Volume 18 Issue 4 Summer 2022

www.nasa.gov

National Aeronautics and Space Administration
cuttingedge • goddard’s emerging technologies

PAGE 2

Volume 18 • Issue 4 • Summer 2022

www.nasa.gov/gsfctechnology

About the Cover

Jack Sadleir stands in his lab with his sensor technology suspended in 

a cryogenic testing setup. His tiny sensor, powered by quantum waveform effects, not only detects incoming photons with unmatched 

precision, but can tell what color of light each photon is. Quantum 

technologies taking advantage of the seemingly impossible physics of 

matter at the atomic level and smaller could change the way NASA 

communicates, collects science data, explores and even lands 

humans safely on other worlds. 

(Image Credit: NASA/Chris Gunn)

2 Goddard’s Innovations in Quantum Technology

4 Our World as a Model Exoplanet

7 Measuring Gravity – By the Atoms

> Satellite Geodesy – Innovation Born at Goddard

10 Quantum Communications – Developing Capabilities for the Future

> Growing Talent for Quantum Investigations

13 Quantum Dots Enable Spacecraft-as-Sensor Concept

15 Tiny, High-Powered Laser to Find Water on the Moon

Summer

2022

in this issue:

Mastering the peculiar behaviors of matter and light

at the smallest measurable levels changes the way

scientists observe and explore the universe at the

grandest scales.

Scientists have refined our understanding of quantum physics, the properties of matter and energy at 

the atomic and sub-atomic scale for more than 100 

years. These investigations are beginning to yield

technological solutions, said Renee Reynolds,

Goddard’s assistant chief technologist for Instrument Systems.

“Principles of quantum mechanics, entanglement

and superposition promise to enable transformational science applications in the areas of quantum

sensing, quantum communications and networking,

and atom interferometry,” she said. “Here at Goddard, we aim to build upon external partnerships

and internal expertise to develop next generation

quantum technologies and infrastructures.”

Goddard innovators utilizing classical quantum

effects – the unique properties and behaviors of

materials at the atomic level – are developing a

Goddard’s Innovations in Quantum Technology

powerful new generation of detectors. These applications promise more powerful space and ground

telescopes, more compact sensors to measure

chemicals and composition of other planets, and

instruments to directly measure gravity itself and

how it changes over time and space.

On another level – often referred to as quantum

2.0 – the capability of a particle or photon to exist in

more than one state or position simultaneously, or

superposition, opens new possibilities for communications, encryption, and computers exponentially

more powerful than currently possible. Superpositioned particles exhibit a trait called entanglement

– meaning any changes to the state of one of a pair

instantaneously affects its entangled twin, regardless the distance between them.

Manipulating entangled photons promises instantaneous communication unbound by the speed of

light over vast distances. Even low-volume data – 

bits or kilobits – offers promise for unbreakable data 

encryption keys.
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology PAGE 3

cuttingedge • goddard’s emerging technologies

Quantum computers may someday 

soon be capable of calculating faster 

than physically possible by conventional computers dependent on ones and 

zeros: the presence or absence of an 

electrical charge in a single capacitor.

Quantum-powered sensors promise to 

overcome a natural barrier to resolving 

the most distant objects in the universe 

known as the Rayleigh limit. In astronomy, larger mirrors are better at resolving distant, faint light sources up to this 

limit dictated by the wavelength of the 

light collected. Quantum sensors could 

allow future telescopes as powerful as 

the Hubble Space Telescope to fit into 

SmallSat packages the size of a common countertop appliance.

Entangled pairs of photons generated by an orbiting laser could enable 

powerful image-correcting optics. 

This could cancel out the distortion 

of Earth’s turbulent atmosphere and 

expand the vision of telescopes on the 

ground deeper into the cosmos.

Quanta of Collaboration

Goddard’s global leadership in sensor, 

communications, and other technologies is inextricably linked with partner 

institutions.

“Our recent membership into the Mid-Atlantic 

Quantum Alliance (MQA) provides a strategic opportunity to build stronger partnerships with our 

regional quantum ecosystem,” Reynolds said.

Facilitated by the University of Maryland, College 

Park, the alliance serves as a hub for quantum 

technology research, development, innovation 

and education organizations. MQA brings together 

expertise from across academia, industry, government, and research laboratories with the goal of accelerating innovation across the range of quantum 

technologies.

Goddard physicist Dr. Peter Brereton has been 

asked to co-lead the Quantum Sensors working 

group, Reynolds said. “This is a great next step in 

our future engagement with the broader quantum 

sensing community.”

Membership in the alliance builds on Goddard’s 

long tradition of collaborating with universities and 

other partners, said Joanne Hill, Goddard’s Deputy 

Director of Engineering and Technology.

“Trying to get outside our walls is really important in 

order to expose graduate students in the sciences 

and engineering to the work being done here,” Hill 

said. “Even at NASA, we have to actively recruit, 

because not everybody is aware of all the players 

and applications.”

Innovators over the decades established Goddard 

as a beacon for researchers hungry to test quantum technology on important science questions in 

space, Hill said. “At the engineering level, however, 

there are fewer opportunities out there to work with 

these technologies. Bringing scientists and technologists closer together and engaging engineers 

early on is crucial.”

