Terraforming Series Complete!

Terraforming Series Complete!

I’ve been busy over at Universe Today of late. In fact, as part of a promotional thing for my upcoming book – The Cronian Incident – I’ve been doing a series of articles about terraforming. And it’s actually kind of an interesting story, which I already touched on in a previous post. In any case, the series is now complete, with articles that cover everything from terraforming Mercury to terraforming the moons of the gas giants in the outer Solar System:

The Definitive Guide to Terraforming
How Do We Terraform Mercury?
How Do We Terraform Venus?
How Do We Terraform Mars?
How Do We Terraform the Moon?
How Do We Terraform Jupiter’s Moons?
How Do We Terraform Saturn’s Moons?

To give people the Cliff Notes version of this series, it is clear that at this point, humanity could colonize and terraform certain worlds in our Solar System. The only real questions are where could we? How could we? And why should we? To answer the first two, we could terraform Mars and Venus, since both planets are terrestrial (like Earth), both exist in our Sun’s habitable zone (like Earth), and have either abundant atmospheres or abundant sources of water we can work with. In any other case, the matter becomes impractical, except within certain contained environments (paraterraforming).

mars_greening
The “greening of Mars”. Credit: nationalgeographic.com

As for the third question – why should we? – that was one of the main reasons I tackled this subject. When it comes to terraforming, the questions concerning ethics and responsibility are unavoidable. And while I did my best to cover this in the course of writing the series, the real debate happened in the comments section. Again and again, people asked the following questions:

How can we live elsewhere when we can’t even take care of Earth?
Shouldn’t we take care of our problems here before we settle other worlds?
Wouldn’t those resources be better spent here?

All good (and predictable) questions. And rather than simply avoiding them or dismissing them as pedestrian, I wanted to seriously have an answer. And so I chose to reply whenever these questions, or some variation, popped up. Here’s the basics of why we should terraform other worlds in this century and the next:

1. Increased Odds of Survival:
As Elon Musk is rather fond of sharing, colonizing Mars was one of the main reasons he started SpaceX (which recently made their second successful landing of the reusable Falcon 9 rocket!) His reason for establishing this colony, he claims, is to create a “backup location” for humanity. And in this, he has the support of many policy analysts and space enthusiasts. Faced with the threat of possible extinction from multiple fronts – an asteroid, ecological collapse, nuclear war, etc. – humanity would have better odds of survival if it were a multi-planet species.

Artist's concept for a possible colony on Mars. Credit: Ville Ericsson
Artist’s concept for a possible colony on Mars. Credit: Ville Ericsson

What’s more, having other locations around the Solar System decreases the odds of us ruining Earth. So much of why Earth’s environment is threatened has to do with the impact human populations have on it. Currently, there are over 7 billion human beings living on planet Earth, with an additional 2 to 3 billion expected by mid-century, and between 10 and12 by the 2100. But it’s not just the number of people that matters. In addition to every human being constituting a mouth to feed, they are also a pair of hands that need to given something productive to do (lest they turn to something destructive).

Every human also requires an education, a place to live, and basic health and sanitation services to make sure they do not die prematurely. And providing for all of this requires space and a great deal of resources. As it stands, it is becoming more and more difficult to provide for those we have, and our ability to do so is dwindling (i.e. thanks to Climate Change). If we intend to survive as a species, we not only need new venues to expand to, we need other resource bases to ensure that our people can be fed, clothed, housed, and employed.

So simply put, creating permanent settlements on the Moon, Mars, and elsewhere in the Solar System could ensure that humanity survives, especially if (or when) our efforts to save Earth from ourselves fail.

Project Nomad, a concept for the 2013 Skyscraper Competition that involved mobile factory-skyscrapers terraforming Mars. Credit: evolo.com/A.A. Sainz/J.R. Nuñez/K.T. Rial
Project Nomad, a concept for the 2013 Skyscraper Competition that involved mobile factory-skyscrapers terraforming Mars. Credit: evolo.com/A.A. Sainz/J.R. Nuñez/K.T. Rial

2. Testing out Ecological and Geological Engineering Techniques:
Basically, there is no way humanity is going to be able to address Climate Change in this century if we do not get creative and start relying on techniques like carbon capture, carbon sequestration, solar shades, and artificially triggered global dimming and fungal blooms. The problem is, any or all of these techniques need to be tested in order to ensure that the results are just right. Altering our environment would not only threaten to disrupt systems human being depend upon for their livelihood, it could also threaten the lives of many people.

Such is the threat Climate Change poses, so we want to make sure the ways in which we address it helps the environment instead of screwing it up further. The best way to do that is to have testing grounds where we can try out these techniques, and where a misstep won’t result in the loss of innocent lives or billions in damages. Ergo, testing our methods on Mars and Venus will give us a chance to measure their effectiveness, while avoiding any of the political barriers and potential hazards using them on Earth would present.

3. Mars and Venus are Perfect Testing Grounds:
Astronomers have been aware for some time that Mars and Venus are similar to Earth in many ways. As previously mentioned, they are both terrestrial planets that are located in our Sun’s habitable zone. But of course, they are also different in several key respects. Whereas Mars’ atmosphere is very thin, it has no magnetosphere, and its surface is extremely cold and dry, Venus has an atmosphere that it extremely dense, hot enough to melt lead, and where sulfuric acid rains are common.

terraforming-mars2
Artist’s impression of a atmospheric generator on Mars. Credit: futurism.com

The reasons for this? Mars sits at the outer edge of the Sun’s habitable zone and receives less warmth. Combined with its eccentric orbit – and a lack of a protective magnetosphere that caused it to lose its atmosphere billions of years ago – this is what has led to it becoming the very cold and dry planet we are familiar with. Venus, sitting on the inner edge of the Sun’s habitable zone, suffered a runaway Greenhouse Effect early in its history, which caused it to become the extremely hot and hellish world it is today.

Terraforming Mars would therefore require that we thicken the atmosphere and warm it up. This means triggering a Greenhouse Effect by pumping lots of CO2 and nitrogen (probably in the form of ammonia) into its atmosphere and then converting them using cyanobacteria and other species of bacteria. So basically, to make Mars more Earth-like, we could build heavy industry there to pollute the hell out of the place – something we’ve been doing here on Earth for hundreds of years! – and then test out techniques designed to convert the atmosphere into something breathable. What we learn could then be applied here at home.

