is followed by the SIF data overlay [right]. It is possible to compare the photosynthetic activity in the reclaimed landfill to nearby green spaces, as well as the plant health in the surrounding neighborhoods. Figure credit: NASA/Jet Propulsion Laboratory OCO-2, OCO-3 2016: Trekking to the Desert to Calibrate OCO-2
A technologist tramps around in the desert for instrument calibration.
Carol Bruegge [OCO-2—Technologist] had been to the Nevada desert so many times that she knew the way by heart. After skirting the Sequoia Forest and stopping for the night just past the Nevada border, she led a caravan of scientists along Highway 6 to mile marker 100, turning right onto a dirt road between two fence posts. Traveling 10 mi (16.5 km) down the road, a cloud of dust raised up from the car tires before the vehicle came to a stop at their destination – a patch of spindly instruments hammered into the barren desert floor. A big plaque marked the spot with the NASA logo and the words, “Satellite Test Site.” Standing under vast blue sky, Carol felt like she’d come home. Over the past few years, Carol had grown accustomed to leading these summer expeditions to Railroad Valley, NV. Often the team from JPL is joined by guests from Japan and other international colleagues representing various satellite missions – see Photo 2.
Photo 2. Group photo at Railroad Valley, NV during a summer field campaign. Carol Bruegge [OCO-2—Technologist, fifth from left] joins JPL members and guests from Japan working on the Greenhouse-gas Observing satellite. The group included [left to right] Hirokazu Yamamoto, Atsushi Yasuda, Hideaki Nakajima, Kei Shiomi, Thomas Pongetti, Bruegge, Dejian Fu, Junko Fukuchi, Makoto Saito, and Rio Kajiura. Photo credit: Tom Pongetti Carol knew that a successful field campaign required that they protect the instruments from the thick corrosive salt on the ground. Then the work could begin. The team hiked through the desert, collecting data that would ensure that OCO-2 could continue to provide high-quality data. As they hiked, the team carried hand-held spectrometers and measured the reflection of sunlight off Earth’s surface – timed precisely to match the moment the satellite passes overhead. By comparing the satellite’s readings with the ground-based measurements, the team can check the accuracy of the satellite readings. Reflection is one ingredient used in calculating the concentration of CO2 in the overlying air.
This remote location in Nevada wasn’t chosen by accident. In this part of the desert, the ground is perfectly flat, free of plants, and surrounded by ground littered with salt. This smooth, bare surface means no bumps and textures could disrupt the signal. For satellite calibration, it doesn’t get better than this.
2018: A Contentious Meeting in Noordwijk, Netherlands Sparks A Revolution
Could OCO-2 data be used to construct a nation-by-nation CO2 budget?
David Crisp [JPL emeritus—original OCO Principal Investigator and former OCO Science Team Leader] was tired. He didn’t know if it was jet lag or a reflection of the 16- to 18-hour workdays that had persisted for weeks. This particular week had started with a 10-hour flight from Los Angeles to the Netherlands. Now, he was standing in front of carbon scientists who had gathered from around the world.
“We need to put together a team that will be brave enough to make a CO2 budget, nation-by-nation,” David said.
His statement was met with thoughtful silence. Neither the data nor the models were ready. The consensus in the room was that the proposed venture may not work. David was magnanimous toward his critics, but he persisted with his idea.
Despite the rocky start, David met with representatives in charge of creating national emission inventories. He could see exasperation on their faces – running ragged, short-staffed, and trying to tally up every single barrel of oil and bushel of coal burned within their country’s boundaries. Even more challenging was tallying other tasks, such as deforestation and agricultural practices. David firmly believed that if OCO-2 could provide independent estimates from space as promised, it would provide the on-the-ground “carbon accountants” a reliable comparison – see Figure 3.
“We might have a satellite that can help,” Dave told them.
Although David has since retired, his perseverance is now bearing fruit. What began as a hypothetical solution is now much closer to reality. OCO-2’s high-precision measurements can now detect CO2 linked not just to countries, but large cities, industrial zones, and even individual power plants – all while researchers continue perfecting efforts to identify contributions from specific city sectors. OCO-2 provides a valuable, independent reference that nations can use to track the progress of their emission inventories. Researchers have created an entire OCO-2-sourced database of CO2 estimates by country, available through the U.S. Greenhouse Gas Center.
