NARRATOR
At his palace on Mount Olympus, Hephaestus, god of the forge, wrought powerful weapons for the Grecian gods and heroes: lightning for Zeus, a winged helmet for Hermes, Agamemnon’s staff, Achilles’ armor, the chariot of Helios.
But, he wasn’t always one with the pantheon, atop Olympus’ heavenly peaks. His place amongst the pantheon was hard-earned. At birth, Hera, his mother, deemed Hephaestus too hideous to reside amongst the gods. She cast him down to the mortal world, only to return when his talents for metallurgy made him invaluable.
He honed these skills on the isle of Lemnos, an irregular brown freckle on the dusky blue of the Aegean Sea. It was there that he found a home amongst mortal men. Using Lemnos’s volcanic fires, Hephaestus learned to smith with skill unmatched by mortal or deity.
The mythic hunter Orion, son of Poseidon, god of the sea, blinded by an angered king, followed the sound of a mighty hammer striking an anvil to Hephaestus and Lemnos. The god, taking pity on a sightless Orion, ordered one of his servants to guide the hunter east. There, Helios, god of the Sun, returned his sight.
Orion was mortal, but his godly lineage enabled impossible heroic feats. He relied on the gods’ mercy and friendship to become the most legendary hunter of ancient Greece.
The gods would also enable his journey beyond, joining the stars in the heavens above.
Though the ancient Greeks dreamed of placing their heroes among the stars, it would take thousands of years for these myths to be made manifest. In 1961, cosmonaut Yuri Gagarin became the first person in space. Since then, generation upon generation of modern heroes have looked down on Olympus from above.
Someone alive today may peer through a telescope at Greece from the rust-hued plains of Mars.
I’m Danny Baird. This is “The Invisible Network.”
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The Moon has no weather. When we return there, much will seem unchanged. The flag placed by Apollo astronauts will still be frozen in space, untouched by any breeze. The footprints left by man’s “small step” on its surface will still be visible across the Moon’s dusty landscape.
Much will be changed, though, about our renewed presence there. Though their booted footprints will look much the same, the next generation of lunar explorers require pioneering innovation to fulfill their missions.
For the journey, NASA has developed its own Orion, a hunter for knowledge not of this Earth, a spacecraft designed specifically for humanity’s triumphant return to the Moon and exploration of deep space. Drawing from over 50 years of spacecraft research and development, Orion will embark on a series of increasingly challenging deep space missions. It will be an advanced spacecraft specifically designed for deep space, flexible and capable enough to support crewed missions venturing ever-further into the unknown.
Orion features many advanced, pioneering technologies on board. A launch abort system significantly increases crew safety, allowing the spacecraft to jettison itself from a rocket during a failed launch. A unique life support system will allow astronauts to stay in deep space for extended durations. Orion’s heat shields enable it to withstand up to a sweltering 5,000 degrees Fahrenheit during reentry.
All in all, Orion is the culmination of the work of thousands of the best and brightest the world has to offer: at NASA, space agencies abroad and in the private sector. Leaning on the work of their predecessors, these scientists and engineers are pushing space science and technology into the future.
In the realm of space communications, Orion must return to Lemnos. The Laser-Enhanced Mission Communications Navigation and Operational Services, or LEMNOS, will supply Orion with an advanced optical communications system, enabling more capable connections than ever before — data rates previously unseen in human spaceflight.
What makes it different than the previous systems? It uses lasers.
Optical communications, also called laser communications, have been in development by NASA over many years. These aren’t the lasers you’d see in “Star Wars,” they’re invisible beams that send information into optical telescopes. Hence why laser and optical are both used to describe the technology.
LEMNOS has dubbed their system the Orion Exploration Mission-2 Optical Communications Terminal, or simply O2O. It is being developed by NASA’s Goddard Space Flight Center in partnership with the Massachusetts Institute of Technology’s Lincoln Lab and will debut on Exploration Mission-2. This mission will be the first crewed flight of Orion, flying NASA astronauts thousands of miles beyond the Moon, some 240,000 miles away. This will be the furthest humans have extended ourselves beyond the shackles of Earth’s gravity. O2O will enable data rates from these distances heretofore unheard of in human spaceflight.
How? NASA’s current communications infrastructure relies on radio and microwave transmissions. Radio waves and microwaves are both forms of electromagnetic energy, like visible light but on the lower end of the electromagnetic spectrum. Optical communications,in infrared, just below visible light on the spectrum, has a higher frequency than microwave or radio, allowing more data to be encoded into each transmission.
