News and Updates

04/22/2015

The list of potential life-supporting planets just got a little shorter

As the search continues for Earth-size planets orbiting at just the right distance from their star, a region termed the habitable zone, the number of potentially life-supporting planets grows. In two decades we have progressed from having no extrasolar planets to having too many to search. Narrowing the list of hopefuls requires looking at extrasolar planets in a new way. Applying a nuanced approach that couples astronomy and geophysics, Arizona State University researchers report that from that long list we can cross off cosmic neighbor Tau Ceti.

The Tau Ceti system, popularized in several fictional works, including Star Trek, has long been used in science fiction, and even popular news, as a very likely place to have life due to its proximity to Earth and the star’s sun-like characteristics. Since December 2012 Tau Ceti has become even more appealing, thanks to evidence of possibly five planets orbiting it, with two of these – Tau Ceti e and f – potentially residing in the habitable zone.

Using the chemical composition of Tau Ceti, the ASU team modeled the star’s evolution and calculated its habitable zone. Although their data confirms that two planets (e and f) may be in the habitable zone it doesn’t mean life flourishes or even exists there.

“Planet e is in the habitable zone only if we make very generous assumptions. Planet f initially looks more promising, but modeling the evolution of the star makes it seem probable that it has only moved into the habitable zone recently as Tau Ceti has gotten more luminous over the course of its life,” explains astrophysicist Michael Pagano, ASU postdoctoral researcher and lead author of the paper appearing in the Astrophysical Journal. The collaboration also included ASU astrophysicists Patrick Young and Amanda Truitt and mineral physicist Sang-Heon (Dan) Shim.

Based upon the team’s models, planet f has likely been in the habitable zone much less than 1 billion years. This sounds like a long time, but it took Earth’s biosphere about 2 billion years to produce potentially detectable changes in its atmosphere. A planet that entered the habitable zone only a few hundred million years ago may well be habitable and even inhabited, but not have detectable biosignatures.

According to Pagano, he and his collaborators didn’t pick Tau Ceti “hoping, wanting, or thinking” it would be a good candidate to look for life, but for the idea that these might be truly alien new worlds.

Tau Ceti has a highly unusual composition with respect to its ratio of magnesium and silicon, which are two of the most important rock forming minerals on Earth. The ratio of magnesium to silicon in Tau Ceti is 1.78, which is about 70% more than our sun.

The astrophysicists looked at the data and asked, “What does this mean for the planets?”

Building on the strengths of ASU’s School of Earth and Space Exploration, which unites earth and space scientists in an effort to tackle research questions through a holistic approach, Shim was brought on board for his mineral expertise to provide insights into the possible nature of the planets themselves.

“With such a high magnesium and silicon ratio it is possible that the mineralogical make-up of planets around Tau Ceti could be significantly different from that of Earth. Tau Ceti’s planets could very well be dominated by the mineral olivine at shallow parts of the mantle and have lower mantles dominated by ferropericlase,” explains Shim.

Considering that ferropericlase is much less viscous, or resistant to flowing, hot, yet solid, mantle rock would flow more easily, possibly having profound effects on volcanism and tectonics at the planetary surface, processes which have a significant impact on the habitability of Earth.

“This is a reminder that geological processes are fundamental in understanding the habitability of planets,” Shim adds.

“Tau Ceti has been a popular destination for science fiction writers and everyone's imagination as somewhere there could possibly be life, but even though life around Tau Ceti may be unlikely, it should not be seen as a letdown, but should invigorate our minds to consider what exotic planets likely orbit the star, and the new and unusual planets that may exist in this vast universe,” says Pagano.

This work was supported by funding from the NASA Astrobiology Institute and NASA Nexus for Exoplanet System Science.

