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#1 2003-12-29 12:29:43

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

Just an (i'm sure not original) idea...

There has been talk about the big solar powered microwave generators in GEO for years, but nobody seems to actually try to build them, because with current energy prices they're just too costly etc... So the idea never gets developed... Small-scale 'test-equipment' would be laughed away, because we're talking MegaWatts and more in this context...

But for Mars a small scale version could be *very* valuable... Energy is much more scarce there, especially if it would be an uninterruptable source... And there would be no need for Megawatts, 50-100 Watts could be enough to power landers, rovers etc...

Imagine one reasonably big sat in Mars 'GEO' with an (unfolded) large solar array and one 'tiny' microwave emitter to the surface. Low-powered probes, robots etc. could use this external powersource, using a simple receiver, making them lighter (no solar panels/RTG etc, only a small back-up battery would be needed. If the sat has it's own battery, it could keep sending power without interruption, helping the probes through the night.

The sat's emitter of course should be 'targetable', making it possible to serve different landers, rovers, depending on their needs... And to different generations of these landers... year after year...

And it's scalable, just add sats... or equip the sat with several 'beamers'

Is this a crazy idea? Would there be enough power, would the weight decrease for landers be interesting?

One thing would be good: t should show the 'proof of concept' of these microwave generators, maybe giving the idea a new impulse, for Earth...

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#2 2003-12-29 12:45:26

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

Oh, yeah...

I got the idea, because i was thinking it was such a waste of these landers, rovers (like Soyourner) prematurely shutting down, not because the hardware wears out, but because the powersource gives out (solar cells getting dust-caked)

Of course RTG would solve this, but political and safety 'issues' -and PLEASE let's not get into that, there are other threads about this- make them expensive, and heavy and all that...

A simple rectenna(sp?) maybe, but not neccessarily motor driven, with a little back-up battery and some simple targeting soft-and hardware would be all that's needed on the surface, so more landing-mass for measuring etc. equipment, AND longer operation cycles...

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#3 2003-12-29 21:03:38

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Microwave power - Testcase on Mars?

Sounds like a very good idea, Rxke!
    I don't know much about the details of the power available from such a solar satellite and how much would be transferable to a surface rover, but in principle I think it could work.
    To avoid power outages, without relying on batteries, would it be worth having, say, half a dozen such satellites spaced out evenly in areosynchronous orbit to achieve a constant supply of solar power?
                                              ???

    I suppose these satellites needn't be very expensive to build and place in martian orbit (?).


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#4 2003-12-30 03:26:12

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

...Forget it. My 'idea' is moronically stupid.

I just realised the landers need a 'big' battery anyway, for the powering-up of systems during landing (and, presumably transfer... though you could put batteries in heatshield etc, and jettison before landing...)

it could be useful as a remote controlled micro-wave-dinner-defrosting service, though!


(Sorry for being so cynical, heard some really sad news today)

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#5 2003-12-30 20:39:06

Shaun Barrett
Member
From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Microwave power - Testcase on Mars?

Hmmm ... I don't know. I still think this idea could be worth some further consideration. I suppose it depends what you're looking to achieve with your probes on the surface and how much continuous power supply is needed.
                                                 ???


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#6 2003-12-30 23:38:50

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Microwave power - Testcase on Mars?

A clever idea, but not practical because of the size of rectenna required to soak up signifigant energy. And what happens if this gets coverd with iron-bearing Mars/Moon dust? Focusing the microwave beam that tightly is not going to happen, even if you could make your transmitter/recievers stay pointed at eachother as the rover bounces over rocks in the 1/3rd G gravity.

When somebody gets around to making a dynamic (moving generator) RTG, and after "Nuclear O'Keffee" gets comfortable telling the eco-wackies to take a long walk out a short airlock, then we won't have to worry about remote low-power sources.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#7 2003-12-31 10:26:18

Shaun Barrett
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From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Microwave power - Testcase on Mars?

Kill joy!!!


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#8 2003-12-31 10:42:47

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

Hmmm... I half-heartedly googled around a bit... Rectenna-on-a-chip stuff is waaaay more promising than i thought, 2-300 Watts/m2... Easily. Of course you have to watch out with the power'density' you beam down... Grilled rovers etc. Also the roll-up solar cells on Hubble are small-package and quite performant... (but don't come cheap, 9 mil)

Maybe next year do some extended googling...

BTW... Bouncing rovers are still waaay in the future, watch the simulations, these things are so s-l-o-w, it's almost emabarrasing.

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#9 2003-12-31 13:01:39

GCNRevenger
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From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Microwave power - Testcase on Mars?

It isn't the efficency of the reciever thats the problem, the big issue is that the microwave "beam" will spread out too much at that distance, requiring a fairly large collector. Concepts for Earth-based recievers for industrial-scale solar satelites are measured in acres, not square centimeters.

