Innovations by Radio Amateurs - Pentagon scientists successfully test solar panel in space

Discussion in 'Amateur Radio News' started by W0PV, Feb 24, 2021.

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  1. VE3VXO

    VE3VXO Guest

    Hey there you go. Maybe we could spend billions more of public money to put a huge heliostat in orbit around Mars. Or even better, Pluto. We need this. Maybe some trinket belonging to Elon Musk could even be a part of the structure somehow eh? Meawhile, millions of people can continue to starve and die of treatable disease back home on mother Earth so that we can flash a greeting card at some folks who are hopelessly far away... just think of it as a make-work project for the elite. Get to that right after the power sats and the Mars colony.
     
    W2ZF likes this.
  2. W1YW

    W1YW Ham Member QRZ Page

    I can't disagree with your point of view. From a power standpoint, there is plenty of sunlight that hits the earth, and great battery technology to store it. Whether powersats, for example, prove useful will depend on the increasing efficiency, and decreasing the cost, of solar 'cell' related technology. IMO beaming power to the ground is not an effective method, except perhaps in some limited military context.

    Burning hydrocarbons , in the long run, is a dumb way to get power. Beaming power to the ground, at the moment, is not an intelligent source of power on a mass scale.
     
    W2ZF likes this.
  3. W1YW

    W1YW Ham Member QRZ Page

    Here's some quick and easy BOTEC calculations to acquiant you with an aperture engine possibiity for power.

    Assumptions:

    roughly a 33m by 33m aperture engine sat: 750m^2 aperture
    less than 30-40% efficiency in transmitted power to ground
    roughly 1395 w/m^2 hitting solar cells
    height roughly 200km above target
    Microwave at 33 cm


    TX power: about 500KW to ground
    Beam width: about 1/100th radian
    diameter of illuminate ground spot: about 2 KM
    Illuminated area: about 3 km^2
    Power density at ground: roughly 150+ watts/m^2

    That's roughly 10-15% efficiency compared to the solar constant impinging on a solar cell array . Still a decent amount of power density. Better than many extant solar farms in overcast conditions.

    The real issue is the DWELL time, which is quite short at low earth orbit. A geosynch orbit will have a far, far bigger spot size on ground and far, far lower power density.

    Interesting.. play with the numbers yourself. You can see that if solar 'cell' technologies have better efficiencies in the future, a power sat in LEO may not pose an advantage,
     
    Last edited: Mar 2, 2021
  4. VE3VXO

    VE3VXO Guest

    As you pointed out, the only "advantage" to doing anything in space is military, and that has been true since the very beginning and why an agency like NASA is needed to put a good PR face on the ugly truth. You can have a slice, all you have to do is think of a nasty application for your aperture engine. If you can live with that.
     
  5. W1YW

    W1YW Ham Member QRZ Page

    Not sure why trickle power from the sky amounts to asymmetric warfare. Seems fair game to me.

    None of the people involved in the PRAM effort were NASA. I believe they were NRL, Raytheon, AF, and so on.

    To answer your question, I sleep well. Lotsa sat apps that aren't beaming power to the ground.
     
    Last edited: Mar 3, 2021
  6. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page

    CHIP,

    TALKING ABT ALL THIS HI TECH STUFF.

    DO U KNOW THIS RASCAL


    EXOTHERMICS STEPHEN DI PIETRO.jpg

    73 - HAVE A FUN FILLED WEEKEND
    K1LKP
     
  7. W1YW

    W1YW Ham Member QRZ Page

    I believe we have crossed paths but I regret I don't recall the details. Certainly nothing negative...
     
  8. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page

    HI CHIP,

    I MET STEPHEN DI PIETRO ABOUT 5 YEARS AGO.

    THERE WAS A RELATIVE OF OURS WHO WAS RETURING FROM DUTY
    OVER IN IRAQ (PETER PAPAGNI ) . ALONG WITH PETERS PARENTS
    THERE WERE ABOUT 10 OF US AT THE AIR PORT TO WELCOME
    HIM BACK.

    I STARTED TO TELL STEPHEN ABOUT MY SUBMARINE DUTIES
    AND HE THEN TOLD ME HOW HE KNEW ADMIRAL RICKOVER
    PERSONALLY.

    TURN OUT THAT STEPHEN IS A THIRD COUSIN OF MINE.

    HE TOLD ME ABOUT HIS COMPANY UP IN AMHERST, NH
    AND HOW HE HAS TO WORK SO HARD TO KEEP THINGS
    GOING.

    THREE CHEERS FOR RELATIVES....... PISANOS

    73 - K1LKP
     
    W1YW likes this.
  9. W4JKL

    W4JKL XML Subscriber QRZ Page

    This is a nice rehash of ideas proposed in the 1960's. A thorough patent search will provide a nice list of prior work.
    W4JKL
     
  10. W1YW

    W1YW Ham Member QRZ Page

    Indeed it has.
     

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