Author: Robert Walker, contact email robert@robertinventor.com

Finding an inspiring vision for the future that works whether or not humans can explore and colonize the surface of Mars in spacesuits

In my open letter to NASA, I talked about how NASA needs to plan in a more flexible way where we have a future that is inspiring and encourages space exploration and settlement for BOTH scenarios,

a future (such as no life or mutually benign life on Mars) where humans CAN SAFELY explore the surface of Mars in person
a future with limited quarantine and other measures for travel between the planets to keep out certain invasive species that would harm Earth’s biosphere, humans, or agriculture
a future (such as mirror life on Mars) where it is NEVER SAFE for humans to explore Mars in person - or at least, never return to Earth after doing so

We need to look at this with clear eyes. The reason we have to do planetary protection is because we don’t know which of those two scenarios we have on Mars.

See my executive summary of preprint

This page is to expand on that idea with a vision that works well for both approaches. We can explore Mars first from Earth - with more and more bandwidth and more and more assets on the surface. By the time we get humans to Mars orbit we have floating aerobots, marscopters, cavehoppers, gliders, rovers, subsurface moles drilling away and many other assets throughout Mars. The astronauts operate these from orbit once they get there, 100% safe for planetary protection both ways.

Text on graphic: 100% planetary protection both ways, even if Mars has vulnerable early life, prebiotic chemistry, or mirror life.

Using NASA’s remarkable Venus HOTTECH technology, all these surface assets can be built to withstand months at 500°C, and so are easily sterilized with a few minutes of heating on the journey out.

Main image: NASA, 2012 “Safely tucked inside orbiting habitat, space explorers use telepresence to operate machinery on Mars, even lobbing a sample of the Red Planet to the outpost for detailed study."

They are able to explore the surface of Mars without need for clumsy spacesuits and with enhanced vision. For instance the muddy brown of the surface turned into the attractive reddish landscapes we are used to from the colour adjusted photos of Mars. Enhanced colour. No problems with the corrosive and poisonous dust and so on.

And with high bandwidth everyone on Earth can join in with the explorations.

If the Mars colonization enthusiasts are correct in their confidence that any Martian life is safe for Earth and terrestrial life safe for Earth then this won’t even delay the landing, we’d want to explore from orbit first. If we make the decision to land humans on the surface of Mars we have all these assets already in place.

While if we are in a scenario where Mars has mirror life or other life that can never be returned to Earth, settlers in orbital settlements or on the Martian moons would first use pre-sterilized rovers but as the settlement develops, they would later make rovers in surface factories controlled as in the game of civilization. These would be free of any terrestrial life already since they were made on Mars.

We have places on Earth we can’t settle currently such as the deep ocean, even the shallow ocean is hard for us to inhabit, for now the atmosphere is hard to inhabit, we have only made a start on sea steading, and some places are well beyond current technology. We can’t explore down to the core of our planet as Jules Verne envisioned in his “Journey to the center of the Earth” (A Journey to the Center of the Earth). But we have never had a frontier due to biology.

TITLES OF SECTIONS ARE LIKE MINI ABSTRACTS

The title of each section also summarizes its main conclusions similarly to an abstract. You can get a good first idea by just reading the titles of sections - and looking at any graphics. Hover your mouse over the left margin of the page to see a floating menu of all the section titles.

I use hyperlinked inline citations in this open letter consisting of the title in brackets hyperlinked to the paper and then the page number after the title like this: (Mars Sample Return: Issues and Recommendations (1997) : pages 6 - 7)

NEED FOR OPTICAL COMMUNICATIONS FROM MARS - ESSENTIAL BEFORE HUMANS GET THERE AND WOULD INSTANTLY INCREASE SCIENCE RETURN - AS GOOD AS SENDING 17 EXTRA HIRISE SATELLITES AND MANY EXTRA ROVERS

We can do a lot of exploration from Earth using

fast semi-autonomous robots
high bandwidth communications.

Those are two of the three things that speed up telerobotic missions from orbit, the third being the low latency of humans in orbit.

