why we need nuclear space probes....

Date: Nov 15, 2004

why we need nuclear space probes....

Date: Nov 16, 2004

Yep, exactly right. Besides, with a rover equipped with an RTG, there will be plenty of excess heat to keep the batteries warm--a simple heat pipe could be used to regulate the internal temperature and keep the 'warm box' warm. Also, I'm not sure how much the power from Spirit's and Opportunities solar photovoltaic cells are tapering off--I've seen some evidence of dust accumulation on the cells, but I have not seen any data. I have actually sent several inquiries, but I'm sure the rover teams are way to busy to respond to my question.

Anyways, a nuclear rover won't have this problem. Infact, I would bet it might even be possible to put some white LED flood (chassis mounted) and spotlights (robot arm mounted) on the rover so it can peer into shadowed areas and still return decent pictures! Now how's that for an idea!

Date: Nov 16, 2004

I would bet it might even be possible to put some white LED flood (chassis mounted) and spotlights (robot arm mounted) on the rover so it can peer into shadowed areas and still return decent pictures! Now how's that for an idea!

Not only a good idea -- it might actually become necessary : evidence is mounting that Mars gullies seen on many photos taken from orbit were likely formed by underground aquifers (see http://www.space.com/scienceastronomy/mars_aquifer_041112.html )

So if some future Mars rover goes investigating them, it might come across one or two with a big cave leading deep underground. Its probably unlikely that a wheeled vehicle could navigate such terrain, but it would certainly help if it had lights, to see where its going

Date: Nov 16, 2004

People...people. The rule, is the ultimate 'nuclear space probe' is human. Sorry, but nothing can replace a human being's ability to do the work needed to test, explore, build and habit any destination you can name in space. Getting healthy humans there and back to earth is the name of the game. Nuclear propulsion & power is the only way to do the solar system till more advanced forms of propulsion and power arise.

Just wish the Bush admin. and NASA stop blowing smoke up the public's behind and get to work on some serious heavy lift, industrial grade space exploration...now!!!

I doubt any present Mars rover would have enough power to light my cigarettes. Not that the value of the science coming out of Mars isn't important. It's just that trying to explore Mars looking through a Coke bottle and waiting years for a Mars Rover with industrial strength exploration capability and a return sample mission ain't gonna cut it. The technical capability to do it now exists. It's always the same excuse, money...money ...money. If Americans would spend less time complaining about not enough money and spend more time realizing their personal dreams in space venture and exploration money would be no object for discouragements in space activity.

Date: Nov 17, 2004

quote:
"People...people. The rule, is the ultimate 'nuclear space probe' is human. Sorry, but nothing can replace a human being's ability to do the work needed to test, explore, build and habit any destination you can name in space.

Yeah -- I figured someone would say something like that, and with good reason (mostly).

However, I wouldn't go as far as saying "any destination you can name in space." The first unlikely destination that comes to mind is the deep ocean of Europa, and the surface at the bottom of it.... But then one can of course add any of the giant gas planets, the surface of Io, the planet Venus, etc..

On the Earth, as early as 1961, W.M. Adams proposed a nuclear probe (hot sinker) for investigating deep underground (UCRL paper 6306). This was later published in a 1965 volume of P A Geophysics under the title "A Thermal Tool for Direct Investigation of the Interior of the Earth" (I made a pdf copy of it, in case anyone is interested). Suffice it to say that unlike Hollywood movies, I doubt very much any sane person could be convinced to travel to the core of the Earth.....

Date: Nov 17, 2004

I have to agree with Jaro here. Robotic probes have their places--exploration of hazardous or risky environments. Also, pre-reconnoiter of possible landing sites by robot probes in preperation for manned missions also comes to mind. This makes good, solid sense. While the robots can never replace humans--they can be a crucial tool when used with human presence to further the goals of exploration. Riskier exploration missions can safely be undertaken with expendible robotic probes, while the human controllers can be safely kilometers away either in a rover, habitat, or mothership. Teleoperation over many kilometers has been demonstrated to be practical, useful, and effective. There is no doubt in my mind that a suitable application of such technology will be utilized when human beings finally do make it to Mars.