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Image 1 caption: How would an alien world like this look? That’s the question that undergraduate art major Joshua Gonzalez attempted to answer. He worked with Professor Patrick Young’s group to learn how to analyze stellar spectra to find chemical abundances, and inspired by the scientific results, he created two digital paintings of possible unusual extrasolar planets, one being Tau Ceti for his Barrett Honors Thesis. Credit: Joshua Gonzales

Written by Nikki Cassis

 

04/22/2015

Save the date!

Sara Imari Walker, assistant professor in SESE, will be appearing in season 6 of “Through the Wormhole with Morgan Freeman”. The episode in which she appears is titled “Are We Here for a Reason?” and it is scheduled to air on Wednesday, May 13th on Discovery’s Science Channel, at 10:00 p.m. ET/PT.

 

04/21/2015

For centuries, humans have sought to learn whether life exists beyond Earth. That answer is closer than ever to fulfillment, and an ASU team is working on a key part of that quest with NASA’s backing.

Thousands of exoplanets (planets around other stars) have been discovered in the past decade, and the next decade likely will bring advances in detecting possible signs of life. One way of doing that is looking at the atmospheric makeup of these planets: Do oxygen or methane – gases that on Earth arise from the action of life – exist there, and are they in fact indicative of life?

“In the field of exoplanets, finding exoplanets that could host life is no longer the goal. The quest is to find the signatures of life,” said Steve Desch, an associate professor in the School of Earth and Space Exploration. “To do that we need to know for which types of exoplanets are oxygen and methane biosignatures, as opposed to natural geochemical outcomes.

“ASU’s strengths lie in bringing together experts across astronomy and geology to answer just these sorts of interdisciplinary questions.”

Desch is principal investigator of an ASU-centered team that is one of 16 teams funded by a new NASA research coordination network, the Nexus for Exoplanet System Science (NExSS). It will receive $6.1 million over five years to investigate the connections between exoplanets and the compositions of their host stars, and especially to focus on understanding the geochemical cycles on exoplanets with different chemical compositions.

NASA’s new network is part of its Astrobiology program. NExSS includes planetary scientists, astrophysicists and heliophysicists who will carry out research to help NASA define future space missions, determine target selection and craft observing strategies, to aid in the characterization of exoplanets and the search for life on them. It is distinct from the NASA Astrobiology Institute, the program that has previously funded astrobiology research at ASU as far back as 1998.

Under the direction of Desch, the present research team brings geophysicists, petrologists and geochemists into the fold of exoplanet research, which has so far been dominated by the astrophysicists and astronomers who discover and characterize exoplanets.

Broad collaborations across disciplines, like the one to be carried out at ASU, are relatively new in the rapidly changing field of exoplanets.

“When I started graduate school a little over 20 years ago,” Desch said, “no exoplanets were known. Today, we know of thousands, with about a dozen orbiting within their star’s habitable zones. … Twenty years from now, we could be talking about known planets with evidence of life. The pace of discovery leaves me in awe.”

Just as the Kepler mission found thousands of exoplanets that transit their host stars (pass between us and the star), NASA’s Transiting Exoplanet Survey Satellite will be launched in 2017 with the hopes of discovering thousands more among the closest stars. The James Webb Space Telescope, to be launched in 2018, will measure the infrared spectrum of starlight that passes through the atmospheres of some of these transiting exoplanets, discerning what gases are present.

“Absorption of starlight by oxygen and methane could be detected by space telescopes, and will be looked for, because on Earth they are produced overwhelmingly by life,” Desch said. “But exoplanets won’t be like Earth. Stars have different chemical abundances, and their planets should, too.

“On a planet with different chemistry, it may be methane is produced naturally by water-rock interactions, or oxygen is produced abiotically. To judge whether these are valid biosignature gases, we have to understand the geochemical cycles on exoplanets with compositions different from Earth’s.”

To understand those cycles, the team will pursue a multifaceted approach combining astronomical observations, astrophysical and geochemical modeling, and geophysical and geochemical laboratory experiments. They will also conduct biological field studies to better understand how the methane cycle works on Earth, and possibly elsewhere.