The same holds true for Venus. In order to terraform that world into something livable for humanity, the first challenge will be to arrest the runaway Greenhouse Effect there and convert the carbon dioxide/sulfur dioxide-rich atmosphere into one composed of nitrogen and oxygen gas. There are many ways to do this, and testing one or more of them out will yield crucial data for using similar techniques on Earth. In a nutshell, transforming Mars and Venus will help us save Earth.

Artist’s concept of a Venus cloud city – part of NASA’s High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab/NASA Langley Research Center
Artist’s concept of a Venus cloud city – part of NASA’s High Altitude Venus Operational Concept (HAVOC) plan. Credit: Advanced Concepts Lab/NASA Langley Research Center

4. Our Solar System has Abundant Resources:
Between the Moon, Mars, Venus, Mercury, the Asteroid Belt, and the systems of Jupiter, Saturn and beyond, there are literally enough resources to last humanity indefinitely. And while we can’t hope to possess them all at once, every step in colonizing the Solar System offers us the chance to expand our resource base, conduct scientific research and exploration, add more land which we can develop and use for human settlement, and ultimately grow as a species.

To break this process down piecemeal, we must start with the Moon. By establishing a colony in its southern polar region, we could leverage the local resources to create a permanent settlement and use it as a refueling base for mission deeper into the Solar System (a move which would save billions on all future missions). Solar operations could also be built on the surface to beam energy to Earth, the Moon’s rich minerals could be mined for Earth industries, and the mining of Helium-3 could power fusion reactors all over the world.

Already, NASA is eying the Shakelton Crater as a possible location, where there is an abundance of water ice and a dome could be built over it to create a contained atmosphere. The moon’s stable lava tunnels also present a good site, since they are large enough to fit entire cities within them and would hold an atmosphere nicely. And from there, humanity could mount missions to Venus and Mars, which would in turn add their abundant supplies of minerals to our economy.

The European Space Agency's concept for a Moon base. Credit: ESA
The European Space Agency’s concept for a Moon base. Credit: ESA

Mercury would also present a major opportunity for mining and solar operations.  And like the Moon, colonies could be built in the permanently shaded regions around the northern and southern polar regions (where there are abundant supplies of water ice) and in underground stable lava tubes. The Asteroid Belt literally has enough minerals and ices to keep humanity supplied indefinitely (hence the interest in asteroid prospecting of late), and the outer Solar System has enough ice, volatiles, and organic compounds to do the same.

In short, step by step, the colonization and/or terraforming of our Solar System offers humanity the opportunity to become a post-scarcity race. While many decry the idea of our species expanding because of the greed and abuse we have demonstrated in the past (and continue to demonstrate today), much of this greed and abuse comes from the fact that our current economic models are based on scarcity. By removing that from the equation, it would be that much more difficult for human beings to hoard resources for themselves while denying their neighbor.

Faced with all of this, the question no is longer one of “why should we”, but rather “why shouldn’t we?” Why shouldn’t we establish a human presence elsewhere in the Solar System, knowing that it could not only help us to save Earth, but ensure our survival as a species for the indefinite future? This of course does not address all the challenges that remain in doing so, but it does tackle one of the biggest arguments there is against space exploration and colonization.

Still pic from Wanderers, by Erik Wernquist
Still pic from Wanderers, by Erik Wernquist

As for the rest? Well, I’m sure we’ll tackle those questions, and then some, when the time comes. In the meantime, I encourage everyone to keep looking up at the stars and saying the question, “why not?”

The Cronian Incident – Factions in the Future

 

future_city
Future City [3] by josueperez79 at deviantart.com
Hi again folks! I’m back with some thoughts from my most recent story project – The Jovian Incident. I know, what else is new, right? Writing can be a self-indulgent process. But if there’s one thing I’ve learned, its that sharing helps when it comes to developing a story. It helps you articulate your thinking and ideas, especially if respected peers tell you what they think (hint, hint!)

As I also learned a long time ago, any science fiction piece that deals with the distant future has to take into account how human beings in the future go about organizing themselves. In this future world, what are the political blocs, the alliances, the rivalries – the ways in which people are united and divided? Well, I gave that a lot of thought before sitting down to pen the book (which is into chapter 11 now). And this is the basic breakdown I came up with.

Extro Factions:
For starters, people in the future I am envisioning are tentatively divided into those that live in the inner and outer Solar Systems. But that geographic divide is merely representative of a much bigger issue that divides humanity. Whereas the people living on Earth, Mars and Venus largely fall into the category of “Extro” (i.e. Extropian, people who embrace the transhuman ethic) people in the outer Solar System live simpler, less augmented and enhanced lives (“Retro”).

But within this crude division between people who believe in going beyond their biological limitations and those who believe in respecting them, there are plenty of different social, political and ideological groups to be found. Here’s a rundown on them, starting with the Extro factions…

The Formists:
Founded by Piter Chandrasekhar, one of the first colonists of Mars, the Formists are a faction dedicated to the full-scale terraforming of the Red Planet. The purpose of this, obviously, is to allow for full-scale colonization, which is something that remains impossible at this point in the story. All inhabitants on Mars lived in sealed domes, all transit takes place in pressurized tubes or on flyers, and anyone venturing out onto the surface is forced to wear a pressure suit with life-support systems.

Mars_terraforming
Mars Terraformed by Daein Ballard

Currently, the Formist faction is run by Emile Chandrasekhar, Piter’s grandson. And for the past few decades, they have been busy procuring resources from the outer Solar System to aid in the terraforming process. This includes supplies of methane, ammonia, ices, and lots and lots of comets.

However, they are also busy trying to ensure that the process will have a minimal impact on the settlements and those living within them. Altering the planet’s atmosphere will definitely have a significant impact on the landscape in the short-term, such as sublimating all the water ice in the Martian soil and in the polar caps. Once that water begins to flow, much of the surface will find itself being swallowed up by newly-created oceans. So naturally, the Formists must proceed slowly, and make sure all settlements on Mars agree to their plans.

While the Formist faction is largely centered on Mars, they have counterparts on Venus as well – known as The Graces (after the children of Aphrodite). Here, the process is significantly different, and involves converting the existing atmosphere rather than increasing its density. But the goal is the same: to one day make Venus a living, breathing world human beings can set foot on.

