Commercial LEO Destinations: the private substitutes for the International Space station

Axiom terminada portada

The International Space Station (ISS) is humanity's masterpiece in space. Two separate space stations merged by the economic problems of the United States and the Soviet Union and then the Russian Federation.

Due to the invasion of Ukraine and the evolution of the American space program, an ISS 2 seems impossible. Will private companies fill the gap?

Gateway vs ISS scaled
Size comparison between the ISS and the Gateway. Source: NASA

NASA leaves Earth orbit

NASA's current strategy is to abandon low Earth orbit, simple as that. He wants to leave that area only for private companies and if he must attend, do so as another client. This already makes the possibility of a hypothetical Freedom or Skylab 2 space station impossible. It can be argued that this has not yet been completely ruled out, because the CLD program (commercial destinations in low Earth orbit) is not closed, but It is difficult to maintain such a posture.

The first step in this strategy, when it had not even been defined, was taken 15 years ago. In that distant 2008, at the dawn of a serious economic crisis, the Obama administration diverted the supply of the international space station to private industry spacecraft. There are many nuances, such as the first case of referral to the private sector in a new area, there are factors that differ in the new programs launched. For example, NASA's monitoring of the development process is less intense, limited more to ensuring that contract needs are met. In any case, once the product is delivered to NASA, it passes rigorous tests carried out by the US space agency. A case of this approach will be the space stations that are born from the CLD, or the Artemis lunar landers.

It must be taken into account that the CLD contract is not yet closed, which leaves almost any possibility open. Although at the moment there are already four candidates to receive astronauts from NASA. Or you can even say to be the successors of the International Space Station

axiom station develop scaled

The gifted student, Axiom Space

Of the four companies there is a clear advantage. Axiom Space Not only is it already building its space station, but it has been waiting for this moment for many more years than its competition.. In addition, it seems the most solid proposal, insofar as they have a waiting list to take tourists to the space station on their flights developed in conjunction with SpaceX.

On these missions they have been sending three paid astronauts and one professional astronaut. A kind of chauffeur, although the analogy requires that the car be completely autonomous and can be controlled remotely before the driver even takes the wheel. Its success is beyond dispute with two full flights already completed and two more already booked.

The proposal of this company is to create a space hotel. When a person who is more or less literate in this regard reads this, they know that it is economic suicide. The demand for tourist space flights is frankly limited and reduced. And this is where NASA's money comes into play under the CLD. Maintaining, say, 6 or 9 tourists is not the same as reducing that number by half thanks to visitors from public space agencies. Not only will the American company lose access to an orbital laboratory. But Canada, Europe, Japan and why not South Korea, the United Arab Emirates and other actors that join human space flight also do not have a clear destination in Earth orbit.

But what will this new space station be like? Small, but not much.

It will be made up of several modules, like the vast majority of stations already. And each one will be specialized in a task, identical to the space station. The first two are of the residential type, that is, they are mainly dedicated to housing astronauts. They do not have life support systems, although they do have solar panels that allow them to meet their electrical needs. And although they will be moderate, because they will also have a small part for research and manufacturing, they cannot take advantage of what the ISS generates.

Samantha Cristoforetti inside cupola pillars
Photograph of Samatha Cristoforetti greeting the crew outside the International Space Station. Source: ESA

After the two initial modules are added, in 2024 and 2025, respectively, one dedicated to research and manufacturing and a kind of imitation of the Cupola of the International Space Station would be jointly launched. This addition clearly responds to the hotel focus of the station. But it will be used by anyone, just like professional astronauts, they fight for a place in the original with the cameras placed there and among themselves.

Finally, a type of large mast dedicated not to the crew but to various systems would be added. The most important, thermal control and life support, which up to this point would depend mostly on those provided by the International Space Station.

Once the assembly of the Axiom station was completed, it would be released and fly on its own as a new and independent one. Beyond this, it is known that the astronauts will arrive aboard SpaceX Crew Dragon ships.

The rest of the CLD

Despite being the outstanding student, Axiom is not alone in a contract as juicy as the one currently being proposed. 

