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#251 2020-09-02 16:32:04

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,449

Re: Technology Updates

An excellent plan Kbd and needed more now than ever before.  OECD economies began experiencing 'secular stagnation' in the 1990s.  Since 2003, the average American has lost 10% of his prosperity.  The root cause of this problem is rising energy cost of energy, or declining EROI.  We now face a situation, for oil especially, where there is no price that is both affordable to consumers and profitable for producers.

For consumers there is always a limit to the price that they can afford to pay for an energy product, because wealth is the result of energy acting on matter.  There are thermodynamic limitations to the amount of goods and services that can be produced from a unit of energy and this places a ceiling on sustainable price.  For producers, production costs are rising as the most profitable oil deposits were exploited first.  Whilst we aren't running out as such, remaining reserves have higher production costs, in both money and energy terms, than the super giant onshore oil fields of yesteryear.

It is the pincer movement of rising production costs and declining affordability that has been crushing the life out of Western economies for the past two decades.  A new engine technology that could halve fuel consumption for the same output of useful work would be immensely valuable, as it would allow consumers to afford more expensive oil and would allow prices to eventually rise to the point where production from unconventional oil would be both affordable to consumers and profitable for producers.  We need this sort of innovation to be rolled out very quickly now.

Gail Tverberg has written some excellent articles on the thermodynamic nature of the economy and the problems that are occurring due to lack of energy affordability.
https://ourfiniteworld.com/

As for aircraft, I do have some doubt that a solid oxide fuel cell would deliver sufficient power to weight.  Are we talking about fitting electric propellers onto aeroplanes?  I would propose that liquefied natural gas may be a more sustainable alternative fuel for jet aircraft.  It could be burned in conventional gas turbine engines and has 30% better mass energy density than aviation jet fuel.  Solid oxide fuel cells could presumably be fitted onto cargo ships.

Last edited by Calliban (2020-09-02 16:58:29)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#252 2020-09-02 16:54:17

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Technology Updates

But that generates Co2 rather than N2 and water of which non greenhouse gas.

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#253 2020-09-02 20:05:25

kbd512
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Registered: 2015-01-02
Posts: 7,440

Re: Technology Updates

SpaceNut,

The algae farms consume atmospheric CO2 to produce more bio kerosene or bio diesel. All heavy vehicles use those distillate fuels.  There are no gasoline powered semi trucks or tanks or transport aircraft.  Since bio kerosene is already used by some US air carriers in blends containing up to 100% bio kerosene, it's not adding any CO2 to the environment.  It's CO2 recycling.  As of right now, it's not yet scaled out to provide 100% of the required input, so we're going to use the farmers and oil companies to scale it out to provide all of the required input.

As for LNH3, it can serve as a gasoline replacement using existing technology created by Toyota for their Mirai.  LNH3 will be used to transport H2 to the fuel pumps, whereupon a plasma cracker at the gas pump removes the unwanted Nitrogen, leaving H2 gas in the tank.  That is the only practical way to produce lighter vehicles.  For people who have enough money, they can still buy battery powered vehicles.

Calliban,

I've already done some math on how much power a 5,000t class transport aircraft would consume using Boeing's Pelican concept as a guide.  NASA Glenn Research Center's new 2.5kW/kg / 7.5kW/L solid oxide fuel cells would weigh 384t (approximately 2m x 8m x 8m in volume) to supply 960MWe.  I intend to use a distributed propulsion system (480 2MW fans arranged around the tail of the lifting body) that uses boundary layer air ingestion to reduce drag through wake filling.  At 15kW/kg, the MAGNAX AFPMMs would weigh 64t.  IIRC, MAGNAX, EMRAX, and Siemens have all demonstrated at least 10kW/kg in actual flying machines that left Earth under their own power and returned in one piece, the standard of measure by which all new technologies intended for aviation applications should be judged.  That's obviously heavier than GE9X gas turbines providing equivalent power, but the goal here is to reduce fuel consumption for very large aircraft that typically spend many hours aloft at moderate to high subsonic speeds.

For a commercial wide body airliner, a pair of GE90-115B engines weigh ~17,524kg.  Equivalent electric motors would weigh ~10,000kg (assumes 1t CF fans) and the fuel cell would weigh 48,000kg, or 59t for both required systems.  Over an 8 hour cruise around FL380 at 554mph, fuel burn for the pair of GE90s should be ~86,497kg.  That's around 104,021kg.  I believe the power requirement is something like 56MW.

