![Progress spacecraft docked at the ISS.](https://i.kinja-img.com/image/upload/c_fit,q_60,w_645/a113d482d26bb950907e009de71582c7.jpg)
![Progress spacecraft docked at the ISS.](https://i.kinja-img.com/image/upload/c_fit,q_60,w_645/a113d482d26bb950907e009de71582c7.jpg)
The ISS may require a boost to counter orbital decay and maintain altitude. The ISS is equipped with its own thrusters, but limited fuel capacity, low power, and the need to conserve onboard resources for other critical operations (such as directional control and space debris avoidance) Therefore, it is not sufficient for a large-scale reboot. Therefore, docked spacecraft are instead used to provide these external boosts. These spacecraft are specifically designed for such missions and carry their own fuel to minimize strain on ISS resources and allow these substantial orbital adjustments. It has a more powerful engine.
However, due to its proven capabilities and compatibility with the ISS, Russia's Progress is currently the only spacecraft officially certified for this mission.Meanwhile, other spacecraft such as Northrop Grumman's Cygnus and Russia's Zvezda also Possible to adapt to reboost mission, they are not authorized for this purpose and will require additional measures, such as the need for Progress to supply fuel to Zvezda for its mission. NASA doesn't like this situation, so they conducted a reboot test on Cygnus.