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Going Interstellar: Will Humanity Ever Reach for the Stars? | Stories From Space Podcast With Matthew S Williams

Episode Summary

The dream of interstellar travel, of reaching another star system and setting foot on another world, has been with us for centuries. Since before the Space Age, several concepts have been proposed.

Episode Notes

Host | Matthew S Williams

On ITSPmagazine  👉 https://itspmagazine.com/itspmagazine-podcast-radio-hosts/matthew-s-williams

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Episode Notes

The dream of interstellar travel, of reaching another star system and setting foot on another world, has been with us for centuries. Since before the Space Age, several concepts have been proposed. As we enter a new era of space exploration, many of these concepts are being reconsidered. But which are feasible and could reach another star in our lifetimes?

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Resources

How Long Would It Take To Travel To The Nearest Star?: https://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/

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For more podcast Stories from Space with Matthew S Williams, visit: https://itspmagazine.com/stories-from-space-podcast

Episode Transcription

Going Interstellar: Will Humanity Ever Reach for the Stars? | Stories From Space Podcast With Matthew S Williams

Episode 89 - Interstellar travel

[00:00:00] The authors acknowledge that this podcast was recorded on the

traditional unceded lands of the Lekwungen peoples. Hello, and welcome back

to Stories from Space. I'm your host Matt Williams, and today I wanted to

discuss yet another topic that is very near and dear to my heart, and that is the

dream of interstellar travel, of not just braving the interstellar medium, traveling

beyond the sun's heliosphere.

In reaching another star system, but of actually setting foot on another planet,

and building a new life there? Possibly terraforming it in the process to make it

more suitable for our needs. And of course, why stop there? Why not send

missions to all of the nearest stars in our galaxy, planting the seed of human

civilization, thus guaranteeing that humanity can survive any cataclysmic events

back here in the solar system, and creating endless opportunities for growth, not

just in [00:01:00] terms of human populations, but in terms of learning, of

exploring, of finding some of the answers to the greatest mysteries of life, up to

and including, Aren't we alone in the universe?

This idea, and this dream of one day achieving it, has been with us for

generations. In fact, as long as human beings have known that there were other

worlds in the solar system that might be like ours, and that other star systems

likely had their own systems of planets, the idea of visiting these places and

making contact with new and exotic forms of life has existed.

However, it has really only been within the last century. Particularly with the

dawn of the space race, that the idea became a matter of serious scientific

thought and speculation, and even detailed mission planning. Before we get into

all that, it should be noted that humanity has already sent two spacecraft into the

interstellar medium.

[00:02:00] This would be the Voyager 1 and 2 missions, both of which launched

in 1977, explored the outer solar system in the 1970s and 80s, and entered the

interstellar medium in 2012 and 2018, respectively. In the not too distant future,

they'll be joined by three more spacecraft, the Pioneer 10 and 11 missions, and

the new Horizons probe.

What's more, four out of five of these probes carry with them special messages

from Earth. NASA This includes the Pioneer plaques that adorn Pioneer 10 and

11, and the Voyager Golden Records mounted on the Voyager spacecraft. ThePioneer plaques are a pair of gold anodized aluminum plates that feature a

pictorial message.

These plaques, which were the brainchild of famed science communicator Carl

Sagan, denude figures of a human male and female along with several symbols

that are designed to provide information about the origin of the spacecraft. This

[00:03:00] includes which planet in the solar system sent it, a graphic depicting

the hyperline transition of hydrogen, the most common element in the universe,

and a representation showing the rotational periods and distances of 15 local

pulsars and their respective distances from Earth.

Which astronomers believe advanced civilizations would use as a navigation

system. Since the periods of these pulsars will change over time, any advanced

civilization that intercepts the probes will be able to determine when it was

launched based on these values. Meanwhile, the Voyager Golden Records

contain sounds and images selected to portray life on Earth.

These phonograph records are contained in a gold anodized case, with

instructions on the front of how to play them, as well as indications of where

they came from. The content of these records were selected by a NASA

committee chaired, once again, by Carl Sagan. In addition to being a message

for any extraterrestrial [00:04:00] civilization that intercepts them, these records

also serve as a time capsule in case humanity, in the course of expanding

beyond the solar system, should intercept them someday.

