Shortly after new Progress freighter docks with ISS, older Progress loses internal pressure

ISS as of February 11, 2023

Shortly after a new Progress freighter docked with ISS early today (shown as Progress 83 in the graphic to the right), the older Progress 82 lost internal pressure, possibly in its coolant system.

On February 11, Roskosmos, citing data from mission control, said that the Progress MS-21 cargo ship docked at the station lost pressure. According to the State Corporation, the hatch connecting the ship’s pressurized compartment with the rest of the station was closed and the vehicle was fully isolated from the ISS’ habitable volume.

…According to unofficial sources, the spacecraft lost all its cooling fluid from its Thermal Control System, SOTR. Several hours after the incident, NASA confirmed that the breach had been limited to the cooling system. At the same time, the US space agency said that the hatches between the cargo ship and the station had remained open, while temperatures and pressures aboard the outpost had remained normal. The subsequent publicly available exchange between the NASA mission control in Houston and a US astronaut Frank Rubio, aboard the ISS, indicated that the coolant system of the Progress MS-21 spacecraft had been completely emptied before the leak stopped.

The report is very unclear. In the first paragraph it suggests the freighter’s atmosphere had leaked out, while its hatches were closed and it was isolated from the station. The second paragraph suggests it only lost pressure and coolant from its coolant system, and the hatches had been open during the event.

Either way, this is the second Russian ferry spacecraft to experience such an event since mid-December, when the Soyuz capsule attached to ISS lost its coolant from what is believed to have been a small impact.

This particular Progress freighter is slated to be undocked from ISS on February 18th, when it will be de-orbited, burning up in the atmosphere over the Pacific. Thus, this leak appears to pose a relatively small risk to the station, as it probably has already been filled with station garbage and was likely ready for disposal anyway.

This incident however raises larger concerns. If it was caused by an impact from an external object, either micrometeorite or space junk, it suggests that the station might face a new increased risk of such events, quite possibly from debris from the Russian anti-satellite test in November 2021. As of November 2022 it was estimated that there were 444 objects still in orbit, with all but 18 expected to fall back to earth by 2025. It could be that one of those tracked objects hit ISS, or a different object that has not been tracked.

Or possibly we are seeing evidence of some quality control problem in the construction of these spacecraft, in Russia. Russia and NASA have still not revealed the results of the investigation into the hole that was drilled into the hull of a Soyuz capsule in 2018. Could there be some sabotage going on the ground in Russia that has not been identified that is designed to cause such leaks sometime after launch?

Some clarity on this issue is now becoming essential.

Soyuz hole not caused by a Geminid meteor

According to an analysis by both NASA and Russian engineers, the 0.8 mm hole in the coolant system on the Soyuz docked to ISS was not caused by an object from the Geminid meteor shower that had occurred about the time the leak appeared.

The Soyuz vehicle, known as MS-22, sprayed its coolant into space on Dec. 14, the same day that the annual Geminid meteor shower peaked. But there’s no causal connection, NASA and Russian space officials said. “We did look at the meteor showers that were occurring,” Joel Montalbano, NASA’s International Space Station program manager, said during a press briefing on Thursday (Dec. 22). “Both the trajectory team in Houston and the trajectory team in Moscow confirmed it was not from the meteor showers; it was in the wrong direction.”

The engineers claim the hole could still have been caused by an impact, just not from these meteors.

Russian official: Soyuz leak possibly caused by micrometeorite hit

According to Sergei Krikalev, who heads Roscosmos’ manned program, the leak of coolant from the Soyuz capsule docked at ISS could have been caused by a micrometeorite hit.

Sergei Krikalev, a veteran cosmonaut who serves as the director of crewed space flight programs at Roscosmos, said a meteorite striking one of external radiators of the Soyuz MS-22 capsule could have caused the coolant to escape.

The malfunction could affect the performance of the capsule’s coolant system and the temperature in the equipment section of the capsule but doesn’t endanger the crew, Krikalev said in a statement.

Krikalev said Russian flight controllers were assessing the situation and following temperature indicators on the Soyuz. “There have been no other changes in parameters on the Soyuz spacecraft and the station, so there is no threat for the crew,” he said.

