Necessary? No. Not much except eating, drinking and breathing is. Even reproduction is optional from the view of a single individual.

A good idea? Absolutely:

1. Exploring space tells us a lot about earth. We currently assume that the moon formed when something big collided with earth and threw lots of material into a stable orbit. This means moon is probably made of the same materials as earth and because there is no erosion nor tectonic activity on the moon, it lets us study what earth may have looked like billions of years ago.
2. Lots and lots of things that were originally developed for space are very useful on earth: teflon coating, memory foam matresses, efficient solar panels and many more. Sure, they could have been developed without space exploration but the pressure to get something exactly right helped a lot. And of course we directly use satellites for a lot of earth stuff, too. Think tv, weather prediction, monitoring of climate change, communication, GPS, accurate maps and many more.
3. It gives humanity something to unite behind. Even during the cold war, the USA and the Soviet Union ignored their feud for a bit to make Apollo-Soyuz happen. These days, the ISS is one of the biggest multinational projects and I dread the day it gets decommissioned because Russia will have one less reason to talk to the rest of the world.

Yes but we need to treat the earth as the only habitable place we will ever have and run sustainably. We need to be using less than one earth year of renewable resources each year and use a minimum number of non renewable. I don’t think we should be sending people into space all that much. We should as much as possible seek to learn how to mine, process, and produce in space. Its certainly something we cannot do now but if we are ever to make any real progess it will have to be something we figure out. Its also likely the best direction for the resources we put to space as far as return. By that I mean the same way much of our technology was spurred by the space race due to the challenge of getting out into it and to the moon. I feel learning to mine and automate in space will have the greatest returns in technological advancement for us. I think ideally any time we send people to space whe have a destination built already for them to go to. So send rovers and such to the moon and try to excavate and build a dome or such and install equipment. I mean if we could figure out a way to automate making rocket fuel in space and could make fuel depots that would be huge. I also want to experiment with things on the moon. Like I think we should make a moon space elevator. Not because its a very necessary thing for the moon but to figure out the tech. maybe later we try to make one on mars. if we made them on a variety of space objects we might get sure enough to do one on earth.

Space exploration is weight lifting for science.

Nothing is really necessary until you develop it enough to make it so. There is potential there. It could turn into something extremely useful, perhaps even life saving. I don’t think we are anywhere close yet, but sometimes you get revolutionary breakthroughs that flip the landscape in a really short time.

It is a virtual certainty that at some point a meteor large enough to wipe out all multicellular life on the planet will strike the Earth. It is an absolute certainty that the Sun will eventually burn out leaving the planet uninhabitable. Something else might wipe out our species long before either of these things happen, but it’s not a bad idea to have another inhabited planet or two as a backups.

Space exploration is relatively cheap compared to our murder machines, and unlike the murder machines has practical benefits for a wide swath of people.

There’s new innovations that come around in order to get into space, new innovations from discoveries made in space, and new innovations made because we’ve gone to space.

Some of these innovations even help address problems on our own planet. GPS helps keep planes from hitting each other (which was the catalyst for making high resolution GPS publicly available in the first place), satellite imagery aids in weather prediction and disaster response, even global communication is in part because of space travel.

I care less about finding backup worlds, but even that search gives us information about the needs of life and can hint at how life came to be–answers which may be helpful in some types of medical work.

Tardigrade can survive for a shockingly long time exposed to the harsh environments of space. We wouldn’t have known that if we hadn’t gone ourselves, and understanding why they can survive so long can help us look for ways to prolong resilience in other complex life forms and environments.

The knowledge gained about keeping people safe in space will be critical to keeping people safe in other extreme environments like through the ongoing climate catastrophe.

So for the sake of progress, yes, it’s necessary. It’s another frontier for humanity to explore, and the more we explore the more we find out about ourselves and how to help people.

Setting aside all the intangible benefits such as answering why we are here and providing inspiration to generations there are tons of short and long term benefits.

In the short/medium term, research is so much about solving problems and your solutions having unexpected applications in other areas. A lot of our minituarization in tech happened because we needed things smaller and lighter to lift into space, think things like your smart phone camera or laptops. Also things like cordless tools and even memory foam were originally developed for their application in space travel.