However, it will be thousands of years before any of these spacecraft reach any

of the closest stars to our solar system. The same holds true for any propulsion

system we are currently capable of creating, which includes chemical rockets,

ion engines, as well as any propulsion system that is realizable using today's

technology.

As an example, consider the closest star to our solar system, Proxima Centauri.

This main sequence red dwarf star is located roughly 4. 24 light years away

from Earth. This star is part of a triple star system that includes the Alpha

Centauri system, which consists of a main sequence G type star, similar to our

Sun, and a main sequence K type star, otherwise known as an orange dwarf.

[00:05:00] Proxima Centauri also contains the closest Earth like planet to our

solar system. This would be Proxima b, the discovery of which was announced

in 2016 by the European Southern Observatory. What's more, this star orbits

within the habitable zone of its parent star. Since its discovery, multiple studieshave been conducted to determine whether or not Proxima Centauri could

support life.

In addition, multiple proposals have been made for sending robotic spacecraft to

explore the planet, its atmosphere, and accelerate through Starshot. The

swarming Proxima Centauri concept, and a few others, all of which call for a

light sail or a fleet of light sails, which are similar to solar sails, except that in

this case, they would be propelled by a series of powerful lasers.

These proposals emphasize that this method is the only one within our grasp

that could deliver a probe to any neighboring star systems within the current

generation's lifetime. [00:06:00] However, this concept only works for small,

lightweight robotic spacecraft. In order to send a crewed mission, which is to

say, a spacecraft with passengers, to even the nearest star, would take much

longer using conventional methods.

So barring any innovations or breakthroughs that could possibly lead to faster

than light travel, or FTL, We'd be forced to rely on a very limited pool of

options. So, what are they? As mentioned, conventional methods basically come

down to technologies that we currently have, or have proven to be effective.

The most common of these are chemical rockets, which rely on either solid or

liquid propellants to generate thrust. To date, the fastest mission to rely on

conventional propellants was the Helios 2 probe, which was launched in 1976 to

learn more about the sun and what drives its contributions to space weather.

This mission established the record for highest speed achieved by a spacecraft.

[00:07:00] Using a gravity assist, this probe was able to reach a top velocity of

240, 000 50, 000 miles. Nevertheless, a probe moving this fast would still take

19, 000 years to reach Proxima Centauri. Another option is ionic propulsion and

Hall effect thrusters, which are much more fuel efficient, but achieve maximum

velocity very slowly.

To give you an example, NASA's Deep Space One mission, which

rendezvoused with an asteroid and comet in 1998, It relied on a xenon powered

ion drive that managed to achieve a maximum velocity of 56, 000 kilometers an

hour, or 35, 000 miles, which took 20 months of constant acceleration to

achieve. At this velocity, it would take a spacecraft 81, 000 years to travel to

Proxima Centauri.

Once again, this involved a robotic spacecraft. In terms of crewed missions, we

should consider the Apollo 10 spacecraft, which holds the record for the highspeed attained [00:08:00] by crewed vehicles. In 1969, it flew to the moon

without landing, achieved a maximum velocity of 39,888 kilometers an hour

24,791 miles, and was able to make it to the moon in just under two days and

four hours to get to Proximus Centuria.

However, the Apollo spacecraft would take roughly 114,800 years. So basically,

conventional methods are completely impractical when it comes to interstellar

travel of any kind. There are, however, a few options for building spacecraft

that would utilize proven technology that we simply haven't built yet.

A good example of this is nuclear propulsion, which NASA and other space

agencies are currently researching. For the sake of conducting long duration

missions to Mars and other locations in the solar system. This technology not

only offers a high level of thrust, but also fuel efficiency, energy [00:09:00]

density, and relies on proven technology.

For example, NASA developed a nuclear engine concept during the 1960s and

70s, known as the Nuclear Engine for Rocket Vehicle Application, or NERVA.

The Soviets experimented with similar technology. In addition, a number of

more advanced and efficient concepts have been proposed, which could also be

realized in the near future.

