• Agenda physics in Wikipedia? - nuclear fission efficiency of 0.1%

    From Dave@21:1/5 to All on Fri Jun 28 18:02:26 2024
    XPost: sci.physics, uk.politics.misc

    Reading
    http://en.wikipedia.org/wiki/Photon_rocket,
    an onboard nuclear engine doesn't look good,
    despite me thinking it is the best option to
    get a rover to an exoplanet.

    Then I looked into why, and the gamma efficiency
    is given as 0.1% for fission,
    this seem like 100 times too low,
    resulting in a maximum quoted speed of 60km/s.

    There are other options also, like having an
    open gamma ray source. This has the advantage of
    no moving parts, just don't look into the beam.

    Posted to uk.politics.mics, because likely the
    information will be assessed differently,
    and a general don't believe everything you can read
    or take everything at face value.

    I can be corrected, but 0.1% is very very low
    for any generator.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Pennino@21:1/5 to Dave on Fri Jun 28 11:41:42 2024
    XPost: sci.physics, uk.politics.misc

    In sci.physics Dave <dwickford@yahoo.com> wrote:
    Reading
    http://en.wikipedia.org/wiki/Photon_rocket,
    an onboard nuclear engine doesn't look good,
    despite me thinking it is the best option to
    get a rover to an exoplanet.

    Then I looked into why, and the gamma efficiency
    is given as 0.1% for fission,
    this seem like 100 times too low,
    resulting in a maximum quoted speed of 60km/s.

    There are other options also, like having an
    open gamma ray source. This has the advantage of
    no moving parts, just don't look into the beam.

    Posted to uk.politics.mics, because likely the
    information will be assessed differently,
    and a general don't believe everything you can read
    or take everything at face value.

    I can be corrected, but 0.1% is very very low
    for any generator.

    For an in depth look at nuclear rockets of all kinds as well as things
    like energy weapons, space war, ship designs, etc., both real and
    sci fi, see:

    https://projectrho.com/public_html/rocket/torchships.php

    Crackpots beware, contains mathematics.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dave@21:1/5 to Jim Pennino on Fri Jun 28 20:28:36 2024
    XPost: sci.physics, uk.politics.misc

    On 24 42, Jim Pennino wrote:
    In sci.physics Dave <dwickford@yahoo.com> wrote:
    Reading
    http://en.wikipedia.org/wiki/Photon_rocket,
    an onboard nuclear engine doesn't look good,
    despite me thinking it is the best option to
    get a rover to an exoplanet.

    Then I looked into why, and the gamma efficiency
    is given as 0.1% for fission,
    this seem like 100 times too low,
    resulting in a maximum quoted speed of 60km/s.

    There are other options also, like having an
    open gamma ray source. This has the advantage of
    no moving parts, just don't look into the beam.

    Posted to uk.politics.mics, because likely the
    information will be assessed differently,
    and a general don't believe everything you can read
    or take everything at face value.

    I can be corrected, but 0.1% is very very low
    for any generator.

    For an in depth look at nuclear rockets of all kinds as well as things
    like energy weapons, space war, ship designs, etc., both real and
    sci fi, see:

    https://projectrho.com/public_html/rocket/torchships.php

    Crackpots beware, contains mathematics.


    I think I misread what the 0.1% was about, it's the percentage
    of usable fuel in the total fuel load. So that figure may be
    correct. The 60km/second figure is still very low, on the same
    order as chemical rockets.

    Approach it by the number of Joules in a KG of lighly
    enriched uranium?

    One thing Wikipedia isn't mentioning is jettisoning the
    spent fuel to lighten the load, which would be making a material difference.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Pennino@21:1/5 to Dave on Fri Jun 28 13:55:25 2024
    XPost: sci.physics, uk.politics.misc

    In sci.physics Dave <dwickford@yahoo.com> wrote:
    On 24 42, Jim Pennino wrote:
    In sci.physics Dave <dwickford@yahoo.com> wrote:
    Reading
    http://en.wikipedia.org/wiki/Photon_rocket,
    an onboard nuclear engine doesn't look good,
    despite me thinking it is the best option to
    get a rover to an exoplanet.

    Then I looked into why, and the gamma efficiency
    is given as 0.1% for fission,
    this seem like 100 times too low,
    resulting in a maximum quoted speed of 60km/s.

    There are other options also, like having an
    open gamma ray source. This has the advantage of
    no moving parts, just don't look into the beam.

    Posted to uk.politics.mics, because likely the
    information will be assessed differently,
    and a general don't believe everything you can read
    or take everything at face value.

    I can be corrected, but 0.1% is very very low
    for any generator.

    For an in depth look at nuclear rockets of all kinds as well as things
    like energy weapons, space war, ship designs, etc., both real and
    sci fi, see:

    https://projectrho.com/public_html/rocket/torchships.php

    Crackpots beware, contains mathematics.


    I think I misread what the 0.1% was about, it's the percentage
    of usable fuel in the total fuel load. So that figure may be
    correct. The 60km/second figure is still very low, on the same
    order as chemical rockets.

    Approach it by the number of Joules in a KG of lighly
    enriched uranium?

    One thing Wikipedia isn't mentioning is jettisoning the
    spent fuel to lighten the load, which would be making a material difference.


    Obviously you did not read the links at the bottom of the wikipedia
    article.

    "Whatever happened to Photon Rockets?" which leads to:

    https://armaghplanet.com/whatever-happened-to-photon-rockets.html

    Near the end it says:

    "When you closely examine the feasiblity of photon rockets the concept
    falls apart. They require materials and techniques that may never exist
    in the real Universe and need outrageous resources and time to attain
    their amazing performance. Sadly, photon rockets appear to be forever an intriguing fantasy."

    Read the entire link to understand why that is the conclusion reached.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)