The greater advances of the Soviet space program at the time allowed their space program to achieve other significant firsts, including the first EVA "spacewalk" and the first mission performed by a crew in shirt-sleeves. Gemini took a year longer than planned to accomplish its first flight, allowing the Soviets to achieve another first, launching Voskhod 1 on October 12, 1964, the first spacecraft with a three-cosmonaut crew. The USSR touted another technological achievement during this mission: it was the first space flight during which cosmonauts performed in a shirt-sleeve-environment. However, flying without spacesuits was not due to safety improvements in the Soviet spacecraft's environmental systems; rather this innovation was accomplished because the craft's limited cabin space did not allow for spacesuits. Flying without spacesuits exposed the cosmonauts to significant risk in the event of potentially fatal cabin depressurization. This feat would not be repeated until the US Apollo Command Module flew in 1968; this later mission was designed from the outset to safely transport three astronauts in a shirt-sleeve environment while in space.

Answer this question, if possible (if impossible, reply "unanswerable"): The US Apollo Command Module flew without spacesuits in what year?
1968