Author: Inara Pey

In my previous Space Sunday piece, I covered the appointment of Jared Isaacman as the new NASA Administrator and the fact that on the day of his appointment, he was effectively given a new set of high priority tasks by the White House. Among these was an order to oversee the decommissioning of the International Space Station (ISS) in 2030, and to move US low-Earth orbit space operations over to the private sector.

The Decommissioning of the ISS is not new – in fact, it was originally intended to only be in operation through until 2015, but such is the success of the mission that it has been periodically extended by mutual agreement of the supporting partners – notably the US, the European Space Agency and Canada, all of who form the nucleus of the International section of the station (officially referred to as the US Orbital Segment, or USOS), together with Russia, operating the Russian Orbital Segment (ROS).

Despite this success, Russia actually started planning to depart the ISS in 2009, when it indicated it would separate the ROS from the ISS in 2016(ish) and use the modules to establish the Orbital Piloted Assembly and Experiment Complex (OPSEK), a new station intended to become the “gateway” to Russian crewed missions to the Moon and beyond. But with the agreements reached to extend ISS operations beyond 2015 and then beyond 2020, Russia opt to push the OPSEK idea to one side, seeing more advantage in remaining part of the ISS programme.

This changed in 2021, when negotiations commenced to extend ISS operations beyond 2024. Roscosmos was initially unhappy about any extension beyond 2024, citing concerns that several of their ISS modules would be approaching their end of life. Whilst a semi-agreement was reached by the majority of parties to see the ISS remain operational until at least 2028, Roscosmos would only commit to the agreed 2024 end-date, stating that Russia would exit the programme some time thereafter. This was an ambiguous statement at best, given that departing the ISS agreement “after 2024” could be taken to mean Russia would remain engaged until 2028 or even 2030 – or could simply announce its intention to pull out at any time in between, simply giving the minimum 12-month notice required of the partnership agreement.

Instead of formally agreeing to stay with the ISS through until at least 2028, Roscosmos indicated that from 2022 onwards, it would start to pivot towards its own new space station, Rossiyskaya orbital’naya stantsiya (or ROS – which, in order to avoid confusion with the existing ROS at the International Space Station, is generally referred to as ROSS: the Russian Orbital Service Station). Under the initial plan put forward, ROSS was to be established in a polar, Sun-synchronous orbit (allowing it to observe the entire surface of the Earth), and would comprise an initial two modules Russia had been developing for the ISS – NEM-1 and NEM-2.

Under this plane, rather than going to the ISS in 2024 and 2025 respectively, the NEM modules would be repurposed, NEM-1 becoming the Universal Node Module (UNM) at the heart of the new station to be launched in 2027. NEM-2 would then become the Base Module (BM) for expanding the station, with a planned launch in 2028. Further brand-new modules would then be added periodically through until 2035.

However, those plans have now changed again. Whilst the repurposing of the former NEM modules continues and their launch dates remain broadly unchanged, on December 17th, 2025, it was announced that Roscosmos plan to detach their ROS modules from the ISS in 2030 and use them to help form the new ROSS facility, which would now occupy a 51.6º orbit (i.e. one on a par with the ISS, as attempting to move the Russian modules into a high inclination orbit isn’t really feasible).

The announcement – made by Oleg Orlov, Director of the Institute of Biomedical Problems at the Russian Academy of Sciences (RAS) rather than by Roscosmos – is something of a surprise. As noted, several of the Russian ISS modules are either approaching or have surpassed their planned lifespan (what Roscosmos refers to as their “warranty period”).

Of the major modules, Zarya (the first module of the ISS to be launched and the module directly connecting to the USOS segment of the ISS) commenced construction in 1994 with completion in 1998, and thus will hit 30 years in 2028; Zvezda, the functional core of the Russian segment of the ISS is even older, having initially been laid down in 1985 as a part of the never-flown “Mir-2” space station. It has also, since 2019, been subject to on-going air leaks likely the result of failing welds within a part of its structure.

Nauka is similar to Zvezda in that its core frame was laid down in the mid-1980s, only for work to the halted for a time and the resumed in the 1990s when it was re-purposed to be the back-up for Zarya, prior to work halting again. Thus, whilst it is the most recent of the large modules to be added to the Russian segment of ISS (2021), it is in part one of the oldest at 30 years. Only the three smaller modules, Rassvet, Prichal and Poisk will have reasonable lifespans after they separate from the ISS.

A further concern in the “recycling” of the current ROS modules as a part of any new station is that of contamination. Orlov himself raised concerns over the potential health risks for cosmonauts using the ROS modules in 2022, after it was found that bacteria and fungi had successfully made themselves at home within some of the modules and have proven particularly hard to eradicate.