The Dysonists:
Among the Extros, there are also those who believe humanity’s future lies not in the stars or in the terraforming the Solar System’s planets, but in the space that surrounds our Sun. They are known as the Dysonists, a faction that is intent on building a massive swarm of structures in the inner Solar System. For some, this calls for a series of rings which house the inhabitants on their inner surface and provide gravity through endless rotation.

fractal_dyson_sphere_by_eburacum45-d2yum16
This artist’s concept of a Dyson sphere is via SentientDevelopments.com

For other, more ambitious Dysonists, the plan involves massive swarms of computronium that will contain a sea of uploaded personalities living in simulated environments. Both the swarms and the powerful bandwidth that connects them will draw energy from the Sun’s rays. These individuals consider themselves to be the more puritan of Dysonists, and believe those who advocate buildings rings structures are more properly known as Nivenists.

The process of converting all the “dumb matter” in the Solar System into smart matter has already begun, but in limited form. Within a few generations, it is believed that the Sun will be surrounded by a “Torus” of uploaded minds that will live on while countless generations come and go. Dysonists and their enclaves can be found on Near-Earth Asteroids, in the Main Asteroid Belt, and with committed supporters living on Venus, Mars, Earth, the Moon, and Ceres.

The Habitationists:
Inspired by Gerard K. O’Neill, the inventor of the O’Neill Cylinder, the Habitationists began as an architects dream that quickly expanded to fill all of known space. In the 21st century, Earthers looking to escape the growing population crisis began migrating to space. But rather than looking to live on distant worlds or the Moon, where the environment was harsh and the gravity limited, they decided to set up shop in orbit. Here, supplies could be shipped regularly, thanks to the advent of commercial aerospace, and gravity could be simulated at a full g thanks to rotating toruses.

By the mid 22nd century, Low Earth Orbit (LEO) Habs had become all the rage and the skies became somewhat saturated. The existence of Earth’s space elevator (The Spindle) only made deploying and supplying these Habs easier, and a steady drop in the costs of manufacturing and deploying them only made them more popular. As such, Terran architect Hassan Sarawak, who had designed many of the original habitats in space, began to busy himself designing a new series of Habs that would allow human beings to live in space anywhere in the Solar System.

Lightfarm Studios
Artistic impression of the inside of an O’Neil Cylinder. Lightfarm Studios

By the end of the 22nd century, when the story takes place, large cylinders exist in several key places in the Solar System. Most are named in honor of either their founders, those who articulated the concept of space habitats, or those who believed in the dream of colonizing space itself (and not just other planets and moons).  These places are thusly named O’Neil’s Reach, Clarkestown, Sawarakand, and New Standford.

The Seedlings:
As the name would suggest, the Seedlings are those intrepid Extropians who believe humanity should “seed” the galaxy with humanity, spreading to all solar systems that have confirmed exoplanets and building settlements there. But in a slight twist, they believe that this process should be done using the latest in nanotechnology and space penetrators, not slow interstellar ships ferrying human colonist and terraformers.

To the Seedlings, who can be found throughout the inner Solar System, and on some of its most distant moons, the idea is simple. Load up a tiny projectile-ship with billions of nanobots designed to slowly convert a planet’s climate, then fire it on a trajectory that will take it to an exoplanet many generations from now. Then, prepare a ship with colonists, send it on its merry way into space, and by the time they reach the distant world, it will be fully prepared for their arrival.

utility_fog
At this point in the story, the Seedlings first few missions are still in the planning stages. They’ve got the technology, they’ve got the know-how, and they know where the right candidate planets are located. All they need to do know is test out their machines and make sure the process works, so that they won’t be sending their colonists into a deathtrap.

Sidenote: this idea is actually one I explored in a short story I am trying to get published. If all goes well, I am the short story and this full-length idea can be connected as part of a singular narrative.

Retro Factions:
And now we come to the people who live predominantly in the outer Solar System, the folks who found life on Earth and the inner worlds unlivable thanks to its breakneck pace and the fact that life was becoming far too complicated. These are the people whom – for religious, personal, or moral reasons – chose to live on the frontier worlds in order to ensure something other than humanity’s survival as a species. For these people, it was about preserving humanity’s soul.

Organics:
In the mid to late 21st century, as biotech and cybernetics became an increasingly prevalent part of society, a divide began to emerge between people who enhanced their biology and neurology and those who did not. While the former were in the minority for the first few decades, by the latter half of the 21st century, more and more people began to become, in essence, “transhuman” – (i.e. more than human).

Cyber_Girl
Cyber Girl by Fausto De Martini

At the same time, fears and concerns began to emerge that humanity was forsaking the very things that made it human. With lives becoming artificially prolonged, human parts being swapped for bionic or biomimetic implants, and brains becoming enhanced with neural implants and “looms”, humanity seemed on course to becoming post-human (i.e. not human at all).

And while the concerns were justified, few who could afford such enhancements seemed to be willing to forsake the convenience and necessity they represented. In a world where they conferred advantage over the unenhanced, choosing not to augment one’s body and mind seemed foolish. But between those who could not afford to, those who were forbidden to, and those who chose not to, eventually a new underclass emerged – known as “Organics”.

Today’s organics, who live predominantly in the outer Solar System or isolated pockets in the inner worlds, are the descendants of these people. They live a simpler life, eschewing most of the current technology in favor for a more holistic existence, depending on various levels of technology to maintain a certain balance.

Fundies:
Naturally, human beings in the late 22nd century still have their faiths and creeds.  Despite what some said in previous centuries, mankind did not outgrow the need for religion as it began to explore space and colonizing new worlds. And when the Singularity took place in the mid 21st century, and life became increasingly complex, enhanced, and technologically-dominated, the world’s religiously-devout began to feel paradoxical. On the one hand, religion seemed to be getting more unpopular and obsolete; but at the same time, more rare and precious.

The-Common-Foundations-of-Religions-and-Theology-Evolutionary-Tree-of-Religions
To be fair, there was a time when it seemed as though the prediction of a religion-less humanity might come true. In the early to mid 21st century, organized religion was in a noticeable state of decline. Religious institutions found it harder and harder to adapt to the times, and the world’s devout appeared to be getting increasingly radicalized. However, in and around all of these observable trends, there were countless people who clung to their faith and their humanity because they feared where the future was taking them.

