Voyager, Apollo, and Hubble. Everything else NASA has done is a distant 4th place. And it's not like 4th place is trash, it's just that the big 3 are just so impressive.
The rovers on Mars as well and New Horizons that went to Pluto. That is also at escape velocity so it will leave this solar system and most likely no human will ever lay eyes on it again. Voy 1 and 2 are still faster but hey they're all going in different directions so it's not exactly a race.
It was sent to Mars with a plan for 5 flights and a total of 7 or 8 minutes flight time. It ended up flying for over 2 hours in 72 seperate flights before it damaged itself with a bad landing. Not quite the "this thing is still doing science almost 50 years later" that Voyager can claim, but impressively engineered so it lasted way beyond it's initial mission plan.
I don't think Apollo was very interesting or useful beyond cold war propaganda. Yes, we're capable of amazing things—but putting a man on the moon pales in comparison to basic healthcare funding. Why must we insist on wasting billions on histrionic braggadocio when we can't perform the basics of a modern society?
There's better things to dump instead of Apollo if you want a basically functioning society. Pick your couple of least favorite wars of choice in America's recent history. Apollo at least gave the country hope and showed that we could accomplish big ideas.
And the reason why is those things must be profitable, and once you accept everything must be profitable, there is no ceiling to exploitation. Whereas with big things like Apollo, we didn't do it because it would make money. We did it because we decided it was the right thing to do.
Stop being a capitalist hellhole, and maybe try being a country that happens to operate under bounded capitalism, and just maybe, maybe, you can see some of that progress.
The US in the 1960s was more capitalist than it is now (by governement size, spending, taxation, regulation and economic freeodm, too-big-to-fail, etc.).
There has to be profit first to be able to fund big things like Apollo. Profit is good.
Fuck all of it is useful besides satellites. Even the HST is only marginally useful; useful for fields of research which will almost certainly never have tangible benefits for life on Earth, built to satisfy our curiosity about phenomena too large and far from Earth to ever be put into use here on Earth.
Nonetheless, interesting? You're bonkers if a system like the Apollo program and all associated hardware isn't at least interesting.
Big multi-disciplinary problems typically yield vast amounts of ancillary technology and solutions that may last generations... small sample fo things that either were invented for the Apollo program or became commercially viable:
Do you really believe we'd have "peace and food for everyone" if not for Apollo? Really?
Or is this an unserious argument you can use to nitpick anything? Why is my local government building another playground when they could be feeding African orphans??
I cannot take anyone making this argument seriously unless they are similarly furious at the expenditure on arts, humanities, historical preservation, luxury goods, entertainment, or other similar vanity projects.
Why is is that science and technology exploration ventures are held to a much higher scrutiny?
I hate this argument. Every time there is some big and expensive technical achievement, someone is going to say that the poor are dying somewhere in the world. As if not going to the moon would have saved them.
I would argue that a healthy population is what allows great things like Apollo to happen. For such a program to succeed, we need lots of highly skilled people. Scientists, engineers, astronauts, tradesmen, managers, etc... Everyone needs to be at the top of their game. Such talent doesn't develop when you are struggling for your life, you need good conditions like health, confort and stability to be able to focus on your craft.
If we use life expectancy as a proxy, we could say that the US had a healthier population during the cold war than the USSR, and they are the ones who succeeded on the most ambitious project in the space race, despite the USSR having a head start. To me, it is not a coincidence.
Also, the cold war era was not just about space, it is also a time of major advance when it comes to medicine, life expectancy has seen a dramatic improvement, so we can put men on the moon and keep a population heathy.
They had pretty good results post WW2. The problem is that they ended up lagging behind the western bloc because of a lack of resources and innovation. Basic healthcare doesn't mean much if you don't have good treatment in the first place. It is a common problem with communist countries, they usually have good access to healthcare, but they don't have the resources to give proper treatment.