2020 era Orion CEV in Venus orbiter mission

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>A solar powered aircraft could stay aloft indefinitely<p><hr /></p></p></blockquote><br />At least until the chemicals got to the aircraft. You would need to stay above those. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

How long of a flight are we talking? If it is longer than about 3 weeks, we should look providing a module shielded from radiation. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[JonClarke]

I would envisage the aircraft would be flying at altitudes where temperatures and pressures were reasonable. So "indefinitely" would mean weeks.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[mithridates]

Apparently it's almost no problem at all to design a craft to withstand the acidic environment. Geoffrey Landis has a few papers on his site on what they could look like. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[willpittenger]

What about acids? <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[gunsandrockets]

"I would envisage the aircraft would be flying at altitudes where temperatures and pressures were reasonable."<br /><br />Geoffrey Landis has already identified a zone of altitude in the Venusian atmosphere he calls the sweet spot; where temperature, pressure and illumination are similar to that on the surface of the Earth.

 

[gunsandrockets]

"A minimum energy round trip to Venus without landing requires 32 km/s, the same as a round trip to Mars without landing."<br /><br />???<br /><br />How does that add up? Figures I found for Mars...<br /><br />http://www.pma.caltech.edu/~chirata/deltav.html<br /><br />...even using all propulsive maneuvers I only come up with a total of 12.2 km/s round trip, going from low Earth orbit to low Mars orbit and back.<br /><br />Could you break down that 32 km/s total for me into the various mission segments? I'm trying to see how you reached that figure.

 

[JonClarke]

You have answered your own question. The 32 km/s is from earth surface and back, not LEO to LEO. <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[gunsandrockets]

"You have answered your own question."<br /><br />Alrighty. Just one more question then.<br /><br />"A minimum energy round trip to Venus without landing ... [requires] the same [delta v] as a round trip to Mars without landing."<br /><br />Is this correct? Do you wish to make any clarifications?<br /><br />I haven't found the delta V numbers for the Venus mission yet, though I am starting to dig around. If you are correct then astronautix.com has made a big error in the article about the Venus orbiter mission, since astronautix describes the Venus mission as much less massive than a comparable Mars mission. If astronautix screwed up, you should send him an email so he can correct the article.<br /><br />UPDATE<br /><br />Never mind. <br /><br />I just finished skimming the NASA source document the astronautix article is based upon. Astronautix is correct.<br /><br />The NASA document has a detailed comparison of the Venus orbiter mission vs a Mars orbiter mission and the delta V needed for each leg of the missions. The Mars mission requires a total of 5.68 miles/sec of delta V, and the Earth reentry capsule hits 52,000 fps. The Venus mission requires a total of 4.58 miles/sec of delta V and the Earth reentry capsule hits 48,000 fps. The initial weight of the Mars mission in LEO (400 miles) is 2.43 million pounds. The initial weight of the Venus mission is 1.41 million pounds.<br /><br />

 

[gunsandrockets]

Here's something fun.<br /><br />http://en.wikipedia.org/wiki/Manned_Venus_Flyby<br /><br />http://upload.wikimedia.org/wikipedia/en/4/49/VenusFlybyCutaway.jpg<br /><br />It's a really detailed description of a manned Venus flyby mission using modified Apollo equipment. The mission, though in some ways nothing but a stunt, could have been flown around the same time as the Skylab mission and for practically the same effort!

 

[JonClarke]

The numbers I have for Venus are:<br /><br />11.2 = Earth escape <br /> 2.5 = Transfer to voyage orbit <br /> 2.7 = voyage orbit to Venus orbit<br />--------------------------------------------------------------<br />16.4 = Earth surface - Venus orbit - Earth surface<br /><br />If you want to land, Venus orbit to surface =10.4<br /><br />All numbers km/s<br /><br />You would want a bit more reserve of course.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[bdewoody]

I agree with Dragon4 on this one. For the foreseeable future a manned mission to orbit Venus would be a massive waste of time, money and valuable resources.<br /><br />It ain't cheaper if we don't get otherwise unobtainable information from the mission, it's just a waste of money.<br /><br />It's like saving money on the cheaper can of tuna and then never eating it. Is that really saving money? <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[rocketman5000]

A earlier trip to Venus would produce otherwise unobtainable information. You are on a long distance cruise, exposed to a higer flux of solar radiation than the trip to mars (simulating a longer exposure at lower flux). Breaking into another bodies orbit. Checking out of procedures that will be used on the trip to Mars. Mars will require much more extensive amount of equipment to go to. Venus could therefore be done sooner to test practices and procedures. <br /><br />The publicity that a "Venus Shot" could create would smooth the development of a Mars Mission.

