Russian astronauts locate coolant leak on spacewalk

Coolant leak on Nauka radiator

In an almost eight hour spacewalk yesterday, two Russian astronauts were able to locate the source of the coolant leak on a radiator unit connected to the new Nauka module on the Russian half of ISS.

The image to the right, a screen capture from the live stream, shows the leak location, where a small white droplet sits on one of the coolant lines that connect two radiator panels. You can also see darkening on the tubes to either side, likely also caused by the leaking ammonia. To locate it ground controllers opened valves to let coolant into the line while the astronauts watched for changes, and were able to see the coolant come out of this spot.

One astronaut