The rovers only really go slow because of the time lag trying to control them. When we have people on the ground or in orbit, then they'll be covering serious distances, and keeping a large antenna pointed with precision would be difficult... which would be about the same time as you would have said miniature power satelite.

Solar power is also not all that efficent at Martian distances, and i'm skeptical that it would be easy to build a satelite that could transmit signifigant power without getting awfully heavy.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#10 2004-01-01 01:04:27

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

I realise the problems... Was only a thought flashing to my reverbating (=empty) skull...

But i geot interested, gonna look up some numbers, just to see how 'far' they got


(sorry if typos, 0800 am here, and *not*sober...

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#11 2004-01-01 04:22:40

Shaun Barrett
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From: Cairns, Queensland, Australia
Registered: 2001-12-28
Posts: 2,843

Re: Microwave power - Testcase on Mars?

How about laser power transmission? The martian atmosphere is thin and dry, so would that mean less scattering of an infra-red laser, say?
    How tightly focused can we make a laser and would it spread too much to be useful in this situation?
                                          ???


The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down.   - Rita Rudner

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#12 2004-01-01 12:18:52

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

LASER... With all the dust in the atmosphere on Mars, i'mafraid scattering would be quite severe, just a guess, though...

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#13 2004-01-01 12:50:57

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Microwave power - Testcase on Mars?

A laser would be an improvement, but still not all that great. I don't think there is any technology that can focus any sort of radiation down to a spot no more than 2-3m through any medium that would be light/compact and reliable. A large laser is a pretty hefty and short-lived device anyway. An optical laser fired through our atmosphere to the Moon will spread out to several miles. An IR laser would also be severely disrupted by accumulated dust on the reciever most likly.

It may one day be practical to build large satelites for fixed microwave transmission to very large recievers, but I still don't see this technology being preferably to an advanced dynamic RTG system for remote low power applications.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#14 2004-01-01 12:54:49

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Microwave power - Testcase on Mars?

Infra-red energy isn't hamperd by small amounts of dust in the air like visible wavelengths, though if your reciever is coverd in a layer of it there would be signifigant loss.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#15 2004-01-01 15:06:02

Rxke
Member
From: Belgium
Registered: 2003-11-03
Posts: 3,669

Re: Microwave power - Testcase on Mars?

*slaps high forehaad REAL hard*
*SLAP*
Ouch; that hurt..

I obviously missed the IR bit... You're 200% right GNCRevenger... IR has far better penetration characteristics than visible.

((maaaan, do i feel stupid, this is stuff i'm supposed to know from my studies, for chrissake...)
...

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#16 2004-01-19 02:08:32

Hazer
Member
From: Texas/Oklahoma
Registered: 2003-10-26
Posts: 173

Re: Microwave power - Testcase on Mars?

If you're talking about focusing a laser on a certain point of your autonomous rover, it shouldn't be a problem. 
Cold-War era lasers (Mid 80's) were easily capable of writing someone's name on the side of an ICBM over 70 miles away traveling at a blistering 16,000 miles per hour.
Mind you, this is a laser fired from a B-52.
Beaming power with a laser isn't a bad idea, it's really just a matter of setting things up.
As I see it, the real trick would be setting up a GPS-like system of satellites for the rovers to use.


In the interests of my species
I am a firm supporter of stepping out into this great universe both armed and dangerous.

Bootprints in red dust, or bust!

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#17 2004-01-19 18:56:41

jadeheart
Banned
From: barrow ak
Registered: 2003-11-03
Posts: 134

Re: Microwave power - Testcase on Mars?

what about a maser?  that way you keep the original microwave advantages but get a tighter focus


You can stand on a mountaintop with your mouth open for a very long time before a roast duck flies into it.  -Chinese Proverb

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#18 2004-01-19 21:18:13

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Microwave power - Testcase on Mars?

Thats all well and good for a anti-missile laser, but the problem is a that the conditions are a liiiittle different...

First of all, the device must be light-weight, survive in the harsh conditions of space, and operate with reasonable reliability while being able to focus a beam of signifigant power.

Then the biggie... this isn't 70mi away. This is several thousand miles away, where the optics involved to make such a system work will get pretty big. Too big.

And then there is the rover itself, which will have to keep its collector very carefully aimed, even though it may be bouncing over rocks and driving through craters... without lasing the surrounding soil to death.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#19 2004-01-20 00:18:09

Hazer
Member
From: Texas/Oklahoma
Registered: 2003-10-26
Posts: 173

Re: Microwave power - Testcase on Mars?