The ASU team is centered in the School of Earth and Space Exploration, an academic unit in ASU’s College of Liberal Arts and Sciences, but also involves several faculty members from other college units including the School of Life Sciences, the Department of Chemistry and Biochemistry, and the Beyond Center. The team also includes researchers from partner institutions, including the American Museum of Natural History; the Global Science Institute in Wisconsin; Johns Hopkins University; Northern Arizona University; San Francisco State University; the University of Rochester; and the University of Washington.

Image: Professor Steve Desch is principal investigator of an ASU-centered team that is one of 16 teams funded by a new NASA research coordination network, the Nexus for Exoplanet System Science. The team will focus on understanding the geochemical cycles on exoplanets with different chemical compositions.
Photo by: Andy DeLisle

Written by Nikki Cassis

04/20/2015

World-famous "Pillars of Creation" image will be the centerpiece of a 25th birthday party for the Hubble Space Telescope, April 24.

One of the most iconic images ever taken by the Hubble Space Telescope — dubbed "The Pillars of Creation" — is the keynote image for a celebration of the space telescope's 25th birthday at the final Earth and Space Open House of the spring semester, on Friday, April 24.

The evening's events will feature two FREE public talks by researchers at the School of Earth and Space Exploration. The first, given by Christopher Groppi, will focus on how astronomers are launching balloon-borne telescopes from Antarctica to investigate the universe.

The second talk, by Paul Scowen, is titled "Hubble Greatest Hits." Scowen, who used Hubble to help make the Pillars of Creation image, will tell the fascinating story of star and planet formation through a tour of Hubble's greatest hits.

"Join us," he says, "for an intimate look at the environment of a stellar nursery and an intriguing connection with the conditions under which our own planet may have formed, all while enjoying some of the best images the Hubble Space Telescope has taken over the past 25 years."

The free talks will be held in at the Interdisciplinary Science and Technology Building IV (ISTB 4) on ASU’s Tempe campus.

The evening's program includes:
• 7:15 pm: First 3D Planetarium Show (Marston Exploration Theater)
• 7:30 pm: Lecture on "Telescopes on Balloons in Antarctica" by Christopher Groppi (Room 240)
• 8:15 pm: Keynote Lecture on "Hubble's Greatest Hits" by Paul Scowen (Marston Exploration Theater)
• 9:15 pm: Second 3D Planetarium Show (Marston Exploration Theater)

Please note: All seating is on a first-come basis.

As usual, there will be telescope sky viewing outdoors next to the James Turrell Skyscape art installation from 8 to 10 p.m. (weather permitting). There will also be several exciting demonstrations and activities in the state-of-the-art ISTB4 Gallery of Scientific Exploration by experts in astrobiology, geology, cosmology and planetary science – as well as a free poster.

The open house can be accessed through the main entrance of ISTB 4, located on the building’s north side.

The monthly open house is sponsored by the School of Earth and Space Exploration, GeoClub, AstroDevils: ASU Astronomy Club, Icarus Rocketry, Students for the Exploration and Development of Space (SEDS), the Center for Meteorite Studies (CMS) and many others.

For more information, visit earthspaceopenhouse.weebly.com or visit the school's Facebook event page. This will be the final open house of the spring semester.

Image caption: The Eagle Nebula, the subject of the famous "Pillars of Creation" image, is a region of space where stars and planets are forming. This image and other famous Hubble images help scientists understand how planetary systems such as our own came into being. (Image credit: NASA)

Writen by Robert Burnham

04/16/2015

Nearly 460 kilometers wide, Greeley Crater on Mars has been named in honor of a pioneering planetary science researcher at Arizona State University.

Throughout his career Ronald Greeley was passionate about exploring Mars, so it’s fitting that the late Arizona State University professor’s name will grace maps of the Red Planet.

