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Science@Ames
 
Space ScienceSpace Science @ Ames features research in infrared astrophysics, laboratory astrophysics, extrasolar planets, planetary sciences, exobiology, and astrobiology.
 
 
Earth ScienceEarth Science @ Ames features basic and applied research in atmospheric and biospheric sciences, and conducts airborne science campaigns.
 
 
Biological ScienceBioSciences @ Ames features research in fundamental space biology, and provides engineering and payload development for the International Space Station.
 

 
Features
 
NASA's Airborne Science Mission Returns to the Skies for Final Flights
March 5, 2015
 

NASA's Airborne Tropical Tropopause Experiment (ATTREX) returned to the skies for its fifth and final year of science flights on March 4. The remotely piloted Global Hawk research aircraft took off from its base at NASA's Armstrong Flight Research Center, Edwards, California, to track the transport of water vapor into the upper atmosphere and help researchers understand how greenhouse gases affect Earth's climate.


This year, NASA ATTREX is collaborating with United Kingdom (UK) researchers to execute their Coordinated Airborne Studies in the Tropics (CAST) project, funded by their country's Natural Environment Research Council (NERC). The mission continues to focus on the transport and exchange of greenhouse gases, in particular water vapor, in the tropical tropopause region, the transition layer between the troposphere, the lowest part of the atmosphere, and the stratosphere, the layer above it. The suite of instruments onboard includes a subset of the ATTREX payload previously flown, with a focus on cloud and water vapor measurements. In addition, two new CAST instruments will be included: the Aerosol Ice Interface Transition Spectrometer (AIITS) and the GreenHouse gas Observations in the Stratosphere and Troposphere (GHOST).

"The combination of ATTREX and CAST instruments will provide new information about the formation of tropical tropopause layer cirrus and the shapes of the ice crystals that comprise them," said Eric Jensen, the ATTREX principal investigator at NASA's Ames Research Center at Moffett Field, Calif. "The cirrus ice crystal sizes and shapes determine how fast they fall and remove water vapor from air rising into the stratosphere. The measurements made in this flight series will add to the extensive ATTREX dataset that is being used to improve our understanding of tropical tropopause layer transport and cloud processes. The science community is using this dataset to evaluate and improve global models used to predict future climate change."

Studies show that even slight changes in the amount of water vapor in the stratosphere can warm the surface temperature by absorbing thermal radiation rising from the surface.

Scientists consider the tropical tropopause to be the gateway for transport of water vapor, ozone and other gases into the stratosphere. For this mission, the Global Hawk will fly in the tropical tropopause layer (from altitudes of 45,000 to 60,000 feet) near the equator over the Pacific Ocean, providing measurements in this critical atmospheric layer.

AIITS was jointly developed by UK's Universities of Hertfordshire and Manchester. It will measure the scattering properties of aerosols and cirrus clouds, providing information about particle shapes and composition. Scientists expect these measurements, combined with those from the ATTREX Hawkeye, a cloud particle probe managed by Stratton Park Engineering (SPEC), Inc., Boulder, Colorado, and water vapor instruments, will provide valuable new information about the formation and impact of extensive, thin cirrus clouds in the tropical tropopause layer.

GHOST was jointly developed by the UK Astronomy Technology Centre in Edinburgh and the Universities of Edinburgh and Leicester. It will measure columns of greenhouse gases, such as carbon dioxide, methane, carbon monoxide and water, below the aircraft's path. It is a novel, compact Short-Wave InfraRed (SWIR) spectrometer built on similar principles to the instrument aboard the NASA Orbiting Carbon Observatory (OCO)-2 satellite launched in 2014, and will provide high spatial-resolution information about these gases as well as validation for the satellite instrument.

ATTREX will conduct three long-duration science flights totaling 66 hours. This year's flights bring the total hours flown in support of ATTREX to about 390 hours since 2011.

Jensen and Project Manager Dave Jordan of Ames have led the ATTREX mission. Investigators include four NASA facilities: Ames, Langley Research Center in Hampton, Virginia, Goddard Space Flight Center in Greenbelt, Maryland, and the Jet Propulsion Laboratory in Pasadena, California. The team also includes investigators from the National Oceanic and Atmospheric Administration, Boulder, Colorado, the National Center for Atmospheric Research, Boulder, University of Cambridge, United Kingdom, the University of California at Los Angeles, the University of Miami, Florida, the University of Heidelberg, Germany, and private industry. The project is managed by the NASA Ames Earth Science Project Office.

ATTREX is one of the first research missions of NASA's new Earth Venture project. These targeted science investigations complement NASA's research satellite missions. The Earth Venture missions are part of NASA's Earth System Science Pathfinder Program managed by Langley.