 

[bdewoody]

Look at the lack of interest in and lack of interesting information from the Venus Express mission. The public wants exciting visual contact with the solar system not a close up look at a 100% solid overcast<br /><br />I still stand by my claim that a manned mission to Venus should be way down on anyone's space budget. <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[JonClarke]

The space program isn't bread and circuses!<br /><br />There should be lots of interest in a crewed mission to Venus, especially if it is the first human mission to another planet and has some interesting probes like RPVs that provide real time video (something you can do on a crewed mission).<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[radarredux]

> <i><font color="yellow">The public wants exciting visual contact with the solar system not a close up look at a 100% solid overcast</font>/i><br /><br />I think you have a valid point. There will be a perception, especially because of the lack of direct observation of ground formations, that the astronauts would provide very little additional value to the mission. This is not saying that there isn't a good argument to be made, but that NASA has been challenged in selling its positions to the general public.<br /><br /> /> <i><font color="yellow">I still stand by my claim that a manned mission to Venus should be way down on anyone's space budget.</font>/i><br /><br />If NASA standardizes on a basic boosters, EDS, CEV, and habitats for these beyond CIS-Lunar missions, then I think the marginal costs of additional missions are going to be very low. As with the shuttle, NASA will need to maintain launch/recovery teams, contractors, and tooling whether they launch 1 mission a year or 5 missions. Might as well use them.<br /><br />I would love to see mutliple beyond CIS-Lunar missions happening simultaneously. I think having humans going to multiple locations in the solar system at the same timer would have a huge psychological impact -- there would be a shift from mission oriented view ("putting a man on the Moon") to the realization that we are becoming a space-faring people.</i></i>

 

[thalion]

I'm with BDE and Dragon04: I don't think the marginal benefits of an manned orbital mission to Venus would be worth the cost, not even for real-time control of surface probes.<br /><br />For instance, if there is no significant improvement in technology that would enable a probe to survive on Venus for more than a few hours, data in real-time would provide little advantage over traditional remote unmanned probes, especially since in the final analysis the light-travel delay is the same from a terrestrial perspective. I'd rather see the money used to develop either long-lived surface probes, or lots and lots of cheap, short-lived--but reliable--probes. Either would negate the importance of a manned orbital mission, in my op.<br /><br />To be fair, I'd support a Venus flyby mission as a kind of "because it's there" adventure to stoke up interest in a woefully neglected planet. But for the near term (20-30 years), I'd rather see some NEO landing missions.

 

[mithridates]

The science provided on climate change alone would be worth the trip. A mission to Venus could be promoted in that way that a trip to another planet couldn't.<br />One thing that can be accomplished that couldn't be done without people (or without a somewhat intelligent solar flyer above) is the use of a dummy rover with all the intelligent circuitry above - the rover itself would be strong and wouldn't have any delicate circuitry to be destroyed by the environment. Landing it on a plateau about 5 km in height (somewhere in Ishtar Terra) would reduce the pressure and temperature somewhat as well.<br />There's also the possibility that life could exist way up in the cloudtops of Venus so that should be checked out too. <br /><br />http://en.wikipedia.org/wiki/Image:Ishtar_terra_topo.jpg<br /><br />That area is the size of the US so there are plenty of places to land a rover. At about 4 km in height we have a full 20 bars less pressure and 30 degrees less heat than at the surface (70 bars, 435 degrees C or so). Venera 13 for example, survived for two hours when the temperature was 457 C and the pressure 84 bars and Venera 14 survived for an hour with 465 °C and a pressure of 94 bars, but in addition that was also the 1970s and the probe had all the fragile circuitry inside. A pressure of 70 bars (really only about the same as 700 m below the surface of the ocean) is certainly doable. MESSENGER will be operating in temperatures up to 450 degrees as well. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[JonClarke]

