Solar-pumped laser power transmission, a way to dramatically decrease launch costs?
in [Physics]
|
From: William Mook on 25 May 2010 23:42 Stephan Boltzmann gives how fast something can radiate away energy per square meter J/m2 = 5.67e-8 * T^4 So, a 6.5 cm ball in space that absorbs all the energy falling on it near 1 AU from the sun absorbs no more than 4.55 watts. This same ball must rise to a temperature of 279 K to radiate away heat at the same rate it arrives. Even if the ball were perfectly reflective and generated more than 5 watts of energy internally, it would overheat. Evaporation of water or some similar compound would carry away heat more quickly, as long as the supply of material lasted.
From: Brad Guth on 26 May 2010 15:58
On May 25, 8:42 pm, William Mook <mokmedi...(a)gmail.com> wrote: > Stephan Boltzmann gives how fast something can radiate away energy per > square meter > > J/m2 = 5.67e-8 * T^4 > > So, a 6.5 cm ball in space that absorbs all the energy falling on it > near 1 AU from the sun absorbs no more than 4.55 watts. This same > ball must rise to a temperature of 279 K to radiate away heat at the > same rate it arrives. Even if the ball were perfectly reflective and > generated more than 5 watts of energy internally, it would overheat. > Evaporation of water or some similar compound would carry away heat > more quickly, as long as the supply of material lasted. Correct. It seems Japan, China and India were each intentionally misinformed as to properly dealing with all that continuous solar plus secondary lunar IR heat, and perhaps not made aware as to the extent of hot sodium which also surrounds our moon/Selene. Perhaps using a supply of HTP (98% h2o2) would be a good coolant, as well as a viable source of energy as long as the supply of material lasted. How about using a conventional closed cycle form of Stirling refrigeration/cooling? How about their using solar and lunar IR shades, in order to block out the sun and moon? ~ BG |