Artist concept illustrating the relative sizes of the one-man Mercury spacecraft, the two-man Gemini spacecraft, and the three-man Apollo spacecraft.
NASA/JSC
circa 1964 <div style="display: none;">date QS:P,+1964-00-00T00:00:00Z/9,P1480,Q5727902</div>
<a rel="nofollow" class="external free" href="https://images.nasa.gov/details-S64-01123">https://images.nasa.gov/details-S64-01123</a> (<a rel="nofollow" class="external text" href="https://images-assets.nasa.gov/image/S64-01123/S64-01123~orig.jpg">image link</a>); see also <a rel="nofollow" class="external free" href="https://archive.org/details/S64-01123">https://archive.org/details/S64-01123</a>