So found a 6 year old article about a plan to get a orbiter into space with a combination railgun and scramjet. Anyone have any more recent information? Did this idea get tested or will it be or was it another ambitious plan that went nowhere.
G force acceleration would completely obliterate any electronics or instruments.
“An EM projector (i.e. rail gun) uses electrical energy to accelerate projectiles to extreme velocities. How fast? Tests conducted at the University of Canberra were able to accelerate a 16-gram projectile down a 5 meter barrel at 250,000 gravities, for a muzzle velocity of 5,900 meters per second. Loosely translated, that’s an acceleration from 0 to 13,000 miles per hour in the span of 0.2 seconds, not bad even for Superman.”
That’s why the plan was to accelerate a bit slower, 3 g or less, over a 2 mile long rail.
I’m sure someone can do the calculations better than I can, but using Jupiter’s gravity as an example, at 2.64 Gravity (because the calculator is on-line), it would take just under 20 seconds to travel those 3 miles and you’d still only be going about 1160 mph. Not even remotely near Earth’s escape velocity.
You’d need about 900 seconds (15 minutes) of acceleration at 2.64 gravities to reach escape velocity, during which you’d have traveled roughly 6500 miles.
That’s what the scramjet is for.
There are already guided artillery shells that withstand tens of thousands of gees. While not as high as the peak loads you mentioned, that’s just a function of length and the velocity you wish to hit.
Strange that they’d target such a low acceleration. Even squishy humans can survive much higher accelerations than that. With proper seating, 10 gees is no problem, and even much higher than that is reasonable for fit individuals (especially if they don’t have to be conscious).
Though 3 gees is very cushy, it’s pretty easy on stuff and the goal is to get to a speed where the scramjets can do the rest.