Man cannot discover new oceans unless he has the courage to lose sight of the shore.
So today we will be looking at some of the missions being contemplated to get us to Mars.
This is a two part episode with Paul Shillito of Curious Droid who is covering the earlier
history of such mission planning.
If you haven't already seen Part 1, take the link over to there and we'll see you
in a bit.
If you are arriving here from there for the first time, welcome, and you might want to
turn the captions on and grab a drink and snack.
So after the Space Race had essentially wrapped up we saw quite a fall off not just in mission
to Mars, but interest in heading there next.
Between 1960 and 1975 over 50 Mars missions were attempted between the US and Soviet Union,
of which only about a quarter were totally successful while most of them were total failures.
This might explain why for the next fifteen years only two missions were attempted.
Nobody had gone back to the Moon during that time either and one can argue Mars lost focus
in favor of wanting to master the moon first.
However even science fiction mostly abandoned Mars in the 1980s; not a single major film
came out about Mars in the 80s until Arnold Schwarzenegger appeared in Total Recall, set
on Mars, in 1990.
Nor were there many books on the topic either, and Kim Stanley Robinson's 90s book trilogy
on Colonizing Mars captured a lot of people's curiosity as it gave a detailed and scientific
look at traveling to, colonizing, and settling Mars.
This changed toward the end of the 1990s but we see this huge gap of lost interest in the
1980s between the Space Race Era and renewed modern interest, and Paul and I felt it was
a natural place to break things.
In this renewed interest we saw Dr. Robert Zubrin's Case for Mars published in 1996,
laying out the foundations for the Mars Direct program which we'll touch on more shortly,
but it was the Pathfinder Mission that I'd say truly sparked folks interest in Mars again.
I was 16 at the time, and for a lot of us in that age range Pathfinder was almost our
Apollo Landing.
Of course it was a robot, not a person, so we wanted to see a person there.
And for many of us that is what brought us to read scientifically detailed works of fiction
like Robinson's Mars Trilogy or Zubrin's very non-fictional and absolutely inspiring
Case for Mars.
I don't know if Robinson will ever see this but Robert probably will and he does visit
the SFIA Facebook forum occasionally so on behalf of myself and many others, let me thank
him for laying out a path to an achievable series of missions and bases on Mars.
Pathfinder certainly sparked renewed public interest in that, and we saw a veritable truckload
of films set on Mars after that, but for me and many others that made it a thing for the
future, not just scifi.
So we'll start there with Mars Direct.
In point of fact, while the book hit in 1996, the plan dates back to 1990 and has been evolving
and updating ever since, with the founding of the Mars Society in 1998 and an updated
edition of the Case for Mars in 2011.
At the time a lot of Manned Mars missions had focused on using nuclear-powered ships
to get there, an option Paul and I have each discussed in his Project Orion episode and
my "the Nuclear Option" episode.
One can argue this was part of the problem too, as treaties severely limited atomic rockets
and such ships needed to be large, assembled in space, and would need shielding both from
cosmic radiation without and reactor radiation within.
Zubrin argues this was the wrong approach and that we should aim for multiple missions,
the first an unmanned one, called an ERV or Earth Return Vehicle, carrying a small nuclear
reactor and a supply of hydrogen to land on Mars and process local carbon dioxide with
that hydrogen you brought along to make methane and oxygen to use for fuel on the return trip,
producing that fuel in situ.
This concept has been, in variations, a staple of a lot of Mars Mission concepts.
It doesn't take much more fuel to get to Mars than it does the Moon, and indeed the
lion's share is consumed just getting into Low Earth Orbit, but it takes a ton to come
home and far more if you are carrying it with you since you need more fuel to push the return
voyage fuel.
That step is simply mission 1 of a series, and essentially an unmanned proof of concept.
The second launch would follow 26 months later, optimal launch windows for Mars occur every
26 months, and would be two launches, another ERV and a MHU, Mars Habitat Unit, a 4-astronaut
manned mission taking 6 months to travel there.
Subsequent missions would use the same double launch, sending the ERV to make their return
fuel and sending the MHU to do the manned mission.
This second ERV is essentially a backup, if something went wrong with the first, or a
replacement to be used for the next mission.