Figure 3. A map of the net emissions and removals of carbon dioxide (CO2) for 2015–2020 using estimates informed by OCO-2. Green depressions represent countries that remove more CO2 than emitted. Tan or red ridges represent countries with higher CO2 emissions than removed. Figure credit: NASA Science Data Visualization Studio 2019: Another OCO Takes flight – This Time to The International Space Station
Using “spare parts” to get more details about plant health and the carbon cycle.
After completing OCO-2, enough spare parts remained to construct a sister mission — OCO-3, which launched in 2019 to continue the work of measuring CO2 in the atmosphere from the International Space Station (ISS). The satellite’s unique orbit gives it a new vantage point. While OCO-2 continues to orbit Earth in a near-polar path, OCO-3 travels aboard the ISS in a lower, shifting orbit that allows it to study different areas of Earth’s surface at different times of day. OCO-3 also features a special scanning mode, called the snapshot area mapping (SAM) that lets scientists zoom in on areas of interest (e.g., cities or volcanoes) to study carbon emissions and vegetation in greater detail. Together, OCO-2 and OCO-3 provide complementary perspectives on Earth’s carbon cycle and plant health at space and time resolutions that have not been possible from space before.
2021: LA During a Pandemic Is a Far Cry from Finland
A data scientist foregoes saunas and berry-picking to make the dream of OCO-2 a reality.
Otto Lamminpää [JPL—Data Scientist] opened the picture his sister had texted him. His family looked back with wide smiles, holding buckets overflowing with scarlet berries and framed by the velvety firs of Finland. It had been almost two years since he’d seen them in person. He’d moved to Los Angeles to work at JPL on the OCO-2 and OCO-3 mission just as the COVID-19 pandemic engulfed the planet – see Photo 3.
Photo 3. Otto Lamminpää and Amy Braveman [both from JPL] in Finland. Photo credit: Otto Lamminpää Otto had never gone a week without seeing his family or skipped a berry-hunting party in the forests of his native Finland. With the forced distance, he placed himself in his home forests in his mind. He used this memory to marvel at the capacity of the vast forests to “breathe in” CO2 and convert it into trunks, branches, and roots through photosynthesis. With the COVID-19-imposed travel restrictions, Otto wasn’t sure how long he’d have to wait to go back home.
But whenever that homecoming occurred, Otto knew that a piece of OCO-2 would be waiting for him. North of the Arctic Circle in Sodankylä, a cluster of Earth instruments nestled in a snowy meadow include a field station that is part of the Total Carbon Column Observing Network (TCCON) of Fourier Transform Spectrometers (FTS). These stations act as OCO-2 and OCO-3’s “ground crew.” As the satellites orbit Earth, the FTS simultaneously measures direct solar spectra in the near-infrared spectral region, which allows for retrieval of column-averaged CO2 concentrations, as well as other key atmospheric constituents, over the snowy meadow. Back in the lab, Otto, along with other OCO-2 and OCO-3 scientists, compare the data collected at the field station to the satellite data. This feature was detailed in The Earth Observer article, titled “Integrating Carbon from the Ground Up: TCCON Turns Ten,” was published July–August 2014, Volume 26 issue 4, pp. 13–17).
Figure 4. Global map of the ground stations, also known as the Total Carbon Column Observing Network (TCCON). The red dots mark the active ground observation stations to validate OCO-2 and OCO-3 data. Figure credit: NASA-JPL/OCO-2 The station in Finland is one of about 30 similar TCCON sites scattered across the world, located in a variety of settings, from isolated tropical islands to the Pacific rim of Asia – see Figure 4. The stations in the far north play an especially valuable role since satellites often struggle to accurately measure CO2 over snow-covered ground. Therefore, reliable measurements from the ground stations become crucial to adjust and improve the satellite data.
Validation efforts such as the one described here are crucial to satellite observations. Comparisons between OCO-2 and TCCON show agreement is good, with a less than 1 ppm difference. It’s an impressive level of accuracy for a satellite orbiting more than 435 mi (700 km) away in polar orbit. The “ground truth” data collected at these field sites help to ensure that the satellite is accurately measuring “Earth’s breathing.”