Date: Nov 17, 2004

quote:
Originally posted by: 10kBq jaro
The first unlikely destination that comes to mind is the deep ocean of Europa, and the surface at the bottom of it.... But then one can of course add any of the giant gas planets, the surface of Io, the planet Venus, etc.. Suffice it to say that unlike Hollywood movies, I doubt very much any sane person could be convinced to travel to the core of the Earth....."

Here we go again..! Wow... people actually know exactly the topographic map and assays of some of the Icy Moons you just mentioned? The fact is very little is known about just what lies on and in most every solar system planetary or moon body plus asteroids. We are still learning about our own damn planet. It's the result of peering though a coke bottle philosophy in space exploration. Until we have industrial strength space nuclear exploration to know beyond any reasonable doubt don't be quick to write off destinations for humans to habit.

Date: Nov 17, 2004

Who said anything about writing them off for human habitation? I only stated that the use of robotic probes for initial reconnoiter is possible, and responsible in the light that many of these places are completely unknowns to humans. Why send a peopled expedition when little or nothing is known of radiation in the environment of Ganymede or Europa? It would be irresponsible and foolish to send people on a mission to Mercury when we have little notion of the surface conditions there. We know it gets hot, and that there is a hard vacuum at the surface. What about radiation flux? What are the soil mechanics at the surface? What about thermal conductivities of the soil? Is it as insulating as the moons regolith, or would we have to tunnel a habitat deeper to better protect a crew from the roasting sunlight/radiation at the surface? If so, how much deeper? How hard is the rock? Can an auger move loose soil and rocks, or will we need to use a diamond drill or tunnel boring machine? Many of these initial condition questions can be answered with a robotic lander mission.

As for the second part of your statement concerning space industrialization: I agree. We need to greatly expand our presence in space. We should send robotic probes to scout the Near Earth Asteroids for possible resource utilization. We should either replace or expand the space station to include the original 1980's concept of Space Port. We should construct larger vessels to actually go and retrieve these resources that I am confident are there.

Eventually, after we have learned enough and grown enough as a species, we will be able to build ships that are huge in comparison to what we have today. Inside those future vessels will be a microcosm of the entire space infrastructure--a mothership with docking bays and multiple airlocks; many teams of scientists and engineers; manned and unmanned landers for planetary reconnoiter; swarms of probes and sattelites for remote immaging, mapping, data and communication relay; machine shops to build items that were not taken, to fix items that break down, and to improvise new ways of utilizing the environments found for resources, data, etc; huge computer systems to catalog and analyze data; and a powerful communication system to pipe data back to Earth. Such a mission would be vast in scope compared to todays probes--and it would literally encompass all aspects of the space program that today are piecemeal.

How long before we develop such a vessel? It depends on the level of commitment we are willing to give: it will take vision and serious sustained financial resources to accomplish this. Building initial infrastructure: I'd guess twenty years. Gaining experience and maturation of various technologies: I'd guess another twenty years. So let's say fifty years until we have an interplanetary vessel capable of the kind of scientific research roles that are typically accomplished by ocean going research laboratories. I think this could be a bit optimistic without significant breakthroughs. A startling breakthrough--while not likely--could accelerate this quite a bit. A more concervative estimate might be sixty to seventy years. Certainly within a hundred.

I do not support a "robot only" view of space exploration such as that proposed by Dr. James A. Van Allen--instead I take the view that robots first and, later, as assistants to human explorers. Humans need to go--it is in our blood and our heritage to actually set foot upon distant and new places. It won't be without risk--I'm sure that accidents will claim the lives of more astronauts, that is inevitable. But this risk can be, and should be, reduced by sending robotic probes first in extremely hazardous situations.

I don't know about you, but I sure don't want to parachute into Jupiter's atmosphere! I would rather send a robot to do the measurements and collect the data. I'd like to see my family again after the mission was over....

Date: Nov 17, 2004

quote:
I don't know about you, but I sure don't want to parachute into Jupiter's atmosphere!

