Saturday Night Science: Humans to Mars

 

“Humans to Mars” by David S. F. PortreeEver since people began to think seriously about the prospects for space travel, visionaries have looked beyond the near-term prospects — flights into Earth orbit, space stations, and even journeys to the Moon — and toward the red planet: Mars. Unlike Venus, eternally shrouded by clouds, or the other planets which were too hot or cold to sustain life as we know it, Mars, about half the size of the Earth, had an atmosphere, a day just a little longer than the Earth’s, seasons, and polar caps which grew and shrank with the seasons. There were no oceans, but water from the polar caps might sustain life on the surface, and there are dark markings that appeared to change during the martian year. Some people interpreted this as plant life that flourished as polar caps melted in the spring and receded as they grew in the fall.

In an age where we have high-resolution imagery of the entire martian globe — obtained from orbiting spacecraft, telescopes orbiting Earth, and ground-based telescopes with advanced electronic instrumentation — it is often difficult to remember just how little was known about Mars in the 1950s, when people first started to think about how we might go there. Mars is the next planet outward from the Sun, so its distance and apparent size vary substantially depending upon its relative position to Earth in their respective orbits. About every two years, Earth “laps” Mars and it is closest (“at opposition”) and most easily observed. But because the orbit of Mars is elliptic, its distance varies from one opposition to the next, and it is only every 15 to 17 years that a near-simultaneous opposition and perihelion render Mars most accessible to Earth-based observation.

But even at a close opposition, Mars is a challenging telescopic target. At a close encounter such as the one that will occur in the summer of 2018, Mars has an apparent diameter of only around 25 arc seconds. By comparison, the full Moon is about half a degree (1,800 arc seconds) making it appear 72 times larger than Mars. Even at a favourable opposition, Mars is a difficult object to visual observers. Before the advent of electronic sensors in the 1980s, it was even more trying to photograph. Existing photographic film and plates were sufficiently insensitive that long exposures, measured in seconds, were required, and even from the best observing sites, the turbulence in the Earth’s atmosphere smeared out details, leaving only the largest features recognisable. Visual observers were able to glimpse more detail in transient moments of still air, but had to rely upon their memory to sketch them. And the human eye is subject to optical illusions, seeing patterns where none exist. Were the extended linear features called “canals” real? Some observers saw and sketched them in great detail, while others saw nothing. Photography could not resolve the question.

Further, the physical properties of the planet were largely unknown. If you’re contemplating a mission to land on Mars, it’s essential to know the composition and density of its atmosphere, the temperatures expected at potential landing sites, and the terrain which a lander would encounter. None of these were known much beyond the level of educated guesses, which turned out to be grossly wrong once spacecraft probe data started to come in.

But ignorance of the destination didn’t stop people from planning or, at least, dreaming. In 1947–48, Wernher von Braun, then working with the US Army at the White Sands Missile Range in New Mexico, wrote a novel called The Mars Project based upon a hypothetical Mars mission. A technical appendix presented detailed designs of the spacecraft and mission. While von Braun’s talent as an engineer was legendary, his prowess as a novelist was less formidable, and the book never saw print; the appendix, however, was published by itself in 1952.

One thing of which von Braun was never accused was thinking small and, in this first serious attempt to plan a Mars mission, he envisioned something more like an armada than the lightweight spacecraft we design today. At a time when the largest operational rocket, the V-2, had a payload of just one tonne, which it could throw no further than 320 km on a suborbital trajectory, von Braun’s Mars fleet would consist of ten ships, each with a mass of 4,000 tons, and a total crew of seventy. The Mars ships would be assembled in orbit from parts launched on 950 flights of reusable three-stage ferry rockets. To launch all of the components of the Mars fleet and the fuel they would require would burn a total of 5.32 million tons of propellant in the ferry ships. Note that when von Braun proposed this, nobody had ever flown even a two stage rocket, and it would be ten years before the first unmanned Earth satellite was launched.

Von Braun later fleshed out his mission plans for an illustrated article in Collier’s magazine as part of their series on the future of space flight. Now, he envisioned assembling the Mars ships at the toroidal space station in Earth orbit which had figured in earlier installments of the series. In 1956, he published a book co-authored with Willy Ley, The Exploration of Mars, in which he envisioned a lean and mean expedition with just two ships and a crew of twelve, which would require “only” four hundred launches from Earth to assemble, provision, and fuel.

Not only was little understood about the properties of the destination, nothing at all was known about what human crews would experience in space, either in Earth orbit or en route to Mars and back. Could they even function in weightlessness? Would be they be zapped by cosmic rays or solar flares? Were meteors a threat to their craft and, if so, how serious a one? With the dawn of the space age after the launch of Sputnik in October, 1957, these data started to trickle in, and they began to inform plans for Mars missions at NASA and elsewhere.

