New Mars Forums

I was at the www.space.com site to find this which I liked, and then did some related searching and thinking:

http://www.space.com/16378-hybrid-rocke … t-spg.html

Quote:

A new hybrid rocket motor fired up Friday (June 29), demonstrating technology that its builders say could lead to efficient, alternative-fuel launch vehicles down the road.

California-based Space Propulsion Group, Inc. (SPG) test-fired the 22-inch-wide (56-centimeter) liquid oxygen/paraffin motor for about 20 seconds Friday, blasting a streak of bright flame into the air at the company's testing facility in Butte, Mont.

The trial was the fifth for this particular motor, SPG officials said, and it demonstrated a flight-weight version of the design.

The company says future propulsion systems using the motor's hybrid technology have the potential to be five to 10 times cheaper than existing rockets. And the paraffin fuel has the added benefit of being non-toxic, officials said.

"We believe propulsion drives the cost of access to space and that complexity generally drives propulsion system cost," SPG president and chief technical officer Arif Karabeyoglu said in a statement after the test-fire. "By using a commercially available paraffin-based fuel, we have created an economically viable alternative that could significantly reduce the price of space accessibility, as well as help preserve the environment."

Hybrid rocket motors use propellants that are in two different states of matter, as opposed to purely liquid or solid rockets.

Proponents of hybrid technology claim that it combines the advantages of the other two types, offering the simplicity of solid systems and the safety of liquid rockets. (Solid rockets, such as the boosters that helped loft NASA's now-retired space shuttle, generally can't be shut off once they've been lit.)

Hybrid rockets are playing a large role in the burgeoning private spaceflight industry. Virgin Galactic's suborbital SpaceShipTwo vehicle employs hybrid motors, as does Sierra Nevada's Dream Chaser, a mini-shuttle that's in the running to transport NASA astronauts to and from the International Space Station.

Follow SPACE.com on Twitter @Spacedotcom. We're also on Facebook and Google+.

Quote Again specifically:

The company says future propulsion systems using the motor's hybrid technology have the potential to be five to 10 times cheaper than existing rockets. And the paraffin fuel has the added benefit of being non-toxic, officials said.

Paraffin
http://en.wikipedia.org/wiki/Paraffin

http://upload.wikimedia.org/wikipedia/c … raffin.jpg

Quote:

Paraffin waxParaffin wax (or simply "paraffin", but see alternative name for kerosene, above) is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 46 and 68 °C (115 and 154 °F),[4] and having a density of around 0.9 g/cm3.[5] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily.[6]

Pure paraffin wax is an excellent electrical insulator, with an electrical resistivity of between 1013 and 1017 ohm metre.[7] This is better than nearly all other materials except some plastics (notably Teflon). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron.[8][9]

Paraffin wax is an excellent material to store heat, having a specific heat capacity of 2.14–2.9 J g−1 K−1 (joule per gram kelvin) and a heat of fusion of 200–220 J g−1.[10] This property is exploited in modified drywall for home building material: a certain type (with the right melting point) of wax is infused in the drywall during manufacture so that, when installed, it melts during the day, absorbing heat, and solidifies again at night, releasing the heat.[11] Paraffin wax phase change cooling coupled with retractable radiators was used to cool the electronics of the Lunar Rover.[12] Wax expands considerably when it melts and this allows its use in wax thermostatic element thermostats for industrial, domestic and, particularly, automobile purposes.[13][14]

In industrial applications, it is often useful to modify the crystal properties of the paraffin wax, typically by adding branching to the existing carbon backbone chain. The modification is usually done with additives, such as EVA copolymers, microcrystalline wax, or forms of polyethylene. The branched properties result in a modified paraffin with a higher viscosity, smaller crystalline structure, and modified functional properties. Pure paraffin wax is rarely used for carving original models for casting metal and other materials in the lost wax process, as it is relatively brittle at room temperature and presents the risks of chipping and breakage when worked. Soft and pliable waxes, like beeswax, may be preferred for such sculpture, but "investment casting waxes," often paraffin-based, are expressly formulated for the purpose

So, I can see making old fashoioned "Potted" electircal devices if necessary.  (You never know what emergency might happen)

Or using the stuff to maintain comfortable/habitible conditions in a habitat, per temperature regulation.  It apparently was already used on the Moon for a cooling fluid, how about a heating fluid on Mars?