A large, ancient crater – nearly as wide as Arizona – now carries the name of Greeley Crater, in honor of the Mars science pioneer and longtime professor of planetary science.

Greeley was involved in almost every major solar system robotic mission flown since the late 1960s and advanced the study of planetary science at ASU.

The crater, which spans 457 kilometers (284 miles), lies in Noachis Terra, the geologically oldest terrain on Mars. Although the crater's exact age is not known, the smaller impact craters superimposed on it plus its preservation state all suggest an age of at least 3.8 billion years.

It is centered just east of Mars' "Greenwich meridian" and is 37 degrees south of its equator.

Kenneth Tanaka, a planetary geologist at the U.S. Geological Survey's Astrogeology Science Center in Flagstaff and longtime colleague of Greeley, proposed the name, noting that it was the oldest, relatively well-preserved impact crater on Mars that remained still unnamed.

Tanaka will announce the crater’s naming in his keynote talk at the 24th annual Arizona/NASA Undergraduate Research Symposium on April 17 in Tempe.  

The International Astronomical Union, the world's authority for feature names on extraterrestrial bodies, formally approved the name on April 11. IAU rules require that a person must be deceased for at least three years before any commemoration can be made; Greeley died in October 2011.

Planetary science pioneer

During his career, Ronald Greeley was involved in almost every major solar system robotic mission flown since the late 1960s. These include the Magellan mission to Venus, Galileo mission to Jupiter, Voyager 2 mission to Uranus and Neptune, and shuttle imaging radar studies of Earth.

Passionate about exploring Mars, he contributed to numerous Red Planet missions, including Mariners 6, 7 and 9; Viking; Mars Pathfinder; Mars Global Surveyor; and the Mars Exploration Rovers. He was a co-investigator for the High Resolution Stereo Camera on the European Mars Express mission.

Joining the ASU faculty in 1977, Greeley was a pioneer in planetary science experiments. For example, he created a vertical gun to study impact cratering processes. Another instance was the use of wind tunnels to study the behavior of wind-blown sand particles and dunes, which are important features on the surfaces of Earth, Mars, Venus, and Saturn's largest moon Titan.

To study sand movement on Venus, where the atmosphere is nearly 100 times denser than on Earth, he built a special high-pressure wind tunnel. This same tunnel was recently reconfigured for Titan's surface conditions, and researchers discovered that to move Titan's sands, winds have to be much stronger than scientists had thought.

At the time of his death, Greeley was Regents' Professor of planetary geology in the School of Earth and Space Exploration (SESE), an interdisciplinary school combining science and engineering studies. Greeley had a key role in creating it and he served as interim director at its inception.

First image: Almost 300 miles wide, Greeley Crater lies in the heavily impacted and ancient southern highlands of Mars. It honors Ronald Greeley, longtime ASU planetary scientist who died in 2011. (NASA)

Second image: A spacecraft view of Greeley Crater shows a heavily modified surface. After Greeley Crater formed billions of years ago by the impact of a small asteroid, later impacts and lava flows on its floor have altered and partly obliterated its appearance. This THEMIS daytime infrared mosaic uses images from an ASU-designed visible and infrared camera on NASA's Mars Odyssey orbiter. (NASA/JPL-Caltech/Arizona State University)

Written by Robert Burnham

04/15/2015

Like something out of “CSI” or “Bones,” researchers at Arizona State University are working to solve the mysteries of unidentified human remains – and just as on those TV shows, science plays a key role.

Gwyneth Gordon, an associate research scientist in ASU’s School of Earth and Space Exploration, will soon be making a trip to academia’s most distinctive research facility: the University of Tennessee’s Anthropological Research Facility, the original “Body Farm.”

At the facility’s open-air crime labs, decomposing corpses are left out in the elements, some on the ground and others in shallow graves. Gordon will collect samples from the cadavers and samples of soil and groundwater; in May, she’ll do the same thing at Texas State University in San Marcos.

