Posts Tagged ‘exploration’

Cloud City on Venus

November 13, 2018

With a surface temperature hot enough to melt lead, Venus would not seem to be a candidate for manned exploration, but NASA seems to think otherwise, if this article in the Daily Mail is any indication.

Popular science fiction of the early 20th century depicted Venus as some kind of wonderland of pleasantly warm temperatures, forests, swamps and even dinosaurs.

In 1950, the Hayden Planetarium at the American Natural History Museum were soliciting reservations for the first space tourism mission, well before the modern era of Blue Origins, SpaceX and Virgin Galactic.

All you had to do was supply your address and tick the box for your preferred destination, which included Venus.

Today, Venus is unlikely to be a dream destination for aspiring space tourists.

As revealed by numerous missions in the last few decades, rather than being a paradise, the planet is a hellish world of infernal temperatures, a corrosive toxic atmosphere and crushing pressures at the surface.

Despite this, NASA is currently working on a conceptual manned mission to Venus, named the High Altitude Venus Operational Concept – (HAVOC).

But how is such a mission even possible? Temperatures on the planet’s surface (about 460°C) are in fact hotter than Mercury, even though Venus is roughly double the distance from the sun.

This is higher than the melting point of many metals including bismuth and lead, which may even fall as ‘snow’ onto the higher mountain peaks.

The surface is a barren rocky landscape consisting of vast plains of basaltic rock dotted with volcanic features, and several continent-scale mountainous regions.

It is also geologically young, having undergone catastrophic resurfacing events.

Such extreme events are caused by the build up of heat below the surface, eventually causing it to melt, release heat and re-solidify.

Certainly a scary prospect for any visitors.

Luckily, the idea behind NASA’s new mission is not to land people on the inhospitable surface, but to use the dense atmosphere as a base for exploration.

No actual date for a HAVOC type mission has been publicly announced yet.

This mission is a long term plan and will rely on small test missions to be successful first.

Such a mission is actually possible, right now, with current technology. The plan is to use airships which can stay aloft in the upper atmosphere for extended periods of time.

As surprising as it may seem, the upper atmosphere of Venus is the most Earth-like location in the solar system.

Between altitudes of 50km and 60km, the pressure and temperature can be compared to regions of the Earth’s lower atmosphere.

The atmospheric pressure in the Venusian atmosphere at 55 km is about half that of the pressure at sea level on Earth.

In fact you would be fine without a pressure suit, as this is roughly equivalent to the air pressure you would encounter at the summit of Mount Kilimanjaro. Nor would you need to insulate yourself as the temperature here ranges between 20°C and 30°C.

The atmosphere above this altitude is also dense enough to protect astronauts from ionising radiation from space.

 

HAVOC

 

The greatest disappointment of this space age in which we have learned so much about the planets is that not only is there no life on the other planets but they are all so hostile to life that manned exploration and colonization is going to be much more difficult than the science fiction writers of an earlier age could have imagines. Venus is not the swampy world with dinosaurs they imagined, but a literal inferno. Mars is not the home of an ancient civilization that may be planning to conquer Earth to rejuvenate their dying planet but a small, cold world with a very thin atmosphere. Even other solar systems do not offer much hope. Hot Jupiters seem to be the rule rather than the exception. It is safe to say that the Earth wouldn’t exist it there were a Jupiter in Mercury’s orbit. Nice Earthlike planets seem to be rather rare, though Earth sized planets are not easy to detect.

Well, if it were easy, it wouldn’t worth doing and the fact that colonizing the other planets is more difficult than we might have thought only adds to the glory once we have done it. We really need to establish humanity on other planets. It is never a good idea to carry all one’s eggs in one basket. The sooner we can spread ourselves far and wide across the universe, the better the chances of the long term survival of the species.

I think we ought to take the idea of a floating base for exploration a couple of steps further. Why not floating cities in the atmosphere of Venus? I can imagine a time in which there will be thousands or even millions of people living and working among the clouds of Venus. Perhaps they will be working on terraforming Venus, lowering the planet’s temperature and altering its atmosphere to something breathable. Maybe someday Venus really will be a tropical paradise. In the meantime, living in the clouds will do.

Future Venus colony

 

Personally, though, I’d rather live on Mars.

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Growing Crops on Mars

June 27, 2016

We may have already a taken a step towards the colonization of Mars. Any colony on Mars whether a permanent settlement or a long-term scientific research expedition will have to be largely self-sufficient because of the long travel time from Earth. At the very least, humans living on Mars for any great length of time will have to be able to get food and water on Mars, if possible. Obviously, given Mars’s thin atmosphere, it will not be possible to plant fields of crops out in the open, but it may be possible to create domed habitations in which vegetables can be grown. This would be a lot easier if Martian soil could be used or modified since bringing soil from Earth, or hydroponic equipment would likely be prohibitively expensive.

Mars

It is not clear whether terrestrial plants can grow in Martian soil, given the lack of organic matter and different chemical composition. There is some encouraging news from The Netherlands in this article in phys.org.

Dutch scientists said Thursday crops of four vegetables and cereals grown on soil similar to that on Mars have been found safe to eat, amid plans for the first manned mission to the planet.

Abundant harvests of radishes, peas, rye and tomatoes all grown on the soil were found to contain “no dangerous levels” of heavy metals, said the team from Wageningen University in the Netherlands.

“These remarkable results are very promising,” said senior ecologist Wieger Wamelink.

“We can actually eat the radishes, peas, rye and tomatoes, and I am very curious what they will taste like.”

Future Mars settlers will have to take food supplies with them and then plant crops in order to survive.

So using soil developed by NASA to resemble that of the red planet, the university has been experimenting since 2013 and has managed to raise 10 crops.

But uncertainty remains about whether they would absorb the high levels of heavy metals such cadmium, copper and lead, present in Mars soil.

Further tests are now needed on the remaining six crops, including potatoes, in research which is being backed by a crowd-funding campaign.

NASA plans a manned trip to Mars within the next 10 to 15 years or so, and similar projects are also being pursued by US billionaire Elon Musk and the Dutch company Mars One, tentatively aiming to set up human colonies on the Red Planet.

The Mars One project has backed the Wageningen experiments and is currently undertaking a third selection to whittle down the remaining 100 candidates hoping to be among their astronauts to 40.

“It’s important to test as many crops as possible, to make sure that settlers on Mars have access to a broad variety of different food sources,” said Wamelink.

When I read the headline, I thought that they had grown the vegetables and grains in actual Martian soil samples and I was a little disappointed to learn that the soil used was Earth soil made to simulate Martian soil. It does show that it is at least possible to use Martian soil, though I think it would be better to obtain actual Martian soil to be sure. No matter how well designed our probes are, there is always a possibility that we have overlooked something that could be only be discovered by human beings in laboratories on Earth.

If the members of a Martian expedition do grow their own food, they will need to bring along bacteria from Earth to add the necessary organic components to make the soil more Earth-like. Such bacteria could be genetically modified to flourish in Martian conditions. No form of terrestrial life can survive on the surface of Mars, at present, the thin atmosphere cannot shield the surface from deadly ultraviolet radiation, but there is no reason Terran life couldn’t survive underground. Conditions wouldn’t that much worse than in Antarctica. This bacteria, adapted for Mars could be the first step in terraforming Mars for human habitation.

So, when can I leave for Mars?

One of these days, I'd like to look out my window and see this.

One of these days, I’d like to look out my window and see this.


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