New Mars Forums

kbd512

Administrator

Registered: 2015-01-02

Posts: 7,812

Re: Lift off and touch down

I would be more worried about GCRadiation falling onto the surface of Mars and the radiation already on the surface in the rocks etc than a reactor because there is no guess about where it is or how to deal with it, the variables are already established.

I'm most concerned with having reliable power output using existing or near-term development technologies that don't push the limits of technology to a point past what that technology is reliably capable of delivering.  There are very few "unknowns" with respect to small nuclear fission reactors.  We've been building them for decades.  The overwhelming majority work well enough to get the job done.  Our cutting edge solar panel and batteries are interesting new technologies that I see as providing reliable power anywhere within the inner solar system... in another two decades or so.

I've already explained why we're never going to achieve higher energy density with any non-nuclear power production technology on the surface of Mars.  The solar panels could be 100% efficient and weigh nothing, charging non-existent batteries achieving theoretically possible energy density, and that solution would still weigh more than a fission reactor for most any static high power application.  A 4MWe reactor is still smaller than a 55 gallon drum and it produces electricity 24/7/365 for years on end.  The energy density of solar cells and batteries can improve by orders of magnitude and fissioning Uranium is still orders of magnitude above that.

For vehicles, lattice-enabled nuclear reactions (LENR's) produce very little radiation that human occupants would require shielding to survive, even though they transmute the fuel, and they still produce incredible amounts of heat.  Gasoline is 34.2MJ/l.  LENR is 342,000MJ/l.  So, no matter which nuclear technology is utilized, you're always going to achieve higher energy density with nuclear technologies compared to solar technologies, partly because solar panels only produce maximum output for 6 hours out of a 24 hour day, partly because batteries are heavy and energy storage densities are quite low, and mostly because the energy released from nuclear reactions of any kind (fission, lattice-enabled transmutation, fusion, or mutual annihilation) is so insanely high.

A workable hot fusion reactor of the kind Lockheed-Martin is working on will make solar panels, RTG's, LENR's, and even fission reactors look like toys at outputs levels near 100MWe.  In another 10 years or so, the best scientific minds in the world will still be fiddling with solar panels while LENR's the size of paint cans are powering vehicles that require several hundred hp or thereabouts.  Given the fact that radiation shielding is not required for LENR's, we may not even bother with fission reactors or fusion reactors until a colony is established.

Solar cells are useful for specific applications, but still a technological dead end if continuous high power output and energy density is a hard requirement, as would be the case for any successful Mars exploration or colonization effort.

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Lift off and touch down

Much like the eb and tide of the suns path accross the sky the energy needs for a crew and operation are not flat either as we will need batteries and other means to allow for the fluctuating needs through out a day and night to be taken care of.
LENR or E-cat are basically the same thing from what is available to read in that these are isotopic reactors in that isotopes are used to create the power electrically and or to make heat for which a turbine system to make the electrical power. This would be a limited time frame device and would need constant replacing to allow for it to always be there for the crews survival.

TonyTMarsBeginner

Banned

Registered: 2016-09-29

Posts: 36

Re: Lift off and touch down

For vehicles, lattice-enabled nuclear reactions (LENR's) produce very little radiation that human occupants would require shielding to survive, even though they transmute the fuel, and they still produce incredible amounts of heat.  Gasoline is 34.2MJ/l.  LENR is 342,000MJ/l.  So, no matter which nuclear technology is utilized, you're always going to achieve higher energy density with nuclear technologies compared to solar technologies, partly because solar panels only produce maximum output for 6 hours out of a 24 hour day, partly because batteries are heavy and energy storage densities are quite low, and mostly because the energy released from nuclear reactions of any kind (fission, lattice-enabled transmutation, fusion, or mutual annihilation) is so insanely high.

A workable hot fusion reactor of the kind Lockheed-Martin is working on will make solar panels, RTG's, LENR's, and even fission reactors look like toys at outputs levels near 100MWe.  In another 10 years or so, the best scientific minds in the world will still be fiddling with solar panels while LENR's the size of paint cans are powering vehicles that require several hundred hp or thereabouts.  Given the fact that radiation shielding is not required for LENR's, we may not even bother with fission reactors or fusion reactors until a colony is established.

