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National Aeronautics and Space Administration

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Nanotech Light-Suppression Te c h n o l o gy Creat e d

Goddard Scientists Set Out to Study Why Hurricanes Intensify

G l o Pac Paves Way for Future Airborne Investigations

QWIP Te c h n o l o gy Finds a Home

Looking for Life on Mars — Just a Little Closer to Home

Goddard Te c h n o l o gy Saves 16-Ye a r-Old Sailor

Volume 6 Issue 4 Summer 2010

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h t t p : / / g s f c t e c h n o l o g y. g s f c . n a s a . g o v Volume 6 Issue 4 Summer 2010

Light has a funny way of ricocheting off instrument com-ponents and contaminating measurements, but a teamof Goddard technologists has created a blacke r- t h a n -pitch material that absorbs stray light, potentially provid-ing orders-of-magnitude improvement over current light-suppression technology.

The nanotech-based material now being developed by ateam of 10 Goddard technologists is a thin coating ofmulti-walled carbon nanotubes packed vertically muchl i ke a shag rug. The tiny gaps between the tubes collectand trap background light to prevent it from reflectingoff surfaces and interfering with the light that scientistsactually want to measure. So far, the Goddard team hasapplied the coating to an instrument component toassess its durability for Earth observations and anotherteam is considering its use on a proposed astrophysicsmission.

“This is a technology that might provide a lot of pay-back,” said engineer Leroy Sparr, who is helping developthe Ocean Radiometer for Carbon Assessment (ORCA), anext-generation instrument that would measure marinephotosynthesis (Goddard Tech Trends, Summer 2008,Page 6). Reflectance tests show that the carbon nanotubes absorb more than 99.5 percent of the lightthat hits them. “It’s about 10 times better than blackpaint” typically used by instrument designers to suppresse rrant light, he said.

Space Qualification Expected

In addition to conducting reflectance tests, the tech-n o l o g y-development team led by Principal InvestigatorJohn Hagopian plans to conduct vibration and acousticstests over the coming weeks to further qualify the coat-ing’s use in space. In fact, Hagopian hopes to achievespace qualification by the end of summer, he said.

Hagopian’s team began working on the technology in2007 in part with Goddard R&D funds. Unbeknownst tothe group, the New York-based Rensselaer Po l y t e c h n i cInstitute also had initiated a similar effort and announcedin 2008 that its researchers had developed the darke s t

carbon nanotube-based material ever made — morethan three times darker than the previous record. “Ourmaterial isn’t quite as dark as theirs,” Hagopian said. “Butwhat we’re developing is 10 times blacker than curr e n tNASA paints that exponentially suppress system straylight. It also will be robust for space applications.”

That is an important distinction, said Carl Stahle, assistantchief for technology for the Instrument Systems andTechnology Division. Not all technology can be used inspace because of the harsh environmental conditionsencountered there. “That’s the real strength ofGoddard,” Stahle said. “We have to find ways to applynew technology and fly it on our instru m e n t s . ”

The breakthrough was the discovery of a highly adhesiveunderlayer material upon which to grow the carbon nanotubes, which are just a few tens of nanometers ind i a m e t e r. To grow carbon nanotubes, materials scientiststypically apply a catalyst layer of iron to an underlayer onthe silicon substrate. They then heat the material in anoven to about 750° C (1,382° F). While heating, thematerial is bathed in carbon-containing feedstock gas.

Stephanie Getty, the materials scientist on Hagopian’steam, varied the underlayer as well as the thickness ofthe catalyst materials to create carbon nanotubes that notonly absorb light, but also remain fixed to the materialupon which they are grown. As a result, they are moredurable and less likely to scratch off. The team also hasgrown durable nanotube coatings on titanium, a betters t ructural material for space use. The team now is fine-tuning production techniques to assure consistent quali-ty and light-suppression capabilities, Hagopian said.