As quantum physics moves from theory to practice, 

Goddard is well situated to engage in developing 

quantum technology and applications.

“This is the place to come to work if you want to be 

involved in quantum technologies,” Goddard Chief 

Technologist Peter Hughes said, “especially as 

we take them into space and put them to work in 

exploring the universe.” v

Extremely small materials like the quantum dot crystal illustrated here alter the way basic

particles such as photons and electrons function within their boundaries. The very size of these 

materials limits how atoms, particles, and photons behave within the crystal, sometimes seeming 

to break the laws of physics. Goddard researchers are putting these and other quantum functions 

and materials to work in groundbreaking technological applications.

Image credit: Florian Sterl/Lukasz Piatkowski, Poznan University of Technology, Poland
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

PAGE 4 www.nasa.gov/gsfctechnology

Our World as a Model Exoplanet

Hunt for Life on Other Planets Requires Patience, Near-Perfect Sensor

Astronomers have one example of a world supporting life to help develop and

inform the search for life on

other planets. Specific colors of Earth’s light as seen

from space reveal an array

of chemicals that support

life or indicate biological

processes.

Scientists can also analyze

the colors of light from an

exoplanet – one orbiting 

another star – but doing so presents two hard

problems, said Goddard

research physicist Jack

Sadleir. The host star will

be billions of times brighter

than the starlight reflecting off its planets, so direct

starlight must be blocked

out as much as possible.

Even then, the light from

the planets will be extremely faint.

“It’s an extremely photonstarved observation,”

Sadleir said. “You need

to collect light efficiently,

because for some targets

we would point our telescope and have it stare for

weeks. We would just see

a slow trickle of photons

that would come in, and 

over time we build up a spectrum, a fingerprint telling us the chemistry present on this distant world. 

If there’s oxygen, water, ozone, or a methane line, 

together these chemicals could suggest potential 

signs of life.”

Sadleir and his team developed a sensor that not 

only detects individual and multiple photon hits with 

unprecedented accuracy but identifies the energy, 

or color, for each photon detected. When a photon 

strikes a surface, its energy heats the impact site. 

Acting like a very precise thermometer, Sadleir’s 

quantum calorimeter measures how much each 

photon’s energy heats the sensor.

“In the visible part of the spectrum, that energy corresponds to the photon’s color,” Sadleir explained. 

“So lower-energy visible photons are red, and as 

you increase the energy, they go from red to orange, yellow, green, blue, and violet.”

His sensor has demonstrated sensitivity in visible, 

ultraviolet, and near-infrared wavelengths, and by 

adjusting the absorber and detector plate or using 

different materials, Sadleir said detectors can even 

be manufactured to identify energy from non-electromagnetic sources.

“Because we measure deposited energy more genJack Sadleir inspects fiber-optic connections in a cryogenic system used to test his life-finding sensors at Goddard. Image credit: NASA/Chris Gunn
Volume 18 • Issue 4 • Summer 2022

PAGE 5

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

erally, we’re not limited to photons,” Sadleir said. “It 

has applications that require measuring the energy 

deposited from other particles, such as phonons, 

electrons, muons, even atoms.”

Astrophysicists, including Nobel Laureate Dr. John 

Mather are always looking to push the limits of 

light-sensing technology to provide more information about the universe and how it began.

“A few grams of better detector is equivalent to a 

few tons of larger telescope, and these detectors 

will collect spectra all of the time,” Mather said.

A Near-Perfect Sensor

Sadleir’s detectors – which measure 20 microns 

across, or less than a third of the width of a human 

hair – are special in a few crucial ways.

He started with a newer technology called a 

transition-edge sensor which depends on the 

properties of superconductors at the point where, 

when chilled, they transition from normal conductors to the superconducting state – but with a twist. 

Sadleir’s detector uses materials like gold, which 

normally never achieve a superconducting state at 

any temperature. He then uses superconducting 

leads to take advantage of quantum effects which 

cause the gold to behave like a weak superconductor, sensitive to disruption by single photons.

The idea for his sensor derives from the field of 

quantum computing, where extraordinary efforts are taken to shield quantum states from any 

outside interference that could collapse that state. 

Sadleir, on the other hand, establishes a sensitive 

quantum state, then exposes it to potential disturbances from the environment. Measuring how 

that quantum state breaks down provides valuable 

information about the source of the disturbance, 

whether it’s light from an exoplanet, cosmic rays, or 

other particles, perhaps yet to be discovered.

Sadleir said these measurements can open a small 

window to a new understanding of the universe.

“The very trait that continues to trouble quantum computing experts today, the fragility of quantum states, 

we utilize to make sensors with exquisite sensitivity,” 

Sadleir said. “We are measuring smaller deposited 

powers and energies than possible before. That is 

quantum sensing in action: using quantum mechanics to achieve orders of magnitude improved performance over the existing state of the art.”

A Life-Sensing Detector

The search for life elsewhere in the universe is a 

high priority for NASA – to answer the question, Are 

we alone?