Radiation was much more of a problem than had been anticipated. The discovery of the Van Allen radiation belts around the Earth and measurement of radiation from solar flares and galactic cosmic rays indicated that short voyages were preferable to long ones, and that crews would need shielding from routine radiation and a “storm shelter” during large solar flares. This motivated research into nuclear thermal and ion propulsion systems, which would not only reduce the transit time to and from Mars, but also, being much more fuel efficient than chemical rockets, dramatically reduce the mass of the ships compared to von Braun’s flotilla.

Ernst Stuhlinger had been studying electric (ion) propulsion since 1953, and developed a design for constant-thrust, ion powered ships. These were featured in Walt Disney’s 1957 program, Mars and Beyond, which aired just two months after the launch of Sputnik. This design was further developed by NASA in a 1962 mission design which envisioned five ships with nuclear-electric propulsion, departing for Mars in the early 1980s with a crew of fifteen and cargo and crew landers permitting a one month stay on the red planet. The ships would rotate to provide artificial gravity for the crew on the trip to and from Mars.

Mariner 4 fly-by photo of Mars
Mariner 4 fly-by photo of Mars by NASA is in the public domain.

In 1965, the arrival of the Mariner 4 spacecraft seemingly drove a stake through the heart of the romantic view of Mars which had persisted since Percival Lowell. Flying by the southern hemisphere of the planet as close as 9600 km, it returned 21 fuzzy pictures which seemed to show Mars as a dead, cratered world resembling the Moon far more than the Earth. There was no evidence of water, nor of life. The atmosphere was determined to be only 1% as dense as that of Earth, not the 10% estimated previously, and composed mostly of carbon dioxide, not nitrogen. With such a thin and hostile atmosphere, there seemed no prospects for advanced life (anything more complicated than bacteria), and all of the ideas for winged Mars landers went away: the martian atmosphere proved just dense enough to pose a problem when slowing down on arrival, but not enough to allow a soft landing with wings or a parachute. The probe had detected more radiation than expected on its way to Mars, indicating crews would need more protection than anticipated, and it showed that robotic probes could do science at Mars without the need to put a crew at risk. I remember staying up and watching these pictures come in (the local television station didn’t carry the broadcast, so I watched even more static-filled pictures than the original from a distant station). I can recall thinking, “Well, that’s it then. Mars is dead. We’ll probably never go there.”

Mars mission planning went on the back burner as the Apollo Moon program went into high gear in the 1960s. Apollo was conceived not as a single-destination project to land on the Moon, but to create the infrastructure for human expansion from the Earth into the solar system, including development of nuclear propulsion and investigation of planetary missions using Apollo derived hardware, mostly for flyby missions. In January of 1968, Boeing completed a study of a Mars landing mission, which would have required six launches of an uprated Saturn V, sending a crew of six to Mars in a 140 ton ship for a landing and a brief “flags and footprints” stay on Mars. By then, Apollo funding (even before the first lunar orbit and landing) was winding down, and it was clear there was no budget nor political support for such grandiose plans.

After the success of Apollo 11, NASA retrenched, reducing its ambition to a Space Shuttle. An ambitious Space Task Group plan for using the Shuttle to launch a Mars mission in the early 1980s was developed, but in an era of shrinking budgets and additional fly-by missions returning images of a Moon-like Mars, went nowhere. The Saturn V and the nuclear rocket which could have taken crews to Mars had been cancelled. It appeared the US would remain stuck going around in circles in low Earth orbit. And so it remains today.

First colour image from the surface of Mars from the Viking 1 Lander
First colour image from the surface of Mars from the Viking 1 Lander by NASA is in the public domain.

While planning for manned Mars missions stagnated, the 1970s dramatically changed the view of Mars. In 1971, Mariner 9 went into orbit around Mars and returned 7,329 sharp images which showed the planet to be a complex world, with very different northern and southern hemispheres, a grand canyon almost as long as the United States, and features which suggested the existence — at least in the past — of liquid water. In 1976, two Viking orbiters and landers arrived at Mars, providing detailed imagery of the planet and ground truth. The landers were equipped with instruments intended to detect evidence of life, and they reported positive results, but later analyses attributed this to unusual soil chemistry. This conclusion is still disputed, including by the principal investigator for the experiment, but in any case the Viking results revealed a much more complicated and interesting planet than had been imagined from earlier missions. I had been working as a consultant at the Jet Propulsion Laboratory during the first Viking landing, helping to keep mission critical mainframe computers running, and I had the privilege of watching the first images from the surface of Mars arrive. I revised my view from 1965: now Mars was a place which didn’t look much different from the high desert of California, where you could imagine going to explore and live some day. More importantly, detailed information about the atmosphere and surface of Mars was now in hand, so future missions could be planned accordingly.