At present the bandwidth is so low that even with a round trip latency which at its best is less than 7 minutes, Perseverance and Curiosity’s teams can only download data from the previous day which they then use to plan operations for the next day which they then send up in commands to Mars. It would be as easy to control a rover on Pluto with round trip latency of 11 hours as a rover on Mars! (NASA Mars Perseverance: A Sol in the Life of a Rover)

[In 2003, the distance was 55,758,006 km center to center (Mars Close Approaches Archives - NASA), or 186 light seconds (55758006 km in light seconds), round trip latency 6 minutes and 52 seconds]

Before we send astronouts to Mars orbit we’ll be able to achieve a huge speedup using a technique from multi-player online gaming called “artificial real time”. This requires a huge increase in bandwidth from Mars which we will need once we have astronauts in orbit there anyway and would make an ENORMOUS difference to Mars exploration science. HiRISE is limited in the number of photographs it can take of Mars mainly because of the bandwidth. It can only send back 6 Megabytes per second.

At MRO's maximum data rate of 6 megabits per second (Mbps) (the highest of any Mars mission), it takes nearly 7.5 hours to empty its on-board recorder and 1.5 hours to transfer a single image back to Earth that the onboard High Resolution Imaging Science Experiment (HiRISE) camera has taken. In contrast, with an optical communications solution at 100 Mbps, the recorder could be emptied in 26 minutes, and an image could be transferred to the Earth in less than 5 minutes.

(Benefits of Optical Communications )

So it could return 18 images in the time it currently takes to return one image with optical communications. There is no way we continue at this low bandwidth once humans are in orbit around Mars. We can put this in place long before then.

This gets rid of this bottleneck of having to wait for data back from Mars before you decide what to do next. It's based on you and the Mars rover both talking to each other simultaneously, continuously. The idea is that this lets you build up a virtual reality copy of the Mars landscape on Earth and drive your rover in that VR world while the real rover drives simultaneously on Mars. The effects of your actions are simulated in the virtual copy before they actually happen on Mars.

This video describes the idea:

https://www.youtube.com/watch?v=EeSGuGw4aJU

Video: Telexploration: How video game technologies can take NASA to the next level

This was later developed into OnSight using Microsoft’s “hololens” software.

https://youtu.be/DXT-ynvI3Lg

Video: Walking on Mars w/ HoloLens [OnSight]

For more about it: (Immersed on Mars — Dr. Jeff Norris)

Here is a journalist’s description of what it was like to use it, which also fills in more details about how it works, by Jessi Hempel:

I slip on the headset and find myself on the parched, dusty surface of the Red Planet. Behind me, the Curiosity rover towers 7 feet tall, its cameras recording the terrain. The illusion is so real my legs begin to quiver, unsure what to make of the disparate information I'm sensing. Norris appears beside me in the Mars-scape, represented as a 3-D golden human-shaped blob. A dotted line extends from his eyes toward what he's looking at. “Check that out,” he says, and I squat down to see a rock shard up close.

Project HoloLens allows me to work on a desktop computer while in the demo, something you can't do in the Rift's virtual world. It also makes it possible for me to pin holographic flags on the virtual scenario, and someday this will be able to set in motion real-world actions. With an upward right-hand gesture, I bring up a series of controls. I choose the middle of three options, which drops a flag. When scientists do this, the command could theoretically be transmitted to the actual rover so that the task can be accomplished in real life, on Mars.

Satya Nadella's Got a Plan to Make You Care About Microsoft. The First Step? Holograms

It will help also to have more autonomous and more rugged rovers.

By the 2030s with fast bandwidth and once we have gigapixel video cameras on Mars we’ll have scenes like this, but far higher resolution than this, building up a 3D virtual world in microscopic detail as the rovers traverse Mars.

(First 4.5-billion-pixel of Mars by NASA's Perseverance Rover)

With gigapixel video cameras on the rovers, streaming back broadband to Earth, scientists and enthusiasts will be able to look at the landscape on Mars with a virtual hand lens, examining any rock the rovers ever passed by in microscopic detail. Their discoveries could then lead to the rover turning around and looking at the rock again - but as rovers get faster, able to move tens of kilometers a day as for the lunar rovers or even faster - and not limited like the lunar rovers were, to remain within walking distance of a base (The Apollo Lunar Roving Vehicle). We need far faster and more robust rovers for human exploration if we do get humans on the surface. We can send them there first, for robotic exploration.