For Otto, not just his family, but OCO-2 and OCO-3 itself was calling him home. As the pandemic began to ease, he returned to Finland to pick berries, jump in the sauna every night, and follow it up with snow angels. The homecoming was also coordinated with a trip past the Arctic Circle to the TCCON field station. The mission was part of him. Wherever he was, OCO-2 and OCO-3 would be there, too.
2023: The Annual Science Team Meeting Continues
Tracking changes in soil moisture during a colorful fall day.
Saswati Das [JPL—Postdoctoral Fellow] had missed the magnificent display of fall colors in deciduous forests of the East Coast of the United States. She’d seen nothing of the sort since moving to Los Angeles in 2022 to work on OCO-2. Before that, she’d been working on her Ph.D. at the Virginia Polytechnic Institute and State University (Virginia Tech), where the surrounding mountain peaks, meadows, and forests burned and sparked with crimson and gold in the autumn – see Photo 4. Now she was in another mountain town, Boulder, CO, to attend the OCO science team meeting. The aspens glittered like golden lanterns as her gang carpooled up the Flatiron Range to the science institute at Table Mesa.
Photo 4. Saswati Das takes a break from her Ph.D studies at nearby Virginia Tech (located in Blacksburg, VA) to enjoy the famous fall colors in the mountains of West Virginia. Photo credit: Saswati Das The research presented that week spanned a variety of topics. OCO-2 was being used to develop early drought forecasts. Because of its ability to detect the SIF “glow” that results from plant photosynthesis, OCO-2 can hint at flash droughts as early as three months before environmental decay unfold. By pairing OCO-2 data from other satellites, such as soil moisture data from NASA’s Soil Moisture Active Passive (SMAP) mission, scientists have opened a new window into drought forecasts and how water supply affects plant growth.
Surprises about our planet have also emerged. The tropical rainforests, long nicknamed the “lungs” of our planet, don’t always inhale and store carbon. At times, this region can exhale CO2, such as during the 2015–2016 El Niño. That period saw large tropical forests temporarily transform into net carbon sources – see Figure 5. The driver for this shift varied by region. The Amazon rainforest was driven by drought. Central Africa was driven by unusually high temperatures. Indonesia was driven by widespread fires.
Figure 5. The 2015–2016 El Niño increased the net carbon dioxide released by Earth’s tropical regions into the atmosphere. Figure credit: NASA-JPL/Caltech Data from OCO-2 and OCO-3 have also been used to study emissions from both cities and large power plants. This approach offers a new way to track changing emissions over time – without needing to continuously measure them on the ground. In addition, scientists are combining the satellite data with wind models and urban maps to trace CO2 to its sources (e.g., factories, ships, and roadways), helping to disentangle emissions from overlapping city sectors. These methods have been used to isolate industrial emissions in places, such as Europe, China, as well as over cities, such as Los Angeles, Paris, and Seoul. It has also revealed pandemic-era drops in traffic-related CO2 and increases in CO2 tied to shipping backlogs at the port. Two representatives from the World Bank shared how they used data from OCO-2 to demonstrate that building subway systems in cities can lower emissions. The goal is to eventually use these tools to evaluate local strategies (e.g., bike lanes and public transit) to reduce local carbon footprints.
When massive wildfires blazed through Australian forests and bushland in 2019, researchers used OCO-2 data to study the unfolding crisis. OCO-2 captured the increase in atmospheric CO2, and scientists used this data to refine estimates of how these events contribute to the global carbon budget.
As her mind wandered from the rich research she’d been immersed in for the past hour, Saswati spied Otto Lamminpää across the aisle in the wood-paneled auditorium. She thought back to the forests she loved on the East Coast, and the forests in Finland where Otto had grown up. OCO-2 was telling a story about the role that forests play in absorbing carbon and how this has changed over time.
2025 and Beyond
The Tapestry Continues to Expand…
In many ways, OCO-2 has had a long and unexpected journey. So has Hannah Murphy, another DEVELOP intern who will be starting a Master’s degree at Hunter College in New York in Fall 2025. She’s studied art and worked as a set designer in Los Angeles. She never pictured herself working with satellite data, but then she saw how visual it could be. The glowing, evocative images of Earth from space spoke to her artistic heart.
