The Cold War's hottest year

In October 1962, during the Cuban missile crisis, the world came close to a full scale nuclear war. Throughout 1962, the USA, USSR, and France together detonated a record 178 nuclear bombs for military power display and research. You've been given a sample of the Nuclear Explosion Database (NEDB) for that year (cumul_nukes_1962_df) with an observation for each date on which a bomb was detonated. The total_bombs variable contains the cumulative number of bombs detonated by a country up to that point in time.

You'll complete the dataset to hold the full sequence of dates, and visualize the total number of bombs per country over time. You'll also use the fill() function from Chapter One to impute missing values.

The dplyr and ggplot2 packages have been pre-loaded for you.