So we can do a huge amount of exploration on Mars from Earth in the very near future, and all this with those 100% sterile rovers that can explore anywhere with no planetary protection restrictions. All of this builds up assets on Mars and knowledge about Mars that will be very useful when humans get there, whether in orbit or on the surface.

In this way we would have many assets already in place when the astronauts get there, and data links working and tested, and capable teams on Earth to do most of the heavy work leaving it for the astronauts in orbit to be used to their maximum for the executive capabilities. For them it might be not unlike playing a game of “civilization” stepping in from time to time to help one of the robots that is stuck on some task or needs to be operated directly for some time sensitive experiment.

WITH FAST BANDWIDTH, HEAVY LIFT TO MARS ORBIT, 100% STERILE LANDERS AND ARTIFICIAL REAL TIME EXPLORATION ON MARS WE COULD HAVE AN EXCELLENT UNDERSTANDING OF MARS EVEN LONG BEFORE HUMANS COULD GET THERE - AND MANY ASSETS FOR ASTRONAUTS IN ORBIT TO COMPLETE THE SURVEY QUICKLY

With such a capability we could do a huge amount of preliminary astrobiological exploration all within normal budgets for NASA, particularly if supplemented by partners in other countries, and research teams at universities, or indeed in the private sector, with their own independent budgets that help operate the various rovers on Mars.

Depending on the level of support for the survey we might have enough of an idea to make an informed decision within a decade of starting this survey. However, as we’ve seen, an informed decision doesn’t necessarily mean a “pass”.

In the very worst case, the surface of Mars could have extraterrestrial microbes that evade all Earth life’s defences, don’t notice our antibiotics, and are an extreme biohazard for Earth life.

We are used to no-go areas in our solar system for humans as a result of physical hazards. If someone wants to fly into the upper atmosphere of the sun, this is way beyond our technology, and Io and the surface of Venus are not likely to see humans any time soon.

It’s not impossible that the surface of Mars is a no-go area too, even dangerous for humans. Not because of heat or ionizing radiation, but because it could be a biohazard.

We simply don’t know enough to assess it yet, or to decide how likely or unlikely this is. That’s why we have NEPA and the need for the EIS and for oversight by other agencies. They are there to protect us against real possibilities, not futures only possible in someone’s imagination.

IF WE FIND THE MARTIAN BIOSPHERE IS FAVOURABLE FOR A HUMAN LANDING - THIS LIKELY LEADS TO NO SIGNIFICANT DELAYS - WITH MEDVAC 2 DAYS FROM THE MOON AND NEARLY 2 YEARS FOR A SPACECRAFT LEAVING EARTH ORBIT FOR MARS - MORE REALISTICALLY THE NEXT GENERATION FOR HUMANS TO MARS SAFELY

Assuming the final outcome of the decision was favourable for a landing, this need not even delay human missions to Mars. We have many life support issues to sort out first before we can send humans safely on long interplanetary flights. It may take a while before we can send them to Mars orbit.

The Moon is a 2 day MEDVAC away from Earth. We can have “lifeboat” spacecraft at the base that can take off and get the astronauts safely back to Earth in case of an explosion, fire, chemical release or other emergency. While for astronauts headed for Mars, if there is a major mishap as the spacecraft leaves Earth orbit, as for Apollo 13, the only way to get back is via Mars nearly 2 years later by which time the astronatus are likely all dead. We need to be very confident in the life support and the safety of the technology before we do that.

Life support in the ISS needs to be replenished every few months and they often have issues with the equipment that needs to be repaired using new components sent up from Earth. Before we can confidently send astronauts to Mars we need to be able to send a mission to the Moon or lunar orbit that can then study the Moon uninterrupted for several years without any resupply from Earth. We are no where near the technical readiness level to do that. We can’t even do that with the ISS.

