Worldbuilding the First Mars Landing

Years ago I established that in my alternate-historical/science-fictional setting a Russian-led expedition is the first to reach Mars in 1963, 22 years after the first manned spaceflight, and 14 years after the first landing on the Moon. Now that I’ve written up the first flight to orbit and the first flight to the Moon, what would the next big step, the first flight to Mars, look like? That’s an interesting question, and I’ve been brainstorming some about it in recent days, along with the future of the lunar program in the 1950s and beyond as well as what sort of super-heavy-lift launchers might be both viable and required to progress in the early age of spaceflight.

This has, naturally, led me to pore over various plans for Mars missions, and honestly all of them seemed a bit stale, at least for my worldbuilding purposes. I wanted something more different, more obscure, even unique. And even aside from that, the more I researched it, the more I realized that something more creative was not just desirable but necessary.

One does not simply land on Mars…

The showstopper? “Entry, descent, and landing”, or, as they say in the business, “EDL”. Most people are unaware that landing a spacecraft on Mars is a very tricky business that we’re nowhere near mastering. The reason is that Mars’s atmosphere is thick enough to interfere with retro-rocket propulsion and necessitate a heat shield when entering, but it’s also too thin to slow you down all that much; the worst of both worlds. Something like the Apollo capsule, which drifted down to a soft landing on Earth, would on Mars hit the ground at Mach 5. Ouch.

For landers we’ve sent in real life we’ve used the likes of airbags, sky cranes, and truly huge parachutes, but the rub is that, like the heat shields originally designed for the Viking probes that we’ve used for every lander since, none of these technologies scale up well for a human-sized vehicle, which will likely mass at least 30 tons, if not more like 100 tons. Worse yet, these techniques limit the landing sites to the lower half or so of Mars’s terrain, since those are the only places the air is thick enough to make them work, closing off about half of the planet to exploration!

Instead of trying to let the air do most of the work, SpaceX proposes to do a primarily propulsive landing, via retrorockets, i.e. the underside of Starship, but that has its own problems: keeping a rocket plume lit up and pointed in the right direction in supersonic airflow that’s screaming in the opposite direction isn’t exactly easy; SpaceX has made progress on the matter in recent years, and will probably have it mastered by the 2030s for all I know. This should solve the whole problem. The rub for my worldbuilding, though, is that such a technology is probably not going to be available until well after 1963, and spacemaster Sergei Korolev and patron Oleg Losev want to get to Mars much faster than that. Compounding the issue is that huge inflatable heat shields, enormous parachutes, and even giant spaceplanes or lifting bodies also demand materials that are likely not available.

There might, however, be an alternative open to them. Atmosphere on Mars is not evenly distributed. Hellas Basin, the lowest point, has a pressure of 14 millibars, whereas Olympus Mons, the highest point, has only 0.7 millibars of pressure. This pressure is similar to Earth’s atmosphere at an altitude of 50 kilometers, and from all the NASA charts I’ve seen Olympus Mons’s altitude is well above the level at which atmospheric flows significantly interfere with rocket propulsion. If the Mars expedition landed at Olympus Mons, therefore, they could use the same purely propulsive landing techniques that are already proven technology in the lunar context.

Mobile Base is Best Base

Of course you want to go to other places on the planet too, not just the part that’s barely one notch above being a moonscape. Mars expedition planning usually calls for a base camp to be established at a fixed location not far from the landing site, but there are a few mission profiles that call for the base itself to be a rover. If you ask me this makes far more sense, considering if you can take all your facilities with you across the planet that’s far more effective than either being stuck within a certain radius of a base or else having to accept a much lighter and less effective vehicle for long-range journeys.

As I’ve written before, if you want to see the whole planet and do science most effectively and in the greatest comfort, there’s really no reason to have a fixed base at all, as opposed to taking a base module and mounting it on a chassis with big wheels (for truly large colonies doming up a crater makes eminent sense, but those will only be built out much later). Interestingly, I’ve read suggestions that a suspension chassis of some sort will be necessary anyway to cushion the landing of a crew module, so there’s even more synergy with this concept than I thought.

Nuclear Rover, Nuclear Descent Stage

Such a rover would be quite heavy, likely massing several hundred tons, but an effective nuclear-powered design should be feasible. The Hyperion power module proposed in 2008, which by my back-of-the-envelope calculations could power a 1500-ton tank at a top speed of 70 mph off the shelf, only masses 90 tons (including shielding) for 30 megawatts, at 10% enriched fuel; presumably 100% enriched fuel would provide 10 times greater power. The power density a state-of-the-art late 1950s reactor could provide would be much lower, of course, but it should still easily be enough to power such a vehicle to a top rated speed of 5-10 mph. The exact numbers would depend on the mass of the rover, but I’m thinking very roughly 1000 tons (ranging from several hundred to several thousand tons).