“Our answer to that question becomes more significant and more impactful the more spectra we 

can collect,” Sadleir said. “If life signatures can be 

found, then faster, more efficient collection of light 

throughout the observation period means increased 

chances of finding life, as it enables searching a 

greater number of planets for a greater number of 

potential life signatures.”

This illustration shows one concept for a mission to search for signs of life on planets orbiting other stars – the Large UV/Optical/IR Surveyor (LUVOIR) telescope.

Image Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

PAGE 6 www.nasa.gov/gsfctechnology

CONTACTS

John.E.Sadleir@NASA.gov or 301.286.3078

“It’s about collecting spectra,” he added, “and our 

detectors collect spectra on everything during each 

phase of the mission.” 

Most light detectors, like those that allow a smart 

phone camera to take pictures, measure single 

photons as either an “on” or “off” signal. When 

a photon hits the sensor and crosses a certain 

energy threshold, it detects a strike. However, most 

detectors falsely report photon hits at a rate that 

can be higher than the number of photons astronomers expect to capture from very dim exoplanets. 

In addition, these detectors must reset before they 

can detect another photon strike, potentially missing a detection. 

“They’re too noisy to make the measurement,” 

Sadleir said. 

Because it measures the energy of each photon 

strike, Sadleir’s detector does not signal false positives. It also performs at an unusually high absorption efficiency – the percentage of photons hitting 

the sensor surface that trigger a detection. His 

sensors exhibited a 93% or better efficiency for the 

1- to 2-micron wavelengths of near-infrared (NIR)

light. Other commercially available NIR sensors

can have an efficiency as low as 7%. “That misses 

too many photons at a critical wavelength for the

search for life,” he said.

Sadleir’s detectors are special in another way. 

Developed for X-ray astrophysics, they were built to 

survive the harmful radiation space-based sensors 

must endure.

And finally, because each detector is also a spectrometer, Sadleir said they eliminate the need for 

bulkier and less efficient optical spectrometers. 

These instruments feed light through a diffraction 

grating or prism down a long path to separate the 

wavelengths before the light ultimately reaches a 

detector array. Which sensor in an array is triggered by a photon after this separation determines 

its energy, or color, but each step in the process 

lowers efficiency.

Efficiency is key for a mission that would count 

individual photons over weeks or even months of 

observations.

“When searching for signs of life,” Sadleir said, 

“every photon is precious, and we need to efficiently extract the information contained in each. We 

need to push the limits, approaching a near-perfect 

detector system.”

For Sadleir – and NASA – answering the big question of life conclusively would be an extraordinary 

claim, requiring extraordinary evidence.

“If planets like Earth are rare, our own world becomes even more precious,” Sadleir said. “If we do 

discover the signature of life in another planetary 

system, it will change our place in the universe in

a way not seen since the days of Copernicus—

placing Earth among a community and continuum 

of worlds.” v

This artist’s impression shows the planet K2-18b, and its host star. It is the only super-Earth exoplanet known to host both water and temperatures that could 

support life. Detailed analysis of Hubble image data revealed the molecular signature of water vapor as well as hydrogen and helium in the planet’s atmosphere.Image Credit: ESA/Hubble, M. Kornmesser
Volume 18 • Issue 4 • Summer 2022

PAGE 7

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

A quantum technology developed by

NASA and industry partners could

help monitor freshwater resources at

the local level by measuring their effect on gravity.

Earth’s gravity changes slightly from 

one region to another and locally, it 

can change over time. Atmosphere, 

tides, and ocean currents account for 

much of that change, as well as water 

moving underground in aquifers, and 

melting snow and glaciers.

Changes in freshwater re-sources 

have immediate impacts on the 

people who depend on them for 

drinking, farming, or industry. Developing methods to monitor and share 

information about these vital 

resources is one way NASA helps 

improve life on Earth.

The Atom Interferometer Gravity 

Gradiometer, developed in partnership 

with the Fremont, California-based 

AOSense, offers the potential for accurate, direct, real-time measurement 

of Earth’s gravitational field and its 

changes over time, said Goddard 

Earth scientist Scott Luthcke. (See 

CuttingEdge, Winter 2019, Page 12).

Luthcke and Goddard physicist Babak 

Saif led development of the gravitymeasuring technology, which works by

pulsing a laser through a cloud of super-cooled 

atoms. Measuring the laser’s interaction with the 

atoms creates an interference pattern. Scientists 

know how the atoms should be-have at a quantum 

level, so the interference serves as a real-time 

measurement of gravity’s pull on the atoms.

“One of these instruments in low Earth orbit could 

advance our current understanding of how Earth’s 

gravity changes over time and in different regions 

by an order of magnitude,” Luthcke said. “It’s like 

being able to improve from looking at large areas, 

say the size of the entire East Coast, down to the 

local aquifer level. This is great, not just for science, 

but as an instrument that provides data for people 

who do local and regional water management; 

that’s real societal impact.”

The team’s ideal gravity gradiometer mission would 

consist of two gravity meters, each consisting of a 

laser pulsing a cloud of 10 million or more atoms. 

