2030 is too soon. A one-way trip takes several months, a round trip takes 34 months. No space agency is going to send a manned vessel to Mars without testing it out extensively. If you are really trying to cut down on time and expense, one way to test is to build a completely identical vessel, fill it with supplies, and fire it unmanned at Mars. Well, at the very least you need to wait to see if that unmanned vessel successfully lands on Mars with the supplies intact. And if anything goes wrong with that unmanned vessel, at minimum you're going to need to figure out what went wrong, and re-engineer the manned vessel so that it doesn't suffer the same problem. Long story short, all this construction and testing will take quite a bit of time. And all of the space programs, even China, are quite public about what they are doing. If one of them were planning to land a man on Mars by 2030, they would already be very publicly constructing the test vessel here in 2024.