Jet A-1 is 43.15MJ/kg, so an 80% efficient fuel cell should extract ~34.52MJ/kg or 9.59kWh/kg, so ~5,854kg/hr, or 46,831kg over 8 hours of cruise.  It clearly doesn't work in exactly this way since the aircraft becomes lighter as it burns fuel, so we're using average power consumption rates.  Anyway, the fuel cell / AFPMM solution has a total weight of 105,831kg.

The fuel burn point should be relatively clear, though.  You burn less fuel using fuel cells, even if the power plant solution weighs considerably more than an equivalent gas turbine solution.  Over time, that really starts to add up.  If you taxi at all, then you burn more fuel with the gas turbines, if you idle at the gate, then you burn more fuel with the gas turbine.  You also have to add in the mass of the APU for the gas turbine solution, which need not be present with the fuel cell solution for obvious reasons.  Add some electric motors into the nose gear of the fuel cell powered aircraft and it can run on minimal power on the ground without idling the electric turbofans.

If the fuel cell power density improves just a little bit and hits the 3kW/kg of the US Army's SOXE fuel cells, then you start running out of scenarios for long distance transport aircraft where a less fuel efficient gas turbine makes economic sense.  We haven't considered the maintenance cost differential, either, which will be considerable.  Fewer and larger moving parts aids durability.

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#254 2020-09-02 20:34:58

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Technology Updates

So long as you are using less fuels it a near zero to negative effect on warming but thats not what we are seeing more vehicles on the roads every day.

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#255 2020-09-02 21:51:08

kbd512
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Registered: 2015-01-02
Posts: 7,440

Re: Technology Updates

SpaceNut,

Well...  This is what happens when environmentalists are anti-everything-that-actually-works.  Wishful thinking doesn't make multi-ton vehicles move at highway speeds.  Current batteries are absurdly impractical for anything other than light duty passenger vehicles.  Sandy Munro, one of his people, actually, gave a good little run down on current and projected battery technology.  If you don't already know who that is, type his name into YouTube to see what comes up.

For various reasons, current Lithium-ion battery energy density is about as good as it gets unless and until someone comes up with a solid state battery.  Sandy said a few dozen people have come to Tesla claiming to have solid state battery technology, but none of their products functioned well enough, or at all in most cases, to even consider further EMD funding.  Translation: All of the "better batteries" are, to the best of his knowledge, vaporware.  Matter of fact, I think he actually used that term.  If anyone had a functioning prototype, then Tesla would cash them out on the spot.  He says Tesla has the best control electronics designs and systems integration by far, but their cells are just ordinary commercial Lithium-ion technology that any car maker can purchase.  The ability to very precisely control the cell voltages of the hundreds or thousands of cells in the battery packs is what sets them apart.  The more Sandy talked about the design of their pickup, the more I came to love the design for its functionality, even if it looks like the Halo video game truck.

Every day there's at least one new claim about a revolutionary new battery technology that's just two years to five years away.  That's been going on for at least two decades.  Our battery technologists are either more interested in satisfying their intellectual curiosity or reinventing the proverbial wheel, as NASA so frequently does, than they are in devising a more energy dense cell chemistry / configuration or they have nothing with better energy density to offer.

If you give a battery powered semi truck equivalent range to a diesel powered semi truck with the same GVWR, then the battery powered truck has to give up half of its payload to stay under 80,000 pounds.  That means you have to double the number of trucks on the road or increase the rolling resistance by adding more axles and more batteries to produce more power to overcome the increased rolling resistance.  That's just how this "orders of magnitude problem" works.  You either use appropriate technology to work around the problem, or you don't, and then you're stuck with whatever you have that actually works.

Is continuing on with combustion engines looking like a better option than fuel cells and electric motors?

I can only speak for myself when I say cutting fuel consumption in half and making our own fuel, using existing technology, looks like a more readily achievable goal.  Whenever we get around to inventing a solid state battery that actually works, then we can switch over.

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#256 2020-09-05 19:34:36

tahanson43206
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Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

This item may fit into the ongoing discussion of materials needed for Mars suits.

It will take someone with a more agile mind than mine to see how this would work on Mars, but it sure does seem (to me at least) as though it ** ought ** to fit somehow.

https://www.yahoo.com/finance/news/harv … 39765.html

This work is still at the laboratory stage (apparently).

(th)

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#257 2020-09-06 08:27:25

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For SpaceNut ... this item would fit in a number of topics that have balloons as a theme...

https://www.yahoo.com/news/french-compa … 00900.html

This is a French company building a dirigible (from the description) for a number of potential customer applications.  It was originally designed to move logs for environmentally friendly forest operations, but the team has expanded its vision as well as its staff.

(th)

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#258 2020-09-07 17:11:53

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For SpaceNut ... here is an item encouraging for human space flight, ** and ** for humans on Earth ...