As a Rocket fuel.

TwinBeam mentioned crash-landing raw materials on another thread, I mentioned a "chain method" also on that thread, but it has other traffic of another nature, and this would step on that so I am starting this thread.

It seems to me that it would be a good candidate for hard landing/crash landing.

If packets of it were strapped on to the sides of a lander, and the lander had a spin at the time of release, the the bags of paraffin would eject from the lander and reduce it's load.  If there were air/Nitrogen bubbles in the plastic phase paraffin, then upon impact, the air bubbles would absorb some of the shock, and perhaps keep the bags from bursting.  Even if they burst, I am inclinded to think that the paraffin would largely be usible for a reasonable period of time, with cleaning.

I am wondering if instead of bringing Hydrogen to Mars, and extracting Oxygen from the atmosphere from it, it would be better to use paraffin as the fuel, and then simply extract Oxygen from CO2 directly, and casting away the CO remnant?

Hydrogen would be hard to deliver to Mars as a liquid.  Water would be expensive to deliver to Mars, since you are delivering a lot of Oxygen.

If Parafin can be eject-landed, and Oxygen pulled directly from the CO2, then the humans would simply pick up the solid pieces of bagged paraffin, and use it during the mission for what utility it had, and the reuse it as a fuel to get to orbit.

The following is not part of this topic, but it is interesting.  Maybe later:
http://www.space.com/16367-private-moon … almaz.html

Actually, I think rail gets built fairly early on Mars - at least just around the main base to start. Some other thoughts...

Railroads, I think, would mostly be a problem because of steel consumption. Construction of a railroad would actually be cheaper and faster per mile, in terms of work, than on Earth.

* You don't need traditional ballast, at least until you start warming Mars up. Just use water - the ice would be fantastically hard and strong under Mars conditions, and you could melt the top to a very fine level. Sink the concrete ties in it and attach the rails

* in the low gravity, bridging and viaducts would be simpler to build than on Earth, as well.

* Steel wheels are easier than rubber wheels on Mars.

An option which might be profitably discussed would be an ice plateway - a flattened ice road with two grooves for steel wheels, rather than two rails. While this would have severe issues in terms of maximum speed, we're not terribly concerned with maximum speed, are we? And such roads would be fairly inexpensive to build, and could be upgraded to rail as steel production allowed.

louis wrote:

Rail doesn't take you to your door. A car does. So does a bike.   I wonder if the survey included the energy expenditure of getting to the rail station and hanging around waiting for trains?

Nope : it's energy per pessenger per kilometer(forgot the unit, just remembers the scale). With streetcars(i.e. american-style small scale tramways), though, you can go rather near home. If we don't find adequate replacement to petrol, public transit will have its importance improved - and cities will need to be more dense, more Washington DC than Calgary. Note though that for cities with heavy slopes, tyres are still useful - that's why inhabitants of San Francisco avoid the cable car & use trollebuses instead. Only tourists use cable car.

Nuclear planes might be useful for transatlantic transport, but won't for going from home to work.

GW Johnson wrote:

All that I said in post no. 18 being what it is,  I think the sense of Robert Dyck in post no. 1 is correct.  We need a cheaper way to fly,  one that is more or less independent of oil prices.  If that's some nuclear engine,  then so be it. 
(.../...)GW

IIRC, I read a french study about the 2000-2009 decade, summarizing the energy consuption of different transport modes per pessenger. It was like :

_Rail : 0.2
_Boat : 0.4
_Tyres : 2.2
_Air : 3.2

For anything not transoceanic, rail it the obvious choice. But Transatlantys is not for tomorrow(it was an advertisment joke promising a train tunnel between France & New York City).

