I'm going too! I sent my name up with the Mars Insigt Rover back in 2016(launch date got pushed back to 2018). They give you this cool little mission badge online which I have on my Observatory page. It looks like this -> https://arkmsworld.neocities.org/insight_mission_patch.png
Actually the viewport is doing what is supposed to do... what you could do make sure that your elements aren't fixed width.
You could use percentages like this -> https://stackoverflow.com/questions/24299990/can-percentage-be-provided-in-iframe-tag-of-html5-tag-for-height-and-width You could also give them a minimum size, too, if you don't want your frames to shrink beyond a certain point. e.g. - width:60&; min-width:120px;