This video is supported by Curiosity Stream.
Hey, Hey Marcus House with you here. We are all very excited to see the continuing development
of SpaceX’s Starship and the new momentum for Starbase 2’s construction over at Cape Canaveral.
We are still some way off seeing this system in full swing, however, in the grand scheme of things
it won’t be long before we are witnessing not just orbital starship launches, but crewed
starship missions that will take humanity back to the surface of the moon, on even longer duration
deep space flights, and eventually out to Mars and beyond. But first, I’m sure you have a whole
host of questions regarding how exactly humans can survive long duration spaceflight, and in this
video we are going to be looking at exactly that. SpaceX’s Starship development is something I’m
sure most of you here have been keeping very close tabs on over the past couple of years. Even
though activity over at Starbase in the form of test flights have slowed down in preparation of
the first orbital flight test, overall starship production is really starting to gear up. With
a huge new Starfactory facility being built at boca chica to replace the production tents, and
the beginnings of Starbase 2 taking shape over at cape canaveral, these are all good signs that
the primary architecture for starship is now ready for its final stage of testing. With this story
and others, it’s the first time in about half a century that we are truly seeing the start of new
advancement in human space travel. A rocket large enough, and cost effective enough to hurl us out
into space and finally advance past the first moon landings. Fun fact I think people often forget.
The launch of Apollo 11 was on July 16th 1969. Following that first successful mission to
the moon, Apollo 12, 14, 15, 16 and 17 with that final mission returning to Earth on Dec 19th
1972. Those 6 very successful missions were all completed in just under 3 and a half freaking
years. Can you imagine that again now? Well, we wait, and hope that SpaceX with NASA
not only matches this astounding feat, but surpasses it. Over the last 50 years though,
we’ve learned a great deal about the health related issues that we need to protect against.
How do humans survive the duration and the hostile environments they will be placed into? Using Mars
as an example is a good exercise simply because of the length of time needed for the journey.
How we will survive long duration space flight is a question that is a lot more complex than one
might first think. Sci Fi driven pop culture and even the Apollo moon landings themselves can leave
us with a false sense of security. It is easy to think that all we really need is a launch system
like starship and all of our deep space dreams finally come true, but diving just a little deeper
we see that this couldn’t be further from reality. SpaceX aspired to send uncrewed Starships to Mars
this year in 2022, but the dates got pushed for many reasons. Now, SpaceX is hoping to send cargo
ships to Mars by 2024. Back in March, Elon Musk tweeted this, guessing that with updated timelines
humans could be stepping on Mars by 2029. Will that guess be true? Can they overcome the
challenges of human spaceflight this quickly? Cargo missions are simple in comparison,
but these squishy fragile human meat bags? Yep. Much different. NASA has been actively
researching how the human body reacts to spaceflight for over half a century, and
being the lovers of acronyms they summed most of the major risks using the acronym
RIDGE. This stands for Radiation, Isolation, Distance from Earth, Gravity, and
Environments that are Hostile or Closed. The first and most critical hazard is
Radiation! Earth has a pretty good magnetic field that protects everything on it. But once
you are on a Starship and on your way to Mars, Earth cannot help you any more, and you are all
alone traveling hundreds of millions of kilometers to your destination while being bombarded by high
energy ionizing radiation. Radiation containing particles which can literally kick electrons
from atoms within the cells in your body! Obviously radiation is all around us all the
time, but not at this magnitude or energy. It is considered perfectly safe to experience
radiation to a degree. After all, the sun releases many types of radiation all the time. Visible
light just as one example. But occasionally the Sun erupts, ejecting billions of tons of charged
particles into space in one hit. These are known as CME’s or Coronal Mass Ejections. Although
it is quite unlikely, if a spacecraft came in direct contact with one of these CMEs, it could be
disastrous. We can forecast these events however. If living on the surface of Mars or even the moon,
underground bunkers would mitigate this issue. On the transit to these destinations though
this isn’t an option. On top of radiation from our star, you also have Galactic Cosmic
Radiation. This is high energy radiation that comes from outside our solar system, primarily
from within our galaxy. These are the nuclei of atoms that have had their electrons stripped
away and are traveling at almost the speed of light. These can come at any time from any
direction. Typically not at any huge volume, but the vehicle will be constantly hit by such
radiation. So not only do we have events that increase radiation exposure but also an
elevated level of background radiation, which adds compounding complexity to the problem.