In the current era, the outer Solar System has become a haven for many sects and religious organizations that felt the Inner Worlds were too intolerant of their beliefs. While there will always be people who embrace one sort of faith or another on all worlds – for instance, billions of Extros identify as Gnosi or Monist – the majority of devout Kristos, Sindhus, Mahavadans, Mahomets, and Judahs now call the worlds of Ganymede, Callisto, Europa, Titan, Rhea, Iapetus, Dione, Tethys, Titania, Oberon, Ariel and Umbriel home.

The vast majority of these people want to live in peace. But for some, the encroachment of the Inner Worlds into the life and economies of their moons is something that must be stopped. They believe, as many do, that sooner or later, the Extro factions will try to overtake these worlds as well, and that they will either be forced to move farther out, colonizing the moons of Neptune and the Kuiper Belt, or find homes in new star systems entirely. As such, some are joining causes that are dedicated to pushing back against this intrusion…

Chauvians (Independents):
Many in the past also thought that nationalism, that sense of pride that is as divisive as it is unifying, would also have disappeared by this point in time. And while humanity did begin to celebrate a newfound sense of unity by the late 21st century, the colonizing of new worlds had the effect of creating new identities that were bound to a specific space and place. And given the divisive political climate that exists in the late 22nd century, it was only natural that many people in the Outer Worlds began preaching a form of independent nationalism in the hopes of rallying their people.

Révolution_de_1830_-_Combat_devant_l'hôtel_de_ville_-_28.07.1830
Collectively, such people are known as “Chauvians“, a slight bastardization of the word “Jovian” (which applies to inhabitants of any of the outer Solar System’s moons). But to others, they are known simply as Independents, people striving to ensure their worlds remain free of external control. And to those belonging to these factions, their worlds and their people are endangered and something must be done to stop the intrusion of Extros into the outer Solar System. For the most part, their methods are passive, informative, and strictly political. But for others, extra-legal means, even violent means, are seen as necessary.

Examples include the Children of Jove and the Aquilan Front, which are native to the Galilean moons of Jupiter. On the Cronian moons, the Centimanes are the main front agitating for action against the Extros. And on the Uranian moons, the organizations known as The Furies and the Sky Children are the forces to be reckoned with. Whereas the more-moderate of these factions are suspected of being behind numerous protests, riots, and organized strikes, the radicals are believed to be behind the disappearance of several Extro citizens who went missing in the Outer Worlds. In time, it is believed that a confrontation will occur between these groups and the local authorities, with everyone else being caught in the middle.


And those are the relevant players in this story I’m working out. Hope you like them, because a few come into play in the first story and the rest I think could become central to the plots of any future works in the same universe. Let me know what you think! 🙂

 

Retweeted by NASA and Inside Space!

Our watery Earth. Credit: NASA
Our watery Earth. Credit: NASA

Good news everyone! After about two months of working for Universe Today, it appears that some of what I say is actually being read by the big names in the bizz! It started three days ago when NASA Earth retweeted an article I wrote entitled “What Percentage of Earth is Water?“, which was part of UT’s Guide to Space section that deals with general knowledge questions about astronomy, geology, the universe, etc.

The second came yesterday when Inside Space retweeted an more recent article I did about the supermassive black hole at the center of our galaxy, and how scientists anticipate that they will be able to view it for the first time in the near future. They were doing a list of the top ten recent news stories of space in recent days, and apparently, my story made the list (I was number 9).

All in all, it’s been a pretty cool week! 🙂

Bad New from Mars: First Colonists Doomed!

Mars_exploreWith the exploration of Mars continuing apace and a manned missions looming, there has been an explosion of interest in the idea of one day settling the planet. As the non-profit organization known as Mars One can attest, many people are  interested in becoming part of a mission to colonize the Red Planet. In fact, when they first went public, some 200,000 people signed on to become part of the experience.

The fact that the trip would be one-way and that the  plans for getting them there did not yet exist was not an deterrent. But if a recent study from MIT is to be believed, those who choose to go will and have the experience televised will be in for a rather harsh experience. According to a feasibility study produced by researchers at the Institute, the plan has potentially deadly and astronomically expensive flaws.

mars_revelationspaceAfter analyzing the Mars One mission plan, the MIT research group found that the first astronaut would suffocate after 68 days. The other astronauts would die from a combination of starvation, dehydration, or incineration in an oxygen-rich atmosphere. The analysis also concludes that 15 Falcon Heavy launches – costing around $4.5 billion – would be needed to support the first four Mars One crew.

The technology underpinning the mission is rather nebulous; and indeed, that’s where the aerospace researchers at MIT find a number of potentially catastrophic faults. While the technology to set up a colony on Mars does technically exist, most of it is at a very low technology readiness level (TRL) and untested in a Mars-like environment. And the prediction that things will be worked out with time and crowdfunding does not appear to be sufficient.

Mars_one2Mars One will rely heavily on life support and in-situ resource utilization (ISRU) – squeezing water from Martian soil and oxygen from the atmosphere. But these technologies are still a long way off large-scale, industrial use by a nascent human colony on Mars. NASA’s next Mars rover will have an ISRU unit that will make oxygen from the Red Planet’s atmosphere of CO2 – but that rover isn’t scheduled to launch until 2020, just two years before the planned launch of Mars One.

Originally, Mars One’s sign-up list included some 200,000 candidates. That number has now been whittled down to 705 – a fairly even mix of men and women from all over the world, but mostly the US. Several teams of four astronauts (two men, two women) will now be assembled, and training will begin. The current plan is to send a SpaceX Falcon Heavy rocket carrying the first team of four to Mars in 2022 – just eight years from now. 

spaceX-falcon9The whole thing will be televised as a reality TV show, an instrinsic part of the plan since much of the funding is expected to come from media sponsors and advertisers. In the interim, a number of precursor missions – supplies, life-support units, living units, and supply units – will be sent to Mars ahead of the human colonizers. More colonists will be sent fairly rapidly thereafter, with 20 settlers expected by 2033.

The new feasibility study was led by Sydney Do, a PhD candidate at the Massachusetts Institute of Technology who has done similar studies on other space missions. Do and his team ran a computer simulation based on publicly available information about the Mars One plan and the kinds of technologies it would rely on. The researchers entered data about the crew’s age, weight and activities to find out how much food, oxygen and water they would need.

Mars_GreenhouseThey took into account information from Mars One, such as its plan that “food from Earth will only serve as emergency rations” and the astronauts will mainly eat fresh food they grow themselves. The simulation monitored conditions in the Mars One habitat over 26 months – the amount of time between spaceships from Earth that would resupply them – or until the death of a crew member, whichever came first.