Should the team prove the material’s suitability in space,the material will provide real benefits to instru m e n tdevelopers, Hagopian added. Curr e n t l y, instru m e n tdevelopers apply black paint to baffles and other compo-nents to reduce stray light. Because the coating is moreeffective than paint, instrument developers could growthe carbon nanotubes on the components themselves,thereby simplifying instrument designs because fewer

Blacker Than BlackGoddard Optics Engineer Develops Light-Suppression Nanotechnology

About The Cover:

Photo Credit: Chris Gunn

Principal Investigator John Hagopian is leading a team of Goddard technologists nowdeveloping a nanotube-based material that is 10 times blacker than paint used by instru-ment designers to suppress errant light. The sample on the left is black paint; the sampleon the right is the new nanotube material. Among its many benefits, the technology wouldallow scientists to gather hard-to-obtain measurements because of limitations in existinglight-suppression techniques or to gather information about objects in high-contrast areas,including planets in orbit around other stars.

C o n t i n u e d , Page 3


h t t p : / / g s f c t e c h n o l o g y. g s f c . n a s a . g o vVolume 6 Issue 4 Summer 2010

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baffles would be required. To accommodate larger com-ponents, the team now is installing a six-inch furnace togrow nanotubes on components measuring up to fiveinches in diameter. And under a NASA Innovation Fu n daward, the team also is developing a separate techniqueto create sheets of nanotubes that could be applied tol a r g e r, non-conforming surfaces.

In addition to simplifying instrument design, the technol-ogy would allow scientists to gather hard-to-obtainmeasurements because of limitations in existing light-suppression techniques or to gather information aboutobjects in high-contrast areas, including planets in orbitaround other stars, Hagopian said. Curr e n t l y, theGoddard team advancing technologies for the proposedLaser Interferometer Space Antenna (LISA) mission,which will measure gravitational waves should NASAselect it for development, is considering its use, said JeffLivas, a LISA scientist.

The ORCA team, which is fabricating and aligning ani n s t rument prototype with support from the NASAI n s t rument Incubator Program, is the first to actually

apply and test the technology. The instrument is the front-runner for the proposed Aerosol/Cloud/Ecosystems (AC E )mission and requires robust light-suppressiontechnologies because more than 90 percent of the lightgathered by the instrument comes from the atmosphere.Therefore, the team is looking for a technique to suppressthe light so that it doesn’t contaminate the faint signal theteam needs to retrieve. “It’s been an issue with all the(ocean sensors) we’ve flown so far,” said ORCA PrincipalInvestigator Chuck McClain.

Working with the ORCA team, Hagopian’s group grew thecoating on a slit, the conduit through which all light willpass on ORCA. “Having an efficient absorber is critical andthe nanotubes could provide the solution,” McClain said.“Right now, it looks promising,” Sparr added. “If they cancontinue advancing the technology so that it can beapplied to other spacecraft components, it could be av e ry important development for NASA.” ◆

C o n t a c t :

[email protected] or 301.286.9991

The team now developing a nanotube-based technology that promises to be more effective than current light-suppre s s i o n

techniques includes (from left to right): Patrick Roman, Alex Maldonado, Jim Butler, Stephanie Getty, Cleophus Hunt, Mary

Li, John Hagopian, and Georgi Georgiev. Not pictured are Greg Hidobro and Manuel Quijada.

Blacker Than Black. . . Continued from page 2


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One of the four instruments flying on the Global Hawk isthe High-Altitude Imaging Wind and Rain Profiler(HIWRAP), a dual-frequency radar that Goddard PrincipalInvestigator Gerald Heymsfield developed in part withI n t e rnal Research and Development (IRAD) programfunding. The solid-state instrument — designedspecifically for use on unpiloted high-altitude aircraft —will measure horizontal winds and precipitation. HIWRAPalso is expected to provide prelaunch simulation data forthe Global Precipitation Mission set to launch in 2013.