And then… nothing. It was a time of malaise and retreat. After the last Viking landing in September of 1975, it would be more than twenty-one years until Mars Global Surveyor would orbit Mars and Mars Pathfinder would land there in 1996. And yet, with detailed information about Mars in hand, the intervening years were a time of great ferment in manned Mars mission planning, when the foundation of what may be the next great expansion of the human presence into the solar system was laid down.

President George H. W. Bush announced the Space Exploration Initiative on July 20th, 1989, the 20th anniversary of the Apollo 11 landing on the Moon. This was, in retrospect, the last gasp of the “Battlestar” concepts of missions to Mars. It became a bucket into which every NASA centre and national laboratory could throw their wish list: new heavy launchers, a Moon base, nuclear propulsion, space habitats, all for a total price tag on the order of half a trillion dollars. It died, quietly, in Congress.

But the focus was moving from leviathan bureaucracies of the coercive state to innovators in the private sector. In the 1990s, spurred by work of members of the “Mars Underground,” including Ricochet contributor Robert Zubrin and David Baker, the “Mars Direct” mission concept emerged. Earlier Mars missions assumed that all resources needed for the mission would have to be launched from Earth. But Zubrin and Baker realised that the martian atmosphere, based upon what we had learned from the Viking missions, contained everything needed to provide breathable air for the stay on Mars and rocket fuel for the return mission (with the addition of lightweight hydrogen brought from Earth). This turned the weight budget of a Mars mission upside-down. Now, an Earth return vehicle could be launched to Mars with empty propellant tanks. Upon arrival, it would produce fuel for the return mission and oxygen for the crew. After it was confirmed to have produced the necessary consumables, the crew of four would be sent in the next launch window (around 26 months later) and land near the return vehicle. They would use its oxygen while on the planet, and its fuel to return to Earth at the end of its mission. There would be no need for a space station in Earth orbit, nor orbital assembly, nor for nuclear propulsion: The whole mission could be done with hardware derived from that already in existence.

This would get humans to Mars, but it ran into institutional barriers at NASA, since many of its pet projects, including the International Space Station and Space Shuttle, proved utterly unnecessary to getting to Mars. NASA responded with the Mars Design Reference Mission, published in various revisions between 1993 and 2014, which was largely based upon Mars Direct, but up-sized to a larger crew of six, and incorporating a new Earth Return Vehicle to bring the crew back to Earth in less austere circumstances than envisioned in Mars Direct.

NASA claim they are on a #JourneyToMars. They must be: there’s a Twitter hashtag! But to anybody who reads this sad chronicle of government planning for planetary exploration over half a century, it’s obvious they’re on no such thing. If they were truly on a journey to Mars, they would be studying and building the infrastructure to get there using technologies such as propellant depots and in-orbit assembly which would get the missions done economically using resources already at hand. Instead, it’s all about building a huge rocket which will cost so much it will fly every other year, at best, employing a standing army which will not only be costly but so infrequently used in launch operations they won’t have the experience to operate the system safely, and whose costs will vacuum out the funds which might have been used to build payloads which would extend the human presence into space.

The lesson of this is that when the first humans set foot upon Mars, they will not be civil servants funded by taxes paid by cab drivers and hairdressers, but employees (and/or shareholders) of a private venture that sees Mars as a profit center which, as its potential is developed, can enrich them beyond the dreams of avarice and provide a backup for human civilization. When the history of that great event is written, I trust it will be as exciting to read about as the chronicle of dead-end, government space programs is exasperating.

Regardless, this is an excellent history of the first half century of manned Mars mission planning. Although many proposed missions are omitted or discussed only briefly, the evolution of mission plans with knowledge of the destination and development of spaceflight hardware is described in detail, culminating with current NASA thinking about how best to accomplish such a mission. This book was published in 2001, but since existing NASA concepts for manned Mars missions are still largely based upon the Design Reference Mission described here, little has changed in the intervening fifteen years. In September of 2016, SpaceX plans to reveal its concepts for manned Mars missions, so we’ll have to wait for the details to see how they envision doing it.

As a NASA publication, this book is in the public domain. The book can be downloaded for free as a PDF file from the NASA History Division. There is a paperback republication of this book available at Amazon, but at an outrageous price for such a short public domain work. If you require a paper copy, it’s probably cheaper to download the PDF and print your own.

Portree, David S. F. Humans to Mars. Washington: National Aeronautics and Space Administration, 2001. NASA SP-2001-4521.

