Silbervogel strikes New York

This is a TL where Nazi Germany triumphed after unleashing their ultimate wunderwaffe "Silbervogel " against the United States.

Timeline
January 9, 1932: Korean assasin Lee Bong Chang successfully killed Japanese Emperor Hirohito in the infamous Sakuradamon incident. As such Yasuhito, Prince Chichibu  ascends to the throne. Point of divergence.

1933: Hitler rose to power as in OTL.

1937: Japanese Empire engages in a full scale war with China.

1938: The Sudeten crisis between the Nazis and the Czechs erupts into World War II in this timeline.

January 1940: Great Britain is invaded by the Nazis under Operation Sea Lion.

1941: After Nazi Germany invades Soviet Russia as in OTL,  Japan attacks Vladivostok and invades the Far East instead of bombing Pearl Harbor in December.

1942: At this year Japan finally attacks Phillipines with a Pearl Harbor style attack. Meanwhile Nazis obtained the gas fields in the Caucasus.

1943: The work on the Silbervogel spaceplane project started.

1944: Nazis succesfully tested the first nuclear weapon in former Ukraine.

March 11, 1945: Nazi pilot Adolf Galland flew the Silbervogel spaceplane over the New York and bombed the city with a nuclear bomb. Millions were dead from the onslaught while Galland receive the Iron Cross upon returning to Berlin. The USA signs an armstice with the Axis afterward.

1950: Beginning of the Cold War between Japan and the Nazis.

1957: Japan obtained its first nuclear weapon. Meanwhile Nazis began building rotating space station "Von Braun" above Earth.

1970: Completion of the Von Braun space station/habitat.

1989: The Cold War deterioriated into a nuclear war. Consequently USA and the Von Braun space station became the remnants of the former humanity.