Speculation is that the move back to continuing to use the ROS elements of the ISS within the new Russian space station despite the risks involved has been driven by economic factors – the cost of the invasion of Ukraine, the impact of western sanctions, and diminishing resources. First Deputy Prime Minister Denis Manturov, when indirectly commenting on Russian space ambitions, indicated the decision to move the new station to 51.6º orbit and use the ISS elements was the result of both economic factors and the fact that operating a station at such an inclination would help facilitate co-operative research between ROSS and the upcoming Indian space station which will occupy a similar orbital inclination, making both stations equally accessible to launches from either nation.

Exactly where all this might lead is still open for debate; critique over the proposed re-use of the ROS elements of the ISS is currently garnering as much concern from inside Russia as it is from the wider international community. As such, exactly if and how ROSS will develop remains to be seen.

And yes, India is also getting in on the space station act, despite never having domestically flown anyone to orbit – yet.

The Bharatiya Antriksh Station (BAS) forms a core part of an ambitious and aggressive drive by India to become a major space power, with the country developing plans for an expanding presence in space extending out to 2047. Part of this involves engaging in partnerships and agreements with other major space players – notably the European Space Agency (ESA), NASA and Roscosmos.

However, India is also already well advanced in its development of a human-rated launch capability, with its Gaganyaan (“celestial craft”) crew vehicle and service module due to make its first uncrewed orbital flight in January 2026. Two further uncrewed test flights planned for 2026 prior to a first crewed orbital flight in 2027.

Capable of flying a crew of up to 3, Gaganyaan carries certain similarities to both the upcoming Russian next generation crew capsule and that of China’s in-development new crew vehicle. It is highly automated and capable of independent on-orbit operations of up to seven days duration, and it will be used to ferry crews to / from the upcoming BAS.

On-orbit assembly of BAS is due to commence in 2028 with the launch of the first module, currently referred to as “Phase-1”. Details of the completed station’s design and appearance are scant, but modules will be launched using India’s LVM3 medium-lift launch vehicle, suggesting they will all not exceed 10 tonnes in mass and thus marking them as slightly smaller than the core modules of the international segment of the ISS. What is known indicates that BAS will likely comprise 5 main modules, including a multiple docking facility, and when complete, mass around 50-55 tonnes orbiting in a 51.4º inclination orbit at an altitude of 400-450km. The size of the station at five core modules suggests it will have an overall pressurised volume of about 260m³, of which roughly 105m³ will be habitable space (the rest being taken up by life support and other essential systems). This would make the completed BAS facility slightly smaller than the current size of China’s Tiangong station.

Not that a lack of size accounts for anything – simply constructing, launching, assembling and operating its own independent orbital facility, capable of supporting 3 or 4 people in relative comfort (and 6 at a squeeze for short periods) would be a truly significant achievement for India. One which would further boost the country to the forefront of dedicated international space research.

Which brings us to China and Tiangong.

With their space station now well established, China is again indicating a potential further expansion to Tiangong. Originally announced in 2023, the expansion now appears to be going ahead, the plan being to add up to three further modules – a new core habitat module (essentially an updated version of the current Tianhe core module with a new multi-port docking module) plus two improved versions of the physically near-identical Wentian and Mengtian science modules.

The new modules will provide increased living and working space allowing for expanded crews on the station, with the science modules including 3D printing capabilities, improved robotic arms and external experiment bays, with crew supported in their work by robot systems.  A new suite of equipment intended for space debris observation, detection and potential collision warning will also be included within the updated core module, underscoring the increasing risk to spacecraft operating in low Earth orbit being exposed to space debris collisions – a lesson the Chinese recently learned with Shenzhou 20.

To further enhance Tiangong’s importance, China has been developing international partnerships to carry out joint research into a range of areas (including human medicine and health) with multiple nations. These cooperative ventures include both Russia and India, and until political and financial tensions ended it, the European Space Agency was forming a collaboration with China that would have seen European astronauts training with Chinese tiakonauts and completing crew rotations on Tiangong.

No time frame has been given as year for the launch of the plan new modules for the Chinese station; the focus right now is in lifting the Xuntian space telescope into orbit.

This state-of-the-art observatory will co-orbit with Tiangong and be capable of periodic automated docking with the station to allow for maintenance and update. Xuntian will have a 2-metre diameter primary mirror (compared to the 2.4 metre diameter primary mirrors on the Hubble Space Telescope and the upcoming Nancy Grace Roman telescope), coupled to a 2.5 gixapixel camera to give it a field of view 300-350 times greater than Hubble and with a higher resolution.