Flying together in one spacecraft, separated vertically by up to six feet (two meters), each instrument 

would measure the subtle differences in gravity – 

the gradient – between them. 

Interferometry measures a fundamental feature 

of quantum mechanics where a single particle, 

electron, photon, ion, or atom can act as a wave, 

occupying more than one position at any point in 

time. This quantum state is known as superposition.

In their instrument, each atom acts as an interferometer, Saif said. The laser pulse reveals detailed 

information about each atom’s superposition. “With 

107

 atoms averaged together, this gives you very 

high-precision measurement,” he said.

NASA Instrument Measures Gravity – By the Atoms

Scott Luthcke studies the movement of ground water and glaciers using satellite data and missions 

designed to measure Earth’s mass.

Image Credit: NASA
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

Navigating Other

Worlds

AIGG has applications

across planetary exploration as well, Saif said. The

Gravity Recovery and

Interior Laboratory (GRAIL)

mission mapped the

Moon’s gravity, providing

insight into our natural satellite’s structure. An AIGG

probe of the Moon or Mars

could locate underground

networks of lava tubes – a

potential target for exploration and source of shelter.

Precise gravitational maps

of other moons, asteroids

or other small bodies

could improve safety and

precision of future landing or sample missions.

Traditionally, missions

compile those maps by

close orbiting over time

and inferring gravitational 

forces from spacecraft positioning data. 

The Origins, Spectral 

Interpretation, Resource 

Identification, SecurityRegolith Explorer (OSIRISREx) spacecraft orbited 

the near-Earth asteroid 

Bennu for almost two 

years before selecting a 

sample site: precision 

mapping the rocky asteroid 

and its low-gravity environment. Saif said their instrument could provide a more 

accurate map within 

months or less, depending 

on the object. 

In addition to mapping 

worlds like these more 

quickly or even whole solar systems, Saif said, the 

AIGG instrument could someday be used to read 

any gravity signature – including the 96 percent of 

our universe that is unknown dark matter or dark 

energy.

“The best part is, there is no telescope is 

required,” he said. “Our system is completely 

PAGE 8

closed – you’re reacting to the gravity field directly, 

and the measurement is all internal. You don’t have 

to measure distance to another spacecraft, or 

object, or read the position of stars. From the point 

of view of radiation, it’s better too, because your 

instrument can be shielded from interference; none 

of it is exposed to the environment.” 

The Atom Interferometer Gravity Gradiometer, shown here at the AOSense Lab in Fremont, California, directly measures 

changes in gravity’s effect on atoms suspended in a cloud at super-cold temperatures. Image Credit: Image Credit: AOSense Inc.
Volume 18 • Issue 4 • Summer 2022

PAGE 9

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

Earth scientists have measured our planet’s 

mass and shape from orbit since the first satellites returned precise data about gravity's effects 

on their position and velocity. In 1955, Dr. John 

A. O’Keefe formally proposed using this data to

infer Earth’s shape by calculating gravity’s influence on the spacecraft. America’s second successful satellite, Vanguard 1, provided the

tracking data scientists used to calculate that

Earth is ever-so-slightly pear-shaped. Since

then, countless missions’ data added to this

model of Earth in a field called satellite geodesy: 

a fundamental necessity for working global

positioning systems.

“I just think it’s really cool, that satellite geodesy 

of Earth really started here at Goddard,” Earth 

Scientist Scott Luthcke said. “If you look at your 

phone and it tells you where you are, that’s the 

result of satellite geodesy.”

Radar and lidar altimetry missions measure the 

round-trip travel time of photons bouncing back from 

Earth’s surface, revealing elevation, tree canopy, ice 

sheet height, and changes of mass over time. More 

recently, NASA’s Gravity Recovery and Climate 

Experiment (GRACE) and the GRACE Follow-On 

mission used range measurements between two 

precision-orbiting spacecraft to show how gravity 

changes from month to month. These missions 

showed changes in mass to Earth’s ice sheets over 

time, as well as changes in groundwa-ter distribution 

over their 20-year record.

To improve resolution of these water resources 

down to smaller scales and shorter time intervals, 

the Atom Interferometer Gravity Gradiometer 

(AIGG) directly measures gravity’s pull against freefalling atoms, Goddard physicist Babak Saif said.

“Usually, when we do gravity measurements 

on the science side,” he said, “we don't measure 

gravity. We always measure something else and 

then infer gravity. With AIGG, you’re actually 

measuring the behavior of the atoms as they are

falling, when they’re not being affected by anything

but gravity.”

To prove their instrument, Saif and Luthcke said they 

would combine a scaled-down gradiometer with a 

GRACE-successor mass measurement mission like 

NASA’s Mass Change future mission. This would 

enhance the science return for a relatively small 

additional cost.

“Now you’re talking about mapping the change 

in gravity even every few days,” Luthcke said, “and 

at a high spatial resolution. You’re not just calculating how deep the water is by measuring individual wells; you’re really measuring the change in 

the mass, where the water moves in the earth. 