Ishtar certainly sounds like a more hospitable environment. <br /><br />But comparisons between Messenger and the Veneras is misleading. Messenger is in interplanetary space and can rely on dark side radiators for cooling, the Veneras. <br /><br />The later Veneras were very innovative, they prechilled the instruments before descent and used eavporation of the cold liquid to keep temperatures to a tolerable level. Once the liquid was lost they gradually over heated, but not before they returned fantastic images and other data. The BBC series "The planets" had some great background on the enormous development work that went into these spacecraft, including a giant presure cooker<br /><br />Any Venus rover, even on Ishtar would have to be either acively refrigerated or be able to function under ambient conditions. does anybody know whether anyone has ever built electronics to survive those sort conditions for long periods of time?<br /><br />One advantage of having a crew in orbit to teleoperate the rover is that as much of the intelligence can be put into the orbiter, rather than the rover. Having a crew to teleoperate would mean that the rover could move much faster than the MERS as well, and adapt faster to unexpected conditions.<br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[solarspot]

Isn't the big problem in overheating, the damage done to the microprocessors themselves? I don't know for sertain, but I remember reading that the electric motors, powersystems and possibly sensors could be made to work at those temperatures. If we had humans in orbit, they could use computers also in orbit to give commands to the individual motors, servos and sensors on those landers. That would allow more science to be done compared to a fully robotic mission.

 

[JonClarke]

That would be my understanding. Maybe for Venus rovers we need macroprocessors, not microprocessors. In that case it would be definitely easier to have as much processing done by a crew in orbit..<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>I don't think the marginal benefits of an manned orbital mission to Venus would be worth the cost, not even for real-time control of surface probes.<br /><br />For instance, if there is no significant improvement in technology that would enable a probe to survive on Venus for more than a few hours, data in real-time would provide little advantage over traditional remote unmanned probes, especially since in the final analysis the light-travel delay is the same from a terrestrial perspective.<p><hr /></p></p></blockquote><br />I think the real-time proposal was for air craft -- not landers. As such (Jon Clarke noted this earlier), air pressure and temperature would not be issues. The real problem I see would the the acidic content of the clouds. Since that would be a natural scientific target, we need aircraft that can handle that.<br /> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p><blockquote><font class="small">In reply to:</font><hr /><p>The public wants exciting visual contact with the solar system not a close up look at a 100% solid overcast<p><hr /></p></p></blockquote>I think you have a valid point. There will be a perception, especially because of the lack of direct observation of ground formations, that the astronauts would provide very little additional value to the mission. This is not saying that there isn't a good argument to be made, but that NASA has been challenged in selling its positions to the general public.<p><hr /></p></p></blockquote><br />Once way to challenge that might be a Magellan-style radar. The crew could be trained how to use it and what to look for. (The same happened with Apollo astronauts.) Rather than waiting for ground crew, the crew on board could make adjustments and whatever to find the needed information.<br /><br />Typical targets would be stuff missed by Magellan or something that Magellan left unanswered. Now, what would it take for a CEV mission to support a Radar?<br /><br />BTW: A Radar might be useful on a NEO mission too. We know very little about how they are constructed. A radar up close would do wonders. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[saurc]

I think I read somewhere that a manned trip to near earth asteroids would cost even lower than a moon mission, though it would take much longer.<br /><br />Definitely I think it should be a higher priority than a manned orbital mission to Venus.<br /><br />But yes, an aeroplane on Venus sounds exciting. I don't think there would be much problem with the high temperature and acidic environment. On the other hand, why haven't they launched a robotic aircraft to Mars? I was seeing a Discovery channel show which indicated it was technically possible.

 

[gunsandrockets]

"I think I read somewhere that a manned trip to near earth asteroids would cost even lower than a moon mission, though it would take much longer."<br /><br />read this thread...<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=missions&Number=661246&page=1&view=collapsed&sb=5&o=0&fpart=1&vc=1<br /><br />"Definitely I think it should be a higher priority than a manned orbital mission to Venus."<br /><br />The main idea is to do BOTH missions.<br /><br />A Venus mission requires use of the Ares V rocket, that's why the mention of '2020 era Orion'. Some NEO missions might not need the large Ares V. Existing smaller launch vehicles, such as the Delta IV heavy might suffice for a NEO mission.<br /><br />"But yes, an aeroplane on Venus sounds exciting. I don't think there would be much problem with the high temperature and acidic environment. On the other hand, why haven't they launched a robotic aircraft to Mars? I was seeing a Discovery channel show which indicated it was technically possible."<br /><br />A robotic Venus airplane is much easier to design than a Mars airplane. <br /><br />The Martian atmosphere is so thin, at ground level about equal to Earth atmosphere at 100,000 feet altitude, that making a Mars airplane is very difficult. Venus has another advantage over Mars. Venus has very high levels of sunlight compared to Earth, making a solar powered aircraft that could in theory fly indefinately much easier to design.