Here is Disney’s 1957 Mars and Beyond illustrating the von Braun and Stuhlinger concept for a Mars mission.

The Mars Underground is a 2007 documentary film about the history of Mars mission planning featuring the efforts of Ricochet contributor Robert Zubrin in developing and promoting the “Mars Direct” concept for a lightweight Mars mission using existing technology.

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There are 29 comments.

  1. Randy Webster Member

    I was counting on canals. After all, Heinlein said they were there.

    • #1
    • June 11, 2016, at 11:10 AM PDT
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  2. John Walker Contributor
    John Walker Post author

    Randy Webster:I was counting on canals. After all, Heinlein said they were there.

    Well, this one is pretty impressive. Valles Marineris is 4000 km long, 200 km wide, and up to 7 km deep. This is about ten times the size in each dimension as the Grand Canyon on Earth. It’s so big compared to the size of Mars, that from one canyon wall the other is over the horizon, and from the centre of the widest part, both walls are over the horizon.

    Valles Marineris on Mars

    • #2
    • June 11, 2016, at 11:30 AM PDT
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  3. Randy Webster Member

    John Walker:

    Randy Webster:I was counting on canals. After all, Heinlein said they were there.

    Well, this one is pretty impressive. Valles Marineris is 4000 km long, 200 km wide, and up to 7 km deep. This is about ten times the size in each dimension as the Grand Canyon on Earth. It’s so big compared to the size of Mars, that from one canyon wall the other is over the horizon, and from the centre of the widest part, both walls are over the horizon.

    Valles Marineris on Mars

    Do they have any idea what caused it?

    • #3
    • June 11, 2016, at 11:38 AM PDT
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  4. John Walker Contributor
    John Walker Post author

    Randy Webster: Do they have any idea what caused it?

    Nobody really knows. After it was discovered in 1971, it was originally thought to have been caused by catastrophic flooding like the canyons in the northwest of the U.S. The most accepted theory now is that it is a crack in the surface like the East African Rift valley on Earth, which may have been enlarged by flowing water and erosion of the rift walls. It may be related to the giant shield volcanoes of the Tharsis Bulge, which lies to its west.

    We’ll probably never know for sure until field geologists with rock hammers and sample bags start to explore it in situ.

    • #4
    • June 11, 2016, at 11:53 AM PDT
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  5. Gary McVey Contributor

    I’m also old enough to remember the disappointment of seeing the Mariner photos (as I recall, John has an earlier post about the persistent problems we had getting the Moon impact and Mars flyby probes working correctly), and also the elation of seeing the Viking lander imagery. We didn’t have a shuttle flying in time for the Bicentennial, but pictures of a sunny, utterly “normal”-looking day on Mars helped make up for it.

    It was about that time that we ordinary people in general began thinking of planetary exploration as likely to be robotic, not human. After Apollo there was, in retrospect, surprisingly little public agitation to keep the program reaching farther.

    It took me years to realize the obvious: there wasn’t going to be “ad ares” for many, many years, if ever, and no “ad astra” in any likely timeframe less than centuries. Space travel, as a practical matter is simply Moon travel and Mars travel; there are no other destinations for the foreseeable future. Yes, I know I’m now hostage to that word “foreseeable”. Anyone perfecting transwarp drive can make me eat my words.

    (Yeah, there’s “land on a comet”; big deal).

    • #5
    • June 11, 2016, at 12:35 PM PDT
    • Like
  6. Percival Thatcher

    Willy Ley. There’s a name I haven’t encountered in decades.

    He had a science column that appeared in Galaxy when I was a kid. That and the one written by Isaac Asimov in Science Digest made up a lot of my early interest in science.

    John Walker: President George H. W. Bush announced the Space Exploration Initiative on July 20th, 1989, the 20th anniversary of the Apollo 11 landing on the Moon. This was, in retrospect, the last gasp of the “Battlestar” concepts of missions to Mars. It became a bucket into which every NASA centre and national laboratory could throw their wish list: new heavy launchers, a Moon base, nuclear propulsion, space habitats: for a total price tag on the order of half a trillion dollars. It died, quietly, in congress.

    A trillion here — a trillion there — pretty soon you’re talking real money.

    • #6
    • June 11, 2016, at 12:38 PM PDT
    • Like
  7. Randy Webster Member

    The discovery of a warp drive, if one is possible, is likely to be serendipitous, much like jaunting in Alfred Bester’s The Stars My Destination

    • #7
    • June 11, 2016, at 12:42 PM PDT
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  8. Dan Hanson Thatcher

    Great article again, John.

