Do you like space stations? Would you like to see more of them in orbit -- maybe even spend a few nights on an orbiting space hotel?

So here's the problem with building space stations: They're really big.

The International Space Station, for example, stretches 357 feet end-to-end (about as long as a football field, including the end zones), masses nearly 420 tons, and encompasses 932 cubic meters of pressurized volume.

ISS looming large over Earth's atmosphere with moon in background

Image source: Getty Images.

And here's the other problem with building space stations: The rockets that carry them up to orbit are (relatively) small, so you can't do it all in one go. Getting all the components needed to put the ISS into orbit required no fewer than 42 separate space missions, spread over 10 years' time. 

Granted, things are a bit easier today. SpaceX's new Falcon Heavy rocket, for example -- currently the biggest rocket in operation anywhere on the planet -- can lift about 64 tons at a time. But SpaceX's Crew Dragon space capsule, which Falcon Heavy can carry, still only has a total payload volume of about 46 cubic meters. Using Falcon Heavy and Crew Dragon together to build another space station would therefore take at least 20 separate launches. 

But what if there's another way to build space stations -- a better way?

Build it in orbit

What if, for example, one could leverage Falcon Heavy's unmatched ability to lift very heavy (but not especially bulky) equipment payloads into orbit, and then install this equipment into hollow, spent fuel tanks from other rockets already in orbit?

This, in a nutshell, is the concept that SpaceX and its partners, Nanoracks and Maxar Technologies (NYSE:MAXR), intend to explore late next year.

In a mission being called "In-Space Outpost Demonstration," Nanoracks, the self-proclaimed "world's leading commercial space station company," will send a payload massing close to 200 kilograms but occupying just over half a cubic meter of volume into orbit aboard a SpaceX Falcon 9 rocket. (This experiment is part of, and funded by, NASA's NextSTEP-2 program to experiment with technologies for building deep-space habitats

Once in orbit, Nanoracks' device will utilize "a new articulating robotic arm" built by Maxar Technologies to "friction mill" (i.e. grind and melt) pieces of metal, similar to the casings of empty upper-stage rocket fuel tanks. Over the course of 30 to 60 minutes, Nanoracks hopes to demonstrate its ability to transform such spent rocket parts into building material that can be used to construct a new space station -- in orbit. 

Successful completion of this demonstration will be first-of-its-kind. As Nanoracks observes, "never before has structural metal cutting been done in-space."

Another first

And this won't be the only first accomplished on this mission. Remember how we told you back in August that SpaceX was planning to offer dedicated rocket rides for companies wanting to launch small satellites into orbit, and guaranteeing the launch dates?

Well as it turns out, Nanoracks' In-Space Outpost Demonstration will go up on the very first ever such "SmallSat Rideshare" launch. As SpaceX has confirmed, in addition to institutionalizing the offering of ad-hoc rideshares aboard rockets carrying the company's system of Starlink internet broadband satellites, SpaceX has also scheduled a series of four missions completely dedicated to (i.e. all passengers will be) smallsats.

Initially, SpaceX advised that the first of these dedicated rideshare missions -- call it the "SmallSat Express" -- would take place somewhere between November 2020 and December 2021. Now, with Nanoracks' announcement, we know that the first SmallSat Express mission will happen in Q4 2020.

Why it's important

And so this mission takes on an extra layer of importance. On the one hand, Nanoracks' In-Space Outpost Demonstration holds the potential to open the door for an entirely new industry for investors to invest in: in-orbit construction of space stations, and probably of space ships as well.

Success here also has the potential to dramatically lower the cost of space exploration by, for example, transforming second-stage rocket boosters (which everyone -- SpaceX included -- currently throws away after launch) from an expensive consumable into a valuable resource useful for orbital construction companies. It could advance the technology of building large objects in space. And in so doing, it could turbocharge Nanoracks' business, and transform Nanoracks from a little-known space start-up into a viable candidate for IPO.

The fact that this mission could also prove the concept of SpaceX's new business line -- launching small satellites in batches on dedicated rockets -- is almost just icing on the cake. Success there could potentially permit SpaceX to dominate the smallsat launch business, much as it's already moving to dominate the large satellite launch business.

All I can say on that score is that, right now, I wouldn't want to be a SpaceX competitor.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.