The results of their study were presented in a paper at the International Astronomic Union conference in Toronto last month. They suggest that serious changes would need to be made to the plan, which would either call for the astronauts to grow all their plants in a unit isolated from the astronauts’ living space to prevent pressure buildup in the habitats, or import all food from Earth instead of growing it on Mars.

mars_one2The researchers recommend the latter, as importing all the necessary food along with the first wave of colonists (not including the costs of development, operations, communications, and power systems) would cost $4.5 billion and require 15 Falcon 9 Heavy Rockets to transport it. Comparatively, flying all the equipment needed for the astronauts to grow their own food indefinitely which cost roughly $6.3 billion.

On top of all that, Do and his research staff have concluded that the project will not be sustainable financially. While Mars One says each subsequent manned mission will cost $4 billion, Do’s study found that each mission would cost more than the one before, due to the increasing number of spare parts and other supplies needed to support an increasing number of people.

mars_roverNaturally, Mars One replied that they are not deterred by the study. CEO and co-founder Bas Landorp – who helped develop the mission design – said the plan was based on the company’s own studies and feedback from engineers at aerospace companies that make space systems, such as Paragon Space Development and Lockheed Martin. He added that he and his people are “very confident that our budgets, timelines and requirements are feasible”.

In any case, the study does not claim that the plan is bogus, just that it may be overreaching slightly. It’s not unreasonable to think that Mars One could get people to Mars, but the prospects for gradually building a self-sustaining colony is a bit farfetched right now. Clearly, more time is needed to further develop the requisite technologies and study the Martian environment before we start sending people to live there.

Mars_simulationOh well, people can dream can’t they? But the research and development are taking place. And at this point, it’s a foregone conclusion that a manned mission to Mars will be happening, along with additional robot missions. These will help lay the groundwork for eventual settlement. It’s only a question of when that could happen…

Sources: cbc.ca, extremetech.com, web.mit.edu

The Future of Space: Smart, Stretchy, Skintight Spacesuits

biosuitSpacesuits have come a long way from their humble origins in the 1960s. But despite decades worth of innovation, the basic design remains the same – large, bulky, and limiting to the wearer’s range of movement. Hence why a number of researchers and scientists are looking to create suits that are snugger, more flexible, and more ergonomic. One such group hails from MIT, with a skin-tight design that’s sure to revolutionize the concept of spacesuits.

The team is led by Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT who previewed her Biosuit – playfully described by some as a “spidersuit” – at the TEDWomen event, held in San Fransisco in December of 2013. Referred to as a “second skin” suit, the design incorporates flexible, lightweight material that is lined with “tiny, muscle-like coils.”

mit-shrink-wrap-spacesuitSpeaking of the challenges of spacesuit design, and her team’s new concept for one, Dava Newman had the following to say in an interview with MIT news:

With conventional spacesuits, you’re essentially in a balloon of gas that’s providing you with the necessary one-third of an atmosphere [of pressure,] to keep you alive in the vacuum of space. We want to achieve that same pressurization, but through mechanical counterpressure — applying the pressure directly to the skin, thus avoiding the gas pressure altogether. We combine passive elastics with active materials.

Granted, Newman’s design is the first form-fitting spacesuit concept to see the light of day. Back in the 1960’s, NASA began experimenting with a suit that was modeled on human skin, the result of which was the Space Activity Suit (SAS). Instead of an air-filled envelope, the SAS used a skin-tight rubber leotard that clung to astronaut like spandex, pressing in to protect the wearer from the vacuum of space by means of counter pressure.

SAS_spacesuitFor breathing, the suit had an inflatable bladder on the chest and the astronaut wore a simple helmet with an airtight ring seal to keep in pressure. This setup made for a much lighter, more flexible suit that was mechanically far simpler because the breathing system and a porous skin that removed the need for complex cooling systems. The snag with the SAS was that materials in the days of Apollo were much too primitive to make the design practical.

Little progress was made until Dava Newman and her team from MIT combined modern fabrics, computer modelling, and engineering techniques to produce the Biosuit. Though a far more practical counter-pressure suit than its predecessor, it was still plagued by one major drawback – the skintight apparatus was very difficult to put on. Solutions were proposed, such as a machine that would weave a new suit about the wearer when needed, but these were deemed impractical.

mit-shrink-wrap-spacesuit-0The new approach incorporates coils formed out of tightly packed, small-diameter springs made of a shape-memory alloy (SMA) into the suit fabric. Memory alloys are metals that can be bent or deformed, but when heated, return to their original shape. In this case, the nickel-titanium coils are formed into a tourniquet-like cuff that incorporates a length of heating wire. When a current is applied, the coil cinches up to provide the proper counter pressure needed for the Biosuit to work.

Bradley Holschuh, a post-doctorate in Newman’s lab, originally came up with the idea of a coil design. In the past, the big hurdle to second-skin spacesuits was how to get astronauts to squeeze in and out of the pressured, skintight suit. Holschuh’s breakthrough was to deploy shape-memory alloy as a technological end-around. To train the alloy, Holschuh wound raw SMA fiber into extremely tight coils and heated them to 450º C (842º F) to fashion an original or “trained” shape.

mit-shrink-wrap-spacesuit-3 When the coil cooled to room temperature, it could be stretched out, but when heated to 60º C (140º F), it shrank back into its original shape in what the MIT team compared to a self-closing buckle. As spokespersons from MIT explained:

The researchers rigged an array of coils to an elastic cuff, attaching each coil to a small thread linked to the cuff. They then attached leads to the coils’ opposite ends and applied a voltage, generating heat. Between 60 and 160 C, the coils contracted, pulling the attached threads, and tightening the cuff.

In order to maintain it without continually heating the coils, however, the team needs to come up with some sort of a catch that will lock the coils in place rather than relying on a continuous supply of electricity and needlessly heating up the suit – yet it will still have to be easy to unfasten. Once Newman and her team find a solution to this problem, their suit could find other applications here on Earth.

Image converted using ifftoanyAs Holschuh explained, the applications for this technology go beyond the spacesuit, with applications ranging from the militarized to the medical. But for the moment, the intended purpose is keeping astronauts safe and comfortable:

You could [also] use this as a tourniquet system if someone is bleeding out on the battlefield. If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it… An integrated suit is exciting to think about to enhance human performance. We’re trying to keep our astronauts alive, safe, and mobile, but these designs are not just for use in space.

