Radio transmissions during the flight of <a href="https://en.wikipedia.org/wiki/Mercury-Redstone_4" class="extiw" title="en:Mercury-Redstone 4">Mercury-Redstone 4</a>, as recorded at the Hangar S communications station at the <a href="https://en.wikipedia.org/wiki/Cape_Canaveral_Air_Force_Station" class="extiw" title="en:Cape Canaveral Air Force Station">Cape Canaveral Air Force Station</a>. NASA historical audio archive reel 413-AAG.
NASA
<a rel="nofollow" class="external free" href="https://archive.org/details/Mercury4">https://archive.org/details/Mercury4</a>