CHRIS HADFIELD - FORMER ISS COMMANDER - “I THINK ULTIMATELY WE’LLL BE LIVING ON THE MOON FOR A GENERATION BEFORE WE GET TO MARS”

The retired Canadian astronaut Chris Hadfield, former commander of the ISS, interviewed by New Scientist, put it like this:

"I think ultimately we’ll be living on the moon for a generation before we get to Mars. If the world and the moon were threatened and the only way to preserve our species was to launch from Earth, we could go to Mars with yesterday’s technology, but we would probably kill just about everybody on the way."

"It’s as if you and I were in Paris, paddling around in the Seine in little canoes saying, 'We’ve got boats, we’ve got paddles, let’s go to Australia!' Australia? We can barely cross the English Channel. We’re sort of in that boat in space exploration right now. A journey to Mars is conceivable but it’s still a lot further away than most people think."

(Chris Hadfield: We should live on the moon before a trip to Mars)

Frame from 28 seconds into this ESA video: Moon Village

This compares evacuation times:

ISS emergency evacuation a few hours, resupply every few months < day to arrive

Moon emergency evacuation 2 days, resupply takes 2 days to reach the Moon

Mars emergency evacuation minimum 6 months, emergency resupply minimum 6 months to arrive

(added text to this infographic from the Canadian space agency: Distances between Earth and the International Space Station, the Moon and Mars - infographic)

Meanwhile, we can speed the Mars exploration so much that using this idea of "artificial real time" from computer games, we can control our rovers almost as easily as a rover on the Moon (say). So we can do a huge amount on Mars from Earth. All of this builds up assets on Mars that will be very useful if we do get a “pass” for human settlement after the biological survey of Mars.

The Mars colonization enthusiasts are so sure that the Martian biosphere will be safe for Earth. If they are right we will get a “pass” as a result of this exploration. It will hardly interrupt their plans at all if their confidence is well placed.

IMPORTANCE GOING FORWARD OF GETTING WIDER ATTENTION FOR THE NEED FOR PLANETARY PROTECTION, AND MORE FUNDING FROM CONGRESS

I also propose that NASA needs extra funding for planetary protection. Just a small fraction of the human space budget would help to keep Earth safe.

It seems perverse for NASA to have to do cost-cutting on its comparatively small budget for robotic missions, for backwards contamination prevention, to protect Earth. This is no longer a special interest for astrobiologists or scientists but has potential impacts in worst cases on all humans globally. I argue that something so important to our civilization as protecting our biosphere from extraterrestrial life needs a budget to recognize it’s wider significance.

It is the same also for forward planetary protection which is to do with preserving the science interest of Mars for our civilization in the future and is therefore really a matter of direct impact on humans about preserving native life on Mars that may be of huge benefit to our civilization in the near future and also for future generations.

I found that the worst case scenarios for forward contamination include early life making its first steps towards the evolution of modern life which may be incapable of competing with any terrestrial microbes. Worst case scenarios in the backwards direction include Martian life that is as highly evolved as terrestrial life or has even evolved faster and is more evolutionarily complext than terrestrial life. I found that some scenarios combine aspects of both such as early life mirror ribocells.

I’m not suggesting we divert anything from the human space budget to costs for planetary protection of Earth. Rather, I recommend this as an item that may need attention of the president and Congress. If society considers that it is important to protect Earth’s biosphere from contamination from Mars, the best way to ensure we do this is to budget for this separately to remove this incentive on NASA to cut costs on planetary protection to achieve mission goals in a strictly limited budget.

