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#1 2021-12-16 11:00:27

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Calliban Postings

Calliban has been and continues to be a significant contributor to the forum.

There are ** many ** posts by Calliban that deserve to be indexed, and indeed, a number already are.

However, this new category of topic, created for us by Louis in recognition of the contributions of Mars_B4_Moon, did not include Calliban.

I'd like to start this new topic with this citation:
http://newmars.com/forums/viewtopic.php … 32#p188832

As is often the case with posts by Calliban, he starts with praise for the work of others, and then extends to idea set further.

The citation is from topic:  Nuclear Powered Crawler-Transporter for Mars

(th)

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#2 2021-12-19 18:39:59

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

Here is a link to another outstanding post by Calliban:

http://newmars.com/forums/viewtopic.php … 3#p188943/

In this (brief) essay, he considers the magnitude of the challenge humans would face, if they were to attempt to create a self-sufficient community on Mars.

He points out that no Nation on Earth has achieved self-sufficiency, even though the circumstances of life are significantly more favorable than would be the case on Mars.

(th)

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#3 2021-12-19 19:33:28

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,753

Re: Calliban Postings

We were more self sufficient back a century ago as individuals and families, as communities we did share and band together more than we do now.

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#4 2021-12-19 21:07:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

For SpaceNut re #3 .... You've got a point .... the Native Americans were self-sufficient for centuries before the Europeans showed up.

Trade flourished within the bounds of the continent.

The life was comparatively low tech, but the technology was sophisticated for it's time.

(th)

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#5 2021-12-22 12:53:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,753

Re: Calliban Postings

Posting in the meta area is intended to be positive commenting only for the individuals post which have been made.

Aka Thumbs up acknowledgement...

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#6 2022-01-05 07:30:09

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

Nirvana!  I am able to highlight a post of Calliban without intruding my ID in the topic!

http://newmars.com/forums/viewtopic.php … 28#p189828

This is another outstanding post by Calliban, of many we are fortunate to have stored in the archive.

This one appears (as I read it anyway) to provide a practical and (comparatively) inexpensive way to construct a landing pad for a vessel at Mars.

It is ** also ** worth noting that construction method proposed draws upon British invention and hard work during World War II.

I asked Google for snippets, and it came up with a nice collection:

Project Habbakuk: Britain's secret attempt to build an ice warship
www.cnn.com › style › article › project-habbakuk-ice-aircraft-carrier

Apr 26, 2018 · The dark depths of Lake Patricia in Canada still hide a secret that was once poised to change the course of World War II.
Project Habakkuk - Wikipedia
en.wikipedia.org › wiki › Project_Habakkuk

Project Habakkuk or Habbakuk (spelling varies) was a plan by the British during the Second World War to construct an aircraft carrier out of pykrete for use ...
History · Shooting incident · End of project · Criticism
British invasion of Iceland - Wikipedia
en.wikipedia.org › wiki › British_invasion_of_Iceland

The invasion of Iceland (codenamed Operation Fork) by the Royal Navy and Royal Marines occurred on 10 May 1940, during World War II. ... To guard against this, troops would drive east to the landing grounds at ...

The Secret Story Of The Ice Airfield | Weapons and Warfare
weaponsandwarfare.com › 2017/04/23 › the-secret-story-of-the-ice-airfield
Apr 23, 2017 · The secret origin of Pykrete was nothing to do with Pyke, and Professor Mark surely deserves his own place in the history of World War II. Share ...
People also ask

(th)

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#7 2022-05-25 08:18:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

Here is another outstanding post by Calliban: http://newmars.com/forums/viewtopic.php … 31#p195331

While this is just one of many equally valuable posts by Calliban, this one stands out because it provides a study of the Prometheus company concept for making synthetic fuel using CO2 and water as input.

SearchTerm:Prometheus analysis by Calliban - note value of CO2 concentration to enhance performance.

I note that output from a fossil fuel power plant is loaded with CO2.

The suggestion of Calliban, to cool the exhaust with liquid air would apply to the power plant output situation.

In the Zoom meeting of May 22nd, 2022, kbd512 pointed out that it takes energy to compress CO2 coming out of a power plant, or it takes energy to make liquid air to cool the exhaust.  The amount of energy required should be identical, but the liquid air suggestion of Caliban has the major benefit that the compression machinery can be located away from the customer plant.  The location of the downstream facility can't be ** too ** far from the customer site, because a pipeline would be the optimum way to deliver the liquid air to the customer site.