Also known as the CSST – Chinese Space Station Telescope – Xuntian is so advanced it has faced several delays in its launch whilst issues were resolved. Originally, it had been planned to lift the observatory to orbit at the end of 2023, this date was first pushed back into 2024 and then to mid-2025. Currently, China is targeting an end-of-2026 launch for Xuntian, after which the focus will switch more to Tiangong’s expansion.

In addition, and further underscoring China’s longer-term intentions in orbit and beyond, 2026 should see the first uncrewed launch of Mengzhou, the country’s next generation crew-carrying vehicle. Capable of carrying up to 6 (or a crew of 3 + a half tonne of supplies), Mengzhou is to form the backbone of Chinese human space activities through the 2020s and 2030s, serving as both a crew transportation vehicle  between Earth and Tiangong and as the principle means of ferrying crews to / from lunar orbit as China seeks to establish a presence there.

Also on the horizon for Tiangong is a new automated resupply vehicle. Called Qingzhou, it is intended to operate alongside China’s existing Tianzhou resupply craft, but provide a lower-cost alternative for delivering small loads (around 2 tonnes) to Tiangong quickly and easily. A focus of this will be in the delivery of food and water supplies for crews on the station, including fresh produce which can be stored in a 300-litre capacity “cold chain” food store. As with Mengzhou, the compact resupply vehicle, roughly 5 metres long and 3 metres in diameter, is expected to make an initial test flight in 2026. Further, once operational, Qingzhou will be offered commercially as a cargo delivery service to other space station facilities including both BAS and ROSS.

As noted in my previous Space Sunday article, the United States has no plans to operate any fully government-funded space station in Earth orbit once the ISS is decommissioned. Instead, it is looking to the private sector to take up the challenge. While there are several in-development private sector space station proposal in development, all of which are seeking partial US government funding, whether any  / all of them will offer the kind of space-based research facilities as offered by the ISS is questionable. As is the question as to which of them will actually fly.

For example, two of the leading contenders in the race to develop a private sector space station are a consortium led by Blue Origin (Orbital Reef), and a solo venture by Axiom Space (Axiom Station). However, despite chasing further NASA funding under the LEO Destinations Programme, both of these stations would appear to be primarily focused on the (potentially lucrative) space tourism business, boasting facilities such as private suites with views of Earth, high-definition audio systems, “mood enhancing LED lighting throughout”, cosy, soft fabric coverings for interior walls, and other creature-comforts.

Another seeker of NASA funding is Vast, a company trying to establish two facilities in orbit. The first is a single module station called Haven 1, intended to be launched some time in mid-2026. More of a proof-of-concept than practical orbital facility, the company plans to follow Haven 1 with Haven 2, starting in 2028.

This is a far more ambitious undertaking, intended to expand from a single module in 2028 to a total of nine by 2032, new modules being added at roughly 6 month intervals. However, whilst billed as a successor to the ISS and capable of EVAs and other activities, and of providing “10 external payload facilities, allowing scientific research, development, and manufacturing to take place outside the station”, the exact science capabilities for Haven 2 have not been publicly released.

A small-scale technology demonstrator, Haven Demo, intended to test the propulsion, flight computers and navigation software to be used on Haven 1 and Haven 2 was successfully launched by SpaceX (who will provide all launch capabilities for the Vast projects, including crew transportation using Crew Dragon, together with communications via the Starlink network), so it will be interesting to see what data this returns and whether or not Vast can meet their mid-2026 launch target for Haven 1.

One further project I’ll mention here is Starlab, a joint venture between Voyager Technologies in the US and Europe’s Airbus Defence and Space. This potentially has the firmest footing in space research and science, as is intended to comprise two 8 metre by 8 metre modules (that is, twice the diameter of the modules in the international segment of the ISS) in which up to 400 experiments per year can be performed, putting it on a par with the ISS. However, the entire project is currently dependent on the SpaceX Starship vehicle as its launcher. Given the overall status of that project (which is well behind its promised schedule, and apparently solely focused on being a Starlink delivery system if / when it does start proving it can reach orbit carrying a decent payload and be successfully reused) the proposed late-2028 launch target for Starlab could be best defined as “optimistic”.

Thus, on the one side of things, national interests in operating relative large-scale space station facilities  – and offering at least some of them (India, China) for international research opportunities – appears to be one the rise, whilst in the US, the emphasis is on turning LEO capabilities for humans over to the private sector wherein revenue, margins and profit are far more motivating than research. As such, it will be interesting as to which plays out better in terms of on-going space-based R&D – and which facilities actually come to pass.