So how do we protect astronauts from these dangers? Well, procedures can be put in place
to bunker down in the center of the vehicle, putting as much mass between the humans on board
and the outside of the vehicle. Water is very good hydrogen-rich molecule that can absorb radiation
very well just as just as one example. A specific radiation sheltered area within Starship
would have all these resources and consumables constantly surrounding it. That area could also
be where the crew sleep. In the case of a CME, you can also rotate the vehicle in such a
way that the engines, bulkheads and remaining propellant shields the crew as well. With the
high amount of potential shielding options it seems as though Starship will provide adequate
risk mitigation for the voyage. SpaceX will certainly be measuring the potential exposure from
initial cargo only missions so that they gain a much better understanding of all these factors.
Radiation exposure doesn’t stop even after the outbound voyage either, as unlike Earth, Mars
doesn’t really have a magnetic field useful enough to protect us. Here our magnetic field
deflects harmful ionizing radiation away, with a great deal of charged particles being
captured and held within the Van Allen radiation belts. The radiation here is very deadly of
course, and this is why you may hear this as a reason that “humans have never visited the moon”
by moon-landing hoax believers. They believe the moon landings never happened, assuming these
belts are instant killers and omnidirectional, neither are the case and the main irony is that
our collective awareness of the Van Allen belt is basically thanks to JPL which to me has always
made this conspiracy more of an oxymoron than usual. In reality, it is more about the time you
spend within these regions and what path you take. Sure, passing right through the middle of the
most dangerous areas would be very problematic, but humans are smart, we are able to take an
inclined trajectory bypassing the worst regions, and at such a high velocity, that the exposure
is only minimal. Just as we did with Apollo missions. Missions to Mars will use a similar
method, so there is no problem there. It is the longer term exposure to deep space radiation
that is more troublesome. Just remember, the longest trip away from low earth orbit and the
protection of the magnetic field surrounding the planet was with Apollo 17. That full mission from
launch to landing was only 12 days. The one way trip to Mars alone could be 6 months or higher.
A side note here, back in the days of the Interplanetary Transport System which was the
first design of what we now know as Starship, numbers like 80 to 150 days were being thrown
around for a potential transit time from Earth to Mars. This of course depends on available delta V
and whether you can slam into the Mars atmosphere much faster than the minimum interplanetary
transfer speeds. The faster you are traveling toward Mars, the more velocity you need to wipe
off to capture into a Mars orbit. And you only get one pass otherwise you shoot off into space. True,
you can also use the engines and propellant to slow down, however it makes no sense to do that
when you can use the Mars atmosphere instead. So yes, the longer term exposure to deep space
radiation is troublesome but manageable with the correct mitigations and shielding configurations,
but you also have the lengthy stay on Mars itself. NASA has reported quite detailed papers on the
expected radiation dose for a mission to Mars. Based on a 6 months trip, a single astronaut would
be exposed to an estimated 300 millisieverts of radiation. To put that into perspective, an
average human on Earth would be exposed to a little over 6 millisieverts per year. If we assume
that the crew would spend 18 months on the surface while they wait for the planets to realign
to make the journey back to Earth possible, they will be exposed to an additional 400
millisieverts on the surface over that time. Then the trip isn’t over, another 6 months
for the return and another 300 millisieverts, so that adds up to a grand total exposure of
about 1,000 millisieverts for a full trip to Mars and back over a 30 month period. That works
out to be about 65 times the radiation an average person on earth is exposed to. This is comparable
to the increased risk in cancer you would get if you just stayed on Earth and took up chain