‘GRIP on Steroids’

The investigation continues under HS3. “GRIP really setsthe stage for us,” said Braun, who will be assisted byDeputy Principal Investigator Paul Newman, who man-aged the maiden flight of the Global Hawk in April (seerelated story, page 5). “What’s not known is why somes t o rms form and others don’t. With HS3, which essential-ly is GRIP on steroids, we can target specific periods inthe life cycle of a storm . ”

Two Global Hawk aircraft will carry out one-month-longmissions during the Atlantic hurricane season beginning

How many times have emergency rescue personnelevacuated people living along the coastline only for apotentially catastrophic hurricane to fizzle out hoursbefore it is supposed to make landfall?

Two NASA-funded airborne missions involving severalGoddard Earth scientists are aimed at ultimately prevent-ing those unnecessary and costly evacuations, which bysome estimates would save $3 billion in a typical hurr i-cane season. Both the Genesis and Rapid IntensificationProcesses (GRIP) experiment and the Goddard-ledH u rricane and Severe Storm Sentinel (HS3) are expect-ed to enhance scientists’ understanding of how tropicals t o rms form and, more import a n t l y, how they developinto major hurricanes.

“The most important factor in whether residents willevacuate is the strength of the storm,” said PrincipalInvestigator Scott Braun, who is leading the $30-millionHS3 mission, one of five selected under NASA’s newE a rth Venture program. (Of that $30 million, Goddardwill directly receive about $8 million.) “While forecastershave made great progress accurately tracking hurr i c a n e s ,t h e y’ve made only small improvements in their ability topredict intensity. ”

The quest to improve scientists’ understanding beginswith GRIP on August 15. For six weeks, NASA willdeploy two instru m e n t - p a c ked piloted aircraft, the DC- 8and the WB 57, over areas of interest in the At l a n t i cOcean to gather data within and in the vicinity of tropi-c a l - s t o rm systems. Should conditions suggest a hurr i c a n ef o rming or intensifying, scientists then will dispatch t h eGlobal Hawk from its base at the Dryden ResearchFacility for an extended investigation of conditions.

The Global Hawk is a new addition to NASA’s fleet ofresearch aircraft (Goddard Tech Trends, Summer 2009,). The unmanned aircraft flies at up to 65,000 feet— nearly twice as high as a regular commercial airliner— for as long as 30 hours.

C o n t i n u e d , Page 5

A few years ago, Goddard set its sights on reinvigorating its airborneinstrument program — a research area in which it had alwaysexcelled — and, if this year is any indication, the investment appearsto be paying off.

Goddard Earth scientists are leading NASA’s IceBridge campaign, thelargest airborne survey NASA has ever flown over Earth’s polar regions.They are playing prominent roles in four of the five new Earth Ve n t u r e -1 missions announced a few weeks ago, bringing in nearly $17 millionin direct new business. And they were instrumental in demonstratingthe value of the Agency’s new unmanned research aircraft — the

Global Hawk. In fact, Center scientists have developed about a dozenairborne instruments and currently are developing 12 more.

Aircraft missions fulfill an important research niche, said BobConnerton, chief engineer for Goddard’s Earth Sciences Division.Scientists use these platforms to test new technologies, calibrate andvalidate spacecraft measurements, and carry out critical scienceinvestigations. “They really complement our space missions,” he added,“and represent a great opportunity for us.”

In this issue, Goddard Tech Trends highlights a few of those successesand their significance to the Center.

S P E C I A L R E P O RT

G o d d a rd Reasserts Leadership in Airborne Instrumentation

Riders on the StormGoddard Scientists Set Out to Study How Hurricanes Intensify

G o d d a rd scientists Paul Newman (left) and Scott Braun (right)

a re leading a $30-million airborne mission to determine how

s e v e re storms evolve into hurricanes.

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with a demonstration flight next year. Full science opera-tions with the mission’s suite of seven instruments arescheduled to begin the following year and run through2014. In essence, HS3 will give scientists somethingt h e y’ve never had before — a sustained look at storm sas they evolve over an extended period of time.

