health-check domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home/admin/web/thespacehistory.xyz/public_html/wp-includes/functions.php on line 6121Space History
Apollo 11 on the moon began researching the exact distance from Earth to the moon. To do this, they brought devices resembling small arrays of mirrors – they are called retroreflectors
Research using such a simple device continues to this day