If NASA estimates that three Progress and a Cygnus (backup) will be enough to deorbit the orbital complex, it still plans to develop a space tug in order to have a back-up solution in the event of a technical failure of the Progress , even if ever Russia decides not to cooperate any more. This American vehicle could cost up to a billion dollars. The price of a secure deorbit.
In January 2031, the era of the International Space Station (ISS) will be over. She will be desorbed. The scenario is known. We presented it to you in the article below, dated February 7, 2022. To summarize, NASA plans to use three Progresses to perform this deorbit maneuver followed by a dive above Nemo point, the most isolated place on Earth, located in the South Pacific Ocean.
Except that relations with Russia being what they are, the United States obviously does not want to depend on the goodwill of the Russians. Although today NASA and Roscosmos are working in good intelligenceintelligence to use and operate the orbital complexorbital complex, and although the Russians have guaranteed the supply of these three Progress, NASA wishes to have a backup solution due to several uncertainties. And as Nasa’s head of human spaceflight Kathy Lueders points out, ” we are always looking for a fallback solution in everything we do “.
Uncertainties over the reliability of Progress and future relations with Russia
Concretely, NASA wants to have its own space tug in the event that major technical or reliability problems affect the Progress cargo ships, as recently happened. Remember, in February Roscosmos was forced to urgently send an empty Soyuz vehicle to replace the SoyuzSoyuz MS-22, docked to the ISS but suffered damage rendering it unusable to transport a crew to safety. As for the Progress freighters, several of them experienced leaks and other technical problems. However, since they only carry freight and are not salvageable like the Dragon capsules of SpaceXSpaceX, we talk about it a lot less. Admittedly, in NASA’s scenario, a Cygnus cargo ship is planned as a backup, but only to guard against a breakdown or a technical problem with one of the three Russian cargo ships.
Finally, just as the ongoing invasion of Ukraine by Russia has severed many space partnerships with Russia, NASA must take into account that Russian-American relations could deteriorate sharply depending on the turn of events in Ukraine or elsewhere. . In addition, Russia has expressed the wish to leave the ISS program earlier, after 2024, without giving more details on its effective date of departure, to concentrate on the constructionconstruction of its own space station.
All of this data was probably a strong decision factor in NASA’s plans to develop a space tug that could be used to deorbit the Space Station when it reaches the end of its operational life. During the presentation of NASA’s 2024 budget, which must be approved by Congress to pass, it was learned that the White House would propose funding of $ 180 million to begin a space tug program and launch an appeal for offers to American manufacturers. The total cost of the program is estimated at less than a billion dollars. An expense that NASA would have done well and that it would undoubtedly have preferred to allocate to other programs.
Article of Remy DecourtRemy Decourt published on 07/02/2022
NASA estimates that three Progress and a Cygnus (backup) will be enough to de-orbit the orbital complex. A compelling storyline.
The end of an era… We had to digest the announcement made by NASA of the deorbiting of the international space stationinternational space station scheduled for January 2031. We knew that the orbital complex was not eternal. He even exceeded thelife expectancylife expectancy for which it was designed. But learning it just days after NASA indicated it was extending its lifespan to 2030 and its intention to get the most out of it until then suggested it might have worked maybe. -be until 2035.
By 2029, the station will continue to operate normally. The latest reviews of the analysis of the state of the structure of the various partners (Russia, Japan, USA and Europe) are reassuring and indicate that the orbital complex can operate until this date without causing any particular risk. The lifespan of the ISS is limited by the proper functioning and resistanceresistance to the space of its primary structure which includes the pressurized modules, the radiatorsradiators heatsinks heatheat and structures in trellistrellis. In May 2021, Walter Cugno, director of Science and Exploration activities at Thales Alenia Space (which built many of the station’s modules), wanted to be reassuring about the solidity of its modules. Other systems such as power, environmental control and life support, or communications for example, are all repairable or replaceable orbitorbit.
The Russian segment is the one that is aging the least well. Among the latest incidents, an atmospheric leak in the service module and minor cracks for the safety of astronauts have since been under constant surveillance. That said, Roscosmos wants to be reassuring and is working in a good spirit with the other partners to ensure that there is no threat to the viability of the ISS.
Did you know ?
Point Nemo is the most isolated place on Earth. As there is practically nothing in this part of the South Pacific (no island, no inhabitant and almost no maritime or air traffic), this place was chosen by the space agencies to deorbit their satellites in end of life, but also launcher stages and other space station modules. If most of the materials that compose them disintegrate during re-entry into the atmosphere, fragments or parts, due to their composition, are on the other hand likely to resist the high re-entry temperature (1,500 degrees) and arrive intact. on earth. To date, it is estimated that nearly 300 satellites lie there alongside the remains of the MIR station, deorbited in 2001 and, more recently, those of the Tiangong-1 orbital module, since April 2, 2018. It is also in focus Nemo that the western part of the International Space Station will be desorbed during the 2030s.
NASA has given information on how it intends to go about plunging the station above Nemo point. In its nominal scenario, ground controllers will program retrograde maneuvers of the ISS to slowly lower its operational altitude. These maneuvers will begin as early as January 2030. The precise dates cannot be determined in advance as they will depend on the activity of the solar cycle and its effect on theatmosphereatmosphere terrestrial (higher solar activity tends to expand the Earth’s atmosphere, which increases the speed resistance of the ISS. This can lead to more contrails and loss of natural altitude). These maneuvers will be carried out by three Russian Progress cargo ships and NASA is studying the possibility of using a Cygnus “just in case”. Indeed, NASA must protect itself from a breakdown or a technical problem of a Russian cargo ship. The propulsion capabilities of the Cygnus, whose module is built by Thales Alenia Space, will be extended.
Once the orbit of 280 kilometers has been reached, the ISS will be aligned on a trajectory with Nemo as its landing point in the Pacific Ocean, the most remote region of the Planet which has become, since the beginning of the conquest of the space, the graveyard of space objects. A final boost will precipitate the ISS into the atmosphere and after a nice firefire of ephemeral fireworks, the remains of the station will sink to the bottom of the ocean.