Solar cells are useful for specific applications, but still a technological dead end if continuous high power output and energy density is a hard requirement, as would be the case for any successful Mars exploration or colonization effort.

It would be interesting to combine LENR's with a contra rotating co-axial rotor system and add aeromagnetic and or x-ray equipment into a larger drone that could be used for mapping, storm detection, mineral prospecting, search and rescue, and that would have a much greater range and load capabilities. Having large deposits mapped might help construction efforts among other things.

RobertDyck

Moderator

From: Winnipeg, Canada

Registered: 2002-08-20

Posts: 7,924

Website

Re: Lift off and touch down

I think Robert Zubrin was the first to suggest Roman arches by the way but not as I recall combined with trenches.

Actually, no. Robert Zubrin has been studying Mars for a very long time. Study includes learning what others have done. Bruce MacKenzie was the first to propose Roman arches. Robert Zubrin repeated that idea.

louis

Member

From: UK

Registered: 2008-03-24

Posts: 7,208

Re: Lift off and touch down

Thanks for the correction, Robert.

I think Robert Zubrin was the first to suggest Roman arches by the way but not as I recall combined with trenches.

Actually, no. Robert Zubrin has been studying Mars for a very long time. Study includes learning what others have done. Bruce MacKenzie was the first to propose Roman arches. Robert Zubrin repeated that idea.

---

Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

kbd512

Administrator

Registered: 2015-01-02

Posts: 7,812

Re: Lift off and touch down

Much like the eb and tide of the suns path accross the sky the energy needs for a crew and operation are not flat either as we will need batteries and other means to allow for the fluctuating needs through out a day and night to be taken care of.
LENR or E-cat are basically the same thing from what is available to read in that these are isotopic reactors in that isotopes are used to create the power electrically and or to make heat for which a turbine system to make the electrical power. This would be a limited time frame device and would need constant replacing to allow for it to always be there for the crews survival.

Batteries are certainly coming along for the trip to Mars.  Power storage is still a required technology and these new technologies don't change that requirement.

With respect to the LENR's, those devices require refueling every six months to one year.  The actual quantity of fuel required is so minuscule that mass penalties associated with carrying several kilograms of replacement fuel are negligible.  At roughly 10,000 times the energy density of gasoline, it's just an extremely high energy density substitute for liquid hydrocarbons for surface and aerial vehicles.

The new QuarkX power pencils are 1mm x 30mm and produce 100Wt at 1,500C using .5We of input power.  That temperature is substantially higher than SAFE-400, so radiators could also be smaller.  The QuarkX is what I had in mind for providing the heat required to expand CO2 for the crewed quad rotor concept I put forth.  I have had a re-think about this and will post what I have come up with in the Mars aerial vehicle thread.

QuarkX could also power that helicopter drones NASA wants to use for surface imagery.  Instead of a flight of a few minutes every day, which is what we'd achieve using the tiny solar cell attached to the rotor hub, the drones could explore continuously for six months or so.  Even with three of the QuarkX modules and 30We worth of electrical power, that's plenty to recharge a small battery and power onboard electronics.  A robotic rover similar to Spirit and Opportunity, equipped with LENR instead of solar cells, could collect and transmit the data collected by multiple drones to orbital communications satellites for bulk data delivery back to Earth.

At this point in its development, LENR is a complementary technology to fission reactors.  It has the potential to replace small fission reactors at the expense of some regular maintenance for refueling.  The major benefit over fission reactors is no radioactive materials, no radiation stigma, no shielding mass required so cores can be substantially lighter and substantially more compact compared to fission reactors, and the characteristics of the design permit simpler operations.  There would be no exclusion zones, no constant dosimeter checks, and no reactor control duties, although monitoring the power plant is still required.  Waste heat could also be collected to provide warmth for habitation modules.