Fifty years ago, today, Apollo X launched from Cape Canaveral to the moon and Command Module Pilot John Young became the first person to fly solo around the moon.
<p>This is an Apollo bubble helmet used in training, the first I have seen in private hands. The one John Young wore on Apollo 10 is in the <a rel="nofollow" class="external text" href="https://airandspace.si.edu/collection-objects/helmet-pressure-bubble-young-apollo-10">Smithsonian</a>.
</p><p>Apollo 10 came to within 50,000 ft of landing on the surface. But NASA knew they could not let them get so close to the lunar surface without a rogue attempt to go the whole way, so they just provided enough fuel on the Lunar Module to do the "dress rehearsal" mission. Had Apollo 10 taken the LM to the surface, they would not have had the ability to get back.  So, NASA sent an under-fueled LM, adding risk to the mission, to make sure they did not make a go for it, with the temptation of being inevitably regarded as heroes if they did.
</p><p>Gene Cernan laments: "A lot of people thought about the kind of people we were: 'Don't give those guys an opportunity to land, 'cause they might!' So the ascent module, the part we lifted off the lunar surface with, was short-fueled. The fuel tanks weren't full. So had we literally tried to land on the Moon, we couldn't have gotten off."
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The Apollo pressure helmet was a transparent bubble designed to attach to the spacesuit neck ring. It was constructed of a polycarbonate shell with a blue (and then red after Apollo 10) anodized aluminum neck ring, a feed port, a vent pad and duct assembly attached to the rear and a valsalva device attached to the inner ring.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/44124348109@N01">Steve Jurvetson</a> from Los Altos, USA
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jurvetson/47089102864/">Apollo Bubble Helmet</a>