With funding from the Department of Justice’s National Institute of Justice, Gordon and professors Kelly Knudson and Ariel Anbar will study how various isotopes in the human body behave during decomposition in different environments. These techniques have long been used in the anthropologic study of migration and lifestyle of ancient peoples, but only recently have begun to be used in modern cases of homicide, mass graves and unidentified migrants.

With some 10,000 open cases of unidentified human remains in the U.S. today, the research’s results will have real-life implications for law enforcement, medical examiners and families looking for answers.

“Can our technique unravel a human story that was previously lost to history? That’s what we’re trying to find out,” Gordon says. “The donor histories provide premortem travel and geographic life histories, and we’ll see if our analyses match their life histories.”

Unlocking clues hidden in bones

Every molecule in our bodies is made up not just of different elements, but of different ratios of stable isotopes of those elements. They leave an isotopic signature that can speak for the dead, revealing diet, birthplace and travel history.

Samples collected at the body farms – including hair, tooth enamel and skeletal elements – will be analyzed at ASU for oxygen and hydrogen isotopes to determine latitude; carbon and nitrogen to obtain dietary history; and strontium and lead isotopes and trace elements to establish the type of bedrock where the deceased was born or lived.

Sample preparation will occur both in the School of Earth and Space Exploration and in collaboration with the Archaeological Chemistry Laboratory under the supervision of archaeological chemist Kelly Knudson, associate professor in ASU’s School of Human Evolution and Social Change and affiliated with the Center for Bioarchaeological Research.

Knudson uses biogeochemistry and bioarchaeology to answer anthropological research questions. She is a world expert on the application of isotopes to archaeological sites and individuals.

“As an archaeologist, I am more used to working with people who died hundreds or thousands of years ago. Applying my knowledge to forensics applications and, eventually, to helping to solve modern cases is one of the things that really appeals to me about our research project,” Knudson says.

Finding migrants’ birthplace

The sites of the two body farms have very different climates and soil types. Tennessee – very wet – is similar to significant portions of the United States, while the dry Texas site is similar to the U.S.-Mexico border.

“We chose that site explicitly because of the large number of undocumented immigrants who die in the desert while trying to get to the U.S. These individuals often have no identification on them, and their families never know what happened to them,” Gordon says. “There’s also commonly no DNA to match them to. If we can get a better idea where they were from using isotopes, the search for their families would be significantly easier.”

According to Knudson, archaeologists have been using isotopic data to figure out people’s diets for more than 30 years, while using that data to determine someone’s birthplace has been common only in the past 15 years.

“These techniques haven’t been used quite as much in forensic anthropology, despite what you may see on ‘CSI’ or ‘Bones,’ ” she says.

While stable isotopes have proven themselves useful, they aren’t staples of forensic science – yet. However, a number of case studies have demonstrated that these types of information can narrow the search and help discover a person’s identification.

“What I think is great about this research is that we are doing the kinds of baseline research into how these isotopes act during decomposition so that the forensics community can use them,” Knudson says.

Image: Armed with a high-tech, chemistry-driven approach, ASU researchers will study how different isotopes in the human body behave during decomposition in different environments. The results will have real-life implications for law enforcement, medical examiners, the military and countless families looking for answers about loved ones.
Photo by: Andy DeLisle

Written by Nikki Cassis

04/14/2015

Two Arizona museums will soon add an astronaut as a docent – a digital docent called “Dr. U.”

The Arizona Science Center and the Arizona Museum of Natural History are partnering with Arizona State University to offer visitors an app to complement their exhibits. Dr. Universe, a mobile app, encourages museum visitors to ask questions and the astronaut responds back from its database.

Dr. Universe is a project spearheaded by students and faculty in the School of Earth and Space Exploration and the School of Computing, Informatics and Decision Systems Engineering. A team of engineering students worked on programming as earth and space exploration and biology students created content – a student from the Herberger Institute from Design and the Arts designed the visuals.