Imagine understanding the mass change at the size 

of individual glaciers and ice-drains. Imagine being 

able to predict what will happen with those currents 

or aquifers or glaciers in the next few days or weeks 

like we do now with weather.” v

Satellite Geodesy – Innovation Born at Goddard

The Gravity Recovery and Climate Experiment - Follow On mission continues the 

legacy of GRACE, tracking Earth’s water movement and surface mass changes across 

the planet.

Image Credits: NASA/JPL-Caltech

Scott.B.Luthcke@NASA.gov or 301.614.6112

Babak.N.Saif@NASA.gov or 301.286.5433

CONTACTS

Bringing it Home

With all the applications for exploration, Luthcke 

said he doesn’t want to get distracted from the 

“singular thing that would have the most impact for 

humans – which is to put one of these instruments 

in low Earth orbit.”

“We’ve got something right in front of us that can 

vastly improve our understanding and model of the 

time variable gravity field of Earth,” he said. “That 

would benefit people everywhere that depend 

on effectively managing Earth’s precious water 

resources.” v
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

Instant, secure communications anywhere – the 

promise of quantum 

communications has 

governments and businesses around the world 

racing to perfect this 

critical technology.

Quantum communications depends on a property of quantum physics 

that allows a photon to 

exist in a state of superposition – occupying 

more than one location 

simultaneously.

When a photon exists 

in two locations, known 

as an entangled pair, 

whatever affects one 

part also affects its mate 

even when separated 

by distance. Measuring 

one of a pair’s quantum 

states, for instance by 

someone eavesdropping

on a communication, collapses the quantum state of

both instantaneously into a single, or distinct, state.

To create entangled pairs, lasers pump high energy

photons through a specialized crystal that can

emit two lower-energy photons for about one in a

trillion photons received. Experiments to date have

transmitted a few kilobits per second of entangled

photon pairs, enough to create an encryption key to

be distributed to a sender and receiver. That information is used to encrypt and decrypt information 

sent in classical bits: ones and zeroes.

Transmitting an entire message through entangled

photons is a long way off Goddard physicist Babak

Saif said. “Right now, optical communications

infrastructure does not even exist,” he said. “These

technologies are still in the testing and demonstration phases. Optical communications performance

metrics come nowhere close to any of the specifications needed for quantum communications.”

Creating a reliable, high-speed quantum communications network faces two critical technology gaps, said 

PAGE 10

Harry Shaw, Goddard staff engineer for the Telecommunications and Network Technologies Branch. No 

one has yet developed a reliable quantum memory, 

and quantum-encoded data cannot be cloned or 

copied without collapsing the quantum state.

“There are some technology bridges that have to 

be built and crossed to enable practical quantum 

communications,” Shaw said. “Until those are 

solved, it’s going to be very interesting, but the applications will be limited.”

Uniquely Situated 

Goddard’s Exploration and Space Communications 

(ESC) projects division, part of NASA’s Space Communications and Navigation (SCaN) program office, 

leads the way in developing a high-speed laser 

communications capability that could enable further 

advances in quantum communications.

SCaN’s proven track record of high data-rates and 

near-zero downtime is driven by NASA’s responsibility for keeping astronauts, the International Space 

Quantum Communications – Developing Capabilities 

for the Future

The Low-Cost Optical Terminal enables communications from laser terminals in orbit or as far as the Moon.

Image Credit: NASA
Volume 18 • Issue 4 • Summer 2022

PAGE 11

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

Station, and fleets of satellites orbiting Earth safe 

and connected.

Recently, SCaN and ESC launched the TeraByte 

InfraRed Delivery (TBIRD) payload – a small satellite demonstrating NASA’s highest-ever optical data 

rates at 200 gigabits per second, and the Laser 

Communications Relay Demonstration (LCRD) – 

the agency’s first-ever optical relay. They are also 

developing a laser communications terminal for the 

International Space Station and the crewed Artemis 

II Moon mission.

These innovations synergize with developments in 

quantum communications Saif said. Both classical 

and quantum communications depend on information 

transmitted by photons. This means research and 

development into quantum communications stands 

to drive improvements to laser communications using 

classical data transmission as well, he said.

Several new initiatives could bring the state of the 

art closer to the needs of future quantum networks.

Goddard Optical Physicist Robert Lafon recently 

helped complete a Low-Cost Optical Terminal, or 

LCOT, for laser communications downlinks. Similar 

to Optical Ground Station 2 at Haleakala, Hawaii, 

and JPL’s Optical Communications Telescope 

Laboratory (OCTL) on Table Mountain, California, 

LCOT’s 70 cm collecting mirror at the Goddard

Geophysical and Astronomical Observatory 

(GGAO), enables communications at least as far as 

the Moon and is capable of tracking relatively faster 

moving satellites in low Earth orbit. Another terminal 

is under development at White Sands in Las Cruces, New Mexico.

“LCOT promises to be a powerful new facility for 

use in laser communication and other research 

right here in our backyard,” Lafon said. “Optical and 

quantum communications will be primarily what we 

do, but we have gotten a lot of interest in using it for 

lidar work, debris tracking and mitigation efforts, and 

other things. Since we designed it to be modular 

and highly reconfigurable, it can easily be set up to 

accomplish multiple objectives.”