To get a complete picture of developing hurricanes, onea i r c r a ft will carry four instruments that study environ-mental conditions surrounding the storm, including theCloud Physics Lidar and the Tropospheric Wind LidarTechnology Experiment developed with IRAD funds byGoddard scientists Matt McGill and Bruce Gentry,r e s p e c t i v e l y. The National Oceanic and At m o s p h e r i cAdministration and the University of Wisconsin are pro-viding the other two instruments.

The second aircraft will carry Heymsfield’s HIWRAP andtwo other instruments provided by the Marshall SpaceFlight Center and Jet Propulsion Laboratory. Thesei n s t ruments will measure conditions within the storm s


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from a vantage point directly above the hurricane vortex. To accommodate the mission, NASA is building a GlobalHawk operations center at the Wallops Flight Fa c i l i t ywhere pilots will remotely control the aircraft and scien-tists will command their instruments and receive data inreal time. The Agency also is expected to develop amobile operations center so that the aircraft can deployv i rtually anywhere.

Other Venture-Class Missions

In addition to HS3, NASA selected four other new Ve n t u r e -class missions. McGill, Ken Pi c kering, and Rolfe Reichle areproviding instruments and science support for three. “A l lin all, Goddard did well with this solicitation,” said BobC o n n e rton, chief engineer for Goddard’s Earth SciencesDivision. “Hopefully this is just the start.” ◆

S P E C I A L R E P O RT

G o d d a rd Reasserts Leadership in Airborne Instrumentation

C o n t a c t :


Global Hawk Pacific (GloPac) paved the way for the twomissions aimed at understanding why hurricanes intensi-fy. “There is no doubt in my mind,” said Goddard scientistMatt McGill, who flew his Cloud Physics Lidar on themaiden science flight of the unpiloted vehicle. “It provedthat these missions were possible and would yield valu-able data.”

G l o Pac, co-managed by Goddard scientist Paul Newmanwho also is serving as the deputy principal investigator onthe Hurricane and Severe Storm Sentinel (HS3) mission,o c c u rred in April. It included four separate long-durationflights over the Pacific and Arctic regions to explore tracegases, aerosols, and atmospheric dynamics and test thea i r c r a ft’s duration, altitude, and connectivity with sciencepayloads. “This flight was quite successful,” said Newman,who shared management duties with David Fa h e y, a sci-entist with the National Oceanic and At m o s p h e r i cAdministration.

The primary purpose was gathering data to validate meas-urements by Aura, an A-train satellite that Goddard devel-oped to study Earth’s ozone, air quality, and climate(Goddard Tech Trends, Summer 2009, Page 4). However,it also collected data showing the breakup of the polarv o rtex, a large-scale cyclone in the upper troposphereand lower stratosphere, and observed dust plumes thatoriginated from China’s Gobi Desert and then traveledacross the Pacific into California, Newman said. Theo b s e rvations confirmed computer models that indicatedthe dust would appear exactly where it was observed.

GloPac Lays Foundation for Future Airborne Missions

The Global Hawk unmanned vehicle made its maiden sci-

entific flight in April, proving it was a viable platform for

high-altitude, long-duration missions.

C o n t a c t :


Just as important, the maiden flight established protocolsand procedures for integrating science instruments and fly-ing an unpiloted vehicle remotely from an operations cen-ter at Dryden Flight Research Center, reducing risk forfuture Global Hawk missions, Newman said.

“The GloPac mission showed that the Global Hawk aircraftis a revolutionary tool for Earth science research,”Newman said. “The Global Hawk has now proven to be ascience platform that can fly to altitudes of 65,000 feet forlong-duration flights approaching 30 hours.” ◆


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TIRS isn’t the only instrument that will benefit from theQWIP technology, which is especially effective for Eart ho b s e rvation. Jhabvala, who would like to use other R&Dfunding to ultimately build a 2,000 x 2,000 imaging arr a yand a 512 x 3,000 wide-swath application arr a y, says thetechnology is applicable to at least one of the NationalResearch Council’s proposed decadal-survey missions forE a rth science.