To break it down, nuclear propulsion comes in two main forms. Nuclear thermal

propulsion, or NTP, and nuclear electron propulsion, or NEP. In the case of

NTP, a nuclear reactor is used to heat liquid hydrogen propellant, which turns it

into an ionized gas, or plasma, which is then channeled through nozzles to

generate thrust.

This type of nuclear engine produces significant acceleration, or delta v, but is

less efficient than its counterpart. In the case of NEP, a nuclear reactor converts

heat into [00:10:00] electrical energy, which in turn powers an ion engine.

When these two methods are combined to create a bimodal nuclear spacecraft,

the advantages are not only high acceleration at the beginning of a journey, but

also consistent acceleration throughout.

According to current estimates, the most sophisticated nuclear concept would be

able to produce enough thrust to reduce travel times to Mars to just 90 days.

When adjusted for a one way journey to Proxima Centauri, a nuclear propulsion

system would take about a thousand years to reach its destination.

Next up, we have a very time honored concept known as Nuclear Pulse

Propulsion, or NPP. This concept was originally proposed in 1946 by StanislavUlam, a Polish American mathematician who participated in the Manhattan

Project. In 1947, he and American physicist Frederick Rains performed the

preliminary calculations for a large [00:11:00] spacecraft equipped with

hundreds or even thousands of nuclear devices.

Which would be released one at a time in the ship's wake, and then detonated.

The shock wave would then strike the rear of a ship, where a large push plate

would convert the force into forward momentum. In 1947, Ulam and American

physicist Frederick Rains performed the preliminary calculations. On how long

it would take such a spacecraft to reach the nearest stars.

Between 1958 and 1963, Ted Taylor of General Atomics and the physicist

Freeman Dyson, for whom the Dyson Sphere is named, came together to

spearhead a project known as Project Orion. This project aimed to harness the

power of thermonuclear devices to generate high velocities that be capable of

reaching Proxima Centauri in just under 20 years.

Unfortunately, according to Dyson's most conservative estimates, the cost of

building such a spacecraft in 1968 dollars was 367 billion [00:12:00] dollars.

Adjusted for inflation, that's roughly 3. 125 trillion dollars. To put that in

perspective, it was just over 100 trillion dollars. To put that in perspective, the

annual revenue for the United States government in 2022 was 4.

92 trillion dollars. It's also the problem of the radiation and nuclear waste the

spacecraft would leave in its wake. In fact, it was the passing of the Partial Test

Ban Treaty in 1963 that led to the project's cancellation. This treaty banned the

testing of nuclear devices in space in order to limit the amount of radiation

humanity was contributing to Earth's upper atmosphere.

Next up, we have the concept for fusion rocket. And much like nuclear thermal

and nuclear electric propulsion, this concept involves rockets that rely on

nuclear power, but with the twist of it being thermonuclear reactions rather than

fission reactions that generate the [00:13:00] thrust. In this case, the concept

calls for pellets of deuterium or helium 3 being compressed inside a reaction

chamber by electron beams to the point where a fusion reaction occurs.

This creates a high energy plasma that would then be focused through magnetic

nozzles to generate thrust. And for Friends of the Expanse, there's actually a

very nice scene in one of the episodes where they illustrate what the interior of a

reaction chamber looks like, and it shows the deuterium pellets being injected

and, and eventually being fused by lasers.And much like your nuclear rockets that rely on fission reactions, this concept

has the advantage of fuel efficiency, high acceleration, high thrust, and

according to some estimates, velocities of up to 10, 600 kilometers per second

can be achieved, or 38 million kilometers per hour. And that works out to 23.

7 million miles per hour, which puts it in the realm of [00:14:00] relativistic

speeds, a fraction of the speed of light. In addition, the technology is validated.

It's been tested, and this has led to multiple variants being proposed over the

years. And this includes the feasibility study conducted by the British

Interplanetary Society between 1973 and 78, which is named Project Daedalus.

And this concept called for a two stage, uncrewed spacecraft that could be

realized using then current technology. And according to the estimates, a ship of

this type would be able to make the trip to Bernard's Star, located roughly six

light years away, within a single human lifetime, roughly 50 years.