To enhance reception for optical receivers like 

LCOT, Goddard physicist Aaron Yevick successfully tested an advanced form of adaptive optics, or 

image correction technology needed to overcome 

distortion created by Earth’s turbulent atmosphere. 

Yevick used an optical fiber device called a photonic 

lantern, to receive and synchronize multiple signals 

The Laser Communications Relay Demonstration (LCRD) communicates data on a beam of light between the International Space Station and ground 

stations like this one in Hawaii. 

Image Credit: NASA/Dave Ryan
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

PAGE 12 www.nasa.gov/gsfctechnology

Growing Talent for Quantum Investigations

Harry Shaw, Goddard staff engineer for the

Telecommunications and Network Technologies Branch, works with graduate students

from around the country to conduct quantum

communications research aimed at bridging

gaps in existing technology. He is a member of

the Advanced Communications Capabilities for

Exploration and Science Systems (ACCESS) 

project. Over the past six years, theproject 

team has built a community of Ph.D.’s with 

expertise in the field while expanding Goddard’s laboratory capacity for developing 

quantum communications solutions.

“We have some interesting theoretical work that 

we’re trying to take from theory and work out on 

the bench,” Shaw said.

Shaw’s students use commercially available 

quantum photon sources in two wavelengths 

of infrared and near-infrared light to experiment 

with two types of superposition or entanglement: 

polarization, the orientation of light’s electric field, 

and energy/time entanglement. ACCESS’s quantum 

lab is expanding to include experiments with orbital 

angular momentum (OAM) entanglement. “Orbital 

angular momentum allows encoding information 

in very high-density codes,” Shaw said, “and they 

will be using this OAM property to experiment with 

encrypted communications.”

Shaw’s work with graduate students interested in 

quantum physics is about more than just keeping abreast of the emerging technology. It’s about 

developing a community of expertise with an affinity 

for Goddard. That doesn’t mean they’ll come work 

for NASA, but the affiliation can’t hurt, he said.

“The ACCESS quantum lab enables graduate 

students to do quantum experiments as part of their 

dissertation research,” Shaw said, “while supporting 

breakthroughs for our academic partners’ research. 

It also broadens diversity in STEM participation by 

bringing on more women and minorities into the 

quantum arena through internships and new hires.”

“We have to grow the pool of researchers with the 

skills to be able to develop the quantum memories 

and repeaters and relays and entanglement sources 

and all the other things we need,” he said. v

Harry Shaw, top center, mentors interns working on theoretical quantum communications experiments.

Image Credits: NASA Goddard/Sandra Vilevac

CONTACT

Harry.C.Shaw@NASA.gov or 301.286.8680

from a single distorted source. The technology 

accurately records the wave phase of each signal. 

Then his team digitally processes these signals into 

a coherent, single phase.

“These technologies provide a testbed for Goddard 

to do classical, and eventually quantum optical communications,” Shaw said.

Shaw also hopes to test quantum photon detectors 

designed by Goddard physicist Jack Sadleir to evaluate their suitability for a quantum-communications 

receiver. “It’s possible that this detector, designed 

to look for signs of life on planets outside our solar 

system, could find applications in detecting and 

characterizing quantum-entangled photons,” Shaw 

said. (See story, page 4) “High-speed, single-photon 

detectors with low false positives and high quantum 

efficiency is what everybody’s working towards.”

Communicating and navigating accurately through 

space also requires extremely precise, synchronized clocks. Space-based clocks like those used in 

global positioning networks must be accurate down 

to 3 nanoseconds and require complex protocols to 

synchronize over vast distances.

Multi-party quantum clock simulation uses entanglement to eliminate the time lag caused by distance 

and simplify those protocols. Shaw is working with 

a team from Tulane University in New Orleans to 

develop a lab test for a quantum synchronization 

protocol they created. v
Volume 18 • Issue 4 • Summer 2022

PAGE 13

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

In NASA’s hunt for water and resources beyond Earth, a new technology 

could coat the “skin” of a satellite turning its entire surface into a sensor that 

tallies the chemicals present on 

distant planets.

Solving the mysteries of our home 

planet, solar system, and beyond is a 

key priority for NASA, and the new 

sensor could be a powerful tool in the 

investigation. Goddard instrument scientist Mahmooda Sultana developed 

the Quantum Dot Spectrometer to 

help. 

Quantum dots are a type of semiconducting nanocrystal that absorbs 

and re-emits different wavelengths of 

light depending on their size, shape 

and chemical composition (See CuttingEdge, Winter, 2017, Page 11).

Sultana gets her dots, which vary from 

2 to 10 nanometers or less than 50 

atoms thick, from the lab of chemistry 

professor Moungi Bawendi, at the 

Cambridge-based Massachusetts 

Institute of Technology.

She then uses them to break down

light from a planet or other target into portions of 

the spectrum, creating a sort of finger-print which 

reveals what elements or compounds that light 

has touched.

