POTD: .47 cal Space Impact Test

    The photo above is from the European Space Agency.


    This image shows the results of a lab test impact between a small sphere of aluminum travelling at approximately 6.8 km/second and a block of aluminum 18 cm thick. This test simulates what can happen when a small space debris object hits a spacecraft.

    Al sphere diameter: 1.2cm
    Al sphere mass: about 1.7 g
    Impact crater diameter: 9.0 cm
    Impact crater depth: 5.3 cm

    In such an impact, the pressure and temperature can exceed those found at the centre of the Earth, e.g. greater than 365 GPa and more than 6000 K.


    The aluminum ball projectile is about .47 caliber 26.23 gr travelling at 22,000 fps.

    The cross section of the aluminum block is interesting. The impact crater looks like a parabola. I am curious about the crack below the crater. I wonder if that has something to do with the grain boundaries of the aluminum and the metal sort of delaminated.