And adjusted for Proxima Centauri, it would be able to make the trip in 36

years. And for those who aren't familiar with the concept, I've been sure to

include some graphics, some images there, as part of the episode Data, and

you'll recognize this one as the massive ship, with all these huge fuel tanks

arranged in two rows, standing next to a Saturn V rocket, [00:15:00] and

completely dwarfing it.

And according to the plan for this ship, the larger stage would operate for

roughly two years before it exhausted its fuel supply, and in the process would

accelerate the spacecraft up to 7. 1 percent the speed of light. And the first stage

would then be jettisoned, and the smaller second stage would accelerate the

spacecraft further, to 12 percent the speed of light, over the course of another

two years.

First, this concept has several obvious drawbacks, not the least of which is the

sheer cost of building it. From its size alone, one can estimate that it would be

punitive. And to put that in perspective, the SpaceX Starship, currently the

largest and heaviest and most powerful launch system in the world, Has a mass

of 4, 536 metric tons when fully fueled, or roughly 5, 000 short tons.

So the cost of manufacturing and launching such a ship would be beyond

anything we can currently fathom. And of course [00:16:00] there's the other

stumbling block, which is the scarcity of Helium 3. Which is very rare on Earth,

so this would mean that it would have to be harvested from somewhere else in

the solar system, most likely the gas giants.And last but not least, the fusion reaction that drives the spacecraft would need

to produce far more energy than what is used to trigger the initial reaction. And

on Earth, using tokamak reactors and experiments involving magnetic

confinement fusion, scientists have managed to surpass the break even point and

have gotten to the point where they're generating more energy from the reaction

than what is needed to initiate it.

Unfortunately, they are a long, long, long way away from producing anything

near to what this spacecraft design would need. However, undeterred, a new

organization, Icarus Interstellar, adopted the concept in 2009, and this

organization, made up of volunteer citizen scientists, [00:17:00] former NASA

and ESA workers, they've been working to realize a smaller, more cost effective

version of it.

And even though their idea was significantly scaled down and much cheaper in

terms of projected costs, there's still the problem of helium 3 scarcity and the

problems of producing enough reaction energy and the cost issue, while less, is

still very, very punitive. And next, we have a very interesting concept that is

similar, and for which multiple designs have been proposed, and it's known as a

fusion ramjet.

And this spacecraft would rely on the same fusion reactions in order to generate

thrust, but has the added bonus of not having to bring its propellant with it. In

all cases, when it comes to spacecraft, propellant is the single greatest source of

mass. So, over the years, many concepts have been proposed where spacecraft

could harvest their propellant or just generate [00:18:00] propulsion directly

from the interstellar medium or from solar wind, a.

k. a. solar sails. And if you're looking at the images provided in the episode

data, this would be the one that looks like a giant blender bus or trumpet. And

the original concept for a buzzard ramjet was proposed by Robert W. Buzzard

in 1960, hence the name. And this, as with similar concepts, because others

have been proposed since this time, they all involve this, this large funnel at the

front, which would generate magnetic fields in order to funnel deuterium or

helium 3 into tighter and tighter space inside the ship.

And with the help of magnetic fields in a reaction chamber, fusion reactions

would occur, and that energy would then be channeled through nozzles with the

help of more electromagnetic fields to generate propulsion. Now, the chief

advantage of this system is, obviously, it doesn't need to bring along its

[00:19:00] propellant, thus leading to a ship of significantly less mass.And at the time of writing, Robert Buzzard was also encouraged by the fact that

hydrogen constitutes over 90 percent of the interstellar medium, is the most

common element in the universe. So on paper, this would seem like a very

elegant solution. However, it also has many drawbacks. Which, once again,

include cost.

While cheaper than building a fusion rocket, a la Daedalus or Icarus, it would

still cost a tremendous amount of money to build. Far beyond anything that we

can currently mobilize or imagine. But there are also issues that have to do with

the nature of the interstellar medium. Basically, since Buzzer's time in 1960,

Our knowledge of the interstellar medium has grown considerably and

investigations of the region surrounding the solar system, it's indicated that this

region has a much [00:20:00] lower density than previously thought.