The laser I made reference to was mounted on the wing of a B-52.  You need to know where you are in relation to the target and the target's position.  The rest is just calculations.  True they may be bloody horrendous, but with enough computing power it would work.
But anyhow, you'd want to put it somewhere in LMO (Low Mars Orbit) along with an array of mirrors so that you could focus it past the curve of the planet.
The real issue is setting the array of satellites up.


In the interests of my species
I am a firm supporter of stepping out into this great universe both armed and dangerous.

Bootprints in red dust, or bust!

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#20 2005-10-10 03:09:11

noosfractal
Member
From: Biosphere 1
Registered: 2005-10-04
Posts: 824
Website

Re: Microwave power - Testcase on Mars?

Just an (i'm sure not original) idea...

There has been talk about the big solar powered microwave generators in GEO for years, but nobody seems to actually try to build them, because with current energy prices they're just too costly etc... So the idea never gets developed... Small-scale 'test-equipment' would be laughed away, because we're talking MegaWatts and more in this context...

But for Mars a small scale version could be *very* valuable... Energy is much more scarce there, especially if it would be an uninterruptable source... And there would be no need for Megawatts, 50-100 Watts could be enough to power landers, rovers etc...

Here is an article along those lines from 1999 ...

http://science.nasa.gov/newhome/headlin … ar99_1.htm

One benefit it cites is that the rectenna, although large (> 20 km), may be able to manufactured out of Martian soil (which is up to 14% iron oxide).  A "bootstrap" rectenna (of 1.5 km) powers an iron ore refinery.


Fan of [url=http://www.red-oasis.com/]Red Oasis[/url]

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#21 2021-11-20 05:48:23

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 8,892

Re: Microwave power - Testcase on Mars?

Japanese Scientists Propose Microwave-Powered Spacecraft
https://futurism.com/microwave-powered-spacecraft

Orbiting Solar Panels Beam Energy From Space
https://www.designnews.com/orbiting-sol … ergy-space

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#22 2021-12-29 19:06:48

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

Re: Microwave power - Testcase on Mars?

Like all topics that no one takes the time to talk about the technology with in it I find it absent of many of the conversations which have been had in other topics.

The Air Force Research Laboratory's and Northrop Grumman's Space Solar Power Incremental Demonstrations and Research (SSPIDR) Project have successfully conducted the first end-to-end demonstration of key hardware for the Arachne flight experiment.

RF is a band of energy frequencies that we can transmit within.
afrl-northrop-grumman-solar-to-radio-frequency-conversion-hg.jpg

The sandwich tile consists of two layers. The first layer is a panel of highly efficient photovoltaic (PV) cells which collect solar energy and provide power to the second layer. The second layer is populated with components that enable solar to RF conversion and beamforming.

The ground demonstration used a solar simulator to illuminate the PV side of the tile and begin the Solar-to-RF conversion process. Because the solar simulator was so intense, attendees viewed real-time RF output data on monitors from behind an industrial grade flexible plastic barrier, and cheered when an RF energy peak appeared indicating successful power conversion and RF radiated power.

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#23 2021-12-29 19:26:02

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,754

Re: Microwave power - Testcase on Mars?

For spaceNut re Post #22

The report you found appears to be about Solar Powered Satellites ... I will have to follow the link to the source later.

The topic itself appears to be another of the many forgotten topics from ancient days of the forum.

(th)

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#24 2021-12-29 19:59:53

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,754

Re: Microwave power - Testcase on Mars?

For SpaceNut .... 2025 seems like a ** long ** time to wait.

We've been talking about SPS since the 60's, when Peter Glazer first published his ideas on the subject.

OK ... 70's ...

In July 1971, while working for the consulting firm Arthur D. Little, Inc. in Cambridge, Massachusetts, Glaser filed for a U.S. patent for his "Method and Apparatus for Converting Solar Radiation to Electrical Power."

Glaser envisioned harvesting solar radiation in space using satellites, which would convert it to microwave energy and then transmit it to Earth for use in electrical power systems. He obtained the patent in 1973.

In fostering the idea, Glaser drew upon his extensive expertise in space science and technology, solar energy conversion and wireless power transmission. He later became a vocal advocate of solar power satellite systems as a solution to the growing global energy dilemma.

This writer had the privilege of working with Glaser from the 1970s into the mid-1980s, while assisting in a detailed appraisal of SPS by the U.S. Department of Energy and its Office of Energy Research's Satellite Power System Project Office in Washington, D.C.

An artist's illustration of a possible space solar power collector.

Above is from https://www.space.com/26175-peter-glase … tuary.html

(th)

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#25 2021-12-29 20:03:23

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

Re: Microwave power - Testcase on Mars?

http://newmars.com/forums/viewtopic.php?id=9992
mentions 2 older topics.
I wish I could split and merge to topics single posts like we used to have...

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