MARS ISN’T SUCH A PRIZE AS A PLANET FOR HUMANS AS IT SEEMS VISUALLY FROM THE ATTRACTIVE REDDISH TERRAIN - NO SOIL - DESERT - NEED FULL PRESSURE SPACESUIT AS LUNGS CAN’T FUNCTION EVEN WITH BOTTLED OXYGEN - DUST HAS POISONOUS PERCHLORATES A BIT LIKE WORKING IN A LEAD MINE - DUST GETS EVERYWHERE IN DUST STORMS - UNLIKE THE MOON WHERE WE CAN CLEAR THE DUST AROUND A SETTLEMENT

[NEED TO CONVERT THESE CITES TO LINKS TO THE PAPERS]

Mars isn’t such a prize as a planet for humans to inhabit as it seems to be visually from the attractive reddish looking terrain. There is no soil there, of course, it’s just desert. And Mars is not habitable to humans in any ordinary sense of the word. The atmospheric pressure of 0.6 to 0.7% is well below the Armstrong limit of 6.3% where water and body fluids boil at body temperature (Murray et al., 2013). The atmospheric pressure is too low for our lungs to function, so we couldn’t breathe even with bottled oxygen. We would go unconscious in seconds, and require a full body pressure suit to breathe.

Suppose we had a plateau on Earth, at a height of 45 kilometers (NASA, n.d.), five times higher than Mount Everest at 8,848.86 km (Dwyer, 2020). The pressure would be typical for Mars, but it would be far more habitable and it would be far easier to colonize such a high plateau than Mars. Yet if such a plateau occurred on Earth, we would likely have few living there permanently except to extract resources or for scientific study. We don’t colonize most deserts, or the shallow continental shelves, which are far more habitable.

Mars has worse dust problems than the Moon. For instance, the Moon doesn’t have dust storms. Several times a decade dust storms on Mars block out the sunlight for weeks making surface conditions as dark as night. On the Moon we can clear the dust from around a settlement, or melt it into paving slabs, and on any landing sites for our rockets, and eliminate the issue at least locally as well as along roads and tracks (Taylor et al., 2005).

Inhaling a few milligrams of Martian dust could exceed the recommended maximum daily dose for perchlorates (Reference dose or RfD) (Davila et al., 2013). When the perchlorates are activated by ionizing radiation they may change to the more deadly chlorates and chlorites with some potential for more serious and immediate effects such as respiratory difficulties, headaches, skin burns, loss of consciousness and vomiting (Davila et al., 2013).

There are methods for dealing with this, used for dust suppression when mining uranium, lead or other heavy metal contaminated areas. But it adds to the complexity of Mars colonization (Davila et al., 2013).

None of this makes Mars settlement impossible, but Mars does not seem to be an optimal place to colonize for its own sake. There has to be another reason to take the tremendous efforts needed to colonize a place like this. If we find instead that we have to explore Mars from orbit, actually it would be a safer and easier way to explore Mars.

DISCOVERY OF MIRROR LIFE ON MARS WOULD INVIGORATE HUMAN SPACE EXPLORATION - EVEN THOUGH IT WOULD LIKELY MEAN HUMANS CAN NEVER LAND ON MARS - OR AT LEAST NEVER RETURN TO EARTH AFTER LANDING ON MARS

A Mars with mirror life, perhaps, becomes a forever unattainable frontier, a world you can never actually land on, but can still explore with high fidelity telepresence. We have never had a frontier like that.

If we do find life on Mars that can never be returned safely, this may stimulate rather than discourage vigorous space exploration and settlement. The first astronauts to Mars might study the surface remotely in a spectacular orbit, a sun synchronous Molniya orbit as proposed by the Mars HERRO study. This orbit is tilted at 117 degrees and it is easy to get to as it needs less delta v than a landing on Earth’s moon, and is similar to the minimal delta v Mars capture orbi (. HERRO mission to Mars using telerobotic surface exploration from orbit) ( Low-Latency Telerobotics from Mars Orbit: The Case for Synergy Between Science and Human Exploration)

In this orbit astronauts fly near to both poles twice a day and skim in close over the equatorial regions, over different parts of Mars on the opposite sides of the planet twice a day. The maximum latency is 147 ms or less than a sixth of a second which means they can control rovers anywhere on Mars in close to real time throughout the orbit, and then they can operate experiments or do anything that needs fine control when close to Mars in each orbit.

