PLEASE SEE THE REVISED VERSION OF THIS CHAPTER.
After receiving many comments from my article, “Mars One: Exciting Adventure or Hoax?“, and exploring many issues of any such undertaking as well as the specifics of Mars One, I have decided that the conversation has become increasingly technical and therefore less interesting to our readers. In order to make our conversation more interesting and to bring more people into the conversation, I am presenting a series of episodes in a fictional future in which the first permanent settlers will arrive on Mars. While Mars One and our discussion have generated many of the ideas, this series does not claim to have a relation to any specific Mars settlement program. It just explores the issues involved in such a venture.
For the purposes of making the exposition and discussion more real, I will name the first four humans to arrive on Mars: Aleka (Hawaiian female: aka Allie) is the flight-trained captain, Balasubramian (Indian male: Balu for short and Bob among the crew) has the crucial survival role of botanist, Chun (Chinese female: aka Chunnie) functions as the engineer, and Dawit (Ethiopian male: everyone just calls him Dave) is the mission communicator. For the purposes of having a broad gene pool, the early settlers have genetic roots that include a worldwide geographical scope of origins.
I’d like to encourage you all to participate. Each chapter will end with a problem that must be solved. I am interested in seeing ideas different from the ones I imagine and may rewrite future chapters if better answers are submitted. If you are a science teacher at any level, please consider discussing these issues in your classes. We’re nearing the end of the school year now, and this sort of discussion may work nicely with the end-of-year mentality that you encounter. A fun, open discussion can make science come alive for students. Use NASA images to liven things up. -Harry E. Keller
s the Google Mars shuttle continues its weeks-long deceleration toward its incredible destination, the crew of four busily checks the instruments on the attached Citigroup crew module where they have lived and worked for four months. They are so involved in monitoring not only their own module but also the Royal Dutch Shell supply module that they momentarily forget they’re about to become the first humans ever to set foot on another planet. The shuttle holds the two attached modules like a parent carrying twins in both arms. The configuration of shuttle and two landing modules may look awkward but creates no impediment to travel in the vacuum of space.
Four years of training guarantee that the anxious crew all know their roles in this landing precisely. The captain, Aleka (Allie), is the only flight-trained pilot on the mission, but all of them have spent countless hours in the landing simulator and can take over if necessary. Redundancy has been the watchword of the Mars mission from the very beginning.
For the landing at Amazon base, however, there could be only one crew module. Everything depends on its successful entry into the absurdly thin Mars air, about 1% of the density of that on Earth and containing 95% carbon dioxide, followed by the powered descent to the surface. Ordinary chemical rockets slow the landers as they approach the surface where the gravity is 38% of that of Earth. While the low gravity means that less fuel is required for descent, it still is strong enough to kill everyone if the landing module crashes. Every element from the heat shield and parachute to the landing engines must function perfectly for a safe landing.
After the braking rockets have done their job, the landers will coast downward and be positioned bottom first so that the heat shield faces the thin air at a speed of nearly six kilometers per second, well beyond the speed of sound. The air slows the landers until they finally begin to drop more directly toward the surface. Careful steering during the heat-shield portion of the descent should put the landers near their landing sites. Next, the large artificial fiber parachute helps to slow the descent even in the thin Martian air. Eventually, this parachute will be recovered and used by the settlers. On Mars, the motto is “Waste not, want not.” The heat shield also drops to the surface. The landers are now falling toward the surface at a speed of about 100 meters per second, roughly the terminal velocity on Mars. The final landing uses the “grasshopper” technology pioneered by SpaceX so many years before.
Five modules have already arrived on Mars during three previous trips of the Google Mars shuttle. These modules contain crucial supplies, machinery, and living space. The Toyota greenhouse module will be crucial to long-term survival. The first two rovers, Sinopec and Gazprom, all-purpose vehicles sent in the space normally occupied by one module, already have slowly moved the modules close enough together so that the settlers can complete the linking of them into a total habitat manually. Once the last two modules have landed safely, the crew will begin final assembly into a working habitat
The module design includes means to move them on the rock-strewn Martian surface. Ultra-lightweight caterpillar treads made of composite plastic/nanofiber that extend after landing allow for slow module mobility. They have low-friction bearings to allow the low-powered rovers to move them over reasonably level surfaces. Once the modules are placed permanently, these treads will be scavenged for use internally as shelves and other purposes.
