Solar Express

The Concept

The Solar Express is a space train that would be designed and used to ferry humans, supplies and minerals between celestial bodies and space stations in our solar system. It would run non-stop, so smaller vessels would need to catch the train when it passed by.

The Background

In space, the most expensive portions of travel are the acceleration and deceleration phases. The energy required for those portions is tremendous, especially for something as heavy as a space train. In addition, if you were to start hauling cargo, it would become very expensive. However, once the train reached its cruising speed, its energy consumption would be minimal. That’s the idea behind the Solar Express concept. It would never stop; instead, space wagons / capsules would rendezvous with it.

How It Works

The Solar Express would take the form of a series of aligned cylinders. Each cylinder would have a length of at least 50 meters, and one train would be composed of six of them placed in a straight line. These cylinders/torus would be split into four cargo bays and could be swapped in-flight with the help of maintenance robots.

The Solar Express would first accelerate with rocket boosters. Stored fuel contained in the vessel’s core could be used to make course adjustments. The train wouId also use the force of gravity to slingshot around planets or moons. The speed of the Solar Express could be set at 1% of the speed of light, or about 3 000km/s.

Huge solar arrays located along the train’s path could be used to capture solar energy and transfer it by laser to supercapacitors. Water harvested from comets or small moons would be used for humans living on the train and transported to other stations. The harvested water could also be used to create hydrogen and propellant, but the main propulsion system should take the form of an ion thrusters.

Mobile Cargo Bays (MCBs) and other spacecraft would allow for transhipment between celestial bodies (planets, moons, asteroids) and the trains. These vessels could use different types of propulsion to rendezvous with the Solar Express. They would need to match the speed of the train to attach and carry on their transhipment.

The Solar Express would be used to transport material, minerals, vessels and even people living in sections under gravity. Of course, on the train they wouldn’t suffer from acceleration or decceleration. A large ‘space city’ would rotate around the longitudinal axis and provide artificial gravity inside so that humans could walk and live there during the long months of travelling.

The faster the Solar Express moves, the more expensive it will be to catch it. As you can imagine, the cost per ton is important, much like parcel shipping services. Some Solar Express trains could be used to make large loops (between distant planets), while others would be assigned shorter routes and their speed will vary.

What It’s Used For

Obviously, there is a lot to consider, starting with dimensions, masses, speed, energy, etc. How do you control such a complex vehicle? The general idea here is to devise a system to transport minerals, materials, and humans from one place to the other in our solar system. The Solar Express is a basic idea and we would like to know how we could improve it.


The Solar Express concept was imagined in March 2016 by Charles Bombardier in collaboration with Olivier Péraldi and Boris Schwarzer, who created the renderings of the Solar Express. Boris is based in Michigan, U.S.A. He went to the College of Creative Studies. He currently works as a contractual designer for the Ford Motor Company. Boris also created the images of the Urban Link driverless electric tuk-tuk and the Snowrama II snowmobile concepts.