It also is being tested for a possible mission to Mars,Jhabvala said. The U.S. Geological Survey (USGS) is inter-ested in one day developing a possible mission that wouldsearch for life on Mars, Jhabvala said. “The question iswhere are the best places to probe? Why not caves? Howthen do you find caves on Mars?”

To find out, Jhabvala and his research part n e r, Jut Wy n n e ,a cave biologist with USGS and Nort h e rn ArizonaU n i v e r s i t y, have set up a QWIP camera near caves in theMojave Desert to monitor diurnal cave temperatures. Theteam has shown a clear thermal contrast between thecave opening and the surrounding landscape.Throughout the course of a day, the cave entranceappears cold during sunlight hours and hot at night. “Thisis exactly the type of thermal signature we might try andlocate on the surface of Mars,” Jhabvala says.

“This information would be collected and then a determ i-nation could be made remotely to send a probe to thislocation and hunt for any signs of life. We will continue torefine our data-collection and reduction capability overthe next few years as the QWIP technology evolves andour experience increases with more field tests.” ◆

An infrared-detector technology that PrincipalInvestigator Murzy Jhabvala developed overnearly two decades will debut on a Goddard-developed instrument that will help states moni-tor water consumption — an important capabili-ty in the West where precipitation is sparse andwater rights are allocated.

The Quantum Well Infrared Photodetector(QWIP), which Jhabvala and his team qualifiedfor actual spaceflight last August, is being inte-grated into Goddard’s Thermal Infrared Sensor(TIRS) — a late addition to the Landsat DataContinuity Mission (LDCM) scheduled to launchin 2012. TIRS, a 286-kg (630-lb.) two-channel far-infrared imager, will provide surf a c e - t e m p e r a t u r edata used operationally to monitor water con-sumption on a field-by-field basis in the West.

It is the first spaceflight instrument to use QWIP;h o w e v e r, Jhabvala believes the detector technology alsois suitable for other potential missions.

TIRS instrument developers selected the QWIP technolo-gy because it could easily meet the instrument’s perf o rm-ance requirements and production schedule, Jhabvalasaid, adding that he and his team began working on thedetector system in July 2008 after instrument developersrealized that another detector technology selected forTIRS would not be ready. “We had a short fuse. That’s whythe technology was selected,” Jhabvala said. “We had littlemore than a year to build the entire focal plane — start i n gfrom scratch.”

With various Goddard and NASA R&D funding sources,Jhabvala had matured the technology and had even creat-ed years earlier a one-million-pixel array that could sense arange of longer wavelength bands — more robust thanthe TIRS requirement of 10.5 to 12.5 micrometers. Inaddition to having the technology already at hand, QWIPtechnology offered another significant advantage: As tech-nology goes, it is relatively easy to build.

The detector is fabricated on a Gallium Arsenide (GaAs)semiconductor wafer, layered with more than 50 coats ofdetector material. The layers act as quantum wells, whichtrap photons and convert them to electrons — the funda-mental particles that carry an electric current — and onlylight with a specific energy can release them.

If the light with the correct energy lands in one of thea rr a y’s quantum wells, the freed electron flows through aseparate readout chip attached to the array where it isrecorded. A computer uses this information to recreate animage of the infrared source. Engineers can build a detector to sense specific wavelength bands by vary i n gthe composition and thickness of the layers.

QWIP Technology Finds a HomeInfrared Detector Cleared to Fly on Landsat Follow-On Mission

C o n t a c t :

M u r z [email protected] or 301.286.5232

G o d d a rd technologist Murzy Jhabvala (seated) and USGS cave biologist Jut

Wynne are testing a new detector system in the Mojave Desert that the pair

hopes could one day find caves on Mars.



07The Mars Science Laboratory (MSL)is expected to touch down on theM a rtian surface in 2012 to assess ifMars was in the past, or is today,capable of supporting life. But in asense the search already has begun— just a little closer to home.

