Why would the first manned Mars mission have a huge crew?

Question

In 1948, Wernher von Braun wrote The Mars Project, in which he outlined a scientific expedition to Mars involving 70 crew members who would stay for around a year before returning to Earth. Since then, innovations in spaceflight technology, political and economic changes, and a better understanding of the science have led to constant changes in space agencies' various designs. NASA mission profiles, in particular Constellation, have proposed a relatively small number of crew for scientific missions, with larger numbers reserved for base-building in the far future. And while SpaceX plans to eventually move hundreds of people to Mars at a time, they don't seem to be focused on research for the time being.

My current story idea takes place in an alternate universe with a research-focused round-trip expedition setting off roughly around the present day and returning after a year's stay. It is fairly similar to von Braun's in basic mission design, except relying on more modern technology (e.g. powered landing instead of gliding, use of drones for aid in exploration, better propulsion, etc.) and fewer vehicles to carry a similar number of crew (40-70). Notably, it is the first mission that actually succeeds in putting boots on the Martian surface in this universe, though it doesn't have to be the first manned spaceflight to Mars to begin with — flybys and orbital missions and such may have already happened.

Presumably there are practical reasons that a von Braun-style expedition is no longer in vogue. Why, then, with minimal subtractions from modern technology and a point of divergence no earlier than 1960 or so, would this be the first successful approach?

Answer 1

Because they're not all coming back

At the same time they're travelling there to form a colony too - because it's a waste to lug all this stuff to Mars and only use it once.

There will be rockets travelling back and forth over the following few decades carrying cargo and people, and it's going to be easier if there's manned bases at both ends. Humanity is going to Mars to stay. Some of them will return, so for some people it's a round trip exactly as the question asks, but for the rest, they'll die on Mars.

Hopefully of old age.

The first few rockets were unmanned and automated, they had robots and equipment on them which built the colony, set up power, fuel, water, and oxygen production, built a viable colony, and reported that everything was good to receive humans.

The savings in cost for combining the research expedition that returns with the permanent settlement is just enough that both can be done under budget. Economies of scale with the rockets, better utilisation of the lunar fuel production base, and such. If it's 100 billion for a settlement, 80 billion for a 1 year return mission, and 110 billion to do both at once, why not do both at once?

After a year on the surface, one of the rockets blasts off with samples, the results of experiments, and a chunk of the crew to return to earth.

The colony is large for a few reasons:

• Genetic diversity - more humans will arrive over the following decades to help dilute the gene pool but the less inbreeding at the start the better.

• There are lots of jobs to do:

  • There are service jobs that shouldn't be done by specialists. Barkeep. Grocer. Warehousing. Shopkeeper. Your lead botanist shouldn't be manning the bar every night. Your chief engineer shouldn't be distributing food.
  • Engineering is a pretty complex field. One person can't specialise in refrigeration, software engineering, hydraulics, robotics, and electrical engineering. For a large base, it'd be best to have specialists for all these fields on site rather than have to rely on 40 minute round trip for consolations about every problem.
  • The medical needs of a small colony increase when you're trying to make kids, especially the first in lower gravity. While a small Mars mission may need 2 medics (so they can treat each other), your mission will need gynaecologists, midwives, nurses, pharmacists, paediatricians, medical imagers, surgeons who can do a caesarean, anaesthetists, and the like. These roles may be partially merged for trip #1, but will still be more than what 2 medics can do.

• Interpersonal conflicts can develop randomly, and they will destroy any small team - a team of 60 is large enough that 2 people who hate each other can avoid each other for the rest of their lives without destroying productivity.

Answer 2

Standing watches without exhaustion

One of the principles of standing watch in an infantry context is that wherever possible there is at least a double-staggered piquet. Let's say 8 soldiers need to stand watch on the gun for 8 hours overnight (from 2000 until 0400), their shifts look something like this:

• Soldier 1 (split shift) 2000-2100
• Soldier 2 - 2000-2200
• Soldier 3 - 2100-2300
• Soldier 4 - 2200-0000
• Soldier 5 - 2300-0100
• Soldier 6 - 0000-0200
• Soldier 7 - 0100-0300
• Soldier 8 - 0200-0400
• Soldier 1 (split shift) 0300-0400

This way (assuming there is no contact during the night):

1. everyone gets six hours of sleep (albeit broken into two periods for all but 3 soldiers);
2. there is always someone relatively fresh on watch with someone who is in their second hour; and
3. if something happens, one person can stay on the gun while the other moves around waking people up.

