div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=nasa-decline-and-fallhtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: NASA: decline and fall loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader035vdocumentsusreader035viewer2022080321575068771a28ab0f07b04c21html5thumbnails1jpg width=140 height=200 divp© 1987 Nature Publishing Groupp div class=annotation div class=annotationTitleanudiv div class=annotationContentsIMAGE UNAVAILABLE FOR COPYRIGHT REASONSdiv divdivdiv class=ts-pagebutton class=gotoPage data-page=2Page 2button div class=ts-imageimg data-url=nasa-decline-and-fallhtmlpage=2 data-page=2 class=ts-thumb lazyload alt=Page 2: NASA: decline and fall loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader035vdocumentsusreader035viewer2022080321575068771a28ab0f07b04c21html5thumbnails2jpg width=140 height=200 divp© 1987 Nature Publishing Grouppdiv