In August, three Goddard scientistswho are helping develop theSample Analysis at Mars (SAM)i n s t rument suite — one of 11i n s t ruments flying on MSL — willtest data-gathering techniques andi n s t ruments at three sites inSvalbard, Norw a y, an island abovethe Arctic Circle that closely resem-bles the environment found onMars. When SAM begins operationson the red planet in a couple years,it will search for carbon com-pounds, including methane, whichare associated with life. It also will explore ways that theM a rtian atmosphere creates and destroys them.

The Goddard contingent is participating in the Arctic MarsAnalog Svalbard Expedition, an international project spon-sored by The Carnegie Institution of Washington, NASA,and several other international academic and researchorganizations. During this particular trip, scientists willdeploy instruments at three sites — methane seeps atK n o rringfjellet, a sediment outcrop near Ny Ålesund, andc a r b o n a t e - e n c rusted volcanic vents at Sigurdfjellet — andoperate them remotely, much like an actual mission toM a r s .

“We’ll be able to simulate some of the experiments we’redoing on SAM to test our systems, verify, and validatesome of the data we’ll be getting,” said Jennifer Stern ,who is taking a Cavity Ringdown Spectrometer, a com-mercial instrument she modified in part with GoddardI n t e rnal Research and Development (IRAD) programfunding.

L i ke SAM’s Tunable Laser Spectrometer, Stern’s instru-ment will measure the isotopic composition of carbonatesthat form in the presence of water and carbon dioxide.Knowing the isotopic ratios of carbon compounds canhelp scientists determine whether biological or abioticprocesses were responsible for their formation.

An Evolved Gas Analysis Mass Spectrometer provided byAmy McAdam will support Stern’s investigation and willemulate some of the tasks SAM will perf o rm on Mars.Instead of examining carbon isotopes, McAdam’s instru-ment will characterize rock and soil samples by monitor-ing the compounds released as they are heated to high

temperatures. In part i c u l a r, it will look for organic materi-als trapped within the samples.

And scientist Inge ten Kate is taking the Goddard-devel-oped Volatile Analysis by Pyrolysis of Regolith (VA PoR), aminiaturized version of SAM that originally was developedfor lunar exploration, but is suitable for investigating otherairless bodies and those with thin atmospheres. Thep o rtable field instrument, developed in part with IRADfunding, will analyze gases in the atmosphere as well asvapors that are produced when its onboard oven heatssoil and rock samples to at least 1,200° C (2,192° F). Theoven is capable of reaching higher temperatures thanSAM. The measurements could help scientists determ i n ewhether organic compounds exist in the sample.

E v e n t u a l l y, the instrument will carry a time-of-flight masss p e c t r o m e t e r, also developed in part with IRAD funding.The new spectrometer contains nano-constructed com-ponents that could make it more capable and much small-er than its predecessors. Ultimately, the VA PoR teamhopes to win a future planetary mission, and the fieldcampaign in Norway is designed to demonstrate thei n s t rument’s capabilities.

“I think it’s a really cool opport u n i t y,” McAdam said. “Theentire campaign will simulate what a real rover teamwould do.” ◆

C o n t a c t s :

A m [email protected] or 301.614.6585J e n n i f e r. C . S t e [email protected] or 301.614.6062


Looking for Life on Mars — Just a Little Closer to Home

Scientists Jennifer Stern, Amy McAdam, and Inge ten Kate are traveling to Norway in

August to test data-gathering techniques and instruments in preparation for a Mars mission

c a r rying the Goddard-developed Sample Analysis at Mars instrument suite.


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G o d d a rd Tech Tre n d s

G o d d a rd Tech Tr e n d s is published quarterly by the Office of the ChiefTechnologist at the Goddard Space Flight Center in Greenbelt, Md.The newsletter describes technology developments at Goddard andexplains how they are helping NASA to achieve its missions. If youwant more information about Goddard technology, contact the ChiefTechnologist. If you wish to be placed on the newsletter distributionlist, contact the editor.