This mass doesn’t include the descent stage. A NERVA-class rocket engine (nuclear thermal) achieves exhaust velocities of 8 kilometers per second, which combined with the delta-v needed of 3.8 kilometers per second means a 1000-ton lander will need to mass 1612 tons in orbit, i.e. 612 tons of propellant will be needed for every 1000 tons landed. This fraction is vaguely comparable to what the Apollo lunar lander dealt with; there’s double the delta-v to deal with on Mars as opposed to the Moon, but early nuclear thermal is about twice as efficient as chemical rockets.

The configuration, however, will need to be somewhat different. Ideally the descent stage would be mounted above the rover (not below, as Apollo did), so as to enable its big wheels to touch down directly on the Martian surface. The maneuver would be not unlike the “sky crane” used for the Curiosity and Perseverance rovers, only on a much larger scale: the top descent stage slows down the rover, the rover plops down to earth, and the descent stage then flies off and lands itself out of the way.

 NASA/JPL-Caltech rendering of the Curiosity sky crane.

The Trans-Martian Expedition

Once they’re on the surface of Olympus Mons, the rovers (there are two of them, so as to ensure redundancy and support) and their crews explore the caldera, no doubt sending some great pictures back to Earth. Broadcasting from the highest mountain in the solar system would if nothing else generate good public relations buzz. From there the convoy will head downslope, following a trajectory roughly like this:

First they’ll encounter the cliffs of Olympus Mons’s perimeter, then they’ll trek through the Tharsis range, before encountering what may well be the most visually spectacular part of the whole trip: the spider’s web of narrow deep canyons known as the Noctis Labyrinthus, the labyrinth of the night. Strong winds, icy fogs, and unpredictable weather prevail in these chasms, strewn with rough terrain, both from the actual topography and from boulders tumbled down in landslides.

Caption from NASA (1989): This artist’s concept depicts a possible scene when the first human travelers might walk on the surface of Mars. The artwork was part of a NASA new initiatives study that surveyed possible future human planetary expeditions. The area depicted is Noctis Labyrinthus in the Valles Marineris system of enormous canyons. The scene is just after sunrise, and on the canyon floor four miles below, early morning clouds can be seen. The frost on the surface will melt very quickly as the Sun climbs higher in the Martian sky. The astronaut depicted on the left might be a planetary geologist seeking to get a closer look at the stratigraphic details of the canyon walls. On the right, the geologist’s companion is setting up a weather station to monitor Martian climatology. In the far right frame is a six-wheeled articulated rover, which transported the pair of astronauts here from their landing site. The vehicle is unpressurized. This artwork is strictly speculative and does not represent any definitely planned or budgeted projects.

From there the broader, deeper, but visually somewhat less impressive Valles Marineris will be their constant companion for a pretty long stretch. By the time they reach the canyon’s mouth, they’ll have already traveled 2700 miles. From there, the expedition will make a beeline toward the real target of the first Mars mission: the south polar region; specifically, the geysers. Yes, Mars has geysers, or so we think, unlike any geysers on Earth, that might be indicative of and/or supportive of biological activity. It’s thought by some scientists that these areas might permit life to thrive in a liquid water layer under a thin transparent layer of ice, supplied with both geothermal and solar energy, to the extent that not just microbes but also simple plants might live there! It’s entirely possible the most vibrant remnants of the Martian biosphere are right there, waiting to be found.

In the 1950s probes spot the same sort of geological formations we’ve found in the 2000s, and thus the geysers would be a priority target for a manned mission, which will come equipped with drilling rigs and a full astrobiological laboratory for finding signs of life. I’m thinking they’ll find fossilized microbes right away, but only later in the trip will they find live microbes, and only at the climax, in the geysers, will they find the real prize: lichen-like forms of Martian life.

Geysers on Mars (by Ron Miller for NASA). What if alien life you can see with the naked eye and feel with the naked hand is a lot closer than we think?

From there the expedition may well head northward again on the other side of the planet, to the Hellas Basin, the lowest part of the planet, and then perhaps to the Vastitas Borealis, the most likely site of a former ocean. They may well visit the northern ice cap and then circle back to the Tharsis range, visiting some of the other volcanic mountains, completing a full circumnavigation of the planet. No particular reason they couldn’t, since their vehicle is nuclear-powered and needs no refueling. The crew, however, only have a certain amount of provisions (yes, they will experiment with in-situ resource utilization, but for the first mission everything will be supplied from Earth, just in case), though there’s no particular reason Earth couldn’t send them additional shipments; this has even been proven technology since as far back as the very first Moon landing, Artemis 1, under the aegis of the Sessr├║mnir missions (even if it was an emergency crash program in their case).