This is a video I did to simulate the orbit for the HERRO study. It uses a futuristic spacecraft just because that was an easy way to make the video in the simulator I used. It’s speeded up 100 times.

https://www.youtube.com/embed/BftmbvBd5m4?feature=oembed

Video: One Orbit Flyby, Time 100x: Mars Molniya Orbit Telerobotic Exploration in HERRO Mission

Early astronaut explorers would likely use two spacecraft joined via tethers for artificial gravity to stay healthy, simulating mars gravity perhaps, and then operate surface marscopters, rovers and other surface assets, similarly to avatars in a computer game.

This is what it might look like from inside the spacecraft

Text on graphic: Mirror life here (one scenario)

Can never land (at least never return) - but can explore via immersive VR experienced more clearly than if they are on the surface

Would stimulate high levels of interest in the public

In the 1960s the public quickly got bored of the Apollo missions after the flag and footsteps succeeded.

Composite of photo from the Cupola of the ISS (Russian cosmonaut Dmitri Kondratyev (left), Expedition 27 commander; and Italian Space Agency/European Space Agency astronaut Paolo Nespoli in the Cupola, use still cameras to photograph the topography of points on Earth. Picture taken by 3rd crew member, Cady Coleman) and Hubble photo of Mars (, Photograph of Mars taken by the Hubble Space Telescope during opposition in 2003. 3)

The Mars colonization enthusiasts are so sure that the Martian biosphere will be safe for Earth. If they are right we will get a “pass” as a result of this exploration. It will hardly interrupt their plans at all if their confidence is well placed. Not only that they would get much broader backing because their confidence will be based on scientific knowledge about Mars rather than optimistic hunches and vivid metaphors.

While if they have to stay in orbit, and colonize the moons of Mars, they can use these assets to exploit Mars with robotic exports to their colony, even grow plants on the surface.

Though we can’t sterilize humans, we can sterilize seeds without any risk of contaminating Mars with Earth micro-organisms.

This is an artist’s concept of a rover designed to grow a single plant on Mars. It’s just an artistic idea and not a real mission plan.

However I’ve included it to illustrate the idea. We could do this with no forwards contamination using hydroponics.

Named after the "Little Prince" who looked after a single rose on his asteroid in the fictional book by Antoine de Saint-Exupéry

It's possible that plants may be the first living Earth colonists of another planet.

. Video of the Little Prince rover

We could do the same with entire greenhouses. Sterilize the greenhouse before delivering it to Mars, use sterile hydroponics and grow plants in it.

Text on graphics: We could grow plants on Mars even if it has mirror life that can never be brought back or Earth has microbes can never be sent to Mars.

Seeds can be sterilized and grown in sterile aquaponics

(The Real Martian Technologies: Our Little Green Friends)

In this way we could have greenhouses on the surface of Mars and these could grow food for the colonists in orbit. They may have plenty to eat in their habitats anyway by then, but they might grow maybe delicacies or things that grow particularly well on Mars or medicinal plants or whatever. Also they might grow large plants, and maybe trees (perhaps growing far larger in the Mars light gravity) or whatever else grows best on the surface of Mars, or for convenience to save space in orbiting habitats.

We can in principle grow many terrestrial crops on the surface of Mars with no risk of contamination in either direction, on most scenarios. We could export those crops to the orbiting colonies, for instance on Phobos. We can also do mining for minerals on Mars, and prospect for assets that may be worth selling to Earth and so on, do everything the colonization enthusiasts want to do except humans on the surface, much like the game of civilization with robotic avatars.

THE MOON IS FAR MORE INTERESTING AND FAR MORE HABITABLE THAN WE REALIZED WITH THE APOLLO MISSIONS - AGREAT PLACE FOR OUR FIRST ADVENTURES IN SPACE EXPLORATION AND SETTLEMENT

The Moon is far more interesting than we realized during the Apollo missions.

The lunar caves are truly vast far larger than lava tube caves on Earth. Some may be up to kilometers wide. Some of the lunar caves probably have an internal steady temperature of around -20 °C, potentially useful as a constant heat sink for a settlement (. Lunar and martian lava tube exploration as part of an overall scientific survey) The challenge of providing energy during the lunar night is a similar challenge to providing energy during Martian dust storms. Then there are the peaks of almost eternal light at the poles with solar power 24/7 nearly year round (Peaks of Eternal Light), the polar ice and so on (, Moon’s South Pole in NASA’s Landing Sites). The Moon is a place where we can make our first steps in sustainable living in space, within easy access of Earth for repairs, supplies, and emergency medvac back to Earth in only two days.