“Final pre-separation check,” snaps Allie as the about-to-be Martians go through procedures necessary to ensure a clean separation from the shuttle. The two modules will be left behind by the shuttle as it continues on its pre-programmed trajectory back to Earth orbit for refueling, refurbishing, and acquisition of another cargo in preparation for the next encounter with Mars in two years. Allie glances out of the small thick window and sees the edge of the red planet against the black of space with its countless bright point lights of stars strewn haphazardly across its seemingly infinite reaches as though a child had thrown diamonds on a vast expanse of black velvet. A few weeks earlier, the entire crew was excited to see the small red dot of Mars expand and grow into a shiny red penny in the black, deep expanse of space – nearly 14 billion light-years deep, far beyond human imagination. Now, it fills most of one side of their view. Earth has receded to a pale blue dot, left forever to the billions living there. A new world awaits. Will the humans or the planet triumph?
Balasubramian (Bob to his crewmates) checks that the elevation radar and computer surface recognition software are functional and ready for the descent. “A-OK,” he sings out, mimicking the astronauts of a half century ago. Extensive mapping of the Mars surface has made it possible to pinpoint landing sites with feature-recognition software operating with high-resolution cameras. Automated guidance systems will take the crew module to within 500 meters of the surface where Allie will take over for the final landing. The human touch still provides a safer landing than machines can perform. The very difficult task of guiding the craft to the right spot requires so many on-the-fly calculations to ensure minimal use of precious fuel that computers do all of that flying unless there’s an unexpected emergency.
With over a billion people watching, this is the most watched event ever on television, far more than the most recent World Cup. While many do not own television sets, they still flock to bars and public squares. The latter have been provided with large television screens in many of the larger towns across the world. Millions may be watching on their mobile telephone screens or the new voice-tablets, called VTs in an odd reversal of the abbreviation for television from nearly a century ago, which have supplanted earlier tablets and, now, laptops. This will be the first time that a human has set foot on another planet, the first anthropod on Mars ever.
Chun (aka Chunnie) is watching the fuel pressure gauges and will monitor the engines as they begin the initial braking burn right through to the final moment of landing when the engines will forever become silent. “All systems go for descent,” she intones in a clear monotone of her unaccented English resulting from growing up near San Francisco. The engines will mix liquid oxygen and liquid hydrogen, ignited by a spark, to produce the fiery thrust to slow the module down and then to drop it gently on the Mars surface. Large quantities of water will be dumped into the Martian atmosphere just as has happened three times previously and will happen again in two years when the second group of intrepid pioneers leave Earth for their final home on a very alien planet. Remaining fuel will find use as reserve oxygen and, under more controlled conditions, as the raw materials for making water.
Dawit sees to all telemetry and communications. He’s already ensured that the systems on the planet are ready and nominal. He must now make sure that the people back home see the entire process in the highest possible resolution. While the relative nearness of Earth and enormous advances in video recording and telemetry make possible high-resolution video, the bandwidth available for this long-distance, deep-space transmission allows for only one feed at a time. Dave, as the world knows him, must act as a sort of television show director and decide on a moment-to-moment basis which of the live video feeds to send to Earth. All are being recorded and will be sent eventually for the documentaries that will be produced. The people on Earth will be viewing the images six minutes after they happen, but no one cares about that delay caused by the finite speed of light. The signals from Mars will travel at 300 million meters per second back to Earth – but no faster or slower. That speed is unaffected by the relative velocities of Earth and Mars, a result of Einstein’s Special Theory of Relativity.
The upcoming moment of hoped-for triumph has been a decade in planning. The most difficult part of the entire project has been ensuring adequate funding for the many very expensive aspects of the undertaking. From the beginning of selecting those who would go to Mars, the entire project has been televised 24/7 on a pay channel with commercials to generate the billions of dollars necessary. Naming rights have been sold to large corporations. Thus, the Mars shuttle that has been and will continue to be seen leaving Earth orbit every two years was named the Google Mars shuttle. The producers of all of the television being transmitted around the world and translated into a dozen languages guaranteed that the Mars shuttle would not be mentioned on television without being called the “Google Mars shuttle.” Every visible man-made portion of the program has a corporate sponsor name. In this manner, a billion dollars was raised early in the program and a guarantee of hundreds of millions of dollars more every year that the program continued successfully.