Peter M. HughesChief Te c h n o l o g i s t

3 0 1 . 2 8 6 . 2 3 4 2Pe t e r. M . H u g h e s @ n a s a . g o v

Lori J. Ke e s e yE d i t o r

3 0 1 . 2 5 8 . 0 1 9 2l j ke e s e y @ c o m c a s t . n e tNP-2007-10-853-GSFC (revised 7/10)

When 30-foot waves damaged her 40-foot sloop whileshe sailed the Indian Ocean 2,000 miles west of Au s t r a l i ain early June, 16-year-old Amy Sutherland activated herdistress beacon and set in motion an international searchand rescue operation that ultimately resulted in her safer e t u rnto Californ i a .

Behind the headlines, however, was a little known fact:NASA technology saved her life.

Her dramatic rescue could not have happened without amultitude of technologies developed by Goddard for theSearch and Rescue Satellite-Aided Tracking (SARSAT) pro-gram, managed by the National Oceanic andAtmospheric Administration (NOAA) as part of an inter-national program, said NASA Search and Rescue MissionManager David Affens. “This case is more interesting thanmost because we contributed to every aspect of it.”

When Sutherland activated her distress beacon — a per-sonal handheld locator developed by MicrowaveMonolithics under a Goddard-managed Small BusinessInnovation Research program award — the device trans-mitted an emergency signal to a geosynchrous-orbitingsatellite equipped with Goddard-developed repeatert e c h n o l o g y. The satellite then relayed the signal via theS A R S AT network to the U.S. Eight minutes aft e rSutherland manually activated her beacon, the U.S. CoastGuard’s Pacific Area Command in Alameda, Californ i a ,contacted her worried parents using information sheprovided when she registered her beacon with NOAA.And less than an hour later, two NOAA weather satellites,launched by a Goddard team, used NASA technology topinpoint her location.

U l t i m a t e l y, a French fishing vessel, which was 400 milesfrom her location when the distress signal was detected,was directed to her location to perf o rm the rescue.

New Search and Rescue System Planned

Now Affens’s organization, along with NOAA, the CoastGuard, and the Air Force, are working to develop a newand improved search and rescue system, called theDistress Alerting Satellite System (DA SS). The next-gener-

ation system will more quickly detect and locate distresssignals generated by the emergency beacons. That’sbecause NASA plans to install the repeaters on the GlobalPositioning System (GPS), a constellation of 24 spacecraftoperating in mid-Earth orbit, and not weather satelliteswhere they currently reside.

Identify Distress Signals Faster

“A few years ago, we looked to see how we couldimprove the system and we concluded that the intern a-tional search and rescue community would benefit fromnew technology installed on GPS,” Affens said. “Wewould be able to identify distress signals faster and with agreater level of precision.” The improved response timeis made possible because of GPS coverage. With GPS, atleast four satellites are in view of any location worldwide.Almost instantly, processing of the signal can begin tod e t e rmine the precise location of the person in distress.

Although the current system is effective, as evidenced bySutherland’s rescue and those of 28,000 others world-wide since the system became operational in the mid-1980s, a weather satellite may not be in position to pickup a distress signal for up to two hours after a user acti-vates the beacon. Fu rt h e rmore, weather satellites in geo-s t a t i o n a ry orbit cannot independently locate a beaconunless it contains a navigation receiver that encodes andtransmits its position — a capability not offered on mostunits. “Right now, it can take an hour or more before wecan even act on a signal,” said Mickey Fitzmaurice, aspace systems engineer for NOAA’s SARSAT program.

The new GPS-based system is now being tested.C u rr e n t l y, nine GPS satellites are flying the proof- o f- c o n-cept technology and an additional 12 are planned.Goddard is testing the technology before transitioning toa final system after 2015, which will be deployed on theAir Force’s Block III GPS satellites. “The bottom-line hereis that within one minute, we'll know where the distresssignals come from,” Fitzmaurice said. “It is the future.” ◆

C o n t a c t :

D a v i d . W. [email protected] or 301.286.9839

NASA Technology Critical to 16-Ye a r-Old Sailor’s Rescue


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