Considering the ambitious plans NASA and other government and private space agencies have for the near-future – exploring Mars, mining asteroids, building a settlement on the Moon, etc. – a next-generation spacesuit would certainly come in handy. With new launch systems and space capsules being introduced for just this purpose, it only makes sense that the most basic pieces of equipment get a refit as well.

And be sure to check out this video of Dava Newman showing her Biosuit at the TEDWomen conference last year:


Sources:
gizmag.com, motherboard.vice.com
, newsoffice.mit.edu

The Future of Space: Building A Space Elevator!

space_elevator2Regularly scheduled trips to the Moon are one of many things science fiction promised us by the 21st century that did not immediately materialize. However, ideas are on the drawing board for making it happen in the coming decades. They include regular rocket trips, like those suggested by Golden Spike, but others have more ambitious plans. For example, there’s LiftPort – a company that hopes to build a space elevator straight to the Moon.

When he was working with NASA’s Institute for Advanced Concepts in the early 2000s, LiftPort President Michael Laine began exploring the idea of a mechanism that could get people and cargo to space while remaining tethered to Earth. And he is certainly not alone in exploring the potential, considering the potential cost-cutting measures it offers. The concept is pretty straightforward and well-explored within the realm of science fiction, at least in theory.

space_elevatorThe space elevator concept is similar to swinging a ball on a string, except it involves a tether anchored to the Earth that’s about 500 km long. The other end is in anchored in orbit, attached to a space station that keeps the tether taut. Anything that needs to be launched into space can simply be fired up the tether by a series of rocket-powered cars, which then dock with the station and then launched aboard a space-faring vessel.

Compared to using rockets to send everything into space, the cost using the elevator is far less (minus the one-time astronomical construction fee). And while the materials do not yet exist to construct 0ne, suggestions have been floated for a Lunar Elevator. Taking advantage of the Moon’s lower gravity, and using the Earth’s gravity well to stabilize the orbital anchor, this type of elevator could be built using existing materials.

space_elevator_lunar1One such person is Laine, who believes the capability exists to build an elevator that would reach from to the Moon to a distance of 238,000 km towards the Earth. Hence why, started two and a half years ago, he struck out to try and bring this idea to reality. The concept behind the Moon Elevator is still consistent with the ball on the string analogy, but it is a little more complicated because of the Moon’s slow orbit around the Earth.

The solution lies in Lagrangian points, which are places of gravitational equilibrium between two bodies. It’s here that the gravitational pull of both bodies are equal, and so they cancel each other out. Lagrangian point L1 is about 55,000 kilometers from the Moon, and that’s the one Laine hopes to take advantage of. After anchoring one end of the “string” on the Moon’s surface, it will extend to L1, then from L1 towards Earth.

lunar_space_elevatorAt the end of the string will be a counterweight made up of all the spent pieces of rocket that launched the initial mission to get the spike into the Moon. The counterweight will be in the right place for the Earth to pull on it gravitationally, but it will be anchored, through the Lagrange point, to the Moon. The force on both halves of the “string” will keep it taut. And that taut string will be a space elevator to the Moon.

What’s more, Laine claims that the Moon elevator can be built off-the-shelf, with readily available technology. A prototype could be built and deployed within a decade for as little as $800 million, he claims. It would be a small version exerting just a few pounds of force on the anchor on the Moon, but it would lay the groundwork for larger follow-up systems that could transport more cargo and eventually astronauts.

liftportTo demonstrate their concept, LiftPort is working on a proof-of-concept demonstration that will see a robot climb the tallest free­standing human structure in existence. This will consist of three large helium balloons held together on a tripod and a giant spool of Vectran fiber that is just an eighth of an inch think, but will be able to support 635 kilograms (1,400 pounds) and withstand strong winds.

Vectran is the same material was used by NASA to create the airbags that allowed the Spirit and Opportunity’s rovers to land on Mars. Since it gets stronger as it gets colder, it is ideal for this high altitude test, which will be LiftPort’s 15th experiment and the 20th robot to attempt an ascent. Laine doesn’t have a prospective date for when this test will happen, but insists it will take place once the company is ready.

LiftPort1Regardless, when the test is conducted, it will be the subject of a new documentary by Ben Harrison. Having learned about Liftport back in 2012 when he stumbled across their Kickstarter campaign, Harrison donated to the project and did a brief film segment about it for Engadget. Since that time, he has been filming Liftport’s ongoing story as part of a proposed documentary.

Much like Laine, Harrison and his team are looking for public support via Kickstarter so they can finish the documentary, which is entitled “Shoot the Moon”. Check out their Kickstarter page if feel like contributing. As of the time of writing, they have managed to raise a total of $14,343 of their $37,000 goal. And be sure to check out the promotional videos for the Liftport Group and Harrison’s documentary below:

Lunar Space Elevator Infrastructure Overview:


Shoot the Moon – Teaser Trailer:


Sources:
 motherboard.vice.com
, lunarelevator.com

News from Space: Rosetta Maps Comet Surface

Rosetta_and_Philae_at_cometLast month, the European Space Agency Rosetta’s space probe arrived at the comet known as 67P/Churyumov–Gerasimenko, thus becoming the first spacecraft to ever rendezvous with a comet. As it continues on its way to the Inner Solar System, Rosetta’s sensing instruments have been studying the surface in detail in advance of the attempted landing of it’s Philae probe.

Because of this, Rosetta has been able to render a map of the various areas on the surface of the comet, showing that it is composed of several different regions created by a range of forces acting upon the object. Images of the comet’s surface were captured by OSIRIS, the scientific imaging system aboard the Rosetta spacecraft, and scientists analyzing them have divided the comet into several distinct regions, each characterized by different classes of features.

rosettamap-1All told, areas containing cliffs, trenches, impact craters, rocks, boulders and parallel grooves have been identified and mapped by the probe. Some of the areas that have been mapped appear to be caused by aspects of the activity occurring in and around the nucleus of the comet, such as where particles from below the surface are carried up by escaping gas and vapor and strewn around the surface in the surrounding area.