    I’d love to see a manned mission to Mars, but I think the notion of a self-sustaining human colony there is fanciful. Or at least, it’s fanciful until we can terraform the atmosphere into something we can breathe naturally, get rid of the perchlorates in the soil, warm the planet, and in general create conditions where humanity could survive without a high technology infrastructure. We currently don’t know how to do any of these things.

    So long as people need high tech to survive there, a Mars colony could never be self-sustaining. A self-sustaining technological society needs millions of people, and there’s no way we are going to be able to send that kind of mass to Mars, or the mass required to sustain them while they become self-sufficient.

    In addition, the short launch windows and long distance means we’re never going to be able to establish a constant rhythm of missions, which has implications for cost and safety.

    A Mars colonization effort might start with a manned permanent base that has to be constantly replenished with supply missions much like the ISS. That base might act as a research station to study Martian geology, look for life, and prove out techniques for making fuels, terraforming, etc. A small colony like that would be entirely dependent on the Earth for hundreds of years, if not thousands. It would also have to survive numerous regime changes on Earth, governments hostile to the concept, funding crunches, wars, and anything else that might cause support for such a colony to be withdrawn. Does anyone think that’s likely?

    I think the most likely result is another Yucca Mountain or Superconducting Supercollider – something we’ll spend billions of dollars on, then abandon as soon as a government hostile to the concept is elected.

    Doing it with private industry partially avoids the government problem (regulation could still do them in), but it then requires the company to survive for that long, long time frame. Have a look at how many businesses that made up the original Fortune 500 are still around… So then the only other way to ensure its survival is to develop a market of profitable goods or services that require a Martian colony. I can’t think of any.

    I just don’t see a path forward to any kind of autonomous human civilization on Mars, which is Elon Musk’s goal.

    Still, Mars is a worthy target for human exploration. Just don’t count on it being the place where we establish a multi-planet civilization.

    • #8
    • June 11, 2016, at 1:37 PM PDT
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  9. Basil Fawlty Member

    Randy Webster:I was counting on canals. After all, Heinlein said they were there.

    Canals? What about the Bouncers?

    • #9
    • June 11, 2016, at 3:17 PM PDT
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  10. Basil Fawlty Member

    Randy Webster:The discovery of a warp drive, if one is possible, is likely to be serendipitous, much like jaunting in Alfred Bester’s The Stars My Destination

    Gully Foyle is my name

    And Terra is my nation

    Deep space is my dwelling place

    The stars my destination.

    • #10
    • June 11, 2016, at 3:23 PM PDT
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  11. Jules PA Member

    Great post. So interesting to read. Thank you!

    • #11
    • June 11, 2016, at 3:38 PM PDT
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  12. Randy Webster Member

    Basil Fawlty:

    Randy Webster:The discovery of a warp drive, if one is possible, is likely to be serendipitous, much like jaunting in Alfred Bester’s The Stars My Destination

    Gully Foyle is my name

    And Terra is my nation

    Deep space is my dwelling place

    The stars my destination.

    You’re making me want to go read it again.

    • #12
    • June 11, 2016, at 3:54 PM PDT
    • Like
  13. John Walker Contributor
    John Walker Post author

    Dan Hanson: I just don’t see a path forward to any kind of autonomous human civilization on Mars, which is Elon Musk’s goal.

    Colonies have always failed—most do. But there are always colonists willing to give a try because their hope for the new land is better than what they’re putting up with in the old country.

    As the circle closes on Earth and the scope of liberty inexorably contracts, it wouldn’t surprise me if there were plenty of people willing to roll the dice as opposed to consign themselves to serfdom.

    But first we need to go there and see what’s involved in living off the land. We know almost nothing about what’s below the top level of the regolith: is there ice, non-reactive material, or what? Can you actually grow potatoes?

    Fortunately, it won’t cost taxpayers anything to find out. Entrepreneurs will try, and fail, and try and fail again until somebody succeeds. That’s how it’s always worked for human expansion into new territories and environments.

    • #13
    • June 11, 2016, at 3:54 PM PDT
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  14. Tom Meyer, Common Citizen Contributor

    John Walker:Well, this one is pretty impressive. Valles Marineris is 4000 km long, 200 km wide, and up to 7 km deep. This is about ten times the size in each dimension as the Grand Canyon on Earth. It’s so big compared to the size of Mars, that from one canyon wall the other is over the horizon, and from the centre of the widest part, both walls are over the horizon.

    I recall reading somewhere that, stand at one wall of the main caldera on Olympos Mons (37×50 mi wide, 2 mi deep) that you could not see the other, but playing around with the Mars module on Google Earth appears to indicate otherwise.