As our spacecraft get more capable (Conceptual design of in-space vehicles for human exploration of the outer planets) , humans can also explore and even colonize Callisto, outermost of the Galilean moons of Jupiter (High power MPD nuclear electric propulsion (NEP) for artificial gravity HOPE missions to Callisto) . This is far more suitable than Europa positioned right in the middle of Jupiter’s deadly ionizing radiation belts.

Elon Musk’s artist’s impression of his spacecraft for a crew of 100, the Interplanetary Transport System. He said his spacecraft would use Europa as a refueling stop in the outer solar system. Callisto is a far better refueling stop because of the lethal ionizing radiation around Europa which is within Jupiter’s radiation belts. The artist’s impression actually more closely resembles Callisto as the surface of Europa is probably broken up and rough on the meter scale, at least with current understanding (Interplanetary Transport System, Official ).

Inset shows artist’s impression of an exploration base on Callisto (, The Vision for Space Exploration : 22)

Then there’s Titan in Saturn’s system, which like the Venusian clouds, has an atmospheric pressure similar to Earth, indeed greater. It is far easier to protect against cold than against vacuum or acid. Explorers only need a thick insulating high tech version of a diver’s dry suit with insulation only 7.5 cm thick, with batteries to heat a visor and gloves, and they could explore Titan’s surface using a closed circuit oxygen or air rebreather system (without bubbles) much like military and deep sea divers use (. Titan: a distant but enticing destination for human visitors. ).

The winds just a few kilometers above the surface can be a source of energy for a settlement, while surface winds are so light as to cause no issues (. Energy Options for Future Humans on Titan. ). It also has organics for making plastics, a stable environment and complete protection from ionizing radiation and the smaller meteorites (as for Earth) . (, Let’s Colonize Titan, ) (, Beyond Earth: Our Path to a New Home in the Planets). Unless there is cryovolcanism, “volcanoes” of liquid water instead of lava, there is no risk of forward contamination. As for backwards contamination, we’d need to find out what is there but it’s plausible that Titan life if it exists would not be able to survive terrestrial temperatures.

The sterilization subcommittee working group’s remarks about extremophiles WOULD work on Titan with typical temperatures -179 C and ice so cold it becomes as solid as rock, amorphous ice (Titan - In Depth), and yet it has lakes of liquid ethane. Some have speculated that Titan may have very exotic life based on methane and ethane instead of water but highly unlikely such life would survive conditions on Earth so warm that the liquids it uses for life go well above boiling point and turn to gases. As NASA puts it:

Titan’s atmosphere is made mostly of nitrogen, like Earth’s, but with a surface pressure 50 percent higher than Earth’s. Titan has clouds, rain, rivers, lakes and seas of liquid hydrocarbons like methane and ethane. The largest seas are hundreds of feet deep and hundreds of miles wide. Beneath Titan’s thick crust of water ice is more liquid—an ocean primarily of water rather than methane. Titan’s subsurface water could be a place to harbor life as we know it, while its surface lakes and seas of liquid hydrocarbons could conceivably harbor life that uses different chemistry than we’re used to—that is, life as we don’t yet know it. Titan could also be a lifeless world.

(Titan - Overview)

Text on graphic: Later humans may colonize Titan - the only other location in our solar system with an atmosphere

in the Saturn system

thicker atmosphere than Earth (mainly nitrogen)

Titan's atmosphere is so thick:

humans don't need spacesuits - just very thick diving suits and bottled oxygen

habitats are as easy to construct as a terrestrial polytunnel

cold is far easier to protect against than vacuum

sources of energy from winds a few hundred meters up

gravity so low humans can fly by flapping wings!

sources for making plastics

ice for water, and for fuel

so very cold backward contamination is unlikely and forward contamination impossible unless it has liquid water in cryovolcanoes

(needs confirmation that there are no planetary protection issues)

(SpaceX Interplanetary Transport System at Saturn)

(Titan, Earth & Moon size comparison)

Whether any of these are easy places to live long term may depend also on the gravity requirements for human health which are not yet known. However it is not yet known if the gravity on the Moon or Mars is suitable for human health long term either. It’s possible that they all need to be supplemented with the use of slow centrifuges spinning for artificial gravity during sleep, exercise etc.