smoking for example. (not great, not terrible). As with any radiation damage, the main risk
is that it can alter the structure of our DNA causing abnormalities and cancers to mutate from
previously healthy cells. At some point we will hopefully develop better treatments to deal
with such factors. We are starting to see the beginnings of quite interesting nano technology
aiming to patrol the bloodstream and kill off target cells. After such treatments are available,
perhaps small radiation damage over long periods of time can simply be “cured”. Certainly not
high doses of course, but it is interesting to think about all the same. The unfortunate fact
is that we don’t have a real lot of experience with travel outside the bounds of our magnetic
field. With the exception of a handful of cases from the Apollo program, we’ve not really
exposed many humans to such an environment. Inspiration 4 was of course conducting research
getting a little higher in their orbit than we have been in a few decades. The next mission
Polaris Dawn aims to go even higher and do even more tests. So yes, radiation there is the
biggest risk outside of a vehicle failure or something more catastrophic. But a few
more factors that you may not consider are equally crucial to prepare for.
[Ad Start] ...I’ll talk about those in a moment but before that, a massive thank you to Curiosity
Stream today for supporting this video. Curiosity Stream is a subscription streaming service that
offers thousands of award-winning documentaries. Their content library includes many great videos
that expand in what we are learning right here today. Do you want to know more about Mars and
the related challenges involved with human space flight? Take this episode of “A Curious World”
just as an example. They also ask the question, Can We Colonize Mars? At almost 55 million
kilometers away from the Earth at its closest, Mars is obviously the first achievable
objective in interplanetary travel. Also, what will it take for humans to establish an
Earth-independent way of life? A topic that expands well past the subject of our video here
today. Scientists propose housing in lava tubes, and in the more distant future even
changing the atmosphere over time. Something we have no current experience with. All
we have are theories. I’ve been a subscriber to Curiosity Stream myself for several years
and there is so much here to check out. Not just the space content that we all obviously
love, but loads of stuff on Travel, History, Nature, Science and Technology. It is all here and
you can stream this incredible content worldwide on all of your devices anytime. If you would
like to satisfy your thirst for knowledge, give it a try by heading to curiositystream.com
slash marcushouse. With that, you can sign up for access at just $14.99 for the entire year. You’ll
find that link in the description below. [Ad End] So yes, the next biggest risk factor for a Mars
mission in my opinion is simple Isolation and Confinement. We are a social species. We wouldn’t
have evolved if we weren’t. The crew is expected to stay in a spacecraft millions of kilometers
away from home for a minimum of 2 and a half years! And however trained one might be, that
is not an easy task. We all know how stressful it has been dealing with the pandemic and many of
us having restrictions in place limiting movements and contact. That was hard enough, but think about
being restricted to a small spacecraft and habitat for even longer and you might get just a small
glimpse into what it could be like. There is no outdoors, you can’t just go outside and clear
your head. Not without a full space suit on at least. Now, if you are feeling cooped up, I’m
not sure if being stuck inside a full space suit would help a great deal or not. Everything you
drink, eat or breathe has been brought with you. Water and air, is recycled. No matter how much
work you throw yourself into, it is the downtime that is the most isolating. That time of rest
where you are with your own thoughts. You can’t just pick up a phone and talk to who you want.
No internet of course. Only the media libraries you’ve bought with you. How do you deal with
the monotony? The crew can bring along state of the art VR headsets. Nowhere near Startrek’s
solution of the holodeck, a useful way to trick your mind into some different experiences.