And so, as a result, the amount of propellant it could actually harness would be

significantly less, too, thus throwing off the calculations. And furthermore,

recent research has suggested that in order for this concept to be feasible, the

magnetic field generated by the ram scoop would have to be enormous.

And this includes calculations done in 2021 by Peter Schatz Schneider and

Albert A. Jackson. who indicated that the magnetic field would need to be 150

kilometers in length, or 93 miles, and 4, 000 kilometers, 2, 485 miles, in

diameter. And that's what would be needed in the interstellar medium, as we

know today, in order to funnel enough fuel to generate thrust.

In addition, multiple studies have been conducted that confirm that drag would

be the greatest impediment to acceleration. One of the beauties of this idea

[00:21:00] is that as you scoop up fuel from the interstellar medium, you

accelerate, thus increasing the amount of fuel you're able to scoop up and thus

accelerating more, so you're able to gradually build speed over time to the point

where you could reach A high percentage of the speed of light.

And this idea was featured in Pow Zero, a very seminal science fiction book by

Powell Anderson. And that was the, the first instance of it being written of

fiction. However, Research has shown that there's a drawback to this, that the

very thing that's accelerating you is also slowing you down. Now, in terms of

going big, that is to say, building very large spacecraft, but also ensuring that

this is a crewed mission, because many of the proposals mentioned already call

for uncrewed explorer craft, but given their size, could probably be equipped

with crew quarters as well.However, this particular concept calls for a very [00:22:00] large crew making

the journey. That is the concept of a generation ship. And whereas all of the

other concepts call for going faster, creating a ship that could reach a nearby

star system in a realistic amount of time, A generation ship accepts the notion

that such advanced propulsion would take a very long time to realize or it would

take multiple innovations and significant growth before anything of that nature

would be considered realizable.

And in the meantime suggests building on equally large spacecraft that would

be able to accommodate a crew of a few hundred or a few thousand over the

course of multiple generations. Transcribed So, basically, don't aim to go fast,

except that you're going to be going slow and prepare for the long haul.

Now, the concept has been explored extensively in science fiction, but as a

matter of scientific proposals, the first recorded example comes from Robert H.

Goddard, [00:23:00] considered one of the forefathers of modern rocketry, and

for whom NASA's Goddard Space Flight Center is named. There was an essay

released in 1918 called The Ultimate Migration.

He described an interstellar arc of cryogenically frozen passengers leaving the

solar system after the sun reached the end of its life cycle. And according to

Goddard, atomic energy could be used to power the spacecraft should that be

realized, which at the time it had not. It would be several more decades.

However, he also said that a combination of hydrogen and oxygen could be

used for propellant and that the ship itself could be powered by solar energy.

And according to those calculations, this would be enough for the ship to

accelerate to a maximum velocity of 57, 936 kilometers an hour, or 36, 000

miles per hour.

And the concept also envisioned that the crew would be kept in stasis, while the

pilot would be [00:24:00] awakened at certain intervals in order to steer the ship

and make any course corrections. And, as he wrote, the spacecraft would take,

perhaps, 10, 000 years for a passage to the nearest star and 1 million years for

great distances or for other stellar systems.

And this was followed by a similar concept proposed by Konstantin

Tsiolkovsky, also hailed as one of the fathers of modern rocketry, who wrote of

a Noah's Ark in an essay published in 1928 titled The Future of Earth and

Mankind. Thank you. Now, in Tsiolkovsky's version, the spacecraft would be

self sufficient and the crews would be awake for the journey, which would take

thousands of years.And in 1964, Dr. Robert Enzman proposed the most detailed concept for a

generation ship to date, known as an Enzim Starship. And in his proposal,

fusion reactions would be harnessed, which would [00:25:00] consist of

deuterium pellets being fused by electron beams, and the ship itself would

measure 600 kilometers in length, and consist of a large sphere at the front of it,

which would house the propellant and also the bridge section.

And with the engine and other sections extending far to the rear. And the

spacecraft would measure 600 meters in length, or 2000 feet. And support an

initial crew of 200 people, but with room for expansion, because of course,

many would be born along the way. Now of course, such a concept is filled with

challenges, all of which would have to be fairly researched and addressed in

advance.