(th)

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#8 2022-10-03 12:56:31

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

This is a noteworthy post by Calliban .... http://newmars.com/forums/viewtopic.php … 29#p201529

It is a concise assessment of the prospects for extraterrestrial life, with a nod to the Drake Equation.

SearchTerm:Drake equation
SearchTerm:Extraterrestrial life prospects for

(th)

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#9 2022-11-17 08:15:06

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,008

Re: Calliban Postings

Innovative ideas are often found in Calliban postings.  Occasionally, one of these rises above the rest, or perhaps fills a (perceived) need at a particular moment.

http://newmars.com/forums/viewtopic.php … 43#p203243

This post contains a vision of design for vehicles to operate on airless or hostile Solar System bodies. While the concept is written for the Lunar environment, it should work on Mars, and it would certainly work on the many airless bodies to be explored in the local neighborhood.

The design addresses distribution of "waste" heat as a beneficial byproduct, to keep the entire vehicle warm enough to retain integrity in space conditions.  While some might imagine fuel cells would be a better solution, if I understand Calliban's argument correctly, the low proportion of waste heat from a fuel cell would fail to adequately heat the vehicle, so part of the output would have to be allocated to resistive heating.

In any case, this post by Calliban ** should ** stimulate additional creative thinking by readers.

(th)

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#10 2022-11-17 12:03:22

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,218

Re: Calliban Postings

The vehicle could use a fuel cell.  I havn't done any detailed calculations, but there are certain factors that make me sceptical of fuel cells for automotive power.  A solid oxide fuel cell could have efficiency up to 60%, twice what you would get from a small GT.  But a solid oxide fuel cell has power density of 10-15W/kg.  That is extremely poor.
https://en.m.wikipedia.org/wiki/Power-to-weight_ratio

Each horsepower would need about 50-75kg of fuel cells.  If you need a lot of power, as you do with soil moving equipment, the fuel cells would dominate vehicle mass.  A turbo-diesel engine has about 50x the power/weight of a SOFC.  But that is with diesel fuel.  The same engine burning hydrogen would have much poorer power density because hydrogen has poor energy density and is an ideal gas under compression.  A gas turbine delivers somewhere between 500-1000x the power/weight of a SOFC.  Even using low energy density hydrogen, its P/W would be respectable.

Using a lightweight and compact engine helps compensate for the bulkiness of those compressed gas tanks.  There are other problems with fuel cells.  They are vulnerable to thermal and mechanical shock and membranes are fragile.  And although efficiency looks good on paper, pumping losses subtract from theoretical efficiency.  If I wanted a stationary powerplant for a CHP system in large building, a SOFC would be a viable option.  For a vehicle it is a much weaker option.

Additional: The Mars Direct mission concept settled on LOX/CH4 bipropellant for rovers.  Although hydrogen can be produced far more efficiently using electrolysis than methane, CH4 is still a better choice for ground vehicles.  Under standard conditions, it has 3x the energy density of hydrogen.  It can be stored as a compressed liquid at soft cryogenic temperatures.  That means compact and lightweight fuel tanks.  The same calculus may apply on the moon.

Last edited by Calliban (2022-11-17 12:11:24)


"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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#11 2022-11-17 13:21:00

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,218

Re: Calliban Postings

This could be promissing.  High power density fuel cells could change the conclusion.
https://technology.nasa.gov/patent/LEW-TOPS-120

This material is interesting as a hydrogen storage material.
https://en.m.wikipedia.org/wiki/Lithium_hydride

It decomposes at 1000°C, about the same operating temperature as a solid oxide fuel cell.  The problem is the decomposition product will be molten lithium.  It would need to be ground to powder and gaseous hydrogen passed through the powder to regenerate the LiH.

A high tensile steel pressure tank is a simple solution.  It can be charged using a centrifugal compressor mounted on the outlet plenum of the electrolysis cell.

A simple means of recharging the vehicle would be to park it within a bay, with electrified rail sections at ground level, either side of the vehicle.  The vehicle would pick up power using pickup shoes which would slide onto the rails as the vehicle enters the bay.  This avoids the need to use EVA to connect a power cable.

Last edited by Calliban (2022-11-17 13:51:12)


"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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#12 2022-11-17 19:30:02

kbd512
Administrator
Registered: 2015-01-02
Posts: 6,228

Re: Calliban Postings

Calliban,

If the vehicle is equipped with one of those remote manipulator arms, then maybe it can pick up and attach its own power cable off a nearby reel.

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