The project is run by Judd Bowman, associate professor at the School of Earth and Space Exploration, Brian Nelson, associate professor at the School of Computing, Informatics, and Decisions Systems Engineering, and Cassie Bowman, associate research professor at the School of Earth and Space Exploration. During Cassie Bowman’s graduate school career, she researched whether it’s possible to have a mentor relationship with a computer in an educational environment. Within the last three years, Judd Bowman said he and his colleagues considered how museum staff need help in evaluating visitors’ experiences.

“It seemed like a natural fit to take this idea of a ‘computerized scientist’ and let people have it within the museums and let people ask questions with it,” Bowman said.

Bowman said museum exhibits tend to have a long lifetime, but they aren’t always updated as quickly as science advances. The app, funded by the National Science Foundation, currently covers more than 12,000 questions on various topics from astronomy to geology. Bowman said he and the team collected many of the questions three years before the development of Dr. Universe. Museum staff will also have access to a dashboard that aggregates the popular topics and questions being asked on the app.

“The idea is it’s a trusted database of information,” Bowman said. “It’s been screened through us, through our students. You know it’s going to be safe for kids, safe for your family members to use it. It’s not just whatever Google happens to bring up.”

Kyle Rogers, a geological science senior, said he goes to the two museums and figures out what content to develop based on the open exhibits. He also talks with the docents to see what questions are commonly asked. In addition to information provided by the museum, Rogers also utilizes textbooks, government websites and peer reviewed articles.

Rogers said he’s worked on approximately 2,500 questions in the past four months. With the previous database and his work, Rogers said currently the database houses around 12,000 Q&As in English. He works about 10 hours a week.

“It’s a great project because it’s furthering someone’s education,” Rogers said.

Ivan Fernandez, biological sciences junior, translates the questions, and Itxier Meziani, earth and space exploration senior, works on translating the answers. Meziani said she spends about 10 hours a week translating the answers.

Meziani said she conducts a lot of research to find the right word because certain words don’t translate exactly into Spanish. Meziani said she’s translated 4,000 answers so far in Spanish. She also helped Fernandez translate questions, and she said it takes her about one hour to translate 200 questions.

Dheeraj Yennam, a computer science senior, said his group chose the project because of the flexibility it provided. The engineering students meet up weekly with the professors to talk about their progress and best next steps.

“They’re asking us for our opinion instead of telling us their opinion and to do it,” Yennam said. “We appreciate that as programmers.”
He said their group has enjoyed working on the project that they use some of their own time to put in extra hours.

The Dr. Universe team had their first testing of the app earlier in the semester at the Arizona Museum of Natural History. Bowman said it was a good testing experience because they had the real museum environment. It helped the whole team see if the speech detection worked in a loud environment or if its design for the iPad mini provided a good feel.

Meziani said that the trial run at the museum went well for the Spanish portion. However, there still needs to be work done for the microphone to catch Spanish accents.

“I was really surprised how much people have done on this application,” Meziani said. “We were able to talk back, and I even had my kids try it, and they loved it.”

The next trial run will incorporate another feature involving iBeacons placed throughout the exhibits that will track when a user is nearby. Bowman said in one exhibit they noticed how photographs' descriptions were in English but not Spanish. If the beacon recognizes the app, it could do something like pull up the Spanish descriptions.

Yennam said they have the bluetooth beacons ready to be tested. He said the beacons have been tested in smaller rooms, but he isn’t sure how it will work in a larger environment.

He said the team is excited that there is potential for the app to expand to other museums. Yennam said the museum staff seem impressed that a user could speak into it and there wouldn’t be spelling errors.

The project is set to last for three years, but Bowman said he hopes it develops into a product that many museums use and tailor to their content.
“This project is a really cool example of ASU getting into the community, students getting involved with the museums and seeing how the things they’re learning and the work they’re doing here applies in that context,” Bowman said.