    Screen Shot 2016-06-11 at 7.59.09 PM

    Still, it hardly looks like you’re at the top of the solar systems largest volcano.

    • #14
    • June 11, 2016, at 5:00 PM PDT
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  15. civil westman Inactive

    Thank you for another fascinating post, John. In an odd coincidence, I spent several hours before your post appeared reading about: Mars missions! There are a number of novel approaches out there. One I hadn’t heard of is launch from pre-supplied distant retrograde (lunar) orbit (DRO). From there, the delta V to escape from Earth gravity well is much smaller. In addition, various other permutations to shorten the travel time, including one by the Russians, using a nuclear propulsion system which would cut the mass and time requirements to Mars orbit in half.

    Surely, some will go and, I suspect, sooner than is generally thought. I also believe the number of those willing to undertake a one-way trip will only grow. As life on Earth reaches progressive-MAX a one way escape to Mars may well become a tempting alternative, with more degrees of freedom. There, constraints will be only related to physical survival; political correctness, as thin as the atmosphere and administrative mass well below 0.4G.

    • #15
    • June 11, 2016, at 5:09 PM PDT
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  16. John Walker Contributor
    John Walker Post author

    Tom Meyer, Ed.:

    John Walker:Well, this one is pretty impressive. Valles Marineris is 4000 km long, 200 km wide, and up to 7 km deep. This is about ten times the size in each dimension as the Grand Canyon on Earth. It’s so big compared to the size of Mars, that from one canyon wall the other is over the horizon, and from the centre of the widest part, both walls are over the horizon.

    I recall reading somewhere that, stand at one wall of the main caldera on Olympus Mons (37×50 mi wide, 2 mi deep) that you could not see the other, but playing around with the Mars module on Google Earth appears to indicate otherwise.

    Screen Shot 2016-06-11 at 7.59.09 PM

    Still, it hardly looks like you’re at the top of the solar systems largest volcano.

    I don’t recall working out the case of standing on the caldera, but I do remember working out that if you were standing on its edge, the terrain surrounding the shield volcano would be below the horizon and that, conversely, if you were standing at its base, the summit would be over the horizon. This deflated some breathtaking scenery in a novel set on Mars I was asked to fact check. The author dropped the passages which didn’t agree with martian terrain, and the book worked just as well without them.

    Mars is a small planet, and landscapes just don’t work the way we’re used to on Earth.

    • #16
    • June 11, 2016, at 5:12 PM PDT
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  17. TeamAmerica Member

    John, in comment 13, what do you mean by non-reactive material?

    • #17
    • June 11, 2016, at 7:10 PM PDT
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  18. Dan Hanson Thatcher

    John Walker:

    Dan Hanson: I just don’t see a path forward to any kind of autonomous human civilization on Mars, which is Elon Musk’s goal.

    Colonies have always failed—most do. But there are always colonists willing to give a try because their hope for the new land is better than what they’re putting up with in the old country.

    As the circle closes on Earth and the scope of liberty inexorably contracts, it wouldn’t surprise me if there were plenty of people willing to roll the dice as opposed to consign themselves to serfdom.

    But first we need to go there and see what’s involved in living off the land. We know almost nothing about what’s below the top level of the regolith: is there ice, non-reactive material, or what? Can you actually grow potatoes?

    Fortunately, it won’t cost taxpayers anything to find out. Entrepreneurs will try, and fail, and try and fail again until somebody succeeds. That’s how it’s always worked for human expansion into new territories and environments.

    I totally agree: I just think Mars is the wrong initial target. When you posted this I was working on a similar article, except I think the colonization effort should be focused on the Moon. Without spoiling the post, I think I can make the case that self-sustaining widespread colonization is orders of magnitude easier on the Moon than it is on Mars, and it’s achievable in a much shorter time frame.

    • #18
    • June 11, 2016, at 8:19 PM PDT
    • Like
  19. TeamAmerica Member

    John, I had a computer science professor at Rutgers in the early eighties who had worked at NASA programming guidance systems on Martian probes. His name was Thomas Talbot. Did you know him by any chance?

    • #19
    • June 12, 2016, at 1:49 AM PDT
    • Like
  20. John Walker Contributor
    John Walker Post author

    TeamAmerica:John, in comment 13, what do you mean by non-reactive material?

    The Viking landers carried four biological experiments intended to detect the presence of microbial life on Mars. One of these experiments, Labeled Release (LR), produced results which, according to the protocols established before the mission, indicated the presence of life through the emission of metabolic products when martian soil was placed a nutrient tagged with radioactive carbon-14. These results are still controversial.