Now six months is a long time to spend in space so that Habitation Unit included artificial
gravity created by spinning the module on a tether and of course you've got radiation
issues too, something we'll see arising as a concern in a lot of designs.
After a six month trip, they spend a year and a half there and return at mission month
24, windows home from Mars are also 26 months apart but trail Earth's window by 24 months,
or predate it by two months if you prefer.
They'd leave all the gear behind except the ERV, the original or the replacement,
for the next follow up mission which will launch from Earth just two months after they've
launched from Mars, and will get to Mars just a little after they arrive home.
Now this does make for missions of about two and half years duration, and also means that
while you are sending constant missions, you've got an 8 month window in each 26-month cycle
where nobody is there doing anything including inspecting and maintaining the equipment.
If you wanted to leave someone there you'd need to have some of the crew stick around
for an extra 26 months and two and half years is already very hard on the mind and body.
That mind part is as important as body.
We just recently finished up the twin experiments with Scott Kelly which will hopefully add
to ability to treat the physical health issues in space, but the mental ones are just as
big a concern.
Kelly spent 13 months in space, the US record, not even half that mission time, and Valeri
Polyakov still holds the record at almost 15 months.
Their combined stays would still be shorter than a single Mars mission.
Dr. Polyakov, whose field is space medicine, was an obvious choice for that study back
in 1994, and since he is turning 76 in a couple months it provides a good indicator that even
long term space missions can be performed without shortening lifespan significantly.
Of course they could talk to mission control and their friends and family real time, and
again they were up there for only half the time a Mars Mission would last.
The stress of longer missions is likely to rise even more, and any number of suggestions
have been made for dealing with this.
Initially we figured on all male crews but others suggested mixed crew later on, or all
female ones, or even married couples.
That last always seems rather popular but has struck me as dubious, you obviously wouldn't
send a couple who already had young kids, they might be a bit old by the time they were
grown up, and since the whole notion is that a married couple is stable, ones who probably
haven't been married long enough for kids would seem a non-ideal test case.
I'm also reminded of the example from Robert Heinlein's Stranger in a Strange Land, where
they had that policy so a single candidate otherwise high on the list illicitly got a
copy of other such candidates and flew down to propose to one the next day.
This is kind of amusing because it might be an ideal case, since the folks involved are
clearly very dedicated to the mission if they'd fake a marriage that it might make them perfect
picks, and to be fair a shared passion of that magnitude is the basis for a lot of successful
relationships too.
But this brings up an example of evolving technology.
We had the nuclear-powered ERV to make fuel from hydrogen we brought along but some newer
designers skip that entirely in favor of using solar panels for power and native Martian
Water Ice for the hydrogen.
In a similar mindset, we've been experimenting with stasis, essentially putting people into
light hibernation, for space voyages in recent years, and we also have emerging technology
like virtual reality to provide entertainment and stress relief.
Back in Heinlein's day any entertainment would be physical books or films, and maybe
radio or TV arriving from home.
Nowadays one could easily include copies of every book, film and TV show mankind has ever
produced and barely make a dent in the ship's cargo allowance, and ultra-high bandwidth
lasers could easily send updates, albeit delayed.
That time lag is a big deal though, not just for help from mission control but because
it means no live conversations except for those folks with you.
In an orbital base, or even a moonbase, you can chat with your family on phone or TV,
or even VR goggles soon enough, and mission control is right there for help and if something
goes wrong you're home in days at most.
As we move into some other Mars Plans, I want to stress that this tends to be my biggest
criticism of many of them.
All the rocketry and fuel and air aspects are important but for manned missions not
one drop more important than the physiological and psychological ones.
Early indications are we can probably find folks who can handle 30 month missions but
we wouldn't be able to say for sure till we either do it or build a prison-bunker we
can stick candidates in for 30 months with intercoms that delay every message twenty
minutes.
I'm pretty sure that would qualify under some definitions of torture and would still
lack the stress of the real deal, since those in the bunker will know we can rush in to
save them and there'd be no obvious threats anyway.
