Why in the future spaceships will be made by extrusion

50 years have passed since the man’s landing on the moon [and 62 years since the first artificial satellite was put into orbit / approx. transl.], but, despite all the incredible technological advances received from that moment, we still have to go into deep space further than the Apollo program did. The giant leap that everyone was waiting for after the moon landing, for example, a manned flight to Venus, did not happen. Since then, we have been stuck in low Earth orbit (DOE), and return to deep space is constantly delayed for a few more years.



But why? In short, space travel is extremely expensive. They are also dangerous and complex, but the last arguments fade before the incredible score that any country will encounter when it tries to send people into space more than a few hundred kilometers above the surface of the Earth. In order for us to have a chance to fly off this stone, the cost of putting a kilogram of cargo into orbit should drop sharply.



Fortunately, we are finally beginning to observe positive developments on this front. Private space companies are starting to lower the cost of putting payloads into space. In the best years, the space shuttle could launch 27500 kg of cargo at the NOU at a cost of $ 500 million per launch. Today, SpaceX’s Falcon Heavy can carry 63,800 kg of cargo in less than $ 100 million. So far, not a trifle, but a practically revolutionary change.





Falcon Heavy rocket payload module



However, there is a nuance. The rockets produced by SpaceX and other private companies are relatively small. Although the Falcon Heavy lifts the load more than twice as much as the shuttle, its internal volume is much less. This would not be a problem if we carried lead bricks into space, but any spacecraft intended for humans would have to be made relatively large, and there should be quite a lot of free space in it. For example, the largest ISS module would not physically fit into the Falcon Heavy fairing, although its weight is only 15,900 kg.



To maximize the capabilities of missiles with a limited volume, it is necessary to change the approach to the development and construction of manned ships. Especially designed for long-term flights. It turns out that it is on this subject that very interesting studies are being conducted. Instead of sending the assembled ship into orbit, there is hope that in the end we will be able to send raw materials into space and print everything in place.

Additional assembly required

It took more than 20 years and 36 shuttle launches to assemble the ISS to its current state, however, in total, all modules are approximately 400,000 kg. If we could work only with the total mass, if we could melt the ISS and put it into orbit in a denser form, commercial rockets like the Falcon Heavy or New Glenn from Blue Origin could do this in a few flights.



Obviously, there are no technologies that allow us to collect in orbit a working space station or ship for flying to Mars from some kind of liquid. But even with the current state of fused deposition modeling (MMD) technology, or 3D printing, according to some researchers, we can create large structures in orbit. Imagine that we launched to the eyeballs a filled rocket with raw materials and a robotic printer capable of extrusion and assembly from structural parts.





Robotic hands collect 3D printer guides



In this case, one heavy rocket, in principle, can collect material for the construction of a farm, the size of which will exceed everything that mankind has ever put into space. Upon completion of the core printing, the following launches can deliver and install equipment, for example, solar panels and residential modules for the team. And although their creation will still require assembly work on Earth, the ability to create a "skeleton" in orbit will incredibly reduce the time and cost of building such structures.



This may sound like science fiction to you, but it was to demonstrate such capabilities that Made In Space from Mountain View, California, recently received a $ 74 million contract from NASA. In the next few years, the company plans to launch the Archinavt-1 satellite, which is capable of using 3D printing technology in space, which it first introduced aboard the ISS in 2014. Having entered orbit, the satellite will create two beams 10 meters long, leaving from both sides of the ship. If successful, the “wingspan” of the Archinaut will be greater than that of the shuttle; despite the fact that he will go into space in a miniature compartment of the launch vehicle "Electron" 1.2 m wide.

Wet workshop listing

In developing the massive Saturn-5 rocket for the Apollo program, Werner von Braun got a great idea. Why not use the second stage of the rocket as a separate space station, instead of dropping it after it runs out of fuel?



He believed that a tank of liquid hydrogen would give astronauts enough space to live and work there - they only need to put the remaining gas into space. Then, the team arriving on the second rocket will open the hatch in the upper part of the tank and enter the “equipment module”, in which there will be inventory, equipment and a docking gate.







Unfortunately, this hypothetical station, which was called the “wet workshop,” since it was supposed to go into space with liquid hydrogen inside, never went beyond the drawing boards. As a result, NASA decided to equip the third stage of Saturn-5 with a separate space station directly on Earth, and launch it directly into space. T.N. The dry workshop eventually turned into Skylab, the first American space station.



And although 3D printing is not as “wet” as Werner von Braun imagined in those years, it can ultimately allow us to create space stations on a similar principle. Companies such as Lockheed Martin and Relativity Space are already using 3D printing to create fuel tanks on Earth. If attempts to print farms in space succeed at Made In Space, the next logical step would be to optimize this technology for printing tanks for space.



If in space it will be possible to print a hollow cylinder of sufficient strength and diameter, it will be possible to install hatches in it and catch air. Having checked for leaks, teams of people could install equipment and all the tools necessary for turning them into residential modules for stations or ships in such cylinders. Such printed modules can be made of any length, depending on the needs of the mission - including lengths that far exceed the capacities of the tanks for payload on any of the existing or planned missiles.

To the moon and beyond

The structures printed in orbit can play a role in the return of mankind to the moon and in a future journey to Mars. The potential savings by launching rockets with building materials are too great to be ignored. Definitely this approach has its technical problems, but they do not look insurmountable, given the studies that are already being carried out with 3D printing on board the ISS.



However, no matter how people get to our closest celestial neighbor, the Red Planet, they will almost certainly find 3D printing an invaluable tool. Although we are just learning how to print in space, we have many decades of experience in additive manufacturing on solid ground. Reduced gravity on the Moon or Mars will not fundamentally change the physics of MMN, and local materials may be suitable for creating large structures from them.



So whether people will use 3D printing to create a space station where they train, a ship on which they will leave the Earth, or structures where they will conduct research on the surface of the planets, one thing is clear: this technology will become an invaluable tool for future study other worlds.