How Close Are We to Next Level Space Travel?

Space architects and experts on intergalactic exploration, Neil Leach and Madhu Thangavelu, are joined by ChatGPT to discuss how close humans are to space travel. What is their prediction on when the first humans could inhabit the moon, or even Mars?

Neil has worked on two robotic space missions. Madhu teaches advanced Space Engineering at USC.

I disagree with Neil about the issue of radiation on human crews in space over the long term.

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.

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.

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. It is like trying to solve the large wave problem on the ocean with a Castaway sized raft or vehicle. Just make it cheap to go big and heavy and then problems of being light and small go away.

When we will go out of the solar system in meaningful ways with people? After we have colonized and developed the entire solar system.

We can also use the large plasma structures of the solar system as a means to use the solar wind to bootstrap to 24% of the speed of light. I have that described. I have many other articles on getting nuclear fusion or nuclear fission that uses 100 times less volume. Dense power sources are better for space. Advanced molten salt nuclear reactors could be 50 times more energy dense than current nuclear reactors in submarines.

I have various videos describing how Space development can be vastly different.

Money, profits and scale are keys to when and how things happen.

Human civilization needs to get millions and billions of times more economically powerful to launch meaningful interstellar missions. One possible path is described in this video. Conquering the solar system completely is needed to enable the resources to send out fleets of large colonization ships.