These optical systems also have lower size, weight and power requirements when compared to radio. A smaller system leaves more room for science instruments, a weight reduction can mean a less expensive launch and reduced power allows batteries to last longer.
The technologies enabling this leap forward in communications technology have been in development by NASA over many years and will continue into the future. Our journey through this “Decade of Light” will see space laser communications technology to fruition, from demonstration to practical application.
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On Christmas Eve, 1968, the Apollo 8 crew gave humanity a great gift… a unique perspective… a piece of art. Unfortunately, it wouldn’t make its way into the public eye for several days, arriving too late to be wrapped in a bow and placed under the tree.
This gift? A photo. A photo taken by a modified Hasselblad camera with 70 mm film developed specially for the Apollo missions by Kodak. The image, taken by NASA astronaut William Anders had a rather dull official name, AS08-14-2383, but you might know it by a rather different name… an iconic name… Earthrise.
The photo features a gibbous blue marble rising over the lunar horizon. It’s been reproduced on everything from stamps to T-shirts. It’s perhaps one of the most recognizable images in the history of spaceflight.
It simultaneously captures the insignificance and magnificence of humanity. We’re a people residing on a small hunk of rock floating through the vast expanse of space, but we are also voyagers who have dared explore other worlds and dream of colonizing them. The photo offers us the opportunity to reflect, but also inspires us to push further into the unknown.
In the Apollo days, this Christmas gift wouldn’t make its grand debut until after our astronauts returned. NASA hadn’t yet mastered a way of sending these images home from space. In 2013, though, NASA launched a laser communications demonstration that could send hundreds of Earthrise images home per second.
The Lunar Laser Communications Demonstration, also known as LLCD, flew aboard the Lunar Atmosphere and Dust Environment Explorer, a robotic mission gathering information about the Moon’s delicate atmosphere. The demonstration transmitted data from lunar orbit to Earth at a rate of 622 megabits per second, six times faster than previous state-of-the-art radio systems.
For context, that’s about the data rate you’d need to download 16 songs to your computer every second.
LLCD didn’t just demonstrate record-breaking download speeds. It was half the weight of a comparable radio terminal and used 25 percent less power.
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In 2014, NASA’s Jet Propulsion Laboratory continued LLCD’s legacy with the Optical Payload for Lasercomm Science, or OPALS. OPALS was flown to the International Space Station aboard a SpaceX Dragon cargo capsule. OPALS managed to connect from the fast-moving space station to its ground terminal at Jet Propulsion Laboratory’s Table Mountain Observatory a remarkable 18 times during its 90-day primary mission.
The space station hurtles around Earth at 17,500 miles per hour. Catching the station in sight of a radio wave is one thing. Catching the station with laser beams? They’re focused onto a much smaller area compared to radio, so it’s an even more challenging endeavor. For OPALS to have a successful transmission, lasers pointed in both directions had to maintain pointing over the narrow, 2two and a half-minute window when OPALS and the ground station were in sight of one another.
Accurately pointing and maintaining this laser link from the space station at OPALS required a high degree of accuracy. The success of the mission proved that low-Earth orbit-to-ground optical communications are not only possible, but could enhance our current ground-based communications capabilities. Additionally, OPALS tested ways to reduce atmospheric distortion of lasers, measured space station stability and even connected with international ground stations in France, Germany and the Canary Islands.
In July of 2014, honoring the 45th anniversary of the Apollo 11 moon landing in 1969, OPALS transmitted a high-definition video celebrating the mission, including original photography captured by the astronauts. It took 12 hours to uplink the video with existing communications infrastructure. OPALS managed the downlink in 7 seconds.
Now, NASA preps to continue its journey through this Decade of Light with a series of increasingly complex optical communications demonstrations.
The Laser Communications Relay Demonstration, otherwise known as LCRD, an upcoming optical communications mission, will send data between ground stations in Hawaii and California through an orbit stationary relative to Earth. LCRD will be an important next step in maturing optical communications technology for space. Innovations tested will inform how NASA develops laser communications for practical use in next-generation space communications satellites, updated versions of the Space Network‘s Tracking and Data Relay Satellites using both laser and radio waves.