I'm not sure coing nuclear would significantly reduce the energy cost of an airplane(in terms of joules, not in terms of $).

RobS wrote:

I like the "log cabin" idea! But all the experts seem to think it's better to send one lander than four, probably because of the multiplier of expense, extra fuel, and more that can go wrong (nonfatally, that is). That's a lot of carbon dioxide filters to replace and other basic maintenance to do. When ISS had a crew of 3, two of them were busy with maintenance.

Since we know that we are not able to deliver the large tonnage to the surface that is needed so why not make it smaller packaged so that we can do what we will need.

I looked it over now, rather entertaining if nothing else.

http://en.wikipedia.org/wiki/Orbital_airship

http://www.jpaerospace.com/atohandout.pdf

http://www.jpaerospace.com/

http://en.wikipedia.org/wiki/JP_Aerospace#Ascender

The PDF is nice to look at.

I guess the part I like the best is where if they do have the "Dark Sky Stations" at 140,000 feet then Oxygen could be collected to fuel the Orbital assender.

I wonder if those stations could also make a buck being communication relays, and also hotels?  That might justify the stations and the ground to station airship.
The orbital assender is really outside of the box though.

I have plenty of reservations about how it could work, but I have thought of a few possible solutions for some problems.

I guess for the issue where space objects might puncture the orbital assender, I would speculate on small robots inside with patch kits, perhaps they would have Gecko feet to stick to the inside walls?

http://geckolab.lclark.edu/dept/geckostory.html

http://www.dailymail.co.uk/sciencetech/ … -mark.html

I am not sure but I am speculating that the "Electric" propulsion for the orbital assender might be a process of compressing electrostatically charged gas and venting it?

If the propulsion were electric, I would think that a powersat in orbit might be able to beam energy to it.  If it were microwave, however I guess I don't know how the airship could convert that to electricity.  If it were laser, and the skin was solar cells of a very thin type, then perhaps that could work.

I guess some time ago there was talk about super strong Nano Materials in the future.  Perhaps that would be required, to make a very thin but strong structure.

It is entertaining however far off it is to our current grasp.  I am glad that people are thinking so way far out.

So you guys want to go green. That's another discussion. Yes, I believe in green technology, and could list what I want to build into a house. However, none are practical for an airplane.

Ships cannot use wave power, they float so wave power is not compatible. The most efficient means of using wind to move a ship is sail, and wind turbines are not compatible with sail. So for a ship that leaves a combination of sail and solar. You could use photovoltaic for electric power generation, and sail to move the ship. Tall sailing ships do not move as fast as deisel, and the ship is at the mercy of weather (wind).

It was a Lunar flyby. That means you go around the moon, and yes, see the Lunar farside. This is in the same league, but almost twice as expensive, with a company that has no experience.

Hmmm. Space Adventures have been offering the exact same experience for some time now, including a stay on the ISS, using a Soyuz capsule. Cheaper too, at 100 million dollars rather than pounds.

That they didn't get anyone taking up the offer says a lot about the market, doesn't it...

Nice quote, Louis, but the thing is we don't know yet how to land more than 2 tons on Mars. We have plans for landing more, but as long as it's just plans & noone does it, we don't really know how.

Landing on earth is not easy for us earthians, but we have a huge advantage over martians : we live here & know all the tricks. Americans did choose water landings because of their carrier fleet making recover easier & safer, USSR did choose desert landings due to lack of carriers & great number of appropriate deserts. Both of them did know & master the environment they did choose for the landings. Martians would not have that luxury. Their capsules would sink in the oceans, burn in the woods, be attacked in urban terran(by dogs or humans), sink in swamps.....

Once again, I believe we can land on Mars. Just, let's not assume it's easy. Politics means failure is not an option. and when you here this sentence, you know that your management has lost control of the situation.