Modified Assembly Sequence for Axiom Space Station
Axiom Space has revised the assembly sequence of its space station to eliminate dependence on the International Space Station (ISS) starting in 2028. This change comes after NASA requested a modification due to ISS deorbit times, the need to support SpaceX’s deorbit vehicle, and a desire to maximize the amount of ISS science and equipment that can be salvaged.
New Assembly Order for Axiom Orbital Station
Initially, Axiom Space won a NASA contract to build a private segment of the ISS, which would later separate and become an independent orbital station. The original plan consisted of two habitable, scientific, and energy modules. However, Axiom Space had to adjust its plans, changing the launch date of the first module to the ISS from 2024 to 2025 and then to the end of 2026.
Maintaining Human Presence in Space
With the ISS set to be decommissioned in 2030, there is growing urgency to put the Axiom station into operation, even in a smaller configuration. Axiom plans to launch an airlock module, a second habitable module, and a research module, each with its thermal and energy capacities. The first habitable module will also have a robotic arm for reconfiguring the station.
Cost of Building a Space Station
The cost of building a four-module station is estimated to be around $3 billion, with each module costing approximately $300 million, and engineering expenses accounting for the rest. A reduced two-module station would obviously cost less, although the exact figure is still unclear.
Implications of the Modified Assembly Sequence
Axiom’s plan to fly free, ahead of schedule, gives the company additional leeway in case of delays. This also means that there is more likely to be another space station available if the ISS retires ahead of schedule. The modified assembly sequence allows for a basic two-module configuration capable of accommodating four people, with the PPTM undocking from the ISS and docking with the habitable module Hab1.