The problem is that this is an exhausting way to live, which is why front line units need to be periodically rotated into rear areas to rest. (It is also something not adequately considered by many survivalists, who do not realise that if their apocalypse scenarios do come to pass that the routine they and their 3 friends may manage for a practice weekend is not a feasible way to live the rest of their lives.)

Now let's look at a spacecraft. Whether correctly or not, there is a perceived risk that automatic systems are not up to the job of handling emergencies and that there must always be an emergency crew of three people in spacesuits ready to act at all times. In an emergency, one handles control and communications while the other two move to and deal with the micrometeoroid impact (or whatever).

Once the expedition arrives, the "3 people in suits ready to respond" principle also applies to the surface team. Which means that between the (orbiting?) ship and the ground party, there must always be six people ready to go. Yet the expedition cannot safely operate while sleep deprived, as this leads to mistakes and space is an unforgiving environment.

Work out how many people you want on the expedition, then work out what watch-standing arrangements are required to justify the number you want. The only requirements are:

• the resources are available to send so many people in such a high-capacity spacecraft; and
• it is perceived as too risky not to have walking, talking people on watch at all times rather than drones/automatic systems. This is best explained by one or two past disasters in which automatic systems were inadequate to manage the catastrophe but people ready to act in spacesuits would have saved the day.

Answer 3

It is not the first approach of this sort. This one just succeeded.

After North Korean leadership gave up on their nuclear program, they turned to the space race as a source of national pride. Their unorthodox approach was surprisingly effective, if wasteful. The 70 Korean cosmonauts who succeeded in reaching Mars were actually in the third ship sent up, the earlier two having each failed to reach Mars in different ways. Why the Koreans want so many cosmonauts on Mars has to do with their motivations in the first place. The photos of the arrayed cosmonauts on Mars are indisputably more impressive than a handful of individuals would be.

The Korean approach is the successful approach because it is the only approach. No-one else is trying, especially after what happened with the second Korean attempt. For the Koreans themselves, the failures only increased their resolve.

Answer 4

OP here: this is my own, not-quite-complete answer, which I'm posting just because no one else got to it. Obviously I won't accept this one, don't worry.

Project Orion

The first idea I had while writing this question was that the mission architecture made sending a large crew no more problematic than sending a small one. What immediately jumped out at me was Project Orion, the nuclear-pulse spacecraft that blows past any of the strict mass limits that space missions tend to have by instead getting more efficient for large payloads. Rather than worrying about assembling a flotilla of spacecraft in orbit over many years (and political shifts) and spending so many billions on launch vehicles, the whole thing could be done in one fell swoop from launch to Martian orbit (depositing landers and return craft on the surface) before returning everyone home. It could also cut transit times dramatically and make the notion of getting it all done a little more logistically convenient.

The rough timeline would look something like this:

• The point of divergence is in the early 1960s, where the Partial Nuclear Test Ban Treaty carves out an exemption for nuclear propulsive units detonated under certain safe conditions (e.g. far from civilization and/or in orbit).
• Orion gets much farther along the development branch, but isn't ready for a Mars mission by the time the Apollo program ends and NASA funding gets cut back.
• The infrastructure for pulse units stays in place, at the cost of a Cold War extension, and thanks to a different sort of climate around nuclear technology, the political and industrial viability of the project isn't totally killed during the intervening decades. It still likely proves controversial when it goes forward.
• It takes until the 2010s, when a sufficiently ambitious/unafraid-of-controversy president (e.g. Trump or alternate-universe analogue) calls up NASA to put together the already-well-fleshed-out Orion Mars plans, perhaps as part of a political gambit or, if something longer-term like a large base is on the itinerary, a jobs program.
• The whole mission can then be executed with one vehicle of the size and capability to efficiently move 40-70 people plus equipment to Mars.

Answer 5

Cost

Like everything it comes down to cost.

Now if you have a job to do and ten people cost X to send but twenty people cost X + 10%, sending 20 is worth it. Thirty people might be X + 15%.

Seventy could just be the sweet spot for the best return on investment.

What a seventy man team would be is the majority of the team remains in space in a self sustaining space station and only the landing crew goes up and down to minimize fuel use.

Crew aboard the station could instruct the landing crew to do tasks or remote pilot drones. Other crew could be working completely in space such as sourcing ice asteroids for water for fuel or metallic ones for construction.

You'd have agronomists for growing the food hydroponically. Engineers, metallurgists, geologists, doctors, IT specialists, drone pilots, astronauts, comms experts etc.

