Introduction

With the recent geopolitical tensions between Russia and Ukraine, the International Space Station (ISS) has found itself at the center of a complex operational challenge. One critical concern is the potential withdrawal of Russia from the ISS program, a move that could significantly impact the station's operations. In this context, Elon Musk and SpaceX proposed a solution involving the use of multiple SpaceX Dragon spacecraft to support the ISS, particularly in the case where Russia decides to leave the program.

Proposed Solution: Utilizing SpaceX Dragons

According to Steve Baker's analysis, if Roscosmos were to leave the ISS program, SpaceX would need to employ three Dragon spacecraft to maintain essential functions typically performed by the Zvezda module. This is a critical module responsible for many aspects of the station's operations, including attitude control and power generation. If Zvezda were to be removed, substantial spacewalks would be necessary to disconnect critical power and data cables, making it infeasible without additional support.

To address this situation, SpaceX would need to redeploy two original Dragons that are compatible with the Common Berthing Mechanism (CBM) system. The CBM is used for docking both crew and cargo versions of the Dragon spacecraft, as well as the Boeing Starliner once it becomes operational. Since one Dragon or Starliner is always latched onto the station, the remaining two can assume control tasks, ensuring the station remains operational.

ISS Configuration with SpaceX Dragons

In the proposed ISS configuration, two old-style Dragons would be docked to the nadir CBM ports, while a third Dragon would be stationed at the forward N2 docking port. This setup would allow for continuous control and maintenance of the station without relying solely on Russian vehicles.

Potential Challenges and Risks

Despite the feasibility of this proposed solution, several challenges need to be addressed to ensure the smooth operation of the ISS:

1. Cygnus Spacecraft's Resupply Needs

The use of two old-style Dragon spacecraft would leave only one free CBM port for Cygnus resupply missions. This means that if one of the station-keeping Dragons needs to move, a third Dragon would be required to dock at the zenith forward port to maintain the necessary functions. This could complicate resupply operations and introduce additional risks.

2. Boeing Starliner's Integration

Boeing's Starliner spacecraft will eventually join the mix, and coordinating control software between Starliner, Dragon, and potentially other vehicles could be challenging. The integration of multiple systems ensures operational efficiency, but it also increases the complexity of potential issues. SpaceX and Boeing must develop procedures to prevent conflicts and ensure safe operations.

3. Russian-Ukrainian Conflict's Impact

The conflict between Russia and Ukraine has affected various aspects of the ISS program. The Antares rocket, used by Cygnus, is built partially in Ukraine and is likely to become unavailable. Similarly, if there is an issue with the Falcon 9 rocket, the entire ISS program could be at risk, leading to de-crewing the station as a last resort. This “all eggs in one basket” approach poses significant risks and highlights the need for a robust backup plan.

Historical Precedents and Backup Plans

America's approach to managing the ISS reflects past experiences and backup plans. In 2000, there was a contingency plan for the Zvesda module in case it failed to reach orbit. This plan, referred to as the Interim Control Module, was shelved and is unlikely to be revived. This historical context underscores the importance of multiple launch vehicles and spacecraft available to maintain the station's operations.

The planned deorbit of the ISS in 2031 involves a Russian Progress spacecraft. If Russia does not cooperate, there may be no alternative to de-orbiting the station, leaving it to tumble into the atmosphere and disintegrate. This further emphasizes the need for a comprehensive and diverse set of solutions to ensure the long-term viability of the ISS.

Conclusion

The proposed use of SpaceX Dragons to support the ISS in the absence of Russia is a viable solution, but it comes with its share of challenges. The need for a robust backup plan highlights the complexity of maintaining the ISS under such geopolitical pressures. While SpaceX's capabilities are commendable, relying entirely on one system is risky. Diversifying the launch fleet and fostering collaboration between different space programs will be crucial in ensuring the long-term success of the ISS.