You would need a rocket strong enough to take you through the atmosphere layers of the earth to be able to reach space. The design of the spaceship would need to be strong enough so it doesn't break while reaching high speeds. There would also need to be systems in place so the Spacemen will able to communicate with people on Earth. The spaceship would also need to have an oxygen system, food storage, and many other commodities. You would also need a lot of fuel, hundreds of thousands worth of fuel, which is illegal to get without government permission.
If you're talking about a small rocket, they sell rocket parts on the internet, you could build one with your selected parts, or get a package with all the parts. Of course, this wouldn't reach space, but usually this is how most people start designing rockets, or spaceships. Alternatively you could computer design your spaceship and send it over to a factory that can print out the design in plastic and metal (and many other materials).
Various alloys.
The Soviet Union in 1957, Sputnik
Oxygen
It is said that John Hillman Jockenhowser was the first to invent a spaceship in the 1400s. In the 1950s, NASA based their spaceship on his designs.
Based on your knowledge, construct a vehicle. Hypothesize that it will fly. Light the fuse and observe the results. Iterate.
They wanted to find out how they could build the spaceship.
Various alloys.
You need to past your spaceship test to get a spaceship then go to a lunch pad then there you have it.
Three years
The Soviet Union in 1957, Sputnik
You will use the saucer Excalibur to reach space, then build a spaceship on the Pewter Moon. (see related questions for how)
Oxygen
He didn't need a spaceship,but he fear his ring would fail him because of a prophecy.
To fly to the Pewter Moon on Astro Knights Island, you need to build a spaceship by collecting spaceship parts found throughout the island. Once you have assembled the spaceship, you can use it to fly to the Pewter Moon by clicking on it and selecting the moon as your destination.
To get to the spaceship in Poptropica, you need to complete the Lunar Colony Island quest. Start by talking to the astronaut near Mission Control and follow the mission to repair the shuttle, launch it, and eventually make your way to the spaceship.
Estimated around 25 million dollars.
a fully operational spaceship