TechEdSat-4 was developed, integrated and tested at Ames by student interns with the support of co-investigators Periklis Papadopoulos, from SJSU, and DavidAtkinson, from UI. TechEdSat-4 is funded by Ames. The total cost of the satellite was less than $50,000 because the team primarily used commercial off-the-shelf hardware that was rigorously tested and simplified the design and mission objectives.

For more information about NASA's Earth science activities in 2015, visit:
http://www.nasa.gov/earthrightnow For more information about NASA Ames Earth Science Project Office, visit: http://nasa.gov/ames

Jessica Culler
NASA's Ames Research Center, Moffett Field, Calif.

Image Credit: NASA Ames

 
NASA Deploys Satellite Designed to Re-enter Atmosphere Using Revamped Drag Device
March 4, 2015
 

Graphic rendering of TechEdSat-4 with exo-brake deployed. Exo-brake is an aerodynamic specially-designed parachute-like device, that causes the satellite to de-orbit and re-enter Earth's atmosphere.


NASA mission controllers confirmed that a small satellite launched from the International Space Station at 5:30 p.m. PST on Tuesday, March 3, has successfully entered its orbit, setting the stage to test technology that could enable rapid return of payloads from space. Over the next four weeks, the TechEdSat-4 satellite will deploy a second-generation exo-brake, an aerodynamic drag device, to perform a maneuver that will cause the satellite to de-orbit and re-enter Earth's atmosphere.

"The exo-brake is a self-stabilizing exospheric deorbiting mechanism that will allow us to return a payload to Earth fairly rapidly from an orbital platform, like the International Space Station," said Marcus Murbach, the TechEdSat-4 principal investigator at NASA's Ames Research Center in Moffett Field, California. "We were able to sendcommands and receive data to and from the satellite via the onboard modem using only a laptop and email account. This capability may greatly benefit the entire nanosatellite community." About 30 minutes after the Nanoracks CubeSat Deployer jettisoned it from the space station, the autonomous free-flying satellite powered on. At approximately 8 p.m., the spacecraft received a command via email and deployed its specially-designed parachute-like exo-brake, which operates as a passivedrag device at the extremely low pressures found at the top of the atmosphere. Engineers also confirmed the satellite has demonstrated new satellite-to-satellite communications technologies to provide precise information about the spacecraft's health and position. TechEdSat-4 arrived at the station aboard Orbital ATK's Cygnus spacecraft July 16, 2014.

TechEdSat-4 is equipped with a short-burst data satellite modem combined with a GPS receiver to perform communications functions, including providing data about the spacecraft's health, space environment and location. Together, these technologies replace ground stations used for tracking, rapid data retrieval and uplink capability, and permit satellite control via secure email.

The ability to accurately re-enter Earth's atmosphere will eventually enable the safe return of scientific samples and valuable cargo from orbital platforms at a lower cost than larger cargo and transfer vehicles. In addition, Murbach and his team intend for this technology to help enable future small or nanosatellite missions to the surface of Mars and other planetary bodies in the solar system. "We've already developed a sample canister that during atmospheric re-entry could slip out the back of the satellite and safely be recovered on Earth," said Murbach. "This could also be adapted to future Mars satellites as a piggy-back or ride-along payload that could jettison independently and study the mid-latitude or other scientifically interesting regions of Mars. Currently, it is extremely challenging to access these sites."

TechEdSat-4 is the first NASA satellite to jettison from the Nanoracks CubeSat Deployer and the fourth satellite in the TechEdSat series to successfully achieve orbit. The TechEdSat series, a technology education collaboration with San Jose State University (SJSU) in California and the University of Idaho (UI) in Moscow, Idaho, uses the standard CubeSat structure, which measures one unit (1U) as approximately four inches cubed (10 centimeters cubed). TechEdSat-4 is a 3U satellite measuring approximately 12-by-four-by-four inches (10-by-10-by-30 centimeters) and weighing approximately five pounds.

Previously, TechEdSat-1, a 1U CubeSat released from the Japanese Small Satellite Orbital Deployer (JSSOD) aboard the station in 2012, successfully demonstrated use of the basic communications subsystem and radiation-tolerant controller. It functioned in orbit for seven months until it re-entered Earth's atmosphere. It was followed by a successful satellite communication system flight test in April 2013 with TechEdSat-2, a 1U CubeSat. TechEdSat-3, a 3U CubeSat released from the JSSOD in 2013, was the first exo-brake to deploy and the first nanosatellite of its size to deploy from the station.

