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Rovers on Venus.


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#1 BlameTheEx

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Posted 12 October 2004 - 05:02 AM

There is now some plausibility for sending rovers to venus. Probes have landed before, but they only lasted as long as their cooling due to the temperature of about 464 C. A rover style mission seemed out of the question, as there would be no way of providing the power over an extended time for cooling.

Right now the probes that landed were the Russian Venera series.

http://nssdc.gsfc.na...ary/venera.html

But now there seems a chance to create a working rover without cooling. Look here:

http://www.grc.nasa..../SiCReview.html

The big problem was the electronics. Silicon circuits won't work much above 100 C, but Silicon carbide works at up to 600 C. In a few years a silicon carbide computer, communications, and silicon carbide image sensors will be possible. The rest of such a rover is already possible.

Why should we be interested in Venus? Apart from the fact that we would like to know more about planets in general, it could be argued that it is a candidate for life. It is far too hot for earth style life, but it does have advantages. In particular it is probably volcanically active. That means fresh high energy chemicals brought to the surface. That is the sort of food that the most primitive of all life needs. There is no liquid water but the atmosphere probably makes a fair alternative to liquids as a medium for chemical reactions, especially at such high temperatures. Life based on gasses rather than water is just about plausible provided that a sufficient range of organic chemicals are gasses at the temperate involved.

#2 Tormod

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Posted 12 October 2004 - 05:50 AM

Agreed! I very much look forward to Venus Express which will be launched in October next year. If it is as successful as Mars Express we are in for a treat.

http://www.esa.int/e..._index_0_m.html

No rovers there but at least a serious look at the planet.

Do you happen to know if NASA has set a date for a possible Venus rover mission?

#3 BlameTheEx

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Posted 13 October 2004 - 03:16 AM

Tormod

Sadly my post is pure speculation. As that article on Silicon Carbide semiconductors is off a NASA page, I expect they are monitoring the situation, but I doubt they have gone much further yet. Better to sit on their hands while private industry pays for the development. It could be that they are more interested in the radiation resistance of Silicon Carbide. Radiation is a real hazard to electronics in space, especial near Jupiter.

#4 Stargazer

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Posted 17 October 2004 - 01:51 AM

I would love to see rovers being sent to Venus, but I would also like to see sample return missions as well as balloons and more orbiters. The Magellan spacecraft gave us a great map of the surface, but I believe a more closer inspection is needed to understand more about Venus. I think it is important to closely study the rocky planets Mercury, Venus and Mars to learn how they became so different. This could possibly be valuable when we start looking for Earth like planets orbiting other stars.

#5 BlameTheEx

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Posted 20 October 2004 - 04:51 AM

Stargazer

Um. Sample returns from venus? Nice idea but not as yet plausible. The gravity of Venus is comparable to earth. You would need to land a multistage booster, that can handle 464C temperatures. Worse, consider the drag of that atmosphere on a small rocket!

#6 Tormod

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Posted 20 October 2004 - 08:56 AM

I just plugged "sample return mission +venus" into Google and found this rather interesting document!

Venus Sample Return Mission Studied
http://www.jpl.nasa...._1986_1106.html

It's 18 years old now. Posted Image

#7 Stargazer

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Posted 21 October 2004 - 12:45 AM

Originally posted by: BlameTheEx
Stargazer

Um. Sample returns from venus? Nice idea but not as yet plausible. The gravity of Venus is comparable to earth. You would need to land a multistage booster, that can handle 464C temperatures. Worse, consider the drag of that atmosphere on a small rocket!

Well yes the mission would be very difficult and expensive, but not at all impossible. Also, you don't need to pick up hundreds of kg, only small samples would do. The gravity is 0.88 G I think, so it's lower than on Earth. I was picturing a rocket that could reach altitudes of a few hundred km or so, exactly at the right moment to be captured by the orbiter. Obviously this would still be quite a task... Maybe we should practice on Mars first?

#8 Stargazer

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Posted 21 October 2004 - 12:47 AM

Originally posted by: Tormod
I just plugged "sample return mission +venus" into Google and found this rather interesting document!

Venus Sample Return Mission Studied
http://www.jpl.nasa...._1986_1106.html

It's 18 years old now. Posted Image


Very interesting and well thought out mission! I never considered balloons for the sample return mission, although it does look like an interesting solution.

