1. Cloud Altitude Maximum altitude for cloud rise is reached after ~ 4min. RATE OF RISE OF THE RADIOACTIVE CLOUD FROM a I-MEGATON AIRBURST Height Time Rate of Rise (miles) (min) (mph) 2.0 0.3 330 3.0 40.7 270 4.0 61.1 220 5.0 102.5 140 6.0 123.8 27 Cloud height & cloud radius depend on the magnitude of the explosion, increase of both radius & height scales with explosion yield.

2. Operation Greenhouse

3. Operation Plumbbob

4. Atmospheric tests at low & high altitude  High Altitude Air Blast: fireball > 100,000 ft (>3000m)  Low Altitude Air Blast: fireball < 100,000 ft (without touching ground)  Surface Blast: fireball in touch with surface  Subsurface Blast: Underwater burst  Underground Blast underground conditions

5. Low Altitude Tests YESO, 3000kT; B52 drop free fall to 8300ft r = 2705 ft ≈ 900 m SWANEE, 97kT; B52 parachute fall 3000ft r = 685 ft ≈ 228 m Pressure surge downward, shock front emission: Fireball evolution R = 110 W 0.4 [ft] (W = yield in kT of TNT)

6. r = 110·W 0.4 = 694 ft ≈ 230 m

7. Development of the Airburst 1.2 s: Shock-front re-bounce 0.5 s: Shock-front fireball evolution 3 s: double shock-front upwards motion 10 s-30 s: Surge and stem evolution

8. Model 225 kT GEORGE test Opertion Greenhouse 10 ms 20 ms 30 ms

10. Altitude Test Delivery Systems

11. Early planning and developments Germany invested successfully in long range missile systems during WW II In the believe to invest into a crucial weapon for final victory. However, the limitations in transport capabilities were too severe to allow sufficient load on explosive material. The production was limited, 1000 V2 missiles were employed, but the final impact on the war development was negligible.

12. ICBM developments After the Soviet success with Sputnik, US sought for development of Intercontinental Ballistic Missiles (ICBM) to complement the bomber fleet and address the new challenge. US military success was limited until NASA took over the missile development.

13. Success at last!

14. e.g. Dominic tests on the Christmas Island 1962 shortly before test ban in 1963; Main purpose is the development of and EM pulse over a large area High Altitude tests The electromagnetic pulse (EMP) from these tests sent power line surges through Oahu, knocking out street lighting, blowing fuses and circuit breakers, and triggering burglar alarms. STARFISH PRIME, 1962; 1450 kT Thor Missile airburst; 248 miles, KINGFISH, 1962; 1000 kT Thor Missile Airburst; 320,000 Feet

15. Long distance observation The blast from Starfish was seen at 800 miles distance from Honolulu, Hawaii. Originated Auroral light phenomena through  -radiation induced excitation effects in atmosphere. prior to blast during blastpost-blast Auroral light

16. High Altitude Tests

17. Atmospheric Effects