Naturally this entails a rather long journey. Just from Olympus Mons to the South Pole is 8000 miles, pacing it out on Google Mars, and that path is straightened out compared to a realistic version; realistically it would probably be more like 10,000 miles. At an average speed of 5 mph that would take 83 days. Realistically with stopovers and slow-poking it for a fraction of the trip we’re probably talking 120 days or even 150 days.

The rest of the trip, from the South Pole to Hellas to the North Pole through the Tharsis and then back to Olympus Mons takes 12,000 miles, and that’s smoothed out. Realistically let’s figure 16,000 miles. At 5 mph that’s another 133 days. With a safety margin let’s say 180 days. So with a circumnavigation the expedition would traverse 26,000 miles and last 300 days.

The ascent vehicle would be included on the rover itself, and would hinge up much like a mobile missile launcher. Only a relatively small capsule would be required, since they’d be docking with the far larger ship waiting for them in low orbit. The vehicle might become more and more laden with samples and so forth; one interesting possibility would be sending such cargo back to Earth early, via ascent vehicles landed from Earth to the area on Mars the rover is in at any one time.

Obviously this all would be a rather big undertaking, but it all should be quite viable. None of the hardware in the expedition will be designed to be reusable, but a vision will be seriously pursued where gradual upgrades in reusability will occur over the years and expeditions.

Mission Profile

The vehicle they’ll take there, and take back, will be rather large. I’m thinking two spaceships, each having two modules much like Skylab but bigger tethered together so as to provide spin gravity (0.38g, same as Mars, would be both easier to provide and more sensible, since they’ll have to get used to it anyway upon arrival) the center of mass hosting the nuclear thermal rocket engines. With a typical nuclear thermal rocket mission profile the journey to Mars would take three to four months.

Launch windows tend to occur a few months before opposition, which was in February 1963, so sometime in the winter of 1963 is when the mission will launch. After 300 days (February or March 1964) Earth will actually be as far away from Mars as it gets in its orbit, about 3 times further away than at opposition, demanding either more time or more fuel (don’t quote me, as I haven’t looked it up, but 3 times more?). The next opposition isn’t until March 1965, the launch window in the winter of 1965, so almost two years, so they might just take off earlier than that and accept the extra travel time and fuel if their mission objectives are completed. Or they might simply stay the two years, or even longer. My vision for the return-trip portion is somewhat hazy.

Spaceship Luxurious? Or would it be Spaceship Goldliocks?

What isn’t hazy is that the spacecraft facilities will be low-density, spacious, airy, and brightly lit by natural sunlight, filled with bright vivid colors and abundant plant life (not unlike the Antarctic aerostats). Several thousand square feet per person of floor area should be provided, so as to minimize any adverse psychological effects on the crew. Skylab’s walls came to 6,100 square feet of floor area. Two such modules come to 12,200 square feet. Assuming a couple dozen crew members total across two ships, that comes to 1000 square feet per person. Dividing much of the area up into floors (remember, we have spin gravity!) and increasing the size of the modules should let us hit that several-thousand-per-person benchmark.

A launcher the size of SpaceX’s Super Heavy combined with a nuclear upper stage would likely be able to loft such modules into low Earth orbit. In-orbit assembly and refueling mean that altogether less than a dozen launches would be required for each expedition. Even in my timeline all of this is pushing the envelope, but with mega-billionaires flush with cash in a general decades-long space craze it should be doable.

It’s about the opposite of Mars Direct, but in my view it does provide a good mission architecture for reaching Mars both quickly and effectively in the context of a mid 20th century early spacefaring era with relatively abundant funding. Over the following several decades, launch costs will come down due to reusability and mass production as well as incremental improvements to heavy-lift rockets, a la what SpaceX is doing now. It’ll help somewhat that Earth-launched propellant requirements will drop over the years as Mars expeditions master living off the land there and asteroidal sources of propellant and raw materials become more readily available.

Audentis Fortuna Iuvat?

Techniques pioneered for the journeys to the Moon and Mars as well as other expeditions to deep-space destinations (such as asteroids and comets) will prove just as useful for interplanetary journeys across the inner solar system. Flights to Venus, Mercury, and much of the asteroid belt would take well under a year, and become relatively routine by the 1970s. Jupiter starts to look doable, tempting the bold.

The truly crazy might be tempted to do a manned version of the Grand Tour track the Voyager probes went on in real life during this period. I’m thinking some eccentric reclusive mega-billionaire on a clean modernist Discovery-esque ship all alone with only a HAL-like artificial intelligence for companionship. But that’s another story…

Conclusion

As it is I think I’ve got quite a bit to work on with this Mars story. I don’t feel like actually writing it up anytime soon, but I’m pretty sure this is the outline I’m going to go for. It’s rather different and creative, yet it also really fits in well with the timeline I’ve established, a combination that pleases and inspires me.

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