 

Image: Dheeraj Yennam (left) and Jared Korinko, a student and faculty member from the School of Computing, Informatics, and Decision Systems Engineering, test the Dr. Universe app at the Arizona Museum of Natural History in Mesa.
Photo by: Judd Bowman

Written by Alicia Canales

 

04/10/2015

Congratulations to Associate Professor Steve Semken for winning the 2014-2015 Zebulon Pearce Distinguished Teaching Award in the Natural Sciences!

The Zebulon Pearce Distinguished Teaching Awards were established in memory of Zebulon Pearce, who graduated from Territorial Normal School at Tempe (now ASU) with teacher's credentials in 1899. These awards recognize teaching excellence in the College of Liberal Arts and Sciences. Last year, SESE Professor Phil Christensen received the honor.

Steve will be seated on the stage and recognized at the CLAS convocation ceremonies.

 

04/03/2015

It doesn’t take a sky-high budget to conduct aerospace research, thanks to weather balloons and a little ingenuity.

Teams of students from across Arizona, including a team from Arizona State University, launched their unmanned research balloons as part of the Arizona Space Grant Consortium’s ASCEND program, short for Aerospace Scholarships to Challenge and Educate New Discoverers. The launch took place March 27 in Pinal County West Park in Maricopa. 

Every semester student teams design and build payloads for launch on high-altitude weather balloons. About 10 feet in diameter when inflated, these hardy balloons can reach altitudes of more than 100,000 feet – higher than a passenger plane – yet can be built on a shoe-string budget.

This semester, a team of 12 ASU students put together a research payload to collect panoramic video and thermal imaging data. Instead of rockets, boosters and expensive control systems, they filled a weather balloon with hydrogen and hung a carbon fiber box underneath to carry the cameras and sensing equipment.

The balloon and camera made it up high enough to see the black sky curling around our blue planet, a staggering 94,687 feet. The flight was approximately three hours. When the balloon burst, the payload took about 45 minutes to come back to Earth, landing about 5.7 miles from the launch site.

ASU/NASA Space Grant provides funding to the ASU ASCEND team for payload materials and travel expenses. The payload cost roughly $1,000. The Arizona Near Space Research provides the balloons for the launch. Launch costs typically run around $5,000, including the “extras,” such as GPS beacons.

“As the team leader, I was required to manage the logistics of a complex project, making sure all systems work together in the final product. Having done this before, I have the opportunity to pass on the lessons I’ve learned to others on the team,” said Jack Lightholder, a paid ASU/NASA Space Grant intern and veteran balloon launcher.

Part of the Arizona Space Grant Consortium Workforce Development program, ASCEND is designed to engage undergraduate students in the full “design-build-fly-operate-analyze” cycle of a space mission.

“This program gives students the experience of developing an experimental question, developing a payload design to test it, building said payload and analyzing the data. The dataset will also be used for some baseline testing of other instruments within SESE labs,” Lightholder said. This was his seventh launch.

The ASCEND team is led by Tom Sharp, a professor in ASU’s School of Earth and Space Exploration and the Arizona Space Grant Consortium’s associate director. This year’s members include: Jack Lightholder, SG intern/team lead, computer science; Mason Denney, SG intern/team lead, computer systems engineering; Tyler McKinney, aerospace engineering; Ines Weber, physics; Clelia Tommi, astrobiology; Trevor Van Engelhoven, astrophysics; Vishal Ghorband, electrical engineering; Jefferson Fleing, aerospace engineering; Claeren Mapili, aerospace engineering; Zach Burnham, electrical engineering; John Gehrke, aerospace engineering; Mateo Orama, mechanical engineering.

Team meetings are once a week. Please contact Jack Lightholder if interested in joining. No prior experience or specific skill sets required.

In addition, ASU/NASA Space Grant Undergraduate Fellowship applications are available for the 2015-2016 academic year at: https://nasa.asu.edu/content/undergraduate-information. Space Grant usually funds one or two team members per year.

