When planetary visits become common practice, two things will need to occur. First, we will need to open up the interstitial highway, and second, we will need to create self-propelled aircrafts that are powered by solar energy. Otherwise, they will never be able to hold sufficient fuel to be able to traverse the distance between planets.
Current plans for interplanetary travel often include vacation packages. However, unless you are able to see extremely well in the realm of the spirit, a trip to Mars will be anything other than a vacation. It will be a sweltering encounter with spirit beings. It also will be a sweltering encounter with demons, as Mars now has a full array of demons from hell.
The Lord God Almighty El Shaddai