Good example. Applies equally well to Venus, no doubt (bring lots of antacid tablets ).

Incidentally, we know quite accurately what the radiation fields at the surfaces of Io and Europa are, from NASA's Galileo probe: the radiation was slowly frying Galileo's electronics, every time it passed around Jupiter within the orbits of those two close-in moons. The radiation levels would certainly be intolerable for astronauts, barring adequate shielding. Note that even the more radiation-hardened JIMO probe will only be designed to investigate Callisto, Ganymede and Europa -- in that order, leaving the greatest radiation damage to the end of the mission -- and leaving out Io altogether, due to its excessively high radiation environment.

The radiation environment on Earth's moon can get pretty nasty too, during Solar flares, but there's a big difference between having to shelter for occasional short periods, versus having to deal with such an environment on a constant basis. Anyway, my hope is that eventually deep-penetrating radar surveys will locate large underground lava tube caverns which will be used for permanent habitation. Similar type of sheltering might be possible on Europa, but the surface work required to secure access to such underground (or under-ice) shelters would be more difficult because of the constant high radiation levels. By the time you get to Io, those radiation levels are so high, any prospects for manned outposts are pretty hopeless. As for the gas giant planets themselves, one could certainly imagine lighter-than-air stations floating in their atmospheres (say, to collect He-3 ?), but not on Jupiter : the gravitational field is uncomfortably strong for humans. But Neptune, Uranus, and maybe even Saturn might be OK (though energetically difficult to get off of....).

Of course if you're talking about the very distant future, with human beings radically modified by technology, then just about any environment may eventually become tolerable. Presumably this might include dispensing with space suits in airless environments like Earth's moon and the asteroids, the rarefied atmosphere of Mars, or the cold, dense atmosphere of Titan. My guess is that this will require a pretty advanced version of nanotechnology -- probably a couple of hundred years away (really not that long, if you think about it, in the context of human evolution since the Stone Age....)

Date: Nov 18, 2004

I have a friend who is an advocate of genetic modification: he talks about exoskeletel meta humans, or some such as that. I suppose that eventually (in the really distant future) designer bodies with downloadable persona's might be possible--but that is beyond me (hopefully the software controls will be more stable than my Windows XP system!) Call me old fashioned, but I wouldn't want to do that to myself. I like having my skeleton where it is--inside where I can't see it!

This is way off topic, but still, I suppose this will eventually happen. It is yet another way humans will explore the cosmos--by adapting themselves to fit the environment. I have to say, that I am much more conventional (perhaps less visionary, I suppose, but this is my personal failing...) It's like trying to project humanity forward a billion years--who knows what humanity will evolve into (probably many different species if we're not extinct by them.) Molusks have been around for less than a billion years--and look at the diversity they have achieved: everything from worms to octupii to snales. Some octupii are quite intelligent, and apparently display a wide range of emotions. Besides whales and porpoises, the octupii are the next most intelligent creatures in the ocean.

Anyways, back on topic, eventually nuclear powered deep space craft carrying a variety of daughter vessels will be the norm. It must carry a complete infrastructure as many ocean going vessels do now. Once colonies and outposts are established, these will be the busy ports of call for all kinds of traffic. I would expect that such patterns will continue, even as humanity takes its first furtive steps to the stars.

Date: Nov 18, 2004

quote:
Originally posted by: GoogleNaut
"I have a friend who is an advocate of genetic modification: he talks about exoskeletel meta humans, or some such as that.

Yuh...Exoskeletal meta humans? Oops... I'm aroused. Where can one find info. on this genetic modification in humans- any links

Date: Nov 18, 2004

I'm not familiar with the genetic modifications cited, but Eric Drexler writes (in his seminal book on nanotechnology) about active nano-scale skin surface layers with various capabilities, including such things as protection against the vacuum of space (basically an imperceptible space suit, complete with thermal management and chemical breathing air recycling), energy conversion from incident sunlight, and potentially even some human muscle power amplification -- the "exoskeleton" - type of function envisaged in the genetic modifications implied in Googlenaut's comments, I believe.....