Ames currently is working on the next iteration in the series. The TechEdSat-5 satellite, scheduled for launch in 2015, will be very similar to the TechEdSat-4 design. It will introduce a modulating exo-brake capable of changing its surface area allowing the satellite to more precisely enter the atmosphere.

TechEdSat-4 was developed, integrated and tested at Ames by student interns with the support of co-investigators Periklis Papadopoulos, from SJSU, and DavidAtkinson, from UI. TechEdSat-4 is funded by Ames. The total cost of the satellite was less than $50,000 because the team primarily used commercial off-the-shelf hardware that was rigorously tested and simplified the design and mission objectives.

"One of the great things about this collaboration is the experience our university students and interns get at an early point in their careers," said Papadopoulos. "With this experience, many of our interns have started successful careers at NASA or in private industry - which is a great benefit that NASA uniquely provides."

For more information about the TechEdSat, visit:
http://www.nasa.gov/mission_pages/station/research/experiments/1027.html

Maria Alberty
NASA's Ames Research Center, Moffett Field, Calif.

Image Credit: NASA Ames

 
NASA's Kepler Marks 1,000th Exoplanet Discovery, Uncovers More Small Worlds in Habitable Zones
January 6, 2015
 

How many stars like our sun host planets like our Earth? NASA's Kepler Space Telescope continuously monitored more than 150,000 stars beyond our solar system, and to date has offered scientists an assortment of more than 4,000 candidate planets for further study -- the 1,000th of which was recently verified.

Using Kepler data, scientists reached this millenary milestone after validating that eight more candidates spotted by the planet-hunting telescope are, in fact, planets. The Kepler team also has added another 554 candidates to the roll of potential planets, six of which are near-Earth-size and orbit in the habitable zone of stars similar to our sun.

Three of the newly-validated planets are located in their distant suns' habitable zone, the range of distances from the host star where liquid water might exist on the surface of an orbiting planet. Of the three, two are likely made of rock, like Earth.

"Each result from the planet-hunting Kepler mission's treasure trove of data takes us another step closer to answering the question of whether we are alone in the Universe," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington."The Kepler team and its science community continue to produce impressive results with the data from this venerable explorer."

To determine whether a planet is made of rock, water or gas, scientists must know its size and mass. When its mass can't be directly determined, scientists can infer what the planet is made of based on its size.

Two of the newly validated planets, Kepler-438b and Kepler-442b, are less than 1.5 times the diameter of Earth. Kepler-438b, 475 light-years away, is 12 percent bigger than Earth and orbits its star once every 35.2 days. Kepler-442b, 1,100 light-years away, is 33 percent bigger than Earth and orbits its star once every 112 days.

Both Kepler-438b and Kepler-442b orbit stars smaller and cooler than our sun, making the habitable zone closer to their parent star, in the direction of the constellation Lyra. The research paper reporting this finding has been accepted for publication in The Astrophysical Journal.

"With each new discovery of these small, possibly rocky worlds, our confidence strengthens in the determination of the true frequency of planets like Earth," said co-author Doug Caldwell, SETI Institute Kepler scientist at NASA's Ames Research Center at Moffett Field, California. "The day is on the horizon when we'll know how common temperate, rocky planets like Earth are."

With the detection of 554 more planet candidates from Kepler observations conducted May 2009 to April 2013, the Kepler team has raised the candidate count to 4,175. Eight of these new candidates are between one to two times the size of Earth, and orbit in their sun's habitable zone. Of these eight, six orbit stars that are similar to our sun in size and temperature. All candidates require follow-up observations and analysis to verify they are actual planets.
"Kepler collected data for four years -- long enough that we can now tease out the Earth-size candidates in one Earth-year orbits," said Fergal Mullally, SETI Institute Kepler scientist at Ames who led the analysis of a new candidate catalog."We're closer than we've ever been to finding Earth twins around other sun-like stars. These are the planets we're looking for".

These findings also have been submitted for publication in The Astrophysical Journal Supplement.

stars like our sun, a key step toward NASA's goal of understanding our place in the universe.

Scientists also are working on the next catalog release of Kepler's four-year data set. The analysis will include the final month of data collected by the mission and also will be conducted using sophisticated software that is more sensitive to the tiny telltale signatures of small Earth-size planets than software used in the past.

Ames is responsible for Kepler's mission operations, ground system development and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate in Washington.

For more information about the Kepler mission, visit:
http://www.nasa.gov/kepler

Michele Johnson
NASA's Ames Research Center, Moffett Field, Calif.

Felicia Chou
Headquarters, Washington
http://www.nasa.gov/kepler


Image Credit: NASA Ames

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