So detailed are these images that many have been captured at a resolution of one pixel being equal to an area of 194 square centimeters (30 square inches) on the comet surface. Dr. Holger Sierks, OSIRIS’ Principal Investigator from the Max Planck Institute for Solar System Science, puts it into perspective:

Never before have we seen a cometary surface in such detail. It is a historic moment – we have an unprecedented resolution to map a comet… This first map is, of course, only the beginning of our work. At this point, nobody truly understands how the surface variations we are currently witnessing came to be.

Rosetta_and_Philae_at_comet_node_full_imageThe newly-generated comet maps and images captured by the instruments on Rosetta will now provide a range of detail on which to finalize possible landing sites for the Philae probe to be launched to the surface . As such, the Rosetta team will meet in Toulouse, France, on September 13 and 14 to allocate primary and backup landing sites (from a list of sites previously selected) with much greater confidence.

At the same time, Rosetta has revealed quite a bit about the outward appearance of the comet, and it aint pretty! More often than not, comets are described as “dirty snowballs” to describe their peculiar composition of ice and dust. But Rosetta’s Alice instrument, which was installed by NASA, has sent back preliminary scientific data that shows that the comet is more akin to a lump of coal.

Rosetta_Artist_Impression_Far_625x469Alice is one of eleven instruments carried aboard Rosetta and one of three instrument packages supplied by NASA for the unmanned orbiter. Essentially, it’s a miniature UV imaging spectrograph that looks for thermal markers in the far ultraviolet part of the spectrum in order to learn more about the comet’s composition and history. It does this by looking specifically for the markers associated with noble gases, such as helium, neon, argon, and krypton.

The upshot of all this high-tech imaging is the surprising discovery of what 67P/Churyumov-Gerasimenko looks like. According to NASA, the comet is darker than charcoal. And though Alice has detected oxygen and hydrogen in the comet’s coma, the patches of barren ice that NASA scientists had expected aren’t there. Apparently, this is because 67P/Churyumov-Gerasimenko is too far away from the warmth of the sun to turn the ice into water vapor.

rosetta-1Alan Stern, Alice principal investigator at the Southwest Research Institute in Boulder, Colorado, had this to say about the revelation:

We’re a bit surprised at just how unreflective the comet’s surface is and how little evidence of exposed water-ice it shows.

Launched in 2004, Rosetta reached 67P/Churyumov-Gerasimenko by a circuitous route involving three flybys of Earth, one of Mars, and a long detour out beyond Jupiter as it built up enough speed to catch up to the comet. Over the coming months, as the Rosetta spacecraft and comet 67P move further into the solar system and approach the sun, the OSIRIS team and other instruments on the payload will continue to observe the comet’s surface for any changes.

alice-first-findings-3Hence why this mission is of such historic importance. Not only does it involve a spacecraft getting closer to a comet than at time in our history, it also presents a chance to examine what happens to a comet as it approaches our sun. And if indeed it does begin to melt and breakdown, we will get a chance to peer inside, which will be nothing less than a chance to look back in time, to a point when our Solar System was still forming.

Sources: gizmag, (2), jpl.nasa.gov, nasa.gov

Forty-Fifth Anniversary of Apollo 11

Apollo11_launch1Today, July 20th, marks the 45th anniversary of the first step being taken on the Moon. And even though the coming decades may involve astronauts setting foot on Mars or a nearby asteroid, the Moon landing will forever remain one of humanity’s greatest accomplishments. And the many speeches, footage and images associated with the mission remain firmly rooted in public consciousness.

Born during the closing months of the Eisenhower administration as a follow-up to Project Mercury – which successfully put astronauts into orbit – Project Apollo was conceived when spaceflight was still very much in its infancy. However, it was under President Kennedy that the goal of “landing a man on the Moon and returning him safely to the Earth” by the end of the decade truly began.

kennedy_moonspeechAnd though some within NASA were already doing some preliminary planning for a manned mission to the Moon in the late 1950s, there was no hardware that could see the mission fly, no rockets large enough to launch a manned spacecraft all the way to the Moon, and no provisions for managing a program of that magnitude. The men and women who brought the lunar landing to fruition were forced to invent almost everything as they went along.

And in the nine years between President Kennedy promising America the Moon and Neil Armstrong’s small step, NASA developed an unprecedented amount of technology and know-how that continues to shape the way NASA and other space agencies plan and implement missions today. These include the Saturn V multistage rockets, which are currently being refurbished for a manned mission to Mars by 2030.

Apollo_11Launching on from Cape Kennedy on the morning of July 16th, 1969, the mission sent Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module Pilot Edwin “Buzz” Aldrin into an initial Earth-orbit. Then, just two hours and 44 minutes after launch, another engines burn put Apollo 11 into a translunar orbit. Four days later, the Lunar Module touched down and the three men – with Armstrong in the lead – stepped onto the Lunar surface.

And for those looking to participate in the anniversary, there are several ways you can participate. On Twitter, @ReliveApollo11 from the Smithsonian National Air and Space Museum is reliving the highlights from Apollo 11 mission to the Moon in “real time”. Also, @NASAHistory is tweeting images and events from the mission, and journalist Amy Shira Teitel (@astVintageSpace) is tweeting pictures, facts and quotes from the mission, again in “real time”.

apollo11_flag2At 7:39 p.m. PDT (10:39 p.m. EDT), when Armstrong opened began the first spacewalk on the Moon, NASA TV will replay the restored footage of Armstrong and Aldrin’s historic steps on the lunar surface. On Monday, July 21 at 7 a.m. PDT (10 a.m. EDT) NASA TV will be broadcasting live from Kennedy Space Center in Florida, where they will be renaming the center’s Operations and Checkout Building in honor of Armstrong, who passed away in 2012.

The renaming ceremony will include NASA Administrator Charles Bolden, Kennedy Center Director Robert Cabana, Apollo 11′s Collins, Aldrin and astronaut Jim Lovell, who was the mission’s back-up commander. International Space Station NASA astronauts Wiseman and Steve Swanson, who is the current station commander, also will take part in the ceremony from their orbiting laboratory 260 miles above Earth.

Apollo_11_bootprintOn Thursday, July 24 at 3 p.m. PDT (6 p.m. EDT), which is the 45th anniversary of Apollo 11′s return to Earth, the agency will host a panel discussion – called NASA’s Next Giant Leap – from Comic-Con International in San Diego. Moderated by actor Seth Green, the panel includes Aldrin, NASA Planetary Science Division Director Jim Green, JPL systems engineer Bobak Ferdowsi, and NASA astronaut Mike Fincke.

