4 ms·
I haven't seen Scott Manley's video; but if the mass cost of a heatshield is so significant that's a problem. However, there's a benefit in this case: heat shi
by gnramires 5y ago
I haven't seen Scott Manley's video; but if the mass cost of a heatshield is so significant that's a problem.
However, there's a benefit in this case: heat shield probably scales with area (often something like mass^(2/3)), making it progressively less significant compared to fuel mass (which is roughly a constant fraction, i.e. it scales like mass^(1)). I think a high altitude launch site could make a significant difference as well (although that creates other logistic inconveniences). Atmospheric pressure approximately halves every 5km, and air resistance is roughly proportional to pressure.
- kurthr 5y agoBuilding and SpinLaunching at above 10k feet (3km) seems like a no-brainer. It reduces heating and weight while increasing terminal altitude substantially... like 2x. It would be more efficient, if they could use a whip effect to (match impedance) capture much more of the rotational energy they put into the spin, more like a trebuchet.
- Schroedingersat 5y agoIs there any material strong enough to provide the whip? Or would you just make the spinning part slower?
- sacrosancty 5y agoIs optimizing efficiency relevant at all? I'd think the electrical power cost must be negligible compared to the rest of the cost of a launch.
- edrxty 5y agoIt's not the electrical cost so much as system complexity. They could use less heat shield, more payload, spin the payload less hard, etc.