Further, the Integrated LCRD Low-Earth Orbit User Modem and Amplifier Terminal, a mouthful that can be abbreviated, simply, to ILLUMA-T, will communicate data from the International Space Station to the ground through LCRD. It will, after testing, be the first end-to-end, bidirectional optical communications relay system to enter operations.
Moving out past the boundaries of Earth orbit, the Deep Space Optical Communications project will test laser technologies against the unique challenges presented by deep space science and exploration.
Just as lasers’ smaller wavelength when compared to radio made pointing OPALS from the space station to the ground such a feat, moving further into space makes pointing a laser back at Earth increasingly difficult. With this comes an added challenge: as the distance from Earth increases, the time it takes for data to reach Earth increases as well.
Spacecraft communications from Mars take between 4 and 24 minutes to reach Earth depending upon where the planets are in their orbits around the Sun. To accommodate this lapse in time, you have to point a laser from Mars to where Earth will be when the signal reaches it, rather than where it was when you send the signal.
As an example, Dave Israel, optical communications project lead at Goddard, relates this problem to one of American football’s most infamous plays: the hail mary.
DAVE ISRAEL
So this is just like that big, long pass play in football. The quarterback fades back, sees the receiver running down the sideline headed towards the end zone, but they don’t throw the ball to where the receiver is when they first see them. They throw the ball to the end zone where the receiver is going to be by the time the ball gets there. Then when the receiver and the ball arrive at the same time, the receiver catches the ball and there it is: big touchdown.
NARRATOR
The Deep Space Optical Communications project will fly aboard a mission to 16 Psyche, an asteroid orbiting the Sun between Mars and Jupiter. It’s a huge mass of metal, with a surface area just smaller than the state of Texas, the only known asteroid to be made of over 90 percent metal. Scientists believe it may be the remnants of a protoplanetary core, one whose development was stunted by a celestial collision of some sort. In addition to proving the efficacy of laser communications for deep space applications, the mission hopes to provide unique insight into the metallic cores that boil at the center of rocky planets, like Earth.
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NASA is by no means abandoning radio. Laser will support NASA missions alongside proven communications tech, supplementing tried and true methods of data transference. But, as missions develops increasingly sensitive science instruments, they may generate more data than today’s networks can handle. Optical communications can help tomorrow’s missions discover more and explore further.
Orion’s optical terminal, O2O, will enable multiple live, 4K ultra-high-definition video feeds from the Moon. By comparison, the early Apollo cameras filmed only 10 frames per second in a grainy black-and-white. A young persons’ experience of NASA’s next journey to the Moon will be a far cry from their parents’ or grandparents’. Video of Orion astronauts will be clear as day, a vibrant journey through deep space beamed to your television through the ether.
Optical communications provide the “giant leap” in communications technology NASA needs to return to the Moon and journey beyond.
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The mythic Orion, upon regaining his sight on Lemnos, joined the goddess Artemis and her mother, Leto, in their hunt. The combined skills of these master hunters threatened all animals with extinction. Fearing for her children, Gaia, Mother Earth, summoned a scorpion to kill Orion. She succeeded. At the behest of the grieving Artemis and Leto, Zeus placed the dead Orion among the stars.
Or so the myth goes…
In his 1893 work “Psyche,” 19th century classicist Erwin Rohde, student of Schopenhauer and friend to Nietzsche, postured that the myth of Orion represented an erasure of the divide between god and man. The people of Greece placed their deities among the heavens, unbound from Earthly limitations… but they also placed the mortal Orion there, a creature like them in the realm of the gods.
If Orion can hunt among the stars, why can’t we?
The gods of ancient Greece walk among us only in myth. The forge of Hephaestus lays dormant on Lemnos. The chariot of Helios is a ball of sweltering gas some 90 million miles away. We can’t rely on Zeus to pluck us from Earth and scatter us among the heavens.
Instead, we rely on our own ingenuity and technological innovation. Nestled in a conical spacecraft, sheathed in metal, the next generation of NASA astronauts will use laser communications to help us take our rightful place next to Orion, a permanent fixture in the firmament above.
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The Invisible Network is a NASA podcast presented by theSpace Communications and Navigation program. This episode was written by me, Danny Baird, and released on Oct. 16, 2018. Editorial oversight provided by Ashley Hume. Our public affairs officers are Clare Skelly and Peter Jacobs. Make sure to subscribe wherever you get your podcasts and share us with a friend. For the full text of this episode, a list of sources and related images visit nasa.gov/SCaN.