USDV Unveils ‘Super Dragon’ That Will Deorbit ISS Around 2030

We already know what the USDV, SpaceX’s vehicle that will be responsible for deorbiting the International Space Station (ISS) around 2030, will look like. It will essentially be a Dragon 2 capsule mated to a huge new service module equipped with 30 engines that will blast off from a Falcon Heavy. At more than 30 tons, the USDV (US Descent Apparatus) will be one of the largest spacecraft ever built, exceeding some space stations in mass and size. For comparison, the Apollo CSM weighed 15 tons, and the current Crew Dragon weighs about 12 tons. Only software shuttles shuttle and Buran, at around 100 and 80 tons respectively, were more massive. Since it includes the Dragon 2 capsule on one end and will be launched by a heavy rocket like the Falcon Heavy, we are looking at a true “Super Dragon.”

Less than a month ago, on June 26, we learned that SpaceX had won a NASA contract worth $843 million to build the USDV, the vehicle responsible for deorbiting the ISS over the South Pacific Ocean after its useful life. Recall that after weighing several options, such as leaving it in a higher orbit, cutting it up or “selling” it to a private venture, NASA came – without much public discussion, it must be said – to the conclusion that the best option was to suddenly deorbit it over the Pacific Ocean. This path chosen by NASA is not without controversy, since it is apparently a political decision, motivated mainly by the American space agency’s desire to focus on the Artemis program, while leaving low orbit to private space stations such as Axiom or Blue Origin. It is also not very clear to what extent other partners in the project, such as Europe, Canada or Japan, were consulted.

As for the other ISS partner, Russia, this country was originally supposed to supply Progress ships for deorbiting the station, but the international political situation after the invasion of Ukraine made the US distrustful of Russia’s intentions and fear that. this could lead to them hanging at the last minute. In addition, Roscosmos plans to leave the ISS two years earlier, in 2028, to build its own all-Russian station ROS. Of course, both this date and the 2030 date are more than possible to change, but for now these are the official dates. When NASA announced the SpaceX contract to build the USDV, it was not officially known whether other companies had tried to take it on, but everything pointed to Northrop Grumman offering a version of its Cygnus cargo ship for this task. It is not for nothing that Lebed has recently begun to perform maneuvers to raise the ISS orbit, which until now only Russian Progress spacecraft and the Zvezda module could do. We now know that this was indeed the case. In fact, these two companies were the only ones to make it to the final stages of building the USDV, but Northrop Grumman’s proposal was rejected because it was more expensive (we don’t know by how much) and riskier (another company, AlphaSpaces, also proposed a deorbit vehicle, though it was eliminated from the final selection).

As we’ve said, SpaceX will build the USDV using a Dragon 2 capsule — the cargo version of the Crew Dragon — at the front, and instead of a traditional “trunk,” it will carry a service module with 16 tons of hypergolic propellant and no more or less than 30 Draco thrusters (experience with Super Heavy has apparently made SpaceX like clustering thrusters). This module will be twice the length of a traditional “trunk,” and will include large solar panels, both on top of the structure and in a deployable form. Between 22 and 26 thrusters can be ignited at each burn, generating up to 10 kilonewtons of thrust (each Draco engine produces 400 newtons of thrust). The capsule is noticeable because the USDV doesn’t need a return module, meaning there’s no need to waste mass on a heat shield or other systems. However, since the launcher will be a Falcon Heavy, it is clear that this extra weight will not be an issue. In total, the USDV will carry 46 Draco engines: 30 in the service module and 16 in the capsule.

According to NASA requirements for USDV, the spacecraft must have a high thrust – more than 3.24 kN – to ensure that the final burn will allow the ISS to deorbit over the Pacific Ocean, but this thrust cannot be higher than 6.2 kN, because otherwise there is a risk of compromising the ISS structure before it deorbits. Therefore, 10 kN of thrust is needed as a reserve, just in case. For the ISS deorbit, the total Delta-V velocity will be between 41 and 47 m/s, but with the need to achieve it in about one hour. According to NASA requirements, the final burn of the USDV must have a Delta-V velocity of at least 30 m/s and a maximum duration of 40 or 60 minutes. These figures will ensure that the final perigee after the maneuver will be 50 kilometers, which will ensure the re-entry of the largest space structure built by humans. The Delta-V throughput of the USDV will be 57 m/s.

Unlike Crew Dragon, USDV will not be owned by SpaceX, but by NASA, and the agency will oversee the ship’s operations. The ship is scheduled to launch no later than May 1, 2029, though ideally it will do so by August 1, 2028. USDV will be able to remain in orbit, flying independently, until it needs to dock with the ISS. That’s what those huge solar panels are for. Once docked to the station, it will be able to remain there for up to a year before reentering the atmosphere. For the last four days before returning to the ISS, USDV will need to be completely independent of station systems. In short, NASA wants USDV to launch a year and a half before the outrageous finale, which could happen sometime in 2030 or January 2031. Given its very specific mission, neither SpaceX nor NASA expects this to be the first in a series, but more versions of the Super Dragon could certainly be created for multiple applications.

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