    At the time they were very confusing because another of the experiments, the Gas Chromatograph — Mass Spectrometer, failed to detect any organic (carbon-containing) molecules in the martian soil it analysed. It was difficult to understand how organisms which metabolised carbon-based nutrients could not themselves be composed in part of carbon.

    The LR results were explained, at the time, by most scientists (but not the principal investigator for the experiment, Gilbert Levin), as being due to a non-biological chemical reaction between some component of the soil and the nutrient medium. Because the martian atmosphere has no ozone layer, ultraviolet radiation from the Sun reaches the surface, and, reacting with minerals in the soil, may form superoxide compounds, probably with the iron known to be present. These compounds are highly toxic to living things (as is the ultraviolet radiation itself), and were believed to be able to have mimicked the results of the LR experiment.

    In 2008, the Phoenix lander detected perchlorate, another strong oxidiser, which might have caused the Viking lander results. In 2013, an experiment showed that perchlorates irradiated by gamma rays as might be found on the martian surface could reproduce the LR results.

    These results suggest that the top level of the martian surface contains compounds, produced through interactions with solar ultraviolet radiation and/or cosmic rays, which are highly chemically reactive (oxidising) and toxic to life. But these reactions would affect only the surface. A few centimetres below the surface, the reactive components may be absent and the composition of the soil hospitable to life. This is an unsettled question at present, because no life detection experiment has been sent to the surface of Mars since the Viking landers in 1976.

    (Note on terminology: Mars researchers use the term “martian soil” for the material that makes up the surface of the planet. Earth-oriented geologists and biologists reserve the term “soil” for material with organic content, and call what is found on the surface of the Moon “regolith”. We don’t know enough about the surface of Mars to decide whether it meets the more restricted definition of soil.)

    • #20
    • June 12, 2016, at 6:28 AM PDT
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  21. John Walker Contributor
    John Walker Post author

    TeamAmerica:John, I had a computer science professor at Rutgers in the early eighties who had worked at NASA programming guidance systems on Martian probes. His name was Thomas Talbot. Did you know him by any chance?

    No, I never met him. I worked with the systems programmers maintaining the operating system and system software (Fortran compiler, etc.), and we didn’t have much contact with the scientists, engineers, and mission operations people who used the mainframes for which we were responsible.

    • #21
    • June 12, 2016, at 6:31 AM PDT
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  22. John Walker Contributor
    John Walker Post author

    Dan Hanson: I totally agree: I just think Mars is the wrong initial target. When you posted this I was working on a similar article, except I think the colonization effort should be focused on the Moon. Without spoiling the post, I think I can make the case that self-sustaining widespread colonization is orders of magnitude easier on the Moon than it is on Mars, and it’s achievable in a much shorter time frame.

    Steven D. Howe’s book Honor Bound Honor Born presents the case for energy-rich lunar colonisation. (I reviewed it here, but I’ve linked to the review on my own site since the review is on the Member Feed and can’t be read by non-members.) He makes the case that if energy is abundant, the lunar regolith (which we understand very well) can be processed into many of the materials required to sustain a colony.

    But if the colony is to be truly self-sufficient, I don’t see how you can get past the near-total absence of carbon and nitrogen on the Moon. Those are two of the big four biological elements (C H O N). Further, the only expected source of hydrogen would be ice trapped in perpetually dark craters, and we haven’t confirmed its abundance or in what form it is present. Any growing lunar colony is going to need to import at least carbon and nitrogen, forever. Plenty of these elements are available in the asteroid belt, but it isn’t clear that delivering them to the Moon is less difficult than going to Mars, where all of the biological elements are available.

    • #22
    • June 12, 2016, at 7:11 AM PDT
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  23. RktSci Member

    Dan Hanson:

    … there’s no way we are going to be able to send that kind of mass to Mars, or the mass required to sustain them while they become self-sufficient.

    In addition, the short launch windows and long distance means we’re never going to be able to establish a constant rhythm of missions, which has implications for cost and safety.

    The missions with people onboard are likely to need to be minimum-time orbits, which have the 26 months apart launch windows. However, bulk supplies can use longer, but less fuel-intensive transfers, such as a “ballistic capture” orbit. You can use highly efficient propulsion such as ion drives or (possibly) solar sails. Think of it as using a 767 to get the crew there and sending the bulk supplies by container ship. Buzz Aldrin has proposed using “cycling” spacecraft that loop back and forth, but I’m not sure that they are feasible.

    Back in the day, I did some analysis work on robotics for lunar bases at Johnson Space Center, and worked on Bio-Plex, a full size mockup of a Mars base. Bio-Plex was going to test recycling and food production systems. Alas, just as the structures were built, the whole thing was shut down.

