It's not really accurate to say that we can't go back to the moon. Setting aside the fact that there have been a number of successful unmanned lunar missions in recent years, whenever your point gets made, it usually glosses over why people make that claim.
The immediate answer is that we simply weren't interested in supporting major new manned missions. Manned spaceflight in general requires serious, ongoing political support across administrations. At the height of the space race, public support pretty much never rose above 50 percent in the United States.[1] The literal high mark was 53% immediately after Apollo 11 successfully landed on the moon, which is honestly mind-boggling to think about. We've completely white-washed the existence of serious political opposition[1] to the Apollo program that plagued it from the beginning to the end because--looking back--it seems almost absurd, as if the very idea that half the country had no interest in going to the moon is an insult to the American psyche.
It's honestly amazing that we managed to follow up with the Space Shuttle at all. The STS program was shaped by a great many compromises NASA had to make in order to elicit political
and military support. John Logsdon's After Apollo is a wonderful read on the subject.
Anyhow, it's not like we can't go back. It's not like orbital mechanics changed on us at some point and now we're all stuck in LEO. It's just a political choice, and we can make a new one whenever we want. It's just hard, in large part because we don't have the cold war and constant fear of imminent nuclear war to push the program through congress.
Beyond the political, to go back means redesigning everything that was done for Apollo. That's not a slight on American engineering or manufacturing capabilities. Everything--from the Saturn V, to the lunar module, and the countless pieces of equipment that helped get both where they needed to go--was designed for the manufacturing capabilities and techniques of the 1960s. You can't just grab the plans for the old Rocketdyne F-1 and start building them anew. The welds alone[2] represent a fundamental shift in capabilities and thinking. Common CAD design and analysis programs would have had Apollo engineers singing in the hallways in joy once they got over the shock.
They took what they had, and they made it work brilliantly. Change that context, and they would have designed a different engine, and the same goes for everything else.
It's interesting how the “scientific we” is used for “we... go to the Moon”, where most folks seem to be referring to the USA? Or the subset of nations with capable space programs, excluding China? But the people writing, “we”: are they engineers working for NASA, or parroting the P.R.?
Because I personally haven't landed on the Moon, and I don't plan to, but “we” is typically assumed to include the speaker.
I'm beginning to suspect that those who perpetuate the meme of “we never landed on the Moon” are coyly defining “we” in a restrictive way that excludes the astronauts who did. “We [our family in California] never landed there!”
Cheap word-games. See also, political slogans designed to be misinterpreted and energize the base.
The immediate answer is that we simply weren't interested in supporting major new manned missions. Manned spaceflight in general requires serious, ongoing political support across administrations. At the height of the space race, public support pretty much never rose above 50 percent in the United States.[1] The literal high mark was 53% immediately after Apollo 11 successfully landed on the moon, which is honestly mind-boggling to think about. We've completely white-washed the existence of serious political opposition[1] to the Apollo program that plagued it from the beginning to the end because--looking back--it seems almost absurd, as if the very idea that half the country had no interest in going to the moon is an insult to the American psyche.
It's honestly amazing that we managed to follow up with the Space Shuttle at all. The STS program was shaped by a great many compromises NASA had to make in order to elicit political and military support. John Logsdon's After Apollo is a wonderful read on the subject.
Anyhow, it's not like we can't go back. It's not like orbital mechanics changed on us at some point and now we're all stuck in LEO. It's just a political choice, and we can make a new one whenever we want. It's just hard, in large part because we don't have the cold war and constant fear of imminent nuclear war to push the program through congress.
Beyond the political, to go back means redesigning everything that was done for Apollo. That's not a slight on American engineering or manufacturing capabilities. Everything--from the Saturn V, to the lunar module, and the countless pieces of equipment that helped get both where they needed to go--was designed for the manufacturing capabilities and techniques of the 1960s. You can't just grab the plans for the old Rocketdyne F-1 and start building them anew. The welds alone[2] represent a fundamental shift in capabilities and thinking. Common CAD design and analysis programs would have had Apollo engineers singing in the hallways in joy once they got over the shock.
They took what they had, and they made it work brilliantly. Change that context, and they would have designed a different engine, and the same goes for everything else.
0. https://www.space.com/10601-apollo-moon-program-public-suppo...
1. https://www.theatlantic.com/technology/archive/2012/09/moond...
2. https://arstechnica.com/science/2013/04/how-nasa-brought-the...