The work is in early stages, and much more needs to be done, but it appears that an experimental treatment was successful in overcoming damage normally caused by weightless conditions ...

https://www.yahoo.com/news/mighty-mice- … 17778.html

The report is  by Marcia Dunn, whose work is generally well regarded.

(th)

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#259 2020-09-07 18:22:53

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

The article at the link below reports on advances in development of exoskeleton systems for humans to use on Earth.

Science Fiction has been painting pictures of this technology for years.  This system appears to be close to ready for market.

https://www.yahoo.com/news/utah-company … 00445.html

(th)

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#260 2020-09-08 05:47:20

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

The article at the link below describes Elon Musk's venture into aluminum casting on a scale which (apparently) is greater than any ever attempted before. The back story appears to be that Mr. Musk's attempt to configure fleets of robots to accurately assemble myriads of stamped parts was not as successful as he wanted to achieve his production goals.

https://www.yahoo.com/news/move-aside-r … 15310.html

If I interpret the article correctly, robots will still play a major role, by removing the complex casting from the mold.

(th)

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#261 2020-09-08 17:40:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Technology Updates

For the new Model Y, Tesla chief executive Elon Musk has said he will replace 70 components glued and riveted into the car's rear underbody with a single module made using an aluminium casting machine.

The more complex machines needed to fold and shape multiple parts that from the quote requires further assembly. Its an attempt to simplfy casting a single sheet rather than multiple pieces.

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#262 2020-09-08 18:47:54

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,440

Re: Technology Updates

tahanson43206 and SpaceNut,

Tesla is ultimately interested in a factory where the only real workers are the robots and they churn out products without the need for highly skilled labor to be involved in the manufacturing process itself.  This has very obvious applications for colonizing Mars.

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#263 2020-09-09 07:45:53

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For kbd512 re #269

I've been thinking about your comment in Post #269 ... Two thoughts came to mind ...

The first is that Tesla (Musk and team) will be employing a ** lot ** of people in thinking jobs, to bring about the vision you see, ** and ** a lot of very highly skilled workers able to create the devices needed, and to set them in place.  In the case of the new stamping equipment installed in Germany, the company outsourced development and construction of the press to another company.

What I see in that is willingness to change policy when doing everything one's self is not satisfactory.

However, Must has adjusted course in the past.  The decision to drop carbon walls for rockets in favor of stainless steel is another example.

To your point about Mars ... Ultimately, the evolution of 3D printers will approach the Star Trek Replicator, as technology rapidly able to place individual atoms precisely on a massive scale becomes available.

Plants (eg, trees) have been placing individual atoms precisely for millions of years.

Humans have been able to place aggregates of atoms (with some precision) for a while.

It seems to me that market forces will continue to drive improvement of atom placement technology.

Ultimately (following up on what I think is your vision) Mars settlers should be able to produce needed shapes of various elements and even alloys by pushing a button on a computer controlled device.

(th)

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#264 2020-09-09 10:18:38

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,440

Re: Technology Updates

tahanson43206,

SpaceX, along with everyone else, has zero practical experience fabricating reusable carbon fiber composite cryogenic propellant tanks.  The labor costs associated with fabricating cryogen tanks of the size required is significantly worse than welding stainless unless you're using tapes and robots, but even at that you need to wait at least a week to cure the composite in an oven and then you have to wait additional weeks to bond the tank domes onto the cylinder.

The extreme temperature deltas from going to ambient to cryogenic to hot enough to soften Aluminum from atmospheric heating causes the tape or fabric plies to delaminate.  There's a hard upper limit to the amount of heat the epoxy can withstand, which is no better than Aluminum.  At that point, he asked himself if it was worth the effort involved if the tanks wouldn't last for the number of flights needed for the vehicle to pay for itself, or if carrying / burning a little more propellant wasn't such a bad thing.  You'd have to burn a hell of a lot of propellant before the fuel costs ended up outweighing the benefits of the vastly cheaper but heavier stainless steel.

The special environment that orbital class rockets are subjected to ensures that the overall solution mass isn't remarkably different if you either add enough TPS to protect the heat-sensitive composite beneath it or use the heat-insensitive stainless that doesn't become embrittled at moderately cryogenic temperatures, nor does it loose all its strengths at temperatures that would turn composites or Aluminum into rubber.

Subsonic aircraft are not subjected to such extreme temperature deltas, but see many years of use in long duration flights, so all extra weight ultimately increases fuel burn and therefore operational costs, so while CFRP is an ideal fabrication material for them, for reusable rockets intended to withstand 100 flights or more... not so much.