The plan would be to establish a self sustaining orbital base that would remain in place to support a proposed planet side base.

By having a space station, crew could be stationed there without the fuel cost and danger of landing missions

Answer 6

Seven months is a long time

That's the approximate time to travel to Mars — seven months. That's a long time! A lot of things can happen in seven months and any one of them could rationalize a larger crew.

Maintenance: One of my favorite movie moments comes from K-19: The Widowmaker when, during a missile launch simulation, a burn-out occurs. When some bureaucrat demands to know the name of the person responsible, Liam Neeson responds, "Why would I know the name of the jackass that supplied a 30 kopeck insulator to do a 50 kopeck job?" Think that's unreasonable? Think "Apollo 13." No ship is perfect, and no space agency would send a ship on a seven month cruise without an ample supply of spare parts and the people to maintain it. (Why don't they do that today? For one thing, the Space Shuttle's longest mission was only a bit more than 17.5 days.)

Emotional Health: Even the most introverted person needs occasional human contact. Emotional stress on such a long journey would be enormous. And you'd be surprised how easy it is to fashion something into the shape of an axe. You might not justify 70 people this way, but you'd justify a few more than 3-5.¹ (This builds on @KerAvon2055's answer, which I upvoted. If the ship can be flown by three people, you'd want at least twelve because someone must always be monitoring the ship and that would get incredibly tedious.²)

Economy of Scale: When the world's national space agencies formed the Global Space Initiative (GSI) in 2031, they realized that economy of scale was very much their friend. The Mars mission ship was already humongous due to basic life support, power, and engines. Not to mention the cargo of equipment to be used on Mars. But that's inefficient! Why not use all that equipment en route, and even add a bit more to do cool things like analyze Space in transit? Need a few more scientists or engineers for that? No problem! Add a bit more living space, a little bit more fuel, food, and oxygen and we're good to go! (This builds on @Thorne's answer, which I upvoted. While governments tend to spend wastefully, NASA and other space agencies have demonstrated the ability to make the most out of the little they get. There would be a fair amount of pressure to make those seven months very, very productive.)

Supporting Labor: The more people you have, the more you need supporting labor. Cooks, janitors, admins (of varying types). It's a nice theory that you could get away with just a few people on that ship, but every person you add means you need to help them live their lives. Remember when three people for seven months would really need to be twelve? Now you need fourteen (at least), two people to care for the other people who need their chance to do their jobs, eat, sleep, and relax. The compounding of labor adds up quickly, otherwise you need to deal with the stress of individuals doing multiple jobs: navigation and cooking, communications and cleaning the bathrooms (so to speak). There's always a price to be paid. If you send 70 people to Mars, you can bet that 15 of them are supporting personnel — the people you never see in the movies because, apparently in Hollywood, space ships clean and cook for you.³

Political Intrigue: OK, the GSI wasn't created in 2031. In fact, due to a massive international financial collapse in 2029, the only space agency left operating is the South African National Space Agency — but that hasn't dampened all other nations' hopes of working in space! The competition to get on that Mars mission is fierce, and South Africa isn't a fool. Rather than risk being bombed by someone for not letting their pet favorite astronaut join the crew, they simply built a bigger ship (with a bit of a donation from those cash-strapped nations) and loaded not one, but ten full crews onto it. One for each participating nation. And, yup, by treaty, each crew gets its turn at the proverbial wheel.⁴

Biological Necessity: Ten years after the COVID-19 panic of 2020 the world is finally vaccinated — but politicians and scientists who spent the decade calming fears know an ugly truth: that virus can mutate a lot more than the public was ever led to believe. Those 70 people aren't on that ship because there's actually 70 jobs that need to be done, they're there because the mutation and mortality rate simulations suggest that when the ship re-enters Earth's orbit two years later, there will only be three living people on board.

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_{¹ And if Hollywood has proven anything, it's that there's always an axe. NASA could go out of its way to be sure there were no axes on the ship and someone would find one anyway. Call it karma, call it fate (call the Ghostbusters!) but 210 days into the 215 day mission, someone would go ape berserk and suddenly there'll be an axe. There's always an axe!}

_{² You might consider reading Frank Herbert's Destination: Void. He did a good job of imagining what space flight might be like when there's too much to do.}

_{³ You know, I get the idea of Star Trek replicators, but they never show anyone actually cleaning. Do you have any idea how many people would be necessary to clean a ship the size of Enterprise?}

_{⁴ It's a mistake to believe that the crew must have mission-related reasons to be on the ship. Frankly, you could justify a dozen people as tourists, the launching space agency having used the funds from the over-priced tickets to pay for the mission. 2001's first space tourist Dennis Tito started a very real trend that you could use.}

Answer 7

Contributing nations want representation.

