
AKATSUKI preparing for orbital insertion around Venus - bane
http://global.jaxa.jp/projects/sat/planet_c/
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throwaway_yy2Di
Here's a very interesting article about this orbit insertion, how the main
rocket engine was destroyed in flight, and how JAXA hacked together a solution
using only RCS thrusters:

    
    
        The Akatsuki story is particularly interesting for two
        reasons. First, because the failure was documented in
        exceptional detail, with telemetry from the propulsion and
        attitude control system available to reconstruct, like the
        “black box” on an airliner, the events leading up to the
        anomaly. JAXA is to be commended on its openness: in the
        challenges of space we can all learn from others, and some
        western agencies are not always as forthcoming with
        technical details of anomalies. And second, because the
        Akatsuki story may yet have a happy ending.
    

[http://www.planetary.org/blogs/guest-
blogs/2015/1204-akatsuk...](http://www.planetary.org/blogs/guest-
blogs/2015/1204-akatsuki-returns-to-venus.html)

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talloaktrees
it's funny how just having played Kerbal Space Program let's me understand
what you are talking about

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hcarvalhoalves
I'm 30 years old and I am not even ashamed to say KSP is awesome. Now I
understand most things going on aerospace.

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3pt14159
I know most people are excited about humans on Mars, but I'm far more excited
about Venus. 40 or 50kms up Venus is actually quite habitable. Similar
gravity, pressure, calm wind speeds. We could build floating cities and create
oxygen with floating bioengineered plants that slowly change the oxygen
content of the planet. We could use particles or strategically placed solar
panel arrays to shield off excess sunlight while we slowly change the
atmosphere from CO2 to O2 + other gases.

Mars is just a cold crappy desert.

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bad_alloc
Problems with Venus:

* Acid atmosphere and extreme winds

* No easy surface access -> No on-site resource extraction

* No magnetic field -> more radiation

* Larger delta-V requirement for a round trip

* We have no launch systems built for a launch while suspendend in the atmosphere

* Low water content

* Much less signs that suggest previous habitability (hence Mars is more interesting)

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3pt14159
* Acid atmosphere is mostly near below the surface, and is fixable in the long run.

* Suface access can be done by robots, resource extraction can happen on the surface and balloons can lift the resources to the habitable zone.

* No magnetic field, agreed. Problem.

* Larger delta-V, less of an issue in the long run. It's easier to get to Detroit than Cuba from Toronto, but most people winter in Havana.

* Launch systems are easier that bioengineering.

* Water can be imported or synthesized. We'll have lots of extra O2 with all that CO2 we'll be converting.

* We haven't really looked at Venus. We've sent some soviet probes in for a couple of hours each back in the 80s, and they focused on the hellish surface.

In terms of long term development of human cities, I still think Venus is a
far better candidate than Mars, even if Mars is easier for now.

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structural
We still don't have a set of robots whose lifetime will be measured in days,
not hours. Really, if the atmosphere was fixed a bit then most of what you
said would become possible, but it's unclear just how that's going to happen,
especially at first.

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shostack
What sorts of implications might there be if we actually had a way of fixing
the atmosphere? I imagine that it is intimately connected to other aspects of
the planet.

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cstross
One huge problem with Venus, even if we could "fix" the atmosphere, is that
there's no working plate tectonic system. It's hypothesized that the build-up
of stresses actually leads to the crust liquefying every couple of hundred
million years. There's also the slight problem of the Venusian "day" being
116.75 Earth days (compared to a year 243.69 days long). It's not tidally
locked but there are some pretty fierce winds in the stratosphere (at ground
level the atmosphere is so dense -- 92 bar pressure -- that wind speeds are on
the order of 1 m/s).

Next, there's a huge amount of heat trapped in the atmosphere. "Fixing" it
isn't just a matter of dumping comets full of water into the atmosphere,
there's the slight matter of Venus being a whole lot closer to the sun that
Earth, and receiving a much higher level of insolation.

All in all, the lack of a magnetic field is relatively minor compared to the
other issues.

Flip side: Earth atmospheric gas mix at STP is actually a pretty efficient
airship lifting gas on Venus and would provide about equivalent lift per unit
volume 30-40km up in the stratosphere as hydrogen provides to a terrestrial
airship at sea level. (In other words, you could in principle build a zeppelin
where you could walk around inside the lift cells of in shirt sleeve
conditions.) And there's still a chunk of atmosphere above that to provide
radiation shielding. So a human "base" in the Venusian cloud tops is
conceivable, albeit technically challenging.

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shostack
Thanks for all the details!

Given your knowledge of the science fiction space, are you able to recommend
any books that delve into what living/working in a Venusian cloud-top base
might be like at the scientific level of Seveneves, or similar to the "slice
of life" approach of PlanetES? I always had a thing for wanting to know more
about the nitty gritty of living in such a "Cloud City" type of place.

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lmm
Coming at this a little sideways, the Eclipse Phase sourcebooks might be what
you're after - Sunward ( [http://eclipsephase.com/releases/sunward-inner-
system](http://eclipsephase.com/releases/sunward-inner-system) ; it's
liberally licensed so there are legitimate torrents around as well ) is likely
to have the most about the Venus aerostat habitats in-setting. Eclipse Phase
is intended as an RPG but it's extremely hard sci-fi that at times feels it's
as much a futurological thesis as a game.

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jgrahamc
This is awesome. Akatsuki failed to enter Venusian orbit five years ago and
the team managing it managed to make it hibernate for almost 5 years.

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robin_reala
After they worked out how to return it the team published this image:
[http://www.cosmonoticias.org/wp-
content/uploads/2015/01/akat...](http://www.cosmonoticias.org/wp-
content/uploads/2015/01/akatsuki.jpg)

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AstroJetson
The update is that burn happened and that it appears to have worked. They are
watching the track to see what the orbit is. Nice job on their part of trying
to the mission.

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TaylorSwift
United States really need more advanced space explorations.

It is good that many other nations such as Russia, China, Japan, and India
have recently been visiting such interest. But their quests are really dwarfed
in terms of technology and vision.

The race against Soviet Union was what drove United States to its great
height. Instead of spending resources on policing the world, space exploration
is really the way to go. Investment allocation on intellectual capital through
space exploration must be prioritized so that we can bring the best out of
human civilization.

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leet
Am I the only one thinking about naruto?

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heapcity
Much praise and glory are due to the people of Japan for such a courageous and
expensive undertaking.