Now, Hannah works on SIF data as a 2025 NASA DEVELOP intern with the OCO-2 team, developing tools for wildfire risks. This project in particular hits close to home for Hannah, because she lived through the wildfires that tore through Los Angeles in January 2025. Although she remained safe, she knew several people who lost their homes, and the air was unsafe to breathe for weeks.
Just a few short months later, Hannah began studying the data from OCO-2. She is now part of the new generation of researchers that will take the mission’s remote sensing data and pave the way for implementing the findings to benefit society. Hannah understands, on a personal level, how closely our lives are linked to Earth systems that satellites, such as OCO-2 and OCO-3, study from space.
OCO-2 (and OCO-3) are built to study CO2 and plant health, but its impact goes deeper to the connections that tie our atmosphere, ecosystems, and lives together. That work continues to the new generation of scientists – one breath at a time.
Mejs Hasan
NASA/Jet Propulsion Laboratory
mejs.hasan@jpl.nasa.gov
Alan Ward
NASA’s Goddard Space Flight Center/Global Science & Technology Inc.
alan.b.ward@nasa.gov
Share
Details
Last Updated Aug 12, 2025 Related Terms
Earth Science View the full article
-
By NASA
NASA’s Nancy Grace Roman Space Telescope will be a discovery machine, thanks to its wide field of view and resulting torrent of data. Scheduled to launch no later than May 2027, with the team working toward launch as early as fall 2026, its near-infrared Wide Field Instrument will capture an area 200 times larger than the Hubble Space Telescope’s infrared camera, and with the same image sharpness and sensitivity. Roman will devote about 75% of its science observing time over its five-year primary mission to conducting three core community surveys that were defined collaboratively by the scientific community. One of those surveys will scour the skies for things that pop, flash, and otherwise change, like exploding stars and colliding neutron stars.
These two images, taken one year apart by NASA’s Hubble Space Telescope, show how the supernova designated SN 2018gv faded over time. The High-Latitude Time-Domain Survey by NASA’s Nancy Grace Roman Space Telescope will spot thousands of supernovae, including a specific type that can be used to measure the expansion history of the universe.Credit: NASA, ESA, Martin Kornmesser (ESA), Mahdi Zamani (ESA/Hubble), Adam G. Riess (STScI, JHU), SH0ES Team Called the High-Latitude Time-Domain Survey, this program will peer outside of the plane of our Milky Way galaxy (i.e., high galactic latitudes) to study objects that change over time. The survey’s main goal is to detect tens of thousands of a particular type of exploding star known as type Ia supernovae. These supernovae can be used to study how the universe has expanded over time.
“Roman is designed to find tens of thousands of type Ia supernovae out to greater distances than ever before,” said Masao Sako of the University of Pennsylvania, who served as co-chair of the committee that defined the High-Latitude Time-Domain Survey. “Using them, we can measure the expansion history of the universe, which depends on the amount of dark matter and dark energy. Ultimately, we hope to understand more about the nature of dark energy.”
Probing Dark Energy
Type Ia supernovae are useful as cosmological probes because astronomers know their intrinsic luminosity, or how bright they inherently are, at their peak. By comparing this with their observed brightness, scientists can determine how far away they are. Roman will also be able to measure how quickly they appear to be moving away from us. By tracking how fast they’re receding at different distances, scientists will trace cosmic expansion over time.
Only Roman will be able to find the faintest and most distant supernovae that illuminate early cosmic epochs. It will complement ground-based telescopes like the Vera C. Rubin Observatory in Chile, which are limited by absorption from Earth’s atmosphere, among other effects. Rubin’s greatest strength will be in finding supernovae that happened within the past 5 billion years. Roman will expand that collection to much earlier times in the universe’s history, about 3 billion years after the big bang, or as much as 11 billion years in the past. This would more than double the measured timeline of the universe’s expansion history.
Recently, the Dark Energy Survey found hints that dark energy may be weakening over time, rather than being a constant force of expansion. Roman’s investigations will be critical for testing this possibility.
