NASA Small Satellites Set to Take a Fresh Look at Earth

Beginning this month, NASA is launching a suite of six next-generation, Earth-observing small satellite missions to demonstrate innovative new approaches for studying our changing planet.

These small satellites range in size from a loaf of bread to a small washing machine and weigh from a few to 400 pounds. Their small size keeps development and launch costs down as they often hitch a ride to space as a “secondary payload” on another mission’s rocket – providing an economical avenue for testing new technologies and conducting science.

“NASA is increasingly using small satellites to tackle important science problems across our mission portfolio,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “They also give us the opportunity to test new technological innovations in space and broaden the involvement of students and researchers to get hands-on experience with space systems.”

Small-satellite technology has led to innovations in how scientists approach Earth observations from space. These new missions, five of which are scheduled to launch during the next several months, will debut new methods to measure hurricanes, Earth’s energy budget, aerosols, and weather.

“NASA is expanding small satellite technologies and using low-cost, small satellites, miniaturized instruments, and robust constellations to advance Earth science and provide societal benefit through applications,” said Michael Freilich, director of NASA’s Earth Science Division in Washington.

A Box of ‘Black Magic’ to Study Earth from Space

That’s what radiofrequency engineers call the mysterious forces guiding communications over the air. These forces involve complex physics and are difficult enough to master on Earth. They only get more baffling when you’re beaming signals into space.

Until now, the shape of choice for casting this “magic” has been the parabolic dish. The bigger the antenna dish, the better it is at “catching” or transmitting signals from far away.

But CubeSats are changing that. These spacecraft are meant to be light, cheap and extremely small: most aren’t much bigger than a cereal box. Suddenly, antenna designers have to pack their “black magic” into a device where there’s no room for a dish -- let alone much else.

“It’s like pulling a rabbit out of a hat,” said Nacer Chahat, a specialist in antenna design at NASA’s Jet Propulsion Laboratory, Pasadena, California. “Shrinking the size of the radar is a challenge for NASA. As space engineers, we usually have lots of volume, so building antennas packed into a small volume isn’t something we’re trained to do.”

Taking Measure of a Remote Slice of Alaskan Forest

Kate Legner points out the next tree in the survey site as other crew members measure key information about the vegetation in a 53-foot diamter plot.

In a birch forest in interior Alaska’s Tanana Valley, there’s a stake with pink plastic tape attached. More than three decades ago, a plane flew over it to take stereoscopic pictures of the surrounding plot, and scientists trekked out to survey the trees and vegetation. Now, scientists are re-flying and re-surveying the site, using advanced airborne instruments and satellite images to track changes in interior Alaska.

“This is going to be 10.3,” called out Sean Cahoon, a scientist with the University of Alaska, Anchorage. He was standing at the end of a tape measure radiating out from the stake, using another tape measure to check the diameter of the base of a birch tree.

Kate Legner, with the University of Washington in Seattle, recorded the number as well as the diameter at breast height, the distance from the stake, and the azimuth (angle from due north) of the tree’s location.

“That’s all you need to recreate this whole area,” Legner said. The area in question is a circle with a 53-foot radius out from the stake. Mostly birch, with a few aspen and white spruce trees, just sparse enough to let some sun filter through to shrubs, seedlings, moss and lichens thick on the ground.

Burrowing into the Arctic’s Carbon Past and Future

The Permafrost Tunnel provides a look back in time, allowing for research into the frozen ground of interior Alaska.

“What we’re going to do is walk back in time,” said Matthew Sturm, standing in front of a doorway that led into a hillside north of Fairbanks, Alaska. Through the doors was a tunnel that provides access to the Alaska of 40,000 years ago, when bison and mammoths foraged in grassy valleys. Now, however, the grasses and the animal bones are frozen in the ground in the Permafrost Tunnel.