Folks who remember the 90s probably also remember the Biosphere 2 mission, which while hardly
up to NASA standards was also a very well-funded effort that did not turn out well, and since
we knew we'd need to get pretty good with such enclosed habitat technology to do any
serious Moon or Mars bases it added to that impression Mars was going to be very hard.
We often talk about using plants to recycle air and water and produce some food but the
challenge of that and the additional mission and payload requirements to do it has seen
it absent from almost all first mission designs.
It's a lot of mass though, just the food alone for a 4 man mission for three years
masses in at about 10 tons.
On ISS levels of water consumption, about 4 tons per person per year, that's about
60 tons of water they'd need, and that's a lot of mass, more than the space shuttle
weighed.
Needless to say we'd like to recycle that, but it's always worth keeping in mind that
all that equipment requires mass and space and maintenance itself.
Not to mention energy, the amount of light needed to comfortably light a room and the
amount outside on a sunny day are nothing alike.
Our eyes are logarithmic in their sensitivity, so a room can seem brightly lit to us when
it is receiving not even a percent of the illumination it would if you pulled the roof
off at noon.
It's rather awkward, not to mention dangerous, to put lots of windows on a spaceship so you'd
probably have to supply it electrically.
Of course most of your mission time is down on Mars and windows are safer there and there
is enough light, but glass or plastic sturdy enough to handle the pressure difference isn't
exactly light and one has to ask if a given square meter of dome glass, by weight, is
going to produce as much food, water, and air in a year to pay for its mass.
Or really just food because there is ice on Mars and while melting that for water and
electrolyzing it for oxygen, or extracting oxygen from carbon dioxide in Mars's atmosphere,
takes a lot of energy, or a hefty amount of solar panels, but its less than such domes
would presumably weigh.
Add to that, you do need to bring nitrogen along for those plants, which doesn't actually
mass that much but it also means you need to use a higher pressure in everything.
Humans don't need the typical 1 atmosphere air pressure so much as they need the regular
oxygen density, so we can go low pressure which is very handy for spacesuits, everything
leaks and the lower the pressure inside the lower that leakage.
All in all, while the advantages of recycling air and water while supplying some fresh food
are immense, it's often seen as more trouble than it's worth.
That's why many Mars base illustrations lack the characteristic domes we so often
picture with space colonization.
However this notion of being able to recycle stuff to cut down on mass you need to bring
along is not the only path, and we often talk about what is called 'in-situ' resources,
things you can get at the destination.
We see an example of that with Mars Direct, where we made fuel for the return trip there.
Such ideas are also incorporated into DevelopSpace's 2008 presentation, "Minimalist Human Mars
Mission".
As an example the zirconia electrolysis process used for extracting oxygen from carbon dioxide
produces carbon monoxide exhaust.
They suggest we could take that exhaust and synthesize ethylene and from that make plastic
for domes or tents.
This is particularly of note since if you can make plastic from local materials you
can also potentially provide it as a feedstock for 3D printers, a technology with a lot of
promise for space missions that potentially simplifies a lot of problems even if you have
to bring your printing material with you.
Of course one of the biggest problems with Mars missions isn't getting there it is
getting back, you either need to bring a lot more fuel along or make it there.
However, when we're discussing missions lasting a few years, and likely including
at least a few years devoted to applying for the job and training for it, some might ask
if the fuel or equipment for making fuel is even worth bringing along.
Maybe you're not spending years on a mission but the rest of your lifetime, and that cargo
space can be devoted to making permanent facilities on Mars.
That was one of the key notions of the Mars One project announced earlier this decade.
You send a 4 person crew there and they don't come home, they are just joined after the
next launch window by another crew, and another and larger ones till you have a colony.
Mars One was pretty controversial, and for good reasons, but they deserve mention as
probably the first serious and well-known privately funded mission design.
And whatever else comes from it, they did get people seriously talking about Mars again,
which hadn't faded from sight as long or much as in the 1980s but had started losing
ground and public interest for a time.
Likely at least in part from the bad global economy, it's obviously hard to get funding
for space exploration when money is tight.
They had a novel approach on funding too, as much as most of us jeer at Reality TV shows,
they are quite popular and also a good way of keeping the public interested in the mission.