And, interestingly, a series of studies, released between 2017 and 2019, did this

very thing. And the studies were led by Dr. Frederick Marin of the

Astronomical Observatory of Strasbourg, using numerical software called

Heritage, which [00:26:00] Dr. Marin developed himself with his colleagues.

And the first two studies, he and his colleagues conducted simulations that

showed that a minimum crew of 98 and a maximum of 500 would be needed

along with a cryogenic bank of sperm, eggs, and embryos in order to ensure

enough genetic diversity and good health upon arrival.

And in the third study, Dr. Mann and a separate group of colleagues, they

calculated how much artificial land would be needed for growing food. And

determined that this space would need to measure 320 by 224 meters, or 1, 050

feet by 735, containing 450 square meters, or 4, 850 square feet, of arable land

would be needed to grow enough food.

And coincidentally, the very first design competition for a generation chip was

launched on November 1st of this [00:27:00] year, known as Project Hyperion.

And the competition is sponsored by the Initiative for Interstellar Studies, and

includes such notable scientists as Andreas Hain, who is the Associate Professor

of Aerospace Engineering at the University of Luxembourg, and Chief Scientist

at the Interdisciplinary Center for Security, Reliability and Trust.

And he was joined by an organization team that included many highly respected

artists, architects, engineers, anthropologists, landscape architects, and

designers, thus representing everything that would need to go into the detailed

planning of a generation ship. And the rules of this competition indicate that

People will need to design a ship that will accommodate a crew of 1, 000people, plus or minus 500 throughout the trip, and that the duration would be

250 years.

And as I said, this is the first competition of its kind, and is based [00:28:00] on

research that, unlike the majority of studies regarding interstellar space travel,

focuses on a concept that ensures Crew safety and crew health over the long

term, rather than speed and getting there sooner. Unfortunately, like all the other

concepts presented, the generation ship has a number of obvious drawbacks.

It would be prohibitively expensive to build, given its size. It would also be very

challenging to see to the needs of a crew that numbers in the hundreds or over a

thousand. And that, of course, extends beyond simply food and water, which

would require a bioregenerative environment. So, basically, an Earth like biome

would need to be created inside the ship.

And this would not only be necessary for maintaining the supply of food, water,

and breathable air, but the psychological health of the crew. And, of course, the

concept also suffers from one invariable flaw, which is that in the time it takes

for this ship [00:29:00] to reach its destination, centuries or longer, faster means

of propulsion will likely have been invented.

Technological advances will be made that would make such a ship obsolete

long before it reaches its destination. But, of course, this is a problem for

virtually all interstellar concepts, including the theoretical ones. So, when it

comes to concepts that are realizable today, using today's technology, that have

any chance of reaching the nearest star systems in a realistic amount of time,

there really only is one concept available.

And as mentioned already, this would consist of a light sail and a gramscale

spacecraft, or nanocraft, basically all the instruments placed on a chip, which is

then accelerated to relativistic speeds by a laser array. This concept was

originally proposed by Robert Forward, physicist at the [00:30:00] Hughes

Aircraft Research Laboratories in 1984.

And the benefits of this concept is, once again, it doesn't require any propellant,

which drastically reduces the mass of the spacecraft. And also the fact that the

laser energy does not dissipate with distance nearly as much as solar radiation

does. That's with the solar sail. This gives the light sail the ability to accelerate

over very long distances.

And in 1999, Jeffrey A. Landis of the NASA Institute of Advanced Concepts,

he conducted a phase one concept study on the possibility of propelling a lightsail with a laser array. And his concept consisted of a light sail composed of

dielectric thin films that could be accelerated up to 30, 000 kilometers per

second or 10 percent the speed of light.

And as he argued, the spacecraft would be ideal for, quote, fast transit missions

to the outer planets, Cooper and Oort cloud [00:31:00] missions, and interstellar

precursor missions. By his own velocity estimates, this mission could reach

Proxima Centauri in the space of about 43 years. And in 2000, a similar

proposal was made by Robert Frisby, who was the director of advanced

propulsion concepts at NASA JPL.