Finally over the centuries, and millennia, with space habitats slowly spinning for artificial gravity and large thin film mirrors to focus sunlight, we could explore and settle the entire solar system to Pluto and beyond (Space settlements: A design study: 175)

“At all distances out to the orbit of Pluto and beyond, it is possible to obtain Earth-normal solar intensity with a concentrating mirror whose mass is small compared to that of the habitat.”

[in space settlements spinning slowly for artificial gravity]

“At all distances out to the orbit of Pluto and beyond, it is possible to obtain Earth-normal solar intensity with a concentrating mirror whose mass is small compared to that of the habitat.”

Space settlements: A design study (1977)

[in space settlements spinning slowly for artificial gravity]

(Catalog Page for PIA21590 )

HUMAN ASTRONAUTS EXPLORING MARS AND SEARCHING FOR MARTIAN LIFE FROM ORBIT WOULD BE OF HIGH INTEREST WITH THE PUBLIC ABLE TO IMMERSE THEMSELVES VIA VIRTUAL REALITY IN THEIR ADVENTURES, FOLLOWING EVERY STEP OF THEIR EXPLORATIONS

Before we send humans to Mars we are likely to have much reduced cost heavy lift able to send tens of tons in one go to Mars. We already have the Falcon Heavy. In the future, we may be able to send as much as 150 tons in one go if we have Elon Musk’s StarShip. What’s more, according to his optimistic projections, it may be low cost too. He is proposing that they could send 150 tons to Mars for a cost of tens of millions of dollars.

If that doesn’t work out, we have the Skylon, which will let us fly to space and will likely be ready by the 2030s, we will have the SLS, and surely many other heavy lift rockets.

We can have many assets on the surface of Mars operated from Earth and human explorers at home can follow along with the rovers. Anyone at home will be able to explore the landscapes in 3D in real time and by then with high bandwidth even look at rocks in microscopic detail as with a geologist’s lens and may notice things and make suggestions for the team to look at something they may have missed.

WE CAN EXPLORE AND EXPLOIT MARS WITHOUT HUMANS ON THE SURFACE, AS PART OF A VIGOROUS PROGRAM OF EXPLORATION AND PERHAPS SETTLEMENT THROUGHOUT THE SOLAR SYSTEM

We can explore and exploit Mars without humans on the surface, settling the Martian moons and orbital space habitats, as part of vigorous exploration and perhaps settlement throughout the solar system. Humans and robots work together each doing what it does best. Torrence Johnson, Galileo Chief Scientist, put it like this in the foreword to Meltzer’s “Mission to Jupiter” (Meltzer, 2007)

Torrence Johnson: What we call robotic exploration is in fact human exploration. The crews sitting in the control room at Jet Propulsion Laboratory as well as everyone out there who can log on to the Internet can take a look at what’s going on. So, in effect, we are all standing on the bridge of Starship Enterprise

We use humans and robots each doing what it does best. Which might or might not involve humans on the surface of Mars but certainly humans in space in many locations in the solar system.

My aim with this open letter and my survey is to do everything I can to help make sure voices and concerns of the public are heard. My wish is that this will encourage space agencies to do a rigorous scientific review with full public involvement.

I am sure at some point, the public and other agencies will get their say, though I don’t yet see clearly when exactly it will happen. I hope this preprint, executive summary, open letter and so forth will help make sure this happens sooner rather than later.

This is an executive summary of part of my preprint:

NASA must protect Earth's biosphere even if Mars samples hold mirror life – a survey of recent planetary protection research plus new scenarios – and how with modern technology we now have an option to keep Earth 100% safe – and protect any Martian biosphere 100% too

Author: Robert Walker, contact email robert@robertinventor.com