Space missions are ridiculously expensive, and a serious space program is a cost even
most countries can't realistically afford, so private funding of something so far-reaching
as a Mars Mission requires some fairly inventive methods of raising capital.
Now Mars One has a lot of flaws though at the same time probably gets more criticism
than it deserves too, personally I don't think there's anything wrong with using
Reality TV to keep up funding and public interest or recruiting from all over rather than from
existing astronaut candidates.
If I can get a mission funded by slapping sponsor logos on the rocket, that's fine
by me.
However their suggested price tag of just 6 billion dollars was always dubious at best
and the technical issues raised were rarely well-rebutted, I suspect the mission would
have ended with crews using those life support capsules as coffins.
That always an issue with missions like this, it would be quite easy to sell the US congress
a Mars Mission for 100 billion dollars if you could tell them you were 99% confident
the crew would come home alive and safe and not fall over dead a year later from all the
health complications of low gravity and radiation.
However if they think there's more than an outside chance of critical mission failure
they know they may have just cut a check for a particularly expensive and elaborate form
of political suicide.
People can talk all they want about the need to take risks but we still tend to be very
harsh on those who took them if it doesn't pan out.
I'm quite sure this is part of the reason robots have become more popular than manned
missions, though of course cost helps, but a lot less heads roll when your robotic rover
crashes into Mars than when your manned capsule does.
Manned or robotic it still takes a lot of money so of course a lot of ideas have focused
around an international expedition rather than one funded by a single country.
There's a lot to be said about competition, I doubt the US and USSR would have achieved
so many amazing successes in the Space Race if they hadn't be striving to one up each
other, but cooperation and teamwork are certainly handy too and of course so is being able to
split the check, and it has worked pretty well so far for the International Space Station.
That was a fairly a large component in Shaun Moss's 2015 book "The International Mars
Research Station", which incorporated a lot of prior architecture and modern technological
improvements into the plan.
Though I should note for the sake of honesty Shaun is a friend and I helped proofread the
book, so I'm probably not neutral on it.
A big focus there was on the SpaceX Falcon and Dragon designs and the ability of those
to land 30 tons on Mars.
Particularly the Red Dragon which would let you do a pinpoint landing on Mars with a crew
of six.
That worked very well in conjunction with the Bigelow BA 330, sometimes called the Nautilus
which is a reworking of NASA's TransHab design from the 90's.
Essentially an expandable or inflatable ship or base, so you could pack it on a conventional
rocket and expand it later.
A point he focuses on and which has been raised a lot for space missions is how incredibly
bulky, leaky, and cumbersome space suits are and some of the efforts being made to produce
new designs like MIT's Biosuit.
This gets skipped a lot in discussion of space exploration and colonization but is an important
aspect and serious problem.
One of the advantages of manned missions is you have a clever and dexterous human on hand,
not a clumsy stupid robot.
If you've seen many spacewalks you know that being in a suit doesn't make one very
nimble.
We are severely limited in missions in space, on the Moon, or Mars or any hazardous environment
by our astronauts needing tons of time to put on a suit that leaves them less agile
than a lot of modern robots.
One might wonder what 4 or 6 people might do on Mars for a mission over a year long,
one cannot spend that whole time collecting rocks, but the simple bulkiness of those suits
makes collecting samples or doing anything else a lot more time consuming than one might
expect.
We've skipped a lot of mission designs and only skimmed the details to get to modern
times and the newest big plan, which of course is Elon Musk's BFR project.
Since this is a family friendly channel we will assume that is short for Big Falcon Rocket,
and of course we've got the usual criticisms Musk tends to get for thinking a little bit
too big.
That may be a valid criticism but is certainly not one I am in any position to level, it's
barely been a month since we were discussing how to move galaxies on this channel.
A lot of talk has been had about being able to land reusable rockets on the ground and
how valuable this is and if it really is all that valuable as opposed to just using parachutes
or landing in the water, but it is pretty important and handy if your landing spot is
Mars, not Cape Canaveral.
More to the point, we've seen a huge drop in launch costs in recent years, and when
you half the launch cost per kilogram you can double the cargo you land on Mars, or
double the crew.