Major events were not only shown on the Mars Channel but also sold to networks and cable channels. All told, over ten billion dollars had been raised before this landing. Another billion will funnel into the mission coffers over the next two years as the second manned mission prepares to go again boldly where people had never gone before – if this mission lands successfully and survives.
The landing is the easy part despite a very complex process in which a myriad of things could go wrong. Landings have been managed before. They’re not new. Soft landings are the hardest and most challenging, but also are not new. Six modules already have landed successfully, although they could withstand a stronger impact than the members of the crew could live through. The landing must not crack the Citibank crew module, with its logo prominently displayed on the outside, although the crew has donned their spacesuits in case of loss of air. A soft landing is crucial because even though a hard landing may not kill the crew outright, it would threaten survival and may injure them so much that they will be unable to perform the strenuous tasks of habitat assembly and set-up required to survive.
That’s the truly difficult part of this unique-in-history exercise – survival. So much must go right, and so much can go wrong. As the settlement grows, the margin of error will expand and allow for mistakes and failures. Right now, four people, with a large fraction of Earth’s population watching, must have everything go right. Even a small mistake will place the entire mission, along with the four pioneer settlers, in danger. Will their training and native ingenuity get them past their inevitable problems? Only time can tell, and the Earth is watching their every move.
As the two landing modules decouple from the shuttle, pulses are racing above Mars and on Earth, literally across the entire globe. The crew uses control vents to increase the separation of the modules from each other and then fires engines to slow down below orbit velocity. The shuttle adjusts its path slightly so that it can use the Mars gravity well as a slingshot to aim it on the trajectory that takes it back to Earth orbit. It begins using its ion-propulsion engine to accelerate, a process that will continue for months as it slowly uses its reaction mass to reach high speeds. It will coast for a very long time and then flip around and begin to decelerate after passing the half way point. There’s no rush, and coasting saves on the total system mass during the trip to Mars. The energy comes from its nuclear reactor, which has more than enough for the purpose. Only the liquid hydrogen supply limits its ability to continue its acceleration indefinitely. The amount has been carefully calculated to allow the shuttle to go to Mars with its cargo and then to return to Earth for refueling and refurbishing in preparation for the next flight to Mars.
All systems are nominal on the crew module as it goes through the complex steps of its landing process. Allie makes adjustments that ensure the closest possible landing to the unconnected habitat modules. Once they land, time becomes important. The crew module and Mars suits can sustain them for a few sols (Martian days), but they absolutely must connect to the other modules with all of their machinery and supplies as early as they can, and it’s a slow process in the awkward suits and with the slow-moving rovers.
On the unmanned supply module, making its way down to land nearby, a cosmic ray hits the housing of a microchip. Such hits happen rather often in space, but this time is different. Cosmic rays are mostly protons of extremely high energy moving at near light speed and can pass through matter, which looks relativistically very thin from their “viewpoint” due to Lorentz contraction, without much interaction. Occasionally, one hits the nucleus of an atom in the material it’s traversing. Matter, even solid lead, is mostly empty space with electron clouds filling it very tenuously. Incredibly tiny atomic nuclei are scattered around, in a regular pattern in crystals, like motes of dust in the air – only smaller and fewer. When a cosmic ray proton hits one of these nuclei, much of its tremendous energy is converted into mass according to Einstein’s famous equation, E = mc2, a miniature version of an atomic bomb. A shower of very energetic, newly created particles rains down on whatever is below, shotgun style.
One of these shower particles hits a microscopic transistor in the microchip and flips a bit. Another hits a different transistor, the redundant partner to the first, and has the same effect, a million-to-one chance event. Bits are the language of computers and can either be a 0 or a 1. Changing a single bit can make either an insignificant difference or a major change in what the computer does. In ASCII code, used to represent written characters in some computer systems, a single bit can change an “A” to a “Q.” A different bit change could result in a “@.” In the supply lander’s computer, the change altered an instruction causing the supply lander to mistake the terrain nearby for the actual landing site. It landed perfectly safely – but over five kilometers away instead of the 100 meters planned.
Five kilometers would not be a large problem on Earth. It’s only about a half-hour’s leisurely walk. Things are different on Mars. The Curiosity Mars rover could travel at 90 m/hr using its RTG (radioisotope thermoelectric generator) power. Improvements since then haven’t changed the speed much, especially because the rovers being used by the settlers are heavier than Curiosity was. Just imagine taking an hour to walk the length of a sports field or pitch a distance that sprinters can run in ten seconds. At a speed of around 100 m/hr (0.10 km/hr), it takes one of the two new rovers 50 hours to reach a site five kilometers distant. The Mars day is only 40 minutes longer than an Earth day meaning that the trip will require over two sols each way, but the return trip requires pushing the supply module and will take longer.
