Many people talk about the technical problem of too much radiation for missions to Mars or long term operations in space beyond the protection of Earth’s magnetic field. The problem comes from the assumption that we fly in Apollo mission like tin-cans.
We can build cruise ships in space with the SpaceX Starship so all of the radiation problems of tiny life rafts go away.
Europe’s space agency talked about the radiation show stoppers for Mars Exploration. Astronauts are exposed to 200 times more radiation on the International Space Station than an airline pilot or a radiology nurse. A human on a Mars mission where the mission did not have radiation shielding would get radiation doses up to 700 times higher than on Earth. Data from ExoMars Trace Gas Orbiter showed that on a six-month journey to the Red Planet an astronaut could be exposed to at least 60% of the total radiation dose limit recommended for their entire career.
The survivability problems for Tom Hanks in the Castaway movie raft are a lot different than a cruise ship with an all you can eat buffet.
If We Can Fly Often and Cheap Then We Can Build Big and Easily Provide Radiation Protection
A 5-meter thick shield of water around a capsule would weigh about 500 tons. So if we have large reusable SpaceX Super Heavy Starship then the costs of each launch could drop to $3 million. Rapid complete reuse could make daily flights a reasonable possibility.
Radiation on a trip to Mars is about 90,000 R/yr or about 10 R/hour. Reducing that to lower than Earth background radiation would only require a layer of water around 1 meter thick. A Mars vehicle cylinder that is 3.5 meter by 20 meters with 1 meter of water shielding would weigh 330 tons.
Twenty flights to orbit could affordably build a 1000-ton mission to Mars. An even larger Mars cycling space station could be built and re-used. A 5,000 ton Earth-Mars cycler would have plenty of mass for radiation protection. It would be like a cruise ship on Earth.
A cycler would be efficiently reusable. Rockets could leave Mars or Earth and dock with the cycler space station. The 100-ton payload SpaceX Super Heavy Starship Version 1.0 would be the ship tender that leaves spaceport to shuttle people to the main ship.
This is why we are not going anywhere if we are depending on good results from NASA putting $4 billion per year into the Space Launch System.
$3 million per flight and multiple flights per day from SpaceX Super Heavy Starship then we scale all of the construction costs and planning based upon useful capabilities.
We just had the 75th anniversary of D-Day.
* 11,590 Allied aircraft fly 14,674 sorties on D-Day.
* 6,939 vessels were in the armada: 1,213 combat ships; 4,126 landing ships/craft; 736 support ships; 864 merchant ships.
On D-Day, the Allies landed around 156,000 troops in Normandy.
Two years before D-Day the Allies had a test assault with 6500 men who were mostly slaughtered.
The failed Dieppe Raid had 237 ships and landing barges including eight destroyers and 6500 men.
You have to have the appropriate size of mission and things are easier if you can go with a lot of stuff.
If those who planned the Dieppe raid kept trying to figure out how to make a 237 ship, 6500 person assault work for D-day they would have failed. Even if they started thinking about fancier, lighter technology. This is what I find annoying when Astronaut Chris Hadfield and others talk about how it will take many decades before we can safely send people to Mars. D-day would be in 2050 or never if we had to figure out how to create a beachhead with 6500 people. Just make it cheap to go big and heavy and then problems of being light and small go away.
SOURCES- ESA, Wikipedia
Written By Brian Wang, Nextbigfuture.com