    One comment on “The Martian” movie – the base and transfer ship concepts were pretty good with one exception – they were way too roomy inside. Think submarine, not cruise ship accommodations.

    • #23
    • June 12, 2016, at 9:22 AM PDT
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  24. civil westman Inactive

    RktSci:One comment on “The Martian” movie – the base and transfer ship concepts were pretty good with one exception – they were way too roomy inside. Think submarine, not cruise ship accommodations.

    Yes! I kept saying to my wife as we watched the movie – “No way there would be that much space in the various modules!” Of course, the book did not exhibit this problem.

    • #24
    • June 12, 2016, at 10:24 AM PDT
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  25. John Walker Contributor
    John Walker Post author

    RktSci: One comment on “The Martian” movie – the base and transfer ship concepts were pretty good with one exception – they were way too roomy inside. Think submarine, not cruise ship accommodations.

    Absolutely—I loved the gym in the Hermes transfer craft where they had two rowing machines. You’d think the crew would be able to share one. Even Andy Weir (author of the novel) laughed when he saw that.

    The Martian was largely based upon the NASA Mars Design Reference Mission (DRM), except the Earth Return Vehicle of the DRM was replaced by the Hermes, an Aldrin cycler, in a permanent orbit looping back and forth between Earth and Mars on a 26 month cycle. Since the cycler would be reused for successive missions rather than thrown away each time, its facilities could be more luxurious than those in the DRM craft, but nothing like those in the movie. The habitat was also scaled up from that in the DRM, since there wouldn’t be enough room otherwise for the potato farm.

    Here is a video of Andy Weir, Adam Savage of Mythbusters, and astronaut Chris Hadfield talking about fact and fiction in The Martian.

    • #25
    • June 12, 2016, at 11:23 AM PDT
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  26. RktSci Member

    When I was working on Bio-Plex at JSC, we had a couple of former USN submarine crew on staff and as part-time consultants. They helped do the layout of the crew quarters and common areas. The largest chamber, the food production area was going to be very tight quarters to get around in. It was multiple levels of hydroponic trays to grow wheat, soy, and rice. There was also a section for the “salad machine” to grow tomatoes and lettuces.

    It it had proceeded, there would have been a series of 30, 90, and 180 day missions, culminating in a 500+ day mission to simulate the full time of a mission that stayed to the next launch window. The crews would have been made up of volunteers from the JSC community and would have swapped out after 90 days.

    One other thing they got wrong in “The Martian”. The spacesuits had nametapes on the front. That’s not enough, as they found out on Apollo 11. The ground people were constantly losing track of who was who on the video feed. You need something to ID people at a distance, so on later missions the commander’s suit has a red band on the right upper arm. For shuttle and ISS, there is also a red band on the right leg.

    • #26
    • June 12, 2016, at 2:14 PM PDT
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  27. Randy Webster Member

    My physics isn’t very good, but even I know that boosting a bunch of useless metal around the solar system is expensive.

    • #27
    • June 12, 2016, at 2:42 PM PDT
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  28. Dave Bagby Member

    Fine article. I suspect that the most significant factor in determining the future of space travel will be developing a far hardier type of human being. At present humans in space are like soap bubbles floating in the air at a child’s back yard birthday party. The slightest hiccup can result in a major deviation from path or even catastrophe. For example, 70% of all seizure disorders are of unknown cause. Sure, histories can be taken, screenings and genetic testing done, etc., but things happen. No doubt pharmacology is taken into account when planning for long space trips but just because a drug is available doesn’t mean it will be effective in any given case. Pancreatic cancer can develop and be terminal very quickly without extremely time and resource consuming, highly technical, intervention. What then?

    • #28
    • June 14, 2016, at 12:12 PM PDT
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  29. John Walker Contributor
    John Walker Post author

    Dave Bagby: I suspect that the most significant factor in determining the future of space travel will be developing a far hardier type of human being. At present humans in space are like soap bubbles floating in the air at a child’s back yard birthday party. The slightest hiccup can result in a major deviation from path or even catastrophe.

    The people who go on early voyages to Mars will be the kind who embarked on long ocean voyages in the age of sail. See Two Years Before the Mast; a voyage from the east to west coast of North America around Cape Horn was as long as a trip to Mars, and with as little hope of rescue in case of sickness or failure of equipment. It was not unusual for one or more crew members to die en route due to accidents or illness, and a fraction of ships on the route went missing without any indication of the cause.

    Elon Musk has said,

    It’s dangerous and probably people will die—and they’ll know that. And then they’ll pave the way, and ultimately it will be very safe to go to Mars, and it will very comfortable. But that will be many years in the future.

    • #29
    • June 14, 2016, at 12:25 PM PDT
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