| Sustained Hypersonic Speed |
Mach 6 (X-51A Waverider, 2013) |
Mach 10–15 plausible (SR-72 programme) |
PUBLIC + CLASSIFIED PROBABLE
|
| Instantaneous Acceleration |
~9g (F-22 sustained, ~30g briefly, missile) |
No plausible path to 1,000g+ for any crewed vehicle |
|
| Stealth / Low Observable |
B-21 Raider, F-35 — radar cross section <0.001 m² |
Full-spectrum stealth (radar, IR, acoustic) classified programmes likely |
WELL WITHIN HUMAN CAPABILITY
|
| Trans-Medium Operation |
None publicly deployed (air + water) |
DARPA SHARK / USO research documented. Supercavitation at speed demonstrated. |
|
| No Sonic Boom |
Lockheed X-59 QueSST — reduced boom demonstration (2024) |
Boom suppression, not elimination. True zero-boom at Mach 5+ has no known mechanism. |
MITIGATION POSSIBLE / ELIMINATION NOT
|
| Directed EM Warfare |
CHAMP HPM (Boeing, 2012) — building-scale electronics suppression |
Miniaturised, precision-targeted versions likely classified |
WELL WITHIN HUMAN CAPABILITY
|
| Right-Angle Turns at Mach 5+ |
Minimum turn radius at Mach 5 / 50,000ft: ~200km |
No plausible engineering path. Physics constraint, not technology constraint. |
|
| Silent Hovering (No Exhaust) |
Ion drive (space only), small-scale electrogravitics |
Advanced ion / MHD atmospheric systems possible at low speed |
|
| Long-Duration Loiter (Days/Weeks) |
Solar HALE UAVs (Zephyr S: 25 days at 70,000ft) |
Nuclear-powered UAV loiter likely classified (Project Pluto heritage) |
|