In addition to Aldrin recounting his experiences, Fincke and the other NASA staff are slated to talk about the new Orion space capsule and the Space Launch System rocket – both of which will carry humans on America’s next great adventure in space – and what the future holds for space exploration. These will no doubt include talk of the planned missions to an asteroid, Mars, and quite possibly the construction of a settlement on the Moon.

apollo11_flag1The NASA.gov website will host features, videos, and historic images and audio clips that highlight the Apollo 11 anniversary, as well as the future of human spaceflight. You can find it all by clicking here. And if you don’t have NASA TV on your cable or satellite feeds, you can catch it all online here. Plenty has been happening already, marking the anniversary of the launch and recapturing the mission in “real-time”.

Forty five years later, and Apollo 11 still holds a special place in our collective hears, minds, and culture. One can only hope that the next generation of astronauts prove as equal to the task as those who made the Moon Landing were. And I’m sure that when they do make history, Neil Armstrong (may he rest in peace) will be watching approvingly.

And be sure to check out this video from Spacecraft Films, showing the entire Apollo 11 mission in 100 seconds:


Sources: universetoday.com, motherboard.vice.com, nasa.gov, spacecraftfilms.com

Friday the 13th “Honey Moon”

image

Friday the 13th may be a time for worry for the more superstitiously inclined. But for those who turned out to gaze at the night sky in the wee hours of the morning, it was also a chance to see something truly rare and beautiful. It’s what’s known as a “honey moon”, and one which won’t happen again in our lifetime.

Basically, a honey moon is something that happens during the summer solstice when the sun’s path across the sky at its highest during this month and the moon at its lowest, which keeps the lunar orb close to the horizon and makes it appear more amber than other full moons this year.

https://i0.wp.com/images.nationalgeographic.com/wpf/media-live/photos/000/806/cache/honey-moon-2014-solstice_80614_600x450.jpgThe amber colors are due to the scattering of longer wavelengths of light by dust and pollution in our atmosphere. As astronomer Raminder Signh Samra of the H.R. MacMillian Space Centre in Vancouver said:

It is a similar phenomenon as seen at sunset, when sunlight is scattered towards the red end of the spectrum, making the sun’s disk appear orange-red to the naked-eye.

The most spectacular part of the honey moon begins hours before midnight, due to an illusion by which the moon appears larger to sky-watchers when it’s near the horizon than when it hangs high in the sky. It reached it’s full phase last night at 12:13 am EDT, at least for those of us living in North America.

https://i0.wp.com/kimberlysnyder.net/blog/wp-content/uploads/2009/06/img_news_solstice_scheme11.gifScientists are not entirely sure what accounts for this optical illusion of a larger moon near the horizon, but they suspect it has something to do with the human mind trying to make sense of the moon’s proximity to more familiar objects like mountains, trees and houses in the foreground.

The monthly full moon always looks like a big disk, but because its orbit around the Earth is egg-shaped, there are times when the moon it is at its shortest distance from Earth (called perigee), some 362,065 km (224,976 miles) away. This month the perigee just happened to coincide with the full phase.

https://i0.wp.com/cdn.images.express.co.uk/img/dynamic/128/590x/moon-482025.jpgHence why it may have made it appear unusually large to some keen-eyed sky-watchers. As Samra explained:

The moon illusion should be more prominent during this full moon as it will graze closer to the horizon than at any other time of the year. This will make the moon appear more amber than other full moons of the year.

A full moon coinciding on Friday the 13th is not all that uncommon, occurring every three or so years. But having the combination of a honey moon and Friday the 13th is rare, last occurring on June 13, 1919. As for the next, we’ll have to wait until June 13, 2098, for the next one.

In short, stellar events like this one – where’s there’s a perfect conjunction between the occult and the night sky – only happen once every 80 or 90 years. So if you missed last night’s and are sad about it… Well, the good news is they are doing great things in medicine these days!

And if guys like Kurzweil are to be believed, clinical Immortality is just a few decades away. Until next time, be sure to keep your eyes to the heavens. Some interesting things happen there, apparently!

Source: universetoday.comnewsnationalgeographic.com

News from Space: Mars Gets New Crater!

martian_craterThe Mars Reconnaissance Orbiter (MRO) captured this image of a 50-meter wide crater on the Red Planet back on March 28th, 2012. But the impressive thing is that this same crater was not there when the MRO took pictures of the area the day before. In other words, this crater was spotted less than a day after the impact that formed it. This is a record=setting events, since it usually takes a few years before the presence of new craters have been confirmed.

In this case, though, the constant sweep of the Mars weather camera (called the Mars Color Imager, or MARCI) picked up the black smudge that is a telltale sign of a fresh impact. Because the imager is low-resolution, it sees a large area of the surface, and does so all the time. It’s also the largest crater in the solar system ever seen with before and after shots. At 50 meters or so across, it’s half the length of a football field, so the impacting object was probably up to a few meters across.

mars_crater_marcimars_crater_marci2Something that small would burn up in Earth’s atmosphere, but given that Mars has a much thinner atmosphere (about 1 percent as thick of Earth’s) rocks of this size make it to the surface with ease. Once they make it to the ground, they hit hard enough to carve out a hole and blast out ejecta debris – which was how the crater was found. But the atmosphere is thick enough to cause a lot of pressure in front of the incoming meteoroid, which can break it up into smaller pieces.

As you can see from the images above – the top which was taken on March 27th and the bottom on the following day – there was one big crater, one smaller one, and quite a few even smaller ones around the main one. These may have been from pieces of the meteoroid that broke up as it came in. Not only that, but landslides were observed in the area that occurred around the same time, so they may have been caused by the seismic ground wave from the impact as well.

mars_avalanche4Events like this are not only novel, they are also very useful for scientists, since they help them to understand how impacts have shaped the Martian landscape. They also help determine the number of small impacts suffered by Mars (and by extrapolation, Earth), and in some cases reveal what’s underneath the surface of the planet (including ice). This latest impact is many ways a gift, since most craters are very old and the atmosphere have eroded them to the point that there results are no longer fresh.

Kudos to the MRO team for their fine work in spotting this new Martian surface feature. And in the meantime, be sure to enjoy this video that explains this record find, courtesy of the NASA Jet Propulsion Laboratory.


Sources:
slate.com, space.IO9.com, mars.nasa.gov