The tunnel, run by the U.S. Army’s Cold Regions Research and Engineering Laboratory, was dug in the 1960s and is the site of much research into permafrost—ground that stays frozen throughout the year, for multiple years. Sturm, a professor and snow researcher at the University of Alaska, recently led a group with NASA’s Arctic Boreal Vulnerability Experiment (ABoVE) to the site. The walls of the tunnel expose the silt, ice, and carbon-rich plant and animal matter that has been frozen for tens of thousands of years. “It’s a legacy of the Ice Age,” Sturm said. Roots of long-buried grasses hang from the ceiling, in a few places bones of Pleistocene mammals are embedded in the wall.

Home is Where the Astronaut Is

The Expedition 43 crew gathers aboard the International Space Station to affix their mission patch to the vehicle. Commander Terry Virts (center left), Scott Kelly (top left), Gennady Padalka (top center), Anton Shkaplerov (top right), Mikhail Kornienko (bottom right), Samantha Cristoforetti (bottom center).

The International Space Station serves as home, office and recreation room for astronauts. They share this confined space far above the Earth with crew members from different countries and cultures for as long as six months or more. At the same time, maintaining individual well-being and crew harmony is important for the crew and mission success.

The Culture, Values, and Environmental Adaptation in Space (At Home In Space) investigation, sponsored by the Canadian Space Agency, looks at changes in perceptions about home in space and the ways a unique culture may develop aboard the station during a mission. Participants answer a series of questionnaires before, during and after flight, enabling researchers to see whether perceptions and the relative importance of values change over the course of a mission. Questions explore individual and culturally related differences, family functioning and relationships, personal values and coping with stress. 

“This is the first study to look at the extent to which a unique, shared space culture develops, whether crews develop customs and celebrations that are part of being on the station and different from what they would do on Earth,” explains Phyllis Johnson, principal investigator, Department of Sociology at the University of British Columbia in Vancouver, Canada.

Gemini XII Crew Masters the Challenges of Spacewalks

Gemini XII pilot Buzz Aldrin, left, and command pilot Jim Lovell stand in a Gemini mockup during training at NASA's Manned Spacecraft Center (now Johnson Space Center) in Houston.

In the 20 months following the first piloted Gemini mission, NASA astronauts demonstrated the ability to change orbits, perform rendezvous and docking, along with spending up to two weeks in space. Spacewalking, on the other hand, remained an enigma. With only one more Gemini flight on the schedule, solving the problems of working outside a spacecraft would be the primary goal for Gemini XII.

As was the case on the previous four missions, the Gemini XII flight plan called for rendezvous and docking with a target vehicle. But, according to Dr. George Mueller, NASA’s associate administrator for Manned Spaceflight, mastering what NASA called an extravehicular activity (EVA) or spacewalk would be crucial in proving the agency was ready to move ahead with Apollo and achieving the goal of landing a man on the moon before the end of the decade.

“I feel that we must devote the last EVA period in the Gemini Program to a basic investigation of EVA fundamentals,” he said. To take on the challenges of this crucial flight, NASA assigned a veteran of the longest spaceflight to date and the astronaut who helped “write the book” on orbital rendezvous. The command pilot was Jim Lovell who served on the 14-day Gemini VII mission in December 1965. A Naval aviator, he went on to be a member of the Apollo 8 crew, the first mission to orbit astronauts around the moon in 1968. As commander of Apollo 13 in 1970, Lovell became the first person to travel in space four times.

New, Space-Based View of Human-Made Carbon Dioxide

Human carbon dioxide emissions from fossil fuel burning and other sources have been mapped from OCO-2's global dataset.

Scientists have produced the first global maps of human emissions of carbon dioxide ever made solely from satellite observations of the greenhouse gas. The maps, based on data from NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite and generated with a new data-processing technique, agree well with inventories of known carbon dioxide emissions.

No satellite before OCO-2 was capable of measuring carbon dioxide in fine enough detail to allow researchers to create maps of human emissions from the satellite data alone. Instead, earlier maps also incorporated estimates from economic data and modeling results.

The team of scientists from the Finnish Meteorological Institute, Helsinki, produced three main maps from OCO-2 data, each centered on one of Earth's highest-emitting regions: the eastern United States, central Europe and East Asia. The maps show widespread carbon dioxide across major urban areas and smaller pockets of high emissions.