They succeeded, and this is far less ambitious.
Taking risks is reasonable, but in the end this is still a vanity project. IMO, figuring out how to do self sustaining spaceships / habitats is much more useful long term than going back to the moon using giant chemical rockets, stored food and oxygen etc. Even just orbiting Mars and coming back without landing would be a new achievement.
As far as I can see, there isn't much point to going around Mars just to go. You could just go to a high Earth orbit (or Lagrange point), and gain similar experience, with better communication. The ISS has spent 20 years in low-earth orbit; we're not going to learn much more from it or a similar station.
From an engineering perspective going to mars orbit means far less sunlight which means a host of new problems. An engine and fuel system to get there would be new and could also be used to send a lander for future missions.
IMO, the Moon might be closer, but Mars is a much better target for long term colonization due to an atmosphere, shorter day, higher gravity, etc.
The ISS is not in a useful orbit for a Mars trip and whatever your sending there can make the trip in the same thing you send into orbit. Trying to shoehorn in the ISS just make the trip more expensive and complex.
Part of this whole moon approach is absolutely about sustaining the long term. Have you ever read the Artemis program concepts? It is very much about using commercial capability to develop moon resources.
You can't start with producing food, if you make the system depended on that it will fail. One you can actually land on the moon or mars with SIGNIFICANT payloads you can actually start to test out system for large scale food growing and things like that.
As to growing food, for on a single mission it’s not that critical, but if you’re sending several missions to Mars unused supplies from one mission can be used on the next mission. Further, the difference between survival and comfort adds up to a lot of food.
> It’s clearly viable, but for that kind of DeltaV across such a long trip, solar powered Ion thrusters have several significant advantages.
Not really. The only potential use for ion thrusters is for cargo transport that is not time depended. If you do that you need to figure out how to do the landing, so the complexity is just higher. The thrust is just to low compared to a few powerful chemical engines. If you can refuel in earth orbit for cheap you are gone be way better off with chemical.
If you move on from chemical, nuclear thermal is by far the best option.
Food is really not the problem. The mass of food needed for humans is pretty small. Clearly you want to produce food on Mars eventually but its not a priority for the first 5 to 10 years. Refuel on Mars is by far the biggest mass saver.
For comparison the ISS’s solar panels are over a decade old and still generate 240kW in direct sunlight. So, you could easily reuse those panels for multiple trips, though power output is cut in half near Mars.
So the argument that 'you can only do this when the government gives NASA military budget' is just nonsense.