Gaming in particular can be a great way to escape for a while. Astronauts living onboard
the Space Station often say the best pastime is to watch the Earth revolve below. A luxury
removed during an interplanetary trip like this. Good sleep and nutritional intake is also just
as, if not even more critical than on earth. Due to sleep routines being so very
important for a human to function properly, it is important to regulate times for sleep as of
course in transit. There is no day/night cycle. Space travel in particular would certainly result
in poor sleep patterns if not kept in check. It has been found that a person’s circadian rhythm
has a profound effect on their neurological and physiological behavior. Living on Mars would also
be unusual in this regard. The Martian daylight is primarily a yellowish-brown compared to Earths
blue-green. We are lucky that a Martian day, also called a “Sol” is very similar in length
to what we have here on Earth at 24 hours and 37 minutes long. Even still, researches suggest
that even this 37 minute longer difference might have a negative influence on human sleep
cycles and circadian rhythms over time. So what is the solution? This is quite difficult to fix is
it not? Well, a simple solution for this problem is to create quite sophisticated, well-equipped
artificial habitats that are capable of mimicking the light from Earth’s atmosphere simply to help
astronaut’s circadian rhythms to improve sleep and their performance. It is obviously however not
practical to try and keep the new Martians synced up with a 24 hours clock. This would be one
issue they would need to learn to live with. Mission control personnel for NASA’s robotic
missions to Mars already work to a Sol centric work schedule which at least gives us
some practical experience in that regard. The next issue is the staggering distance. Mars
on average is around 225 million kilometers away from Earth! At this distance, even light speed is
frustratingly slow. It does differ a lot too as it depends where both planets are in their orbits. It
would take us between 5 and 20 minutes to send a message to Mars in one direction, and then double
that up for a response. This detachment can have a very negative effect on the psychology of the
crew. The mental aspects alone need to ensure the brave people training for such a mission, have the
needed support and resources to deal with these issues. The crew need to be compatible too. You
don’t want to confine a group of people together for years that create conflict with each other.
Again, a lot of preparation is needed simply to select the right people. NASA has recruited
people for a Yearlong Simulated Mars Mission. A one-year analog mission in a habitat to simulate
life on a distant world such as Mars. The research and results of these tests are essential to
understand and plan around. Astronauts can’t depend on scientists and professionals here on
earth for immediate solutions, they must be able to come up with quick solutions by themselves
and be socially compatible with each other. The International Space Station is
a terrific resource of course. Here, the crew perform ultrasound scans on each
other to monitor organ health just as one example. If a crew member is sick, they can help
diagnose and treat them! The huge distance also means you cannot be resupplied potentially for
years. The obvious things like food, water and typical medicines would be pre delivered, but
it is hard to imagine everything you may need to solve any predicted problem. This is where a
number of critical pre-supply ships are needed. With the colossal volume of Starship, anything
imaginable could be delivered to ensure the first crew landing teams have many years of supplies.
It also means the first crewed mission can have a little more space dedicated to their comfort
and morale. Some Crop Food Production would help here as one example. It needs a lot of space, but
as all food is nonperishable, growing some leafy greens and other useful crops would add a little
extra nutrition to the diets of the crew, and it would be a nice bonus to psychological well-being
spending a little time taking care of the farm. Astronauts will come across three different
kinds of gravity fields on their Journey, Firstly, micro gravity in outer space, then one
third gravity on Mars, and of course regular old 1G back here on Earth. The crew must get
used to these three different gravity fields, and transitioning from one to another is actually
really hard on our squishy human bodies. In micro G, where the mechanical strain put on our skeletal
system is essentially non-existent, our bones are not subjected to the same level of stress they
would normally be. As a result you experience progressive bone loss of around 2% a month, in
other words the moment you enter orbit your bones start to undergo osteopenia which if unaddressed
eventually leads to severe osteoporosis. This also reduces the formation of bone building cells and
breaks down calcium stores in the boes heavily reducing their strength. Where does this calcium
go? It’s released into the bloodstream, and increased levels of calcium in the blood lead to
