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#1 2002-02-12 14:31:15

Timotaytatortot
Member
Registered: 2002-02-12
Posts: 1

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

In one of my old chemistry books I saw a picture of Magnesium burning in C02.  Could Magnesium be used as an effective propellant on Mars?  Just a thought.

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#2 2022-09-18 07:02:29

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,749

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

This post by Member 111 from 2002 never received a reply ...

My expectation (having only limited command of the subject) is that Magnesium might be a difficult material to apply for propulsion.

However, in recognition of this unanswered question by Member #111, I'm hoping someone with actual training in chemistry will consider the question.

That may be why the original question was never answered.

Persons with actual training in chemistry, ** and ** who are active in the forum, are rare.

I'm only aware of two in 2022.

Related to the initial question, is the question of how Magnesium might be selected for an application Mars.

Is there a need for a signal flare on Mars?  There might be. 

(th)

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#3 2022-09-18 11:05:21

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

Magnesium hydride reacts spontaneously with oxygen.  It is pyrophoric.  So it is a good way of igniting a magnesium / oxygen hybrid.  This would be a good option for a single-use, long term storable application.  Maybe ordnance?
https://cameochemicals.noaa.gov/chemical/3797

Last edited by Calliban (2022-09-18 11:08:14)


"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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#4 2022-09-18 13:36:15

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,749

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

For Calliban re #3

As a reminder, the original post (and the reason I brought it back into view) was the proposition that magnesium might have some place on Mars.

Please go back and read the original post.

We have written to the original poster, and it would be terrific if we could have a reply ready for him to consider if he shows up.

Any application of magnesium on Earth may be interesting, but it does not seem to me a good fit for the gent's inquiry.

It seems to me (without having the background to do more than guess) is that what the gent's idea might provide is a way to operate a jet engine in the atmosphere of Mars.

In this scenario (and again, referencing post #1) the designer might bring CO2 into the intake port, burn magnesium to add energy and mass, and deliver the resulting toxic product to the tail pipe.

Since no one on Mars will be breathing the atmosphere directly, perhaps the pollution of the magnesium engine might not be a problem?

Or perhaps there is a down side that I'm not aware of.

In any case, thanks for giving this topic from 2002 a bit of a lift.

(th)

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#5 2022-09-18 15:57:14

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

Mars air breathing engine has been worked on with this as its a hybrid solid gas engine.

my post for magnesium co2

Martian air breathing engine

Thos contains the work by John Wickman Air breathing engines on Mars

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#6 2022-09-19 17:28:15

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

I have added a post to: http://newmars.com/forums/viewtopic.php?id=6157

A jet engine could work using solid fuels that produce some solid combustion products.  However, the compressor must be driven by a seperate combustion chamber, burning a different fuel, with no solid products hitting the turbine blades.  The CO2-Magnesium combustion would take place in bypass combustion chambers, which have no moving parts exposed to the combustion gases.  So the engine woukd have two fuel systems: one would be oxygen-hydrocarbon which drives the gas turbine powering the compressor via a central combustion chamber; the second would be magnesium-CO2 and would burn magnesium in radial combustion chambers driven by the compressor.

This is a crazy idea.  I wonder if we could build an engine like this on Earth the runs on coal or wood chips?  I bet it would produce awful air pollution.  But would it work?  The idea of a jet engine fuelled with solud biomass is compelling.

Last edited by Calliban (2022-09-19 17:34:51)


"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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#7 2022-09-19 18:14:02

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,749

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

For Calliban re #6

Thank you for giving our long-ago member something to think about if he returns!

I like your characterization of the idea.

The realistic propulsion system for Mars that has received a fair amount of attention in the forum, is CO and O2.

This fuel is notable for it's low energy delivery >> low ISP.

So! If you are willing to spend another moment or two with our long-ago one-post member, please consider using magnesium as an afterburner for a CO-O2 rocket.

The magnesium would be injected into the combustion flow from the CO-O2 primary propellant.

Is there a way to design a combustion chamber able to permit the magnesium to "burn" CO2 as the original poster seemed to think he had seen?

I have no idea (of course) if there is enough magnesium on Mars to make this a useful technique.

(th)

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#8 2022-09-19 20:42:47

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Magnesium - Magnesium/Magnesium Hydride(MgH2)

Calliban, ICE engines can and do run on these as a combustion gas as demonstrated back in the world wars

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