Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Nuclear Explosions in Space to stop Nuclear Missiles

  1. Apr 4, 2016 #1
    Missile Defense has been a big thing over the past decades to one day stop Intercontinental Ballistic Missiles. (ICBMs)Today's Missile Defense system is limited and the only defense against ICBMs is Mutually Assured Destruction. But that may change in the future.

    Early programs like Nike Zeus relied on nuclear explosions while the missile reentered the atmosphere. Nuclear explosions in space were proposed during Ronald Reagan's "Star Wars" program, but EMP from upper atmosphere explosion might damage satellites of the Star Wars programs. However today's military satellites and ground radars can very shielded against EMP unless they were very close to the blast. US Missile Defense still relies on kinetic kill vehicles to physically slam in the warhead.
    But in a full out nuclear war, can a nuclear missile be used to stop another nuclear missile if it was in accurate proximity?(lets say 200-1000 meters, accuracy range for most ICBMs)

    However, nuclear warheads can be shielded as well. Nukes are not very damaging heat and shock wise in space since there is no atmosphere to deliver that massive heat cloud, nor is their air to make that big shock wave. What greatly increases is radiation, but are they damaging enough? How resilient can a metal case be to nuke radiation, especially if they need thrusters and holes to maneuvers?

    Also does it produce a small blast and fireball at least in a couple hundred of meters for lets say a 500 Kiloton warhead?
     
  2. jcsd
  3. Apr 5, 2016 #2

    Astronuc

    User Avatar

    Staff: Mentor

    The bombs used at Hiroshima and Nagasaki produced a great amount of radiative thermal energy that initiate fires, or burned people, well before the shock wave reached them.

    http://www.aasc.ucla.edu/cab/200708230004.html
    http://www.aasc.ucla.edu/cab/200708230006.html

    Yield and distance. The higher the yield, and the shorter the distance, the more thermal and ionizing radiation from the source to the target.
     
  4. Apr 5, 2016 #3
  5. Apr 5, 2016 #4

    Astronuc

    User Avatar

    Staff: Mentor

    This is incorrect.

    How does sunlight warm the earth since it must travel through space (1.4960×1011 m)?

    How does a radiative heat element in a vacuum heat an object to the same temperature?
     
  6. Apr 5, 2016 #5
    Yeah thanks for the correction. What about the blast since there is no air or little air?

    Also most nuclear explosions generate heat hotter than sun correct? How does it compare a warhead designed for atmospheric reentry?
     
  7. Apr 5, 2016 #6

    Astronuc

    User Avatar

    Staff: Mentor

    The blast in space (which comes from the vaporization of the warhead) would not amount to much unless the detonation was very close to the target. Otherwise, it's the radiative thermal energy (from the high temperature) and ionizing radiation (X-ray and gamma ray) from the fissioning or fusing material that does the damage.

    Any object traveling through the earth's atmosphere at high speed (supersonic or hypersonic) require special designs and materials.
    See for example - https://en.wikipedia.org/wiki/Sprint_(missile)

    Surface of the sun is about 5,778 K. Compare that to the melting point of the tungsten (3695 K) or a substance made using hafnium, tantalum and carbon (Hf-N-C), which melts at a temperature of 3,526°C (3799 K). At such temperature, one would need a special heat shield like those used on the Space Shuttle or Mercury/Gemini/Apollo capsules.
     
  8. Apr 5, 2016 #7
    Since you can't really start fires in space, do metals just melt from the heat? How atmospheric reentry heat compare to nuclear radiation heat?
     
  9. Apr 5, 2016 #8

    Astronuc

    User Avatar

    Staff: Mentor

    A lot depends on how much radiative heat and ionizing radiation is present. The ionizing radiation also causes heating as it penetrates material (e.g., gamma heating). With respect to the second question, one should research the temperature profile for the Space Shuttle or Apollo capsule as it passes through the earth's atmosphere.

    https://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system


    There is an international treaty to which nations agree not to detonate nuclear weapons in space.
     
  10. Apr 5, 2016 #9
    I did research and a nuclear blast can be 100,000,000° Celsius from the fireball. The Space shuttle design is for temperatures of around 1600 C.

    But is the diameter of the heat blast greater in space due to lack of atmosphere to stop the thermal radiation?

    Are you ionizing radiation produces heat? Since X-rays for example do heat up the human body.
     
  11. Apr 5, 2016 #10

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Stationing Nukes in orbit as a shield just creates an arms race to counter the countermeasures or find other ways to get the nukes to the target.
    Assessing the effectiveness of countermeasures on the current crop of strategic weapons is short sighted, but one could use it as an exercise to anticipate the next development.

    Have you researched orbital weapons? There were a bunch of morbidly entertaining ideas around during the cold war.
    I think Edward Teller used to lecture on using nukes to defend against nukes... look up "SDI".

    One would hope that ICBMs are hardened against the sorts of conditions likely in a nuclear war ... if a nation's ability to reach the target depended on their ability to strike first, that would be very unsettling. It is, of course, difficult to get good information about the ability of ICBM's to withstand radiation and EMP etc.

    Shockwave in space discussion here:
    http://physics.stackexchange.com/questions/17957/would-a-high-explosive-in-a-vacuum-be-less-harmful

    Thermal radiation through space:
    https://en.wikipedia.org/wiki/Thermal_radiation
    (there must be a better one)
    Consider: how big is the fireball (the surface of which has the referenced temperature), how big, therefore, is the radius at which significant damage would be done to the type of target expected?
    Now... how big is space?
     
  12. Apr 5, 2016 #11

    Astronuc

    User Avatar

    Staff: Mentor

    That is small volume just after detonation. In fractions of a second, that volume expands rapidly and the energy per unit volume decreases rapidly.

    X-rays (coming from atomic electrons) have energies in the low (100 eV - 100 keV) range, as compared to gammas (from nuclear reactions) that have energies in the high (100s) keV and MeV range, so X-rays don't penetrate metal as well as gammas.

    The effects of a nuclear detonation depend on the yield (and type of reaction fission or fusion, or combination) and the distance from the detonation.
     
  13. Apr 5, 2016 #12
    I am saying using an Nuclear ABM to stop a ICBM, not stationing a nuke on satellite. That would be too deescalating. Orbital nukes have one problem. Hacking. You need some sort of computer device to release it.
    ICBM fleets are HIGHLY regulated using very old technology to prevent any sort of outside contact. You wouldn't want to put the destruction of mandkind on something that could be hacked or glitched.

    From what I know nukes usually detonate individually over an area through MIRV, you never want to explode them together.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Nuclear Explosions in Space to stop Nuclear Missiles
  1. Stopping a nuclear bomb (Replies: 41)

  2. Nuclear explosion (Replies: 3)

Loading...