In the long term, let’s take a look back, what if we had the same stance when we looked at the ocean, and thought why its even necessary to figure out how to navigate the waters. For our species to propagate or even survive, we need to expand. Right now we are one decently sized asteroid from extinction, but if one day we figured out how to expand to multiple worlds, then we become a heck of a lot of more resilient.

I am of the opinion that space exploration and settlement is the single most important thing humanity should be doing. Currently humanity exists only on this planet, which through the course of its existence has had numerous mass extinction events. It is hubris to believe that we will never be affected by one. Right now all of humanity’s eggs are in this single basket, and if that basket gets kicked over, humanity could cease to exist.

Now I will grant you that there are lots of things down here on earth that we should be spending money on to better the lives of humans generally, but these things are not mutually exclusive. Right now we’re spending orders of magnitude more money and resources waging war on one another than space exploration. In the US in 2025, the US military budget was around $920b, whereas NASA’s was $25b. The military budget was 36 times higher than the space budget. It’s not even close. Space is not where dollars are being wasted.

Studies have also shown that NASA’s impact is a net positive on the economy, consistently generating more economic impact than is put into it. It creates well paying jobs that employees find fulfilling and satisfying, generates public interest in the sciences, and benefits society as a whole as new technologies are developed that we all get to enjoy.

I would argue that what we NEED to do is stop needlessly murdering each other over religious and social disagreements, and spend our resources on feeding, clothing and taking care of one another such that we all have the time, security and ability to watch humans go out into space with wonder in our hearts.

There’s a special kind of nerd that I call Puzzle Demons. They have big brains and they get satisfaction from solving puzzles without thinking about them. It doesn’t matter what the puzzle is so long as it’s a challenge to solve. They’ll look back on their work with satisfaction because they solved the puzzle, regardless of what that work is.

Puzzle Demons in the 1940s built V-2 rockets. We gave them space travel and the puzzle became making the rocket leave the atmosphere instead of hitting cities. That space travel made helpful consumer technologies to survive in extreme environments, things that were otherwise too expensive for commercial R&D.

Then we killed NASA in the 1980s. The Puzzle Demons had no socially positive puzzle. They built the tech industry instead. I dated a Puzzle Demon whose fun little puzzle to solve every day was designing the UI for smart locks that go on the bunkers of the wealthy. She was thrilled to make locking herself out of the bunker more user-friendly. There are Puzzle Demons at the social media websites whose entire job is making them more addictive for children. Puzzle Demons gave us crypto, guided missiles, murder robots, AI slop, and corporate efficiency consulting.

We need space exploration to pacify the Puzzle Demons. Without it, the population is still encouraged to go into STEM but most of the STEM jobs are profoundly evil. You stick them in a NASA office and they’re just building useful things. Otherwise the prestige jobs are with defense contractors, tech companies, and multinationals.

Yes

We’re boiling the planet. Yes, it’s essential. Lest we perish.

There have been over 1800 “spin-off” technologies that came from the world’s various space agencies. Some of those inventions are life saving and there’s people alive today thanks to the pioneering spirit of man and the funding of countries. I don’t see the benefit of stopping now.

Humanity has already outgrown the cradle called earth, the longer it takes us to leave it behind the greater the risk that will destroy it and ourselves.

We had problems on earth before space exploration, and we’ll have problems on earth after space exploration. And if we colonize other planets we’ll have problems there.

Because every time humans solve a problem they create more, bigger, harder to solve problems.

Space exploration doesn’t affect this.

1. The amount of money spent on NASA is negligible compared to the MIC
2. Human intuition about what STEM stuff is useful is very poor. The basis for your ability to securely do online banking is a quirky little number theory equation that was useless for centuries. Or think about the reactionary complaints about “they’re paying scientists to study cat urine” or whatever. Those studies typically have a practical reason for getting some and practical implications once they’re finished. Even the stuff that is practical looks impractical to the layperson. Space travel is very similar in that the technology it enables can have other uses.
3. Whoever figures out asteroid mining first is going to make a lot of fucking money