  • Orbital Reef, the proposal led by Blue Origin and Sierra Space
  • starlab, led by Nanoracks and with collaborators as diverse as Hilton and Airbus
  • Northrop Grumman lines up with Dynetics for the least publicized proposition of all.

Three proposals that are very different from each other, and each one stands out in a different section.

Starting at the end, Northrop Grumman took all the operational space designs it has and from the resulting hodgepodge a proposal is born that promises to be cheap to develop.

Seated on the solid base of the Cygnus supply capsule, which would form the main modules of the station, it draws on other derivatives of this ship. If you study the work of this company in space in recent years you can see how everything revolves around this project. The propulsion and electricity module they are building for Gateway, NASA's lunar station, which also appears in this design for the CLD. Beyond knowing that the Cygnus will resupply the supply station, which is a fundamental pillar in its construction, and that the crews will fly with SpaceX, there are many unknowns. 

Photo by Starlab
Image of Starlab showing the two modules, the robot arm and an airlock that would allow satellites to be launched or experiments to be exposed to a vacuum and then recovered. Source: Starlab

Starlab dominates due to simplicity, the proposal presented by Nanoracks is two simple modules. One of them pressurized for the crew, laboratories and manufacturing facilities and another for services.

This proposal stands out in the degree of specialization of some of the collaborators. For example, it is difficult to believe that any of the alternatives to this proposal can design better accommodations for a luxury hotel than the Hilton company. Airbus, Lockheed Martin and Voyager Space all have equipment already working on the current International Space Station, which is another point of experience for the design.

Another important thing about the design is that it allows it to be launched with a single rocket. Which reduces the cost and deployment time, which is several years in other competitors. Simplicity is its great strength, but even so, it is not far behind in features compared to its competition. It has capacity for four astronauts in a volume of 340 cubic meters.

Orbital reef is probably the most bombastic proposal. Blue Origin is in charge and is primarily supported by Sierra Space.

Composed of multiple rooms of various kinds, these are so large that they will require the New Glenn. Blue Origin's rocket to compete with the Falcon Heavy. Not only the disproportionate dimensions of the project stand out, but also the use of Boeing spacecraft. This, as part of the station, provides its CST-100 Starliner manned capsule. A ship that continues to have problems and is not yet certified to fly with humans. They will also build a laboratory.

Sierra Space will be in charge of delivering the supplies using its space plane, the Dreamchaser. Not to be confused with Boeing's ship of the same name, unlike that, this new shuttle has fewer delays and has not yet had any catastrophic problems in any test. It also hasn't flown into space yet, but is expected to make its maiden launch before the end of this year. The rocket chosen, the United Launch Alliance Vulcan is partly responsible for the delays needless to say. In addition, they are also in charge of the life support module. Blue Origin would be in charge of launching the different parts.

Orbital reef scaled
Image of the Orbital Reef station

The old continent is drowning in its old season

Claims that NASA is abandoning Earth orbit are perhaps exaggerated. Although NASA's brand new space station will be the Gateway, it is designed to be autonomous as long as there is no need to support Artemis missions. Meanwhile, space agencies, which will not make even two annual flights to the Moon, want to continue exploring space with humans. This requires new destinations in Earth orbit that have been commissioned from private American companies.

Airbus, apart from collaborating in Starlab, is trying to sell its own station to the European Space Agency (ESA) without much apparent success. But it is not known if it can participate in private American stations. So it is not known what will happen to the European astronauts. In conclusion, in five years Europe may be with a rocket that does not convince the market, the Ariane 6. In addition to not having its own manned capsule, and not being able to carry out manned space flights to any space station.

It is early to know how the CLD program will develop. but the replacements for the international space station are here. And thanks to NASA money they will be a reality sooner rather than later. There are still doubts about whether there is enough market for them, but their small sizes are expected to increase their profitability on the ISS. What is certain is that this will expire, and most likely before the end of the decade with serious consequences throughout the world.

Martin Morala Andres