Image courtesy of Jack Lightholder.

(Nikki Cassis)
 

04/02/2015

The first space instrument to be built at Arizona State University has just received the electronics it will use in flight. This starts the final laboratory tests leading to its launch next year on a NASA rocket.

The last major subsystem for the OSIRIS-REx Thermal Emission Spectrometer — its electronics — has arrived in a cleanroom at Arizona State University's School of Earth and Space Exploration (SESE). The electronics are the third of three subsystems making up the spectrometer, called OTES for short. The other two are the spectrometer's optical and mechanical systems.

On March 31, 2015, NASA gave a green light for the OSIRIS-REx mission to transition from development to bringing instruments and their components together. This will be followed in the months ahead by integrating and testing the spacecraft's combined systems.

The OSIRIS-REx mission will launch in September 2016 and fly to an asteroid, 101995 Bennu. There it will collect a sample of its rocks and dirt and bring them back to Earth in 2023. (OSIRIS-REx is short for Origins Spectral Interpretation Resource Identification Security Regolith Explorer; the University of Arizona in Tucson leads the mission.)

OTES plays a key part in the mission to Bennu. Its task is to use long-wavelength infrared light to map the asteroid's minerals, which will help mission scientists select where to collect samples. Designed at ASU, OTES is the first space-qualified instrument to be built at the university. ASU is one of only a handful of universities in the United States capable of building NASA-certified space instruments.

"We have already built the spectrometer part of OTES, and attached it to the telescope that collects light so it can work," says Philip Christensen, OTES' designer and principal investigator. Christensen is a Regents' professor of geological sciences in SESE. "The final element is the electronics that will control the instrument. OTES has now received its brain and nervous system."

Next come tests as engineers working in a cleanroom in Interdisciplinary Science and Technology Building 4 on the Tempe campus work to integrate the electronics with the optical and mechanical parts of OTES.

Testing will include placing OTES in a chamber where it is subjected to the same conditions it will experience during the mission. Aerospace engineers call this process "shake and bake" because it reproduces the vibrations of a rocket launch as well as the extremes of heat and cold that OTES must survive to do its job.  

"NASA's rules for testing flight instruments and other space hardware are detailed and thorough," Christensen says. "They need to be. Once the spacecraft leaves Earth, there are no repair calls. Everything has to work perfectly."

Primitive target

Scientists chose asteroid Bennu as the target for the OSIRIS-REx mission because it has undergone relatively little change since it formed early in the solar system's history. Thus samples from Bennu may give us a better look at how the solar system formed.
 
With an orbit that brings it inside Earth's orbit, Bennu is the most accessible asteroid rich in organic materials. It is about 575 meters (1,900 feet) wide, roughly spherical, and spins once every 4.3 hours. Reflecting only three percent of the sunlight falling on it, Bennu is about as dark as a charcoal briquette.

The flight plan calls for the OSIRIS-REx spacecraft to launch in September 2016 and rendezvous with Bennu in November 2019. It will spend up to 15 months surveying Bennu's mineralogy with OTES and another spectrometer working at shorter visible and infrared wavelengths. A suite of three visible-light cameras and a laser altimeter will draw a complete picture of the asteroid.

Mission scientists will then select a target area. The spacecraft will approach Bennu, touch it briefly, and collect at least 60 grams (2 ounces) of dust, soil, and rubble from its surface. Then OSIRIS-REx will cruise back to Earth and deliver the encapsulated sample to a landing site in Utah in September 2023. After dropping off the sample as it flies past Earth, the spacecraft may go on to survey other asteroids, although it will not be able to collect samples from them.

Christensen says, "As we put all its flight parts together and start on this final series of testing, it's very exciting to see OTES come to life in our hands."

The School of Earth and Space Exploration is an academic unit of the College of Liberal Arts and Sciences.