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.
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
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.