a higher incidence of renal stones. Not a problem you want when on a distant mission from home. It’s
also worth noting that these changes to your body, along with getting used to different environments,
drastically increase your chances for injury. You can just imagine how big an issue a broken arm
or leg would be on such a critical mission. Gravity also helps us in maintaining our blood
pressure. We’ve evolved to have that pressure distributed differently across our body. For
example blood pressure in our feet is 200 mmHg and in the brain, it is only 60 to 80. In space
though at micro G, the pressure is equalized all over our body. This makes it around 100 mmHg
everywhere. Although short term missions in micro G don’t seem too problematic, for long
missions this might cause severe problems. It increases the amount of blood in our brains,
which can over time potentially damage various parts of it. Optic nerves can swell as
well causing vision impairments. NASA is specifically working on solutions to these
problems. Monitoring astronauts closely through frequent organized scans and check-ups alone can
go a long way, it can help us detect and prevent any harmful effect the journey might be having
on them. There are devices astronauts can wear that’ll help them control their blood pressures,
by drawing fluids from the head into the legs or vice versa. NASA has also been researching
effective medicines astronauts could use on a long space journey. When on the Mars surface at
one third gravity, these problems are minimized, but still problematic to a degree. A lot of
exercise in the transit stage of the mission would be essential to ensure you don’t land,
and are then incapable of doing any useful work when you get there. We see how difficult
it is returning to Earth after a lengthy stay at the ISS. You might think that the one third
gravity of Mars will be easier to adapt to, than returning to the full 1G, but sadly probably
not. Though equipment will weigh a little less than it would back on earth, the time spent in
micro g would completely rearrange your balance and coordination, potentially incapacitating
someone for at least the first few days. With no ground crews in situ to assist, the crew
will need their own solution to assist themselves. Finally, you have the problems associated
with closed environments for years at a time. The health of the internal ecosystem of the
space habitat is something you may not think about. Microbes change behavior in space. They
transfer between humans much easier. Researches have shown that space travel might actually weaken
our immune systems as well. Research on the ISS has been critical to learn as much as we can from
such a closed environment. Various samples are taken from the crew and the station itself is
swabbed regularly for analysis of the microbial population. What we have already achieved on the
ISS is a testament to the brilliant minds out there already putting solutions in place to ensure
we all know what is needed to explore a new world. So yes, I’m super interested in your thoughts
on all these areas. We could literally make full videos on each of the risk factors alone. So do
let us know what interested you the most in this video below in the comments. It is always great to
dive even deeper where we can in the near future. After having a greater understanding of all
these areas, how long do you think it will be before we see humans exploring the Mars surface.
Is Musk’s guess of around 2029 remotely possible? Realistic for a HLS mission to the moon sure,
but for a crewed mission to mars and back? As always, it is the unknown unknowns that
are always the biggest problems we face. What else can you think of that we haven’t yet
covered. Let me know in the comments. And thanks for subscribing here to follow the industry and
what we do. To all of you all incredible viewers and supporters. You could be a regular viewer of
our content. Perhaps a Patron or Youtube member supporting what we do or you could be picking some
gear from our merch store including this shirt you see here. That design is also available in a
wide range of products and clothing styles. No matter how you support, know that it contributes
significantly to what we do, and it allows us to increase the time we can collectively spend in
research, editing and quality control especially for videos like this one that take a little
more research. If you like what we are doing and would like to help assist us with what we do
directly, you can join as a Youtube member via the join button below or you can become a patron at
patreon.com/marcushouse. Either of those options gives you access to chat to us more directly
via the linked roles on our Discord server, you can get your name listed right
here like these other amazing people, and you also get earlier and ad free access
to the videos to watch before anyone else. In the tile in the bottom left today, we have my
video talking more about the travel to Mars. In the top right is my latest video and in the bottom
right... content that Youtube has selected from my channel, just for you! Thank you, everyone, for
watching and we'll see you all in the next video.