There's an extreme cost differential between stainless and CFRP, though.  Electron Labs can slap their comparatively tiny CFRP tanks together in about 24 hours and their rockets are expendable.  That same technology doesn't work / scale acceptably well for a reusable Starship.

Aluminum and stainless are approximately $1 per pound in bulk quantities.  High modulus CF fabric is well over $100 per square yard and the new epoxies are eye-wateringly expensive.  The cost only makes sense for reducing fuel burn in aircraft that fight drag and gravity for their entire service lives.  That's why a CF structure half the weight of Aluminum is still many times more expensive than Aluminum.  The base material lets you halve the weight for the same strength as common Aluminum alloys, but the sheer mass of fiber and epoxy ensures that it will always cost more.  The rocket fights against drag for 2 minutes and gravity for 8.5 minutes per flight, which is why using durable and temperature-degradation resistant stainless steel makes more economic sense than anything else.  If the temperature resistance requirements weren't so extreme, then CFRP would provide an advantage in terms of operational costs.  Airliner cost reduction logic doesn't directly apply to space liner cost reduction logic.

Normal aircraft and motor vehicles will benefit enormously from cheap and fast CFRP or CNTRP structures fabrication, using the previously mentioned carbon forging technology (smashing carbon fabric and epoxy together with tons of force and heat, over a period of mere minutes).  Reusable rockets will benefit most from robotic steel welding of complex sheet metal structures.  In-space only transport vehicles can use a combination of Aluminum and Iron based alloys, with some CFRP for certain applications like water pipes (no corrosion, far less weight than metal; even stainless is not immune to corrosion from water), dependent upon the requirement.

If we could build structures at the atomic level, then we would have CNT fibers of arbitrary length that approach their theoretical strength.  We still wouldn't use it for high temperature applications where the fibers would oxidize, but cutting the weight of most normal vehicles to a quarter of what's practical with Aluminum would have a dramatic impact on transportation and fuel cost all on its own.

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#265 2020-09-10 08:45:06

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For kbd512 re #271

SearchTerm:CompareCompositeStainlessSteel

This long post by kbd512 goes into some depth in describing the tradeoffs that may have persuaded Elon Musk to give up on the idea of making spacecraft components (ie, rocket bodies) out of Carbon based materials.

(th)

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#266 2020-09-18 05:45:10

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

This is for Calliban re Calliban's Spider ....

I've been holding this for a few days, and just now remembered to add it to the forum ...

A while back, when the term "Calliban's Spider" was generously released for public use, the discussion underway was about wrapping loose material comprising an asteroid in a basalt thread.  At the time, the only ideas I recall involved sending a thread dispensing robot around the asteroid in a series of loops.

In recent days, while looking for something else, I noticed a report of a robot that has been designed and constructed to weave a web.  ** That ** struck me at the time as a ** much ** better solution than the flying robot idea!  A great number of web laying robots could be deployed to build a set of small webs all around the asteroid, until they find another web already present, at which point they would automatically join the web they are working on to the new one.

When the spider finishes sealing the edges of its web to other webs all the way around the perimeter, then it would assume free flight mode and return to the webmaster vehicle for supplies and a new assignment.

(th)

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#267 2020-09-18 15:40:19

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Technology Updates

The low gravity of the asteriod rock / boulder is why we are not walking the thread around it for the cocoon as we need a point of connection for it to travel around its surface.

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#268 2020-09-19 17:41:47

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,958

Re: Technology Updates

Blowing one's own trumpet or is a real tech update for landing with the use of laser, high speed cameras and computers...
https://www.spacedaily.com/reports/NASA … t_999.html

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#269 2020-09-20 05:48:05

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For SpaceNut re #275

Thanks for the link to that encouraging article!

I am glad to see the private-public partnership at work here ...

Three of SPLICE's four main subsystems will have their first integrated test flight on a Blue Origin New Shepard rocket during an upcoming mission. As the rocket's booster returns to the ground, after reaching the boundary between Earth's atmosphere and space, SPLICE's terrain relative navigation, navigation Doppler lidar, and descent and landing computer will run onboard the booster. Each will operate in the same way they will when approaching the surface of the Moon.

While the SpaceX landing technology is impressive in performance, my guess is it relies upon ground stations delivering useful data to assist the onboard computer in navigation.   The NASA work is intended to help with landings on unprepared sites.

That said, I note that plenty of overhead observation is needed to fill the image compare subsystem with data, so this is not yet a landing system for a totally unfamiliar site.   That is a capability for the next generation.

(th)

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#270 2020-09-20 11:07:35

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

The article at the link below was forwarded by a relative.  It reports on PhD level research on the data reported back by the Voyager spacecraft.