The settlers cannot survive on the Mars surface for that long, even in their Mars suits equipped with the most advanced imide aerogel insulation. Such long EVAs (extra-vehicular activity – some acronyms persist even when the literal meaning no longer applies) were never considered as part of the suit design. In fact, the batteries will only maintain temperatures for ten hours. Oxygen supply and, more importantly, carbon dioxide removal, are similarly limited. Water is also in limited supply and is not recycled in the suits, but you can go for a few days without water. Earth designers are working on a rover that will run on batteries charged from the extensive solar arrays the settlement will have along with air and water capability for long trips on the harsh Mars surface. These trips will raise more funds by allowing scientific research and save NASA and other countries’ space agencies vast sums of money. For now, the settlers much make do with what they have.
The supply module is crucial to longer survival on the planet. It contains supplies, especially food to tide the settlers over until their farm begins producing, that must be available. In one month, the situation will become dire. That module must be retrieved within four weeks. Even before retrieval, the settlers must connect the remaining modules, deploy the solar collectors, and get all air, water, and recycling facilities started. The time allowed for this purpose cannot be delayed.
The radiation shielding efforts were planned to take months and can wait even though one living unit should be shielded as soon as possible. The food growing operations can wait a day or so, although the group would love to have any fresh food as early as possible. The food stores, plant growing, and battery facilities of the missing module must be retrieved right away.
Completing the landing takes all of their attention even though they know they have a huge problem waiting when they land. The final braking runs smoothly, and they’re on Mars, the first humans ever to be there. It’s still morning on Mars, leaving plenty of time to complete post-landing procedures. Their module already has its treads down, and Gazprom is linking up to move the module into place. While being moved, the crew continues their checks and reports to Earth that all systems remain nominal. Finally, all four suit up and make final suit and module checks before depressurizing the module and stepping out. Dave will stay behind to handle communications.
With cameras on Sinopec beaming the event back to Earth, Allie steps out of the module onto the Martian surface. This moment has been planned for so long, required so much work, involved so many people. What to say to those back on their home planet? She would not echo the words of Neil Armstrong and say, “One small step for a woman; one giant leap for mankind.” That just would not do.
Once both feet were firmly planted on Martial soil, she spoke to the entire planet of Earth. “Greetings to the people of Earth on behalf of the first Martians. While we can only fervently wish for peace on Earth, we can and do declare peace with Earth now and forever.” Balu had joined her by now. Chun soon followed. Dave showed himself at the module hatch, and a picture of momentary triumph flashed across the vacuum of space, carried by photons, for all of the news organizations on Earth. Finally, well into the 21st century, we were on two planets. The team now splits up for work. There’s no time to lose.
Allie directs the crew to begin assembling the modules while using their comlinks to discuss ways to retrieve that missing module. A rover might or might not be capable of finding the wayward module on its own. It wasn’t designed to traverse uneven terrain for such long distances without help. The slower return trip lies even farther from its design parameters.
– end of chapter 1 –
Special note to our readers: Please consider all ideas, rational or irrational but definitely scientific, to solving the question of bringing that module back. The rovers are powered by RTGs and produce very little power, maybe 150 watts. They travel at a speed of 100 m/hr (that’s meters, not miles) when unburdened. Pushing or pulling a Mars module may approximately halve the speed.
Extra special note to science teachers: You might consider, in addition to the solution to this problem, how heavy the rovers (or how light the modules) have to be in order to push or pull the modules without slipping in the sandy, dusty Martian soil. Both the rovers and the modules have caterpillar-style treads on which they roll. As a starting point, the Curiosity rover has a mass of one metric ton. Estimate the module mass based on it being about 5 m in diameter and 3 m tall in a truncated cone shape and filled, but not solidly, with materials for use on Mars. Assume that both objects have the same style of treads and the same coefficients of friction. A really light rover might just spin its treads in the loose material, unable to move the large module mass. What is the actual speed that the combined rover and module can achieve if they can get moving?We at ETC Journal will be watching and responding as much as possible to your ideas. The next chapter awaits your pleasure.
Harry E. Keller