Harold Horton Sheldon
... that the scientist Harold Horton Sheldon wrote as early as 1929 about the serious possibility of man visiting other planets one day with the aid of rockets?
... that the scientist <b id="mwA_8"><a class="new" data-mw-i18n='{"title":{"lang":"x-page","key":"red-link-title","params":["Harold Horton Sheldon"]}}' href="./Harold_Horton_Sheldon?action=edit&amp;redlink=1" id="mwBAA" rel="mw:WikiLink" title="Harold Horton Sheldon" typeof="mw:LocalizedAttrs">Harold Horton Sheldon</a></b> wrote as early as 1929 about the serious possibility of man visiting other planets one day with the aid of rockets?