- January 25, 2024
- Posted by: admin
- Category: Emilio Cozzi
The agency has issued a Request for Proposals to the industry. A means is needed to dock with the International Space Station and deorbit it to end in the Pacific.
BY EMILIO COZZI
For nearly a quarter of a century, it has traversed the sky inhabited by astronauts who live there for months, work, conduct experiments, and become ambassadors of the technological and scientific progress that benefits all of humanity. The International Space Station is a silent presence, an outpost that, after more than twenty years, has risen to become almost a “natural” cornerstone of a civilization increasingly projected beyond the atmosphere. It is also the most effective symbol of peaceful international collaboration that has continued over time and through terrestrial tensions. However, age and technological limits are increasingly evident: it is time to think about how to dispose of it. NASA is doing this by preparing for the “scrapping” of the orbiting laboratory, a task almost as difficult as its construction, which began on November 20, 1998, with the launch of the Russian module Zarya, followed just sixteen days later by the American Unity module carried into orbit by the space shuttle Endeavour.
The completion of the International Space Station took over a decade to achieve. In the meantime, from 2000, the laboratory began to be permanently occupied by crews of various nationalities: Expedition 1 arrived on board on November 2, 2000, and since then, there has always been someone up there. The ISS will likely continue to be inhabited until the end of this decade. NASA has decided that the epilogue of this extraordinary adventure will be consumed with a re-entry into the atmosphere and a plunge into the Pacific Ocean far from any emerged land, in that place known as the “space graveyard” or “Point Nemo.” To do this, it has issued a tender for the construction of a vehicle capable of docking with the ISS and pulling it down. A service that will be provided by a private entity.
The Old Station
The International Space Station is now obsolete, and maintenance costs are no longer in line with the times. It is time to pass the baton. For example, to Axiom Space, a Texas company that has already been the protagonist of several commercial missions in low Earth orbit – including the one with Colonel Walter Villadei – which is creating the modules for the first private station (some Made in Italy thanks to Thales Alenia Space). They will dock with the “old” ISS and then detach to become an autonomous outpost. Other companies (Blue Origin, Sierra Space, and Boeing; Nanoracks, Voyager Space, and Northrop Grumman) are designing their own with the support of NASA, which has tried to “place” some elements of the ISS for reuse but has not received any “concrete interest from the industry.”
The reason was directly explained by the American space agency: “The modules and main components of the International Space Station have a specific architecture for power, data, and structure that might not be compatible with future platforms. Moreover, disassembly is very complex and expensive, and some levels of disassembly are impractical.” Not to mention that “much of the Station’s structural hardware was designed and built between the late 1990s and the 2000s. New commercial destinations will benefit from more recent technological advancements.”
A Charon is Needed
The options considered for “decommissioning” the ISS were various: beyond reuse, which is not practicable, it was thought to dismantle it and bring it back to Earth in pieces, perhaps to be displayed in a museum. Too difficult and expensive as the structures were not designed for this and each element would require a specific space mission. Letting it fall uncontrolled is another unacceptable possibility. The ISS is huge: as large as a soccer field and with a mass of 400 tons, it is the most imposing infrastructure ever built in space. Many of the elements would survive re-entry into the atmosphere and could fall anywhere, a risk to be avoided. And its size makes the “graveyard orbit” solution impractical. The ISS orbits the Earth at an altitude of 400 kilometers, which would mean “parking” it at over 36,000 kilometers. Again, too challenging and costly. Controlled re-entry is the only solution to prevent its pieces from falling on populated areas. Given the disengagement announced by the Russians, which could materialize well before 2030, it is difficult to imagine guiding it using the engines of the Progress capsules, for example. The study conducted by NASA indicates the need for a new vehicle to ferry the Station to its end.
The “Charon” – or USdv – will be chosen from a range of proposals that will come from the industry (the extended deadline is February 12). It will be a “Deorbiting Vehicle” that can be “a new design or the adaptation of an existing vehicle that must work on its first flight and have sufficient redundancy and anomaly recovery capacity to continue the deorbiting process. We expect it will take years to develop, verify, and certify a vehicle of this type,” writes NASA in the Request for Proposals. The name of the company selected to carry out the project will be known between May and June 2024.
Farewell to the ISS
Among the 630 pages of the RFP, there is also a list of “Assumptions” that gives an idea of the timing: according to NASA, this decade will be the most intense in terms of studies, experiments, and technological advancements, also to support future space exploration: the Moon, Mars, but also new commercial outposts that will continue the work done so far by space agencies. NASA specifies that it will be one of the best customers of the Axiom Space Station and other orbital destinations that will arise. The USdv’s launch is scheduled for the second quarter of 2030, while the last chapter, the descent towards the Pacific Ocean, will take place in the second quarter of 2031.
NASA describes the ISS’s final moments as follows: “First, the solar panels and radiators will detach, then the breaking and separation of the intact modules and the truss – the ‘backbone’ of the structure, will occur. Finally, there will be the fragmentation of the individual modules and the loss of structural integrity of the truss. As the debris re-enters the atmosphere, the outer coating of the modules is expected to melt and expose the internal hardware to rapid heating and melting. Most of the Station’s hardware is expected to burn or vaporize during the intense heating associated with atmospheric re-entry, while some denser or heat-resistant components, such as sections of the truss, are expected to survive re-entry and fall into an uninhabited region of the ocean.”
Many of us have seen it at sunset and in the early hours of the night speeding among the stars, at times the brightest object in the sky. It has been the stage for scenes that will remain in the history of our civilization. International collaboration, scientific dissemination, studies, discoveries, and inventions that – sometimes unbeknownst to us – have made collective life better. Hundreds of astronauts from over twenty countries, predominantly Russian and American, have alternated in orbit, who, despite ongoing political and military tensions, continue to work shoulder to shoulder for the benefit of peaceful progress where the view allows embracing the Planet. Witnesses to the changes caused by humanity. Those are also seen from above the sky, unlike the borders drawn on maps that give rise to conflicts. Nothing will remain of the most glorious palace ever erected by humankind. This will make it even more difficult to say goodbye.