“Basically, we are converting the entire optical 

problem into a math problem,” Sultana said. “The 

dots can be identified in the lab to register light of 

a particular wavelength – a fraction of the chemical fingerprint. Detectors on the other side of the

dots collect the fractions, then the data is handed 

over to computers on the ground to reassemble the 

complete fingerprint.”

“The math is complex,” she added, “but using 

machine learning, we are able to get amazing accuracy, even on more complex spectral curves.”

A typical spectrometer can be a relatively bulky 

piece of equipment, taking up precious real estate 

aboard a satellite. What sets Sultana’s Quantum 

Dot Spectrometer apart is a literally small miracle 

of modern chemistry.

Enabling new applications on SmallSats as well as 

solar sails, Sultana’s instrument has potential for 

studying Earth’s surface composition, ocean color, 

vegetation, and atmospheric chemistry, as well as 

providing insight into auroral interactions. 

As an engineer interested in planetary science, 

Sultana said her quantum dot spectrometer could 

identify water and other chemicals in lunar soil and 

characterize surface and atmospheric elements of 

other planets.

Quantum Dots Enable Spacecraft-as-Sensor Concept

Mahmooda Sultana investigates new applications of quantum physics using nano-scale materials 

with unique characteristics that make them particularly attractive for spaceflight uses.

Vials of quantum dots glow in different colors under ultraviolet light. The 

colors of light emitted are determined by the nano-scale size and composition of the crystals in suspension.

Image Credit: NASA/Pat Izzo

Image courtesy: Mahmooda Sultana
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

PAGE 14 www.nasa.gov/gsfctechnology

ScienceCraft – a New Vision

for Exploration 

The versatility of the quantum dot technology could 

enable a low-cost mission to an outer solar system 

planet. 

Sultana’s concept – ScienceCraft for Outer Planet 

Exploration, or SCOPE – capitalizes on the sensor’s 

versatility and low mass. A solar sail, printed with 

separate layers for readout electronics, detector array, quantum dot spectrometer, and microlens array, 

would serve as a spacecraft, propulsion system, 

and science instrument in one. 

Sultana calls this vision for future exploration vessels ScienceCraft.

She is working to develop this mission concept 

through a Phase I NASA Innovative Advanced 

Concepts (NIAC) Program award granted this April.

Her team has already automated the dot printing 

process The sail is being developed by coinvestigator Artur Davoyan, a professor at UCLA.

“This is a game-changing concept,” she said. “We 

are essentially addressing three of the key barriers 

to outer solar system exploration: the high cost, long 

travel time, and a narrow window to launch a mission that can rendezvous with these distant planets.”

Driven by the gentle pressure of sunlight across a

CONTACT

Mahmooda.Sultana@NASA.gov or 301.286.6973

large area, the sail would pick up speed by orbiting 

close to the Sun, propelling it into the outer solar 

system.

Once there, Sultana’s vision could accomplish 

critical science goals, Goddard planetary scientist 

Conor Nixon said.

“There is currently a gap for exploring the NeptuneTriton system,” he said. “Can we do some Neptune 

science on a fast-flyby, lower-cost mission? It’s the 

sort of planetary system that SCOPE could find a 

niche in exploring.”

In 1989, Voyager 2’s close-up images of Triton first 

revealed its icy surface, marked by plumes that 

hinted at an active geology and a hidden ocean beneath the ice. Investigating how Triton has changed 

over time would help scientists better understand 

how solar system bodies evolve and function.

“As people around the world develop the capability 

to print electronics or produce different materials 

and structures, more instruments like the Quantum 

Dot Spectrometer can be printed directly with the 

solar sail to create additional ScienceCraft 

opportunities,” Sultana said. v

Data from spectrometers is displayed as a spectrum, as in this image capturing the signature of water vapor, clouds and haze 

from exoplanet WASP-96 b. Coming from a puffy gas giant orbiting a star 1,150 light years away, the blue line shows peaks 

where specific colors (wavelengths) of light are bright and valleys where colors are dim or absent. Each element or chemical 

compound contributes its unique spectral curve that serves as its “signature” within the bigger picture.

Image Credits: NASA, ESA, CSA, and STScI
Volume 18 • Issue 4 • Summer 2022

PAGE 15

cuttingedge • goddard’s emerging technologies

www.nasa.gov/gsfctechnology

Finding water on the Moon could be easier 

with a Goddard laser that capitalizes on an 

effect called quantum tunneling to generate 

a high-powered beam in a bandwidth where 

water is known to absorb light.

Locating water and other resources is a NASA 

priority crucial to exploring Earth’s natural 

satellite and other objects in the solar system 

and beyond. Previous experiments inferred, 

then confirmed the existence of small amounts 

of water across the Moon. However, most 

technologies do not distinguish among water, 

free hydrogen ions, and hydroxyl, as the 

broadband detectors used cannot distinguish 

between the different volatiles.

Goddard engineer Dr. Berhanu Bulcha said 

a type of instrument called a heterodyne 

spectrometer could zoom in on particular 

frequencies to definitively identify and locate 

water sources on the Moon. It would need a 

stable, high-powered, terahertz laser which 

was prototyped in collaboration with Longwave 

Photonics through NASA’s Small Business Innovation Research (SBIR) program.