Date: Nov 19, 2004

I have actually met K. Eric Drexler--a very interesting fellow indeed! I'll see if I can cajole my friend to expound on his ideas further...

Date: Nov 19, 2004

This site really needs an edit feature.

The link above won't work but just go to google.com and type in "the end of evolution" as your search criteria and choose the link at the smh web site to read the article.

Date: Nov 19, 2004

I am pretty sure Drexler only used a suit in that example because the concept of modifying the human body would have been too hard for people to believe at that time. "Engines of Creation" was a radical book back then when hardly anyone had ever heard of nanotechnology. The logical next step in the suit idea is to just modify our bodies. He most likely did not say this because he didn't want people to think he was a nut when he was trying to sell them the nanotech idea.

The idea is Directed Evolution. The goal is Maximum Survivabiity in extreme environments. It is far easier to imagine making ourselves tougher biologically for the colonization of spacethan it is to build and carry around huge portable Earth-like environments everywhere we go.

With adequate advances in biological knowledge, genetics, computers, and materials science, and advanced nanotechnology I can see how this might be possible to do. Humans, being evolved for Earth environments, are fragile when placed in other environments. Imagine where we could go if we could apply the full potential of our engineering abilities to alter ourselves for maximum survivability. We could start out with making small changes to our skin and lungs to allow us to survive for progressively longer in vacuum environments without space suits. Eventually we could start implementing progressively more elaborate changes such as adding sensory modifications (see in UV or IR, add sonar, add radio tuners for example), building in computer network interfaces to our brains, modifying our cells to be more radiation resistant, modifying our skeletons to be more resistant to falls (adding reinforcing metalic fibers to our bones for example), making modifications to our muscles to make us stronger, etc. Even farther down the road we might try something like adding a tertiary metabolic pathway based on perhaps a hydrogen peroxide reaction where we could take in water, use solar cells built into our skin to supply electrical energy to make hydrogen peroxide and oxygen and store it in our bodies to be used for later (also, rocket thrusters built into our skin would be a nice thing to have if we are living in space).

At the end of a few hundred years, the humans who choose directed evolution would be able to live in places like the seafloor of the oceans on Earth or the surface of Mars or any moon in the solar system with orders of magnitude less difficulty than we would have trying to do it now. That would give them a huge advantage over the ones who chose not to adapt themselves.

Basically, I see our entire global technological machine pushing us towards something like this. We have several evolving technologies which, when merged, will allow this to be possible. If you extrapolate forward with nanotechnology, biological and genetic science, and computer science then the union of those three fields is exactly what I described. Life always evolves to fill every possible environment. Life needed intelligent beings like us in order to expand past Earth and so here we are. We are still evolving no matter what we would like to believe and this is where I see it going.

Positronium

Date: Nov 19, 2004

I found this article.

http://www.smh.com.au/articles/2003/11/14/1068674378878.html?oneclick=true

It is similar to what I just wrote. The writing is on the wall. Lots of scientists are thinking about this and it can't really be stopped because it has already begun.

Positronium

Date: Nov 19, 2004

If the link above doesn't work, then go to google and type in "The End of Evolution" as your search criteria and it should be a link at the smh web site.

Positronium

Date: Nov 19, 2004

This is even better:

http://www.extropy.org/

Look at the Transhumanism FAQ in the FAQ area. There are also some good links to fringe web sites if that interests you.

These guys get a little overly philosophical for me but there are lots of interesting ideas here if you keep an open mind. New idea often come from very odd places.

Positronium

Date: Nov 27, 2004

RTGs for a Mars hopper ?

http://www.universetoday.com/am/publish/mars_gashopper.html?25112004

Future Robots May "Hop" Across Mars

Summary - (Nov 25, 2004) NASA's Spirit Rover has just completed a long hard slog across difficult Martian terrain to reach the Columbia hills. The short journey of just a couple of kilometres has taken Spirit months. Imagine if it could thoroughly analyze an area and then just pick up and fly somewhere new? NASA has awarded a contract to a proprosal from Pioneer Astronautics, which envisions a vehicle that could land on Mars, refuel with local materials, and then fly hundreds of kilometres to explore; repeating this process over and over again - the Martian Gashopper Aircraft.