A (to me surprising) result of the study was that a very large percentage of cosmic radiation is slowed down or deflected before it reaches Earth.

I had no idea that anything other than the Earth's magnetic field might be working to protect us on Earth

https://www.bbc.com/future/article/2020 … lar-system

(th)

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#271 2020-09-22 11:40:33

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

This item came in with a tech newsletter .... It is a reminder that in design of an Interplanetary Passenger Ship, in which communications will be almost exclusively digital, starting out with an optical fiber network might be worth considering.

THE EVOLUTION FROM COPPER TO OPTICAL CONNECTIVITY
As system speeds increase, the limitations of copper are becoming more apparent, and fiber optics are becoming a more viable alternative. [speaker] explores this evolution in the latest installment of his Tech Trends series.

(th)

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#272 2020-09-22 22:53:18

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,813
Website

Re: Technology Updates

NASA Found Another Way Into Nuclear Fusion
futuristic-holographic-nuclear-fusion-particles-royalty-free-image-1600716990.jpg?resize=768:*

NASA has unlocked nuclear fusion on a tiny scale, with a phenomenon called lattice confinement fusion that takes place in the narrow channels between atoms. In the reaction, the common nuclear fuel deuterium gets trapped in the “empty” atomic space in a solid metal. What results is a Goldilocks effect that’s neither supercooled nor superheated, but where atoms reach fusion-level energy.

“Lattice confinement” may sound complex, but it's just a mechanism—by comparison, tokamaks like ITER and stellarators use “magnetic confinement.” These are the ways scientists plan to condense and then corral the fantastical amount of energy from the fusion reaction.
...
With atoms packed so densely within the atomic lattice of another element, the required energy to induce fusion goes way, way down. It’s aided by the lattice itself, which works to filter which particles get through and pushes the right kinds even closer together. But there’s a huge gulf between individual atoms at energy rates resembling fusion versus a real, commercial-scale application of nuclear fusion.

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#273 2020-09-24 10:53:19

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For RobertDyck re #279

Nice Find!  Bravo!

SearchTerm:LatticeFusion
SearchTerm:Fusion Lattice vs Magnetic confinement

I'm reminded of the will-o-the-wisp of "cold" fusion ...

(th)

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#274 2020-09-24 11:00:23

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

For SpaceNut ... this item could go multiple locations!

https://www.yahoo.com/lifestyle/spacesh … 11646.html

I'm picking up on it because of recent discussion of what it would take to develop a fire shelter that could protect a small group of people for as long as a week.  The capsule being developed (or at least promoted) for the Neptune balloon project would have to solve most of the problems that confront the fire shelter designer, with the ONE significant exception of NOT having to deal with heat soak,

The nearest example I can think of to the heat soak problem is trying to design a capsule to keep people safe at the surface of Venus, where temperatures are sufficient to melt lead, and where a planetary heat sink is unlikely to be readily available.

In the case of a fire shelter for Earth, at least the Earth itself offers a heat sink of sufficient size to offer some hope of being able to accept heat transferred from a shelter exterior wall to a set of radiator coils inside the Earth.

The design of a capsule for the Neptune balloon project would also appear to have a LOT in common with RobertDyck's Large Ship project. While RobertDyck has not identified luxurious surroundings as a primary consideration, he ** has ** hinted that luxury is not out of the question if prospective passengers can afford extra touches.

(th)

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#275 2020-09-24 13:23:32

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Technology Updates

If anyone is interested, I would be happy to provide the company name ...

Thermal Analysis Webinar

"Understanding Thermal Expansion"

... invites you to our upcoming webinar, "Understanding Thermal Expansion." The webinar is free to attend with advance registration.

Registration Button

Date/Time:
Thursday, October 15, 2020
1 PM EDT (12 noon CDT/10 PM PDT)
(approx. 45 min long)

Using the Coefficient of Thermal Expansion (CTE)

Thermal expansion is one of the fundamental properties of material. Reported as the coefficient of thermal expansion (CTE), it allows us to match how material will interact when exposed to heating and cooling cycles. This affects products as dissimilar as wine bottle, car engines, medical devices, aerospace components, etc. It’s the main reason people buy thermomechanical analyzers (TMA). We will discuss the reason why free volume is important, how to handle and prepare samples, and how to interpret data.

A spacecraft intended to cycle between Mars and Earth over a substantial lifetime is going to be subjected to severe heat flows.

Existing spacecraft appear to have been designed to handle frequent expansion and contraction cycles.

It seems reasonable (to me at least) to suppose that there must be an engineering discipline that brings focus to this aspect of system design.

(th)

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