“This laser allows us to open a new window 

to study this frequency spectrum,” he said. 

“Other missions found hydration on the Moon, 

but that could indicate hydroxyl or water. If it’s 

water, where did it come from? Is it indigenous 

to the formation of the Moon, or did it arrive 

later by comet impacts? How much water is 

there? We need to answer these questions 

because water is critical for survival and can 

be used to make fuel for further exploration.”

As the name implies, spectrometers detect spectra 

– wavelengths of light – in order to reveal the chemical properties of matter that light has touched. Most

spectrometers tend to operate across broad sections of the spectrum. Heterodyne instruments dial

in to very specific light frequencies such as infrared 

or terahertz. Hydrogen-containing compounds like

water emit photons in the terahertz frequency range

– 2 trillion to 10 trillion cycles per second – between

microwave and infrared.

Like a microscope for subtle differences within a 

bandwidth like terahertz, heterodyne spectrometers

combine a local laser source with incoming light. 

Measuring the difference between the laser source 

and the combined wavelength provides accurate 

readings between sub-bandwidths of the spectrum.

Traditional lasers generate light by exciting an electron within an atom’s outer shell, which then emits 

a single photon as it transitions – or returns to its 

resting energy level. Different atoms produce different frequencies of light based on the fixed amount 

of energy it takes to excite one electron. However, 

lasers fall short in a particular portion of the spectrum between infrared and microwave known as 

the terahertz gap.

“The problem with existing laser technology,” Dr. 

Bulcha said, “is that no materials have the right 

properties to produce a terahertz wave.”

Electromagnetic oscillators like those that generate 

radio or microwave frequencies produce low-powered terahertz pulses by using a series of amplifiers 

and frequency multipliers to extend the signal into 

the terahertz range. However, this process

Tiny, High-Powered Laser to Find Water on the Moon

Berhanu Bulcha shows off his terahertz laser technology in his lab at NASA’s Goddard 

Space Flight Center in Greenbelt, Md. 

Image Credit: Michael Giunto
Volume 18 • Issue 4 • Summer 2022

cuttingedge • goddard’s emerging technologies

PAGE 16 www.nasa.gov/gsfctechnology

CuttingEdge is published quarterly by the Office of the Chief Technologist at NASA’s Goddard Space Flight 

Center in Greenbelt, Maryland. The publication describes the emerging, potentially transformative technologies that Goddard is pursuing to help NASA achieve its missions. For more information about Goddard technology, visit the website listed below or contact 

Chief Technologist Peter Hughes, Peter.M.Hughes@NASA.gov. If you wish to be placed on the publication’s distribution list, contact 

Editor Karl Hille, Karl.B.Hille@NASA.gov. Publication Number: NP-2022-8-833-GSFC

consumes a lot of voltage, and the materials used 

to amplify and multiply the pulse have limited 

efficiency. This means they lose power as they approach the terahertz frequencies. 

From the other side of the terahertz gap, optical 

lasers pump energy into a gas to generate photons. 

However, high-powered, terahertz-band lasers are 

large, power hungry, and not suitable for space 

exploration purposes where mass and power are 

limited, in particular hand-held or SmallSat applications. The power of the pulse also drops as optical 

lasers push towards the terahertz bandwidths.

To fill that gap, Dr. Bulcha’s team is developing 

quantum cascade lasers that produce multiple photons from each electron transition event by taking 

advantage of some unique, quantum-scale physics 

of materials layered just a few atoms thick.

In these materials, a laser emits photons in a 

specific frequency determined by the thickness of 

alternating layers of semiconductors rather than 

the elements in the material. In quantum physics, 

the thin layers increase the chance that a photon 

can then tunnel through to the next layer instead 

of bouncing off the barrier. Once there, it excites 

additional photons. Using a generator material with 

80 to 100 layers, totaling less than 10 to 15 microns thick, the team’s source creates a cascade of 

terahertz-energy photons.

This cascade consumes less voltage to generate 

a stable, high-powered light. One drawback of this 

technology is its beam spreads out in a large angle, 

dissipating quickly over short distances. Using 

innovative technology supported by Goddard’s Internal Research and Development (IRAD) funding, 

Dr. Bulcha and his team integrated the laser on a 

waveguide with a thin optical antenna to tighten the 

beam. The integrated laser and waveguide unit reduces this dissipation by 50% in a package smaller 

than a quarter.

He applied for Research Opportunities in Space 

and Earth Sciences (ROSES) funding to continue the work and prepare a flight-ready laser for 

NASA’s Artemis program.

The laser’s low size and power consumption allow 

it to fit in a 1U CubeSat – about the size of a teapot 

– along with the spectrometer hardware, processor,

and power supply. It could also power a handheld

device for use by future explorers on the Moon,

Mars, and beyond. v

CONTACT

Berhanu.T.Bulcha@NASA.gov or 301.286.7418

This tiny laser capitalizes on quantum-scale effects of materials just tens of atoms across to generate a high-powered beam in a portion of the spectrum 

where traditional lasers fade in strength.

Image Credit: Michael Giunto