Seeking Exotic Phenomena
To detect transient objects, whose brightness changes over time, Roman must revisit the same fields at regular intervals. The High-Latitude Time-Domain Survey will devote a total of 180 days of observing time to these observations spread over a five-year period. Most will occur over a span of two years in the middle of the mission, revisiting the same fields once every five days, with an additional 15 days of observations early in the mission to establish a baseline.
This infographic describes the High-Latitude Time-Domain Survey that will be conducted by NASA’s Nancy Grace Roman Space Telescope. The survey’s main component will cover over 18 square degrees — a region of sky as large as 90 full moons — and see supernovae that occurred up to about 8 billion years ago.Credit: NASA’s Goddard Space Flight Center “To find things that change, we use a technique called image subtraction,” Sako said. “You take an image, and you subtract out an image of the same piece of sky that was taken much earlier — as early as possible in the mission. So you remove everything that’s static, and you’re left with things that are new.”
The survey will also include an extended component that will revisit some of the observing fields approximately every 120 days to look for objects that change over long timescales. This will help to detect the most distant transients that existed as long ago as one billion years after the big bang. Those objects vary more slowly due to time dilation caused by the universe’s expansion.
“You really benefit from taking observations over the entire five-year duration of the mission,” said Brad Cenko of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the other co-chair of the survey committee. “It allows you to capture these very rare, very distant events that are really hard to get at any other way but that tell us a lot about the conditions in the early universe.”
This extended component will collect data on some of the most energetic and longest-lasting transients, such as tidal disruption events — when a supermassive black hole shreds a star — or predicted but as-yet unseen events known as pair-instability supernovae, where a massive star explodes without leaving behind a neutron star or black hole.
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
This sonification that uses simulated data from NASA’s OpenUniverse project shows the variety of explosive events that will be detected by NASA’s Nancy Grace Roman Space Telescope and its High-Latitude Time-Domain Survey. Different sounds represent different types of events, as shown in the key at right. A single kilonova seen about 12 seconds into the video is represented with a cannon shot. The sonification sweeps backward in time to greater distances from Earth, and the pitch of the instrument gets lower as you move outward. (Cosmological redshift has been converted to a light travel time expressed in billions of years.) Credit: Sonification: Martha Irene Saladino (STScI), Christopher Britt (STScI); Visualization: Frank Summers (STScI); Designer: NASA, STScI, Leah Hustak (STScI) Survey Details
The High-Latitude Time-Domain Survey will be split into two imaging “tiers” — a wide tier that covers more area and a deep tier that will focus on a smaller area for a longer time to detect fainter objects. The wide tier, totaling a bit more than 18 square degrees, will target objects within the past 7 billion years, or half the universe’s history. The deep tier, covering an area of 6.5 square degrees, will reach fainter objects that existed as much as 10 billion years ago. The observations will take place in two areas, one in the northern sky and one in the southern sky. There will also be a spectroscopic component to this survey, which will be limited to the southern sky.
“We have a partnership with the ground-based Subaru Observatory, which will do spectroscopic follow-up of the northern sky, while Roman will do spectroscopy in the southern sky. With spectroscopy, we can confidently tell what type of supernovae we’re seeing,” said Cenko.
Together with Roman’s other two core community surveys, the High-Latitude Wide-Area Survey and the Galactic Bulge Time-Domain Survey, the High-Latitude Time-Domain Survey will help map the universe with a clarity and to a depth never achieved before.
Download the sonification here.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Melbourne, Florida; and Teledyne Scientific & Imaging in Thousand Oaks, California.
By Christine Pulliam
Space Telescope Science Institute, Baltimore, Md.
Share
Details
Last Updated Aug 12, 2025 EditorAshley BalzerLocationGoddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Dark Energy Neutron Stars Stars Supernovae The Universe Explore More
6 min read NASA’s Roman Mission Shares Detailed Plans to Scour Skies
Article 4 months ago 6 min read Why NASA’s Roman Mission Will Study Milky Way’s Flickering Lights
Article 2 years ago 7 min read One Survey by NASA’s Roman Could Unveil 100,000 Cosmic Explosions
Article 4 weeks ago View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.