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[EN VIDÉO] ISS: until 2030, and after? The International Space Station will continue to welcome astronauts from all over the world for scientific missions until 2030. And to support space conquest missions which must take humans to the Moon and even to Mars. (in English) © NASA
Relations being what they are with Russia, and there is little chance that this will improve in the near future, the Nasa and its Western and Japanese partners are forced to find an alternative to the Russian Progress freighters used to “pilot” the orbital complex.
That said, a disengagement from Russia is not on the agenda, nor is it the scenario favored by NASA at the moment. But, if there is no indication that Russia could carry out the threats of Dmitri Rogozin, the head of the Russian space agency Roscosmos, NASA is obliged to take this rather uncertain situation into account.
Since the withdrawal of European ATVs (ATV for automatic transfer vehicle), the Progress cargo ships are the only vehicles used to raise the orbit of the ISS and correct its trajectory to avoid debris for example. The other two cargo ships in service, the Dragon from SpaceX and the Cygnus from Northrop Grumman and Thales Alenia Space, were not designed for this very specific task.
Apparently, only the Cygnus freighter could replace the Russian Progress. Among the improvements made to the Cygnus since its entry into service in 2013, there is the “reboost” function. In the conditional therefore because, for the moment, the Cygnus has not demonstrated that it could perform this oh so important maneuver. Without a regular boost, the orbit of the International Space Station would fall inexorably, week after week.
An apparently conclusive maneuver
NASA and Northrop Grumman have teamed up to test Cygnus’ ability to lift the ISS. It’s not the first time that Cygnus is used in this way. In July 2018, a Cygnus ignited its engine for about fifty seconds, which raised the Station’s altitude by 86 meters. A conclusive maneuver but insufficient to qualify the freighter for this task.
This test demonstrated the ability of Cygnus to raise the station’s orbit
A new attempt took place on June 26. This time, the maneuver lasted longer. The Cygnus moored at the station turned on its engine for 301 seconds increasing the perigee from the station about 0.8 km and its apogee nearly 0.2 km. This test demonstrated Cygnus’ ability to raise the station’s orbit. The maneuver was successful. At least that’s the opinion of Steve Krein, Vice President, Civil and Commercial Space, Tactical Space Systems at Northrop Grumman who points out that ” this ISS boost using the Cygnus adds an essential capability to fly the space station “.
NASA did not communicate on the maneuver. It is therefore too early to say whether the future Cygnus freighters could be used as a complement or replacement for the Russian Progress. In addition, the future of these vehicles is rather uncertain! Indeed, Antares, their appointed launcher, uses the Russian RD-181 engine for its main stage, which is under Ukrainian prime contractorship. However, since the invasion of Ukraine by Russia, these two items are unavailable. However, Northrop Grumman confirmed that it had two operational Antares launchers and that it had a “contingency plan” after these two launchers, but did not give further details. To be continued then.
NASA is urgently seeking a solution to pilot the Space Station without Russia
Article of Remy Decourt published on 05/03/2022
Could the SpaceX and Northrop Grumman cargo ships, which supply the International Space Station, be used to pilot the orbital complex? Until now, NASA had never bothered to find a replacement solution in case the Russians, the only ones capable of piloting it, decided to abandon the Station to its fate. Although Russian-American space relations have always resisted storms past geopolitics, with the conflict in Ukraine, they have never been so close to breaking up. There is therefore a certain urgency for NASA to answer this question in the affirmative and to see how.
NASA wants to be far-sighted. In the event that Russian-American relations reach a point of no return, Russia “ could withdraw from the International Space Station as Dmitry Rogozin, the head of the Russian space agency Roscosmos, aptly put it.
Dmitri Rogozin obviously did not say that he would project the Space Station on the United States, but implied that he could leave the Russian segment abandoned.
However, while the American side provides electricity and life support to the entire orbital complex, the Russians are responsible for propulsion, keeping the ISS at an altitude of around 400 kilometers and attitude control and course corrections.
Without Progress to pilot it, the Station’s orbit would drop inexorably, week after week.
For this, they use Progress freighters, one of which is permanently moored to the Zvezda module. Without Progress to pilot it, the Station’s orbit would drop inexorably, week after week. It would also be unable to correct its trajectory to avoid debris for example.
It is in this very uncertain context, and although Russia is still cooperating with NASA for the smooth running of the Space Station, that NASA has decided to study emergency solutions to pilot it. In case the Russians decide to abandon him to his fate overnight.
American freighters maneuvering to pilot the station?
Northrop Grumman, which supplies the station with the Cygnus cargo ship (whose module is built by Thales Alenia Space) and SpaceX which does the same with its dragon freighter, proposed to NASA to “do the job”. However, if the freighters of the two industrialists can be converted and adapted to a “reboost” mission of the ISS to raise its orbit, it should be known that the ports of docking of the American freighters are really very badly located to carry out this task. !
They moor via the ports LDCs Unity and Harmony modules (Pressurized Mating Adapters) equipped with an active CBM system to catch cargo. This is also why theEuropean Space Agency ATV docked in the same place as the Russian Progress freighters to ascend the Station’s orbit.
It will be interesting to see the solutions proposed by Northrop Grumman and especially those of SpaceX when we know thatElon Musk always has very original and daring ideas!
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