Britain’s biggest weapons manufacturer, BAE Systems, has agreed to buy the US space technology company Ball Aerospace for $5.6bn (£4.4bn), in one of the largest takeovers by a UK company this year. The FTSE 100 defence company said the purchase of the Colorado-based business would help it to expand in technologies that were US defence priorities. The deal comes amid a surge in spending on global military and spying technology prompted by Russia’s invasion of Ukraine. It also follows the US setting up a separate arm of the military, space command, to try to keep up with China. Ball Aerospace’s…