A dozen or so of nations contributed to remotely building the Mars base and the Lunar launch station. It was a large, multinational collaboration to make the Mars mission possible, and each nation that contributed was willing to cover costs for their astronauts in order to gain the recognition for putting the first boots on Martian soil. The Martian mission committee decided it would allow this because each astronaut's additional costs would be covered by their respective sponsors, and increasing the crew size allowed for a much more diversified (and redundant) skill set.

Answer 8

The point of the mission is to take as many people away from the Eatth as possible.

You are not simply building a base - Mars is intended to be the next Alcatraz. Most of the crew are inmates who will help build their cells. The very first expedition is a proof of concept, and if successful the criminals will either be pardoned or have their jail time reduced upon arrival back on Earth.

Any trips after that will have many people due to economy. The more people and material you can transport in a single trip, the more efficient your business is.

Answer 9

Get rid of the rich.

A lot of rich and influent, to the point of being cumbersome, people offer to finance the mission provided they can join the crew. Some young engineer making a review of the mission plan find a lot of issues which might add unforeseen risks and the planners decide to accept all the contributions on offer.

Answer 10

The initial supply and colony building missions where more successful then expected. People had planned for a very high failure rate, so had launched many robotic missions ahead of time to build the initial colony. But surprisingly everything worked fine. So now there is this well stocked, well provisioned base with plenty of space available. So people decide to make the best of it and send a larger crew to take advantage of this (with all the benefits the other answers give to having more people).

Answer 11

We're Not Alone
With additional probes and surveys, it becomes clear that there's life on Mars. Life sophisticated enough that it's possible that there is or were intelligent beings that have retreated below the surface.

The possibilities for study are endless and so is the potential payoff. You need at least that many people just to represent the obvious research disciplines, handle diplomatic issues and provide for defense.

Answer 12

The mission is twofold:

• do science stuff on Mars
• 'practice' living on mars

The mission setup will be to send robots ahead to build a base - as far as robots are able to do so! - then the human crew will follow. Quite a few will work on making the base self sufficient. However the basic assumption is that a lot of unknown unkowns will make a self supporting colony on the first try hard. So the mission plan is, from the start, to ship everyone back. The life support systems are left in place, with a few pigs to simulate the humans and see when and how life support fails.

Answer 13

First mission failed

It was a smaller mission, and it failed due to a mixture of exhaustion and failure to be able to handle emergencies locally. On the trip there where multiple close calls before complete mission failure.

We built it in space

Before humans get to mars, we have built automated orbital factories. We have robots tearing apart metal rich asteroids and constructing things, sending what where once precious metals back to Earth for the cost of atmospheric breaking in the atmosphere and retrieval.

Space has full (automated) industrial capacity, and the Earth-Mars ships where built in space.

The failed first mission was intended to be followed up with annual resupply runs. But when the first mission failed, they kept on building the resupply ships.

Dress rehearsal

Multiple antarctic dress rehearsals where started, with various mission mixes and simulated disaster rates. In some cases, actual interplanetary drone ships where sent to Mars, and whatever went wrong on those ships where used to simulate the disasters back home.

The dress rehearsal with 50 people in it succeeded. Almost all of the smaller ones failed. These dress rehearsals took years to complete, as they went all the way from a simulated launch, a simulated trip, a simulated landing, a simulated time on Mars, and finally a simulated return journey.

The failures where due to a lack of local specialists, exhaustion in harsh conditions, lack of astronaut emergency response teams, etc. With the multi-hour lag time relying on Earth-based experts wasn't reliable enough over the 2+ year journey.

We have the ships

In the time it took for the investigation into the original 12 person disaster to complete, they built multiple interplanetary ships in orbit. Original plan involved sending a new ship every orbital alignment; they chose to not stop building them just because the first mission failed, as most of the material involved in making them where mostly waste products from space mining anyhow: Space mining's limit is how much atmospheric braking the Earth can afford, heating wise.

They kept on going to Mars and dropping off more supplies with a modest failure rate (but too high for actual astronauts). Those that returned, well, they are still functional. The fleet has and supplies on mars have grown to the point where sending 40-70 people is well within the transport budget and base supplies and rations.

Politics, not Economics

There is little actual reason to send people to another planet like this. Automation is a better solution. As this is the safest way to get the mass of people there, the cost is relatively cheap.