#9 Tormod

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Posted 21 October 2004 - 01:35 AM

Originally posted by: Stargazer
Maybe we should practice on Mars first?


Yes. No dates are set as of yet, AFAIK. NASA has very little on the subject.

Here's one page:

JPL: Beyond 2009
http://marsprogram.j...reMissions.html

#10 Aki

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Posted 22 October 2004 - 12:10 AM

About Venus... since the temperature is so high there, would there be any organisms that could live at such temperature?

#11 Stargazer

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Posted 22 October 2004 - 01:46 AM

Originally posted by: Tormod


Originally posted by: Stargazer
Maybe we should practice on Mars first?


Yes. No dates are set as of yet, AFAIK. NASA has very little on the subject.

Here's one page:

JPL: Beyond 2009
http://marsprogram.j...reMissions.html


One thing I like about space exploration today is that a lot of it is done through international cooperation. About sample return missions, it is part of the long term exploration programme that ESA has initiated, called Aurora. The sample return mission will be launched as two missions between 2011 and 2014, and before that, in 2007 if I remember correctly, ESA will send a rover to Mars, and one of its main objectives is to search for life. Link to the Aurora programme: http://www.esa.int/S...rora/index.html

#12 Stargazer

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Posted 22 October 2004 - 01:49 AM

Originally posted by: Aki
About Venus... since the temperature is so high there, would there be any organisms that could live at such temperature?


Personally I would doubt that, but there are some new ideas about life in the atmosphere. I don't know enough about chemistry or biology to say if this is at all possible, but here is an article: http://www.newscient...p?id=ns99992843

#13 BlameTheEx

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Posted 22 October 2004 - 03:36 AM

Tormod

That "Venus Sample Return Mission Studied" sums up the problems well. You can't use a small rocket from the surface. It does offer solutions, but they are so complex I doubt the projected research budget, or the odds against success would make pleasant reading.

May I congratulate the article on reaching its majority, but I rather suspect it will be collecting its pension before anything happens.

Aki

The limits for life are, to say the least, uncertain. Wherever there are chemical reactions there is some hope of self reproducing catalysts. That is my definition of life, but it might not be yours. The wider the range of elements, and complex molecules available, the greater the number of chemical reactions possible, the more likely that such life will start.

Temperature might not be a problem. Lots of complex molecules are stable at such temperature. The big problem is liquids. For molecules to interact, they must be moved. On earth life uses water as the medium. In theory any liquid in which a good range of molecules can be dissolved might suffice. At those temperatures I would suspect that almost any liquid would dissolve just about anything, but what would be liquid? Given the absence of free oxygen, complex carbon based molecules might be possible. Some sort of wax, or grease? Carbon bonds are strong enough to survive the temperature, and a large enough molecule should be liquid.

However, my main hope is chemistry with gas as a medium.

But these are arguments for life on Venus now. Maybe there is none now, but there was once. There is a good argument that Venus had water, and thus perhaps life, in the past.

Check this out:

http://spacelink.nas...nus.Discoveries

#14 alexander

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Posted 26 October 2004 - 07:01 AM

I dont see a reason why it is not possible to find any form of life on Venus. There are organisms on earth that have adapted to survive in extreme environments, some bacteria can suvive temperatures of -90 degrees celcius, others like the thermoasidphile can survive temperatures of up to 110 degrees celcius. I really dont see why an organism can not adapt to 400 degree weather, well i can see where someone who will argue can come from, but if a bacteria developed a really thick cell wall, mutated in some way, i dont see why it isnt possible for it to suvive temperatures that are 4 times of those on earth.

#15 BlameTheEx

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Posted 26 October 2004 - 09:36 AM

alexander.

Earth style life can't adapt so easily. A thick cell wall or mutation can't alter the lack of liquid water. There is not even water vapour on Venus, but it wouldn't help if there was. Nothing is going to make it liquid at those temperatures.

Any life that exists there now will not be water based, and will have no relationship whatsoever to earth life. This is not a mater of adaptation. It is a mater of starting from a completely different chemistry. DNA for instance, would not take those temperatures. Genetic information must be coded using something else.

#16 alexander

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Posted 26 October 2004 - 12:16 PM

i guess you are right, but it doesnt mean that nothing can survive the conditions....