Full Story -

Part lander, part aircraft, the gashopper (no, not grasshopper) is a unique concept being considered by NASA for future robotic exploration of Mars. Unlike landers, such as the Viking spacecraft, Beagle 2, or the upcoming Phoenix lander which can only examine a few square metres of ground, the gashopper could land, perform scientific analysis and launch itself back into the air to fly hundreds of kilometres to a new location.

The gashopper would get its electricity from a large set of solar panels built on top of its wings. It would use this electricity to retrieve carbon dioxide from the Martian atmosphere, and then store it as a liquid inside the aircraft. When enough gas was stored up to make a flight, it would heat up a hot bed of pellets and then pass the CO2 through it. Now hot, the gas would act as a propellant, and allow the gashopper to lift off vertically from the surface of Mars. Once airborne, it could then fire more gas out a rear thruster and begin flying as an airplane, using its large wings for lift and maneuverability. When it was ready to land, the aircraft could slow its airspeed, and then touch down gently as a vertical lander.

[...this sounds like it might be relatively easy to do on a low-gravity, dense atmosphere world like Titan..... but on Mars, with its very thin atmosphere, the dynamic lift speed would have to be pretty fast - so the vertical landings would in reality probably look more like a controlled crash....]

The proposal comes from the mind of Robert Zubrin, author of The Case for Mars, President of the Mars Society, and the President of Pioneer Astronautics. It's one of 219 research projects selected by NASA for Small Business Research and Development contract awards.

Zubrin sees the gashopper not only as a technology for exploring Mars, but as a proof of concept for many engineering challenges that NASA will have to overcome in future missions, both robotic and human. "If we're going to do a sample return mission, we'll want to know how to make propellant for the return journey," explains Zubrin, "and the gashopper will also let us test many liftoffs and landings with hazard avoidance in all kinds of terrain.

"The gashopper will be using native carbon dioxide for fuel, so it won't contaminate the soil with hydrocarbons," continues Zubrin. This is important, because spacecraft from Earth using hydrocarbons for fuel could contaminate the landing site with chemicals that could confuse the search for life. "Once the gashopper gets moving, it'll find a pristine Martian surface to explore."

The simplest gashopper could actually be quite light, as little as 50 kg (110 pounds). Compare this to the current Mars Exploration Rovers, which both weigh in at 185 kg (380 pounds). Tack on some more weight, and the gashopper could carry a few mini-rovers, like the tiny Sojourner that visited Mars as part of the Pathfinder mission. These could be targeted at the most interesting features based on the gashopper's aerial reconnaissance of the area.

Another advantage of the gashopper is that is could completely ignore terrain. When NASA selected the landing sites for its Mars landers, it purposefully chose locations that were relatively flat, so the rovers could drive at a useful speed. The gashopper could land at the edge of a deep chasm, examine the area, jump down to the bottom and get back out again. It would give scientists unprecedented range and flexibility when searching for evidence of past water or life on Mars.

Of course, there's a catch. The limiting feature of the gashopper is the electricity required to pressurize and heat the carbon dioxide propellant. This process consumes a lot of power, and the gashopper would need more than a month using its solar cells to refuel and recharge its batteries before it could take off again.

To generate more electricity, NASA could consider using a Radioisotope Thermal Generator, similar to those carried by Cassini, the Viking landers, or the upcoming Mars Science Laboratory (due for launch in 2009). With a more powerful electrical system, the gashopper could lift off every few days, and essentially be able to roam the entire planet of Mars.

Zubrin's company, Pioneer Astronautics, has already done a significant amount of testing and research for the concept, and they developed a prototype ballistic gashopper for NASA's Jet Propulsion Lab in 2000. The engine worked well in the lab, and they were able to get a remote-controlled vehicle with a mass of 50 kg to fly in a simulated Martian gravity (using a helium balloon to provide stability).

Instead of sitting on one spot, or slowly crawling across the surface of Mars, future robotic explorers to visit the Red Planet may take to the skies and soar. Well... hop, anyway.