And in his version, the light sail would measure 320 kilometers in diameter, or

200 miles, and could be accelerated to as fast as 35 percent the speed of light,

which would cut the trip down to 12 years. He also estimated that a sail

measuring 965 kilometers, or 600 miles in diameter, could go even faster.

At roughly 47 percent the speed of light, it would be able to make the journey in

just under 9 years. But, of course, that would require tremendous amounts of

power, according to Frisbee's own estimates, 17, 000 terawatts. And that's close

to what the entire world currently consumes in a single day. [00:32:00] But, in

recent years, the concept has been updated with new variants proposed, the most

notable of which is the Breakthrough Snare Shot concept that was proposed by

the Breakthrough Initiatives in April 2016, founded by Russian billionaire Yuri

Milner.

Once again, the concept was all about sending a mission that could reach the

nearest star system in our lifetimes. And several leading scientists were part of

this project, including Professor Loeb of Harvard University, and Professor

Philip Lubin of UC Santa Barbara, who's done extensive work into directed

energy concepts, including a NASA mission known as Starlight, which is very

similar to Starshot, and the development of wafer craft.

In addition, his laboratory, the UCSB Experimental Cosmology Group, they

were also looking into lasers as a form of planetary defense for deflecting

asteroids. This concept that they proposed [00:33:00] leverages a lot of

advancements made in the field of miniaturization, so that this small spacecraft,

known as a star chip, be about the size of a smartphone, would be studded with

sensors, guidance and navigation systems, and even tiny little electron thrusters.

And by their own estimates, this spacecraft, when powered by a 100 gigawatt

array, would be able to reach velocities of about 60, 000 kilometers a second, or37, 280 miles per second, or 20 percent the speed of light. And at that speed, it

would be able to make the journey to Proxima Centauri in 20 years.

Now this concept grew from a mission study known as Project Dragonfly,

which was hosted by the Initiative for Interstellar Studies, or I4IS, in 2013. And

both Starshot and another Dragonfly concept were the two top designs. Now, in

recent years, Starshot has sort of quieted down as [00:34:00] breakthrough

initiatives have come to focus on other initiatives, especially Breakthrough

Listen, the largest, most sophisticated SETI project ever mounted.

However, other proposals have emerged to sort of fill the vacuum. And again,

most notable among them is the swarming Proxima Centauri concept, proposed

by Marshall Eubanks, a former NASA scientist and the current chief scientist at

Space Initiatives, Inc. And this concept was one of NASA's Phase 1 selections.

And interestingly, this concept was selected for phase one development as part

of the 2024 NASA Innovative Advanced Concepts Program. And the basic idea

is to create a swarm of small, very lightweight disks with reflective material that

would, again, use a 100 gigawatt array to boost them to relativistic speeds.

And they would rely on swarm intelligence and autonomous systems in order to

maintain contact with each [00:35:00] other, make course corrections, and to

send high bandwidth communications back to Earth. And as I said, this concept

is, right now, the only feasible means of sending a spacecraft to Proxima

Centauri or any other nearby stars.

But of course, this one concept is uncrewed. So, as it stands, the dream of

sending human beings to the nearest star systems, the nearest planets, and

setting up shop on them, that is something that is destined to remain a dream for

how long, we don't know. So far, We discussed the ones that are feasible using

today's technology or with advances made in the near future involving

technologies that are known to work.

In order to do this subject justice, we also need to talk about the theoretical

approaches that are not yet possible and probably won't be for some time.

However, [00:36:00] given the richness of this topic, that's going to have to wait

for our second installment coming soon. So stay tuned for part two of our look

at interstellar travel concepts, where we will take a look at antimatter

propulsion, the Alcubierre warp drive, possibility of wormholes, and the

concept of black hole propulsion.Also, stay tuned for upcoming episodes where we'll take a look at what the

James Webb Space Telescope has revealed about our universe so far, the

ongoing question of whether or not rocky planets orbiting red dwarf suns are

habitable, as well as episodes that look at other famous and historic missions

like the Pioneer Probes, and Kessler Syndrome and the growing problem of

space junk.

In the meantime, thank you for listening. I'm Matt Williams, and this has been

[00:37:00] Stories from Space.