The loose idea is that the BFR gets to orbit, refuels from other vehicles there, and launches
to Mars.
Not carrying a crew of 4 or maybe 6 but potentially a couple hundred.
This is not planned as a one-way trip but it also isn't planned to leave material
behind to sit around dead on Mars or awaiting a new crew from the next mission.
Rather it aims to establish a permanent presence and keep expanding, and that's a lot more
realistic when you have hundreds of hands to work on projects.
It also lets you get around the timelag issue.
In orbit, or even on the moon, you can talk to experts real time, you can't on Mars,
so ideally you want to bring a crew big enough to understand everything in a fairly in-depth
way, just consulting home rather than being utterly dependent on them for anything that
goes off script.
I am not sure if any of these missions will ever get off the ground, but they are all
a step in the right direction, with the big approach my pick for the right path.
It's been almost half a century since we went to the Moon for the first time and nearly
as long since the last time, and while that can make folks pessimistic about each new
proposed mission it's easy to forget the huge leaps we've made since then and are
continuing to make.
3D Printing will allow us to make specialized tools and equipment on Mars instead of needing
to pack every widget we need or go without.
Improvement in the weight, endurance, and efficiency of solar panels, batteries, and
fuel cells will let us run missions without having to either bring along cumbersome and
dangerous small nuclear reactors or otherwise be energy-starved and limited while we do
it.
Drops in launch costs will let us send far larger missions for far lower price tags.
We are getting there, and again I do think Musk's mindset of going big is the right
one, though I'm sure that won't surprise any channel regulars.
I can't say I'm super optimistic about his 2022 or 2024 mission dates, but I don't
think we're too far off from the point where all the technological improvements across
the board will mix with growing public enthusiasm for this to snowball into a mission.
We've come a long way since the projects Paul discussed in Part 1, and we have a ways
yet to still go, but I believe making this dream reality is in sight.
So we've just finished a wide ranging discussion on the history of plans for space colonization
and touched on everything from the political will needed for a successful mission to the
logistical uncertainties of supporting a crew on another planet.
In particular, we questioned what mix of transported and acquired resources would be best to minimize
costs without sacrificing the viability of the mission.
For any such in-situ resource harvesting, crews will need to have dependable ways to
scour alien planets for subterranean deposits like ice or methane.
A planet's gravitational field is often approximated, for the sake of convenience,
to be uniform in all locations, but in reality, it depends on the local structure of the planet.
In particular, local increases or decreases in the average density, due to resource deposits,
give telltale signatures in readings of the gravitational field.
If you like, you can rest easy with the knowledge that this is possible, but then you'll never
be able to colonize the Solar System.
Our sponsor for this collaboration, Brilliant.org helps you build the toolset that will require.
In fact, they've built a lesson just for this purpose, how to detect subterranean deposits
using a gravimeter, a field device that allows sensitive measurement of gravity on the go.
To support the channel and learn more about Brilliant, go to Brilliant.org/IsaacArthur
and sign up for free.
And also, if you're ready to expand your mental toolbox, the first 200 people will get 20%
off the annual Premium subscription.
That's the subscription I've been using to entertain myself with thought-provoking puzzles.
If you haven't already seen part 1, take the link in the episode description to head
over and watch that, and don't forget to hit the like and subscribe buttons while you're
over there and check out some of the great content on Curious Droid.
If you're coming from there, try out our Outward Bound series here at SFIA, which makes
a century long journey of colonizing the solar system starting with Mars with a modestly
large base already established, and see some of the options on the table when we look just
a bit further over the technological horizon and when you have an established orbital infrastructure
so you don't have to build everything down on Earth and launch it.
Next week we'll be begin exploring that concept a bit more as we return to the Upward
Bound series to look at Spaceports, and the week after that we revisit the Fermi Paradox
to examine the notion of civilizations that have essentially entered stasis to wait on
certain events, including a new solution proposed for the Fermi Paradox called the Aestivation
Hypothesis, in Sleeping Giants.
For alerts when those and other episodes come out, make sure to subscribe to the channel,
and if you enjoyed this episode, hit the like button and share it with others.
Until next time, thanks for watching, and have a great week!
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