The “equipment section of the capsule” is its service module, not its habitable orbital module or descent module.

Krikalev, the first Russian to fly on the space shuttle and occupy ISS, is a generally very reliable source. He is speculating, but not wildly but based on what is so far known. The upcoming inspection of the Soyuz using an ISS robot arm will soon tell us whether he is right or not. Krikalev also said that the inspection will tell them whether this capsule can be used to return its astronauts to Earth.

Leak search on ISS narrows further

Further work on ISS by the astronauts has now narrowed the location of the station’s long-term slow leak to the aft area of the Russian Zvezda module.

As of Monday, the station crew had not located the precise site of the leak, but officials believe they have traced it to a transfer compartment at the rear section of the Zvezda module, near an aft docking port where a Russian Progress resupply freighter is attached.

The rate of leak continues to be slow and thus not any danger to the crew. It is also a concern, as it could become a safety issue should it increase. They want to find it and patch it. Furthermore, Zvezda is ISS’s second oldest module, launched in 2000. If this leak is a sign of that age is even more essential to know.

Leak hunt continues on ISS

Two stories today indicate that the search for the elusive source of the slow leak on ISS is continuing.

The problem is that the two stories appear to have no overlap, making it hard to figure out what is planned and why.

The first story describes how engineers, based on the first isolation test, now think the leak must be coming from one of two modules:

…the ones the crew didn’t test because they were inside them while monitoring the rest of the station. One is the Zvezda Service Module, which provides life support for the station’s Russian side. The other is the Poisk Mini-Research Module 2, which serves as a port for docking spaceships and a place where crew members prepare for spacewalks.

The second story, from the Russian press, does not mention this detail. All it says is that the astronauts are going to once again isolate themselves in “the Russian segment” so the rest of the station can be tested for leaks. Since the two modules in question are both in that Russian segment, it is unclear where the astronauts will be isolated, especially since Zvezda is also where the Soyuz descent capsule is docked and if sealed from astronaut access it also seals them from their lifeboat.

It could be that the plan is to do another test of the American side of the station, then do these two Russian modules after the arrival of the next manned Dragon mission in a little less than a month. Dragon can then replace Soyuz as a lifeboat, allowing a test of Zvezda.

Regardless, the leak is a slow one, and is not yet life-threatening. That the leak rate has recently increased however requires action to find and fix it.

The rupture of a drum at a nuclear waste site in New Mexico has shut down a neutrino experiment.

The rupture of a drum at a nuclear waste site in New Mexico has shut down a neutrino experiment.

This article, from Nature, focuses on the harm done to the science experiment, which is considerable and very unfortunate. However, scroll to the end of the article to learn a little about the drum rupture, which has serious implications for the storage of nuclear waste anywhere.

SpaceX discovered a lot of water inside their Dragon capsule after splashdown.

SpaceX discovered a lot of water inside their Dragon capsule after splashdown.

This has got to be fixed. Though it does not appear that any cargo inside was damaged, this is the second time this has happened. More important, it suggests that the capsule integrity cannot yet be trusted in the vacuum of space. If water can seep in, it is just as possible for atmosphere to leak out.

Keep this in mind when you read reports about SpaceX’s unveiling of their manned version of this capsule on May 29. As much as I am supportive of this company, the worst thing anyone can do is be blind to problems such as this.

Astronauts today spotted an ammonia coolant leak in ISS’s left-side power truss.

Astronauts today spotted an ammonia coolant leak in ISS’s left-side power truss.

They are monitoring it, but have so far not made any decision about what to do about it, if anything.

This problem is a perfect illustration of why a flight to Mars is more complicated in terms of engineering than first appears. We might at this time be able to build that interplanetary spaceship (with the emphasis on the word “might”) but could its passengers maintain it millions of miles from Earth? Right now I’d say no. We need to learn how to build an easily repaired and self-sufficient spaceship. ISS is neither. It is also not a very good platform for testing this kind of engineering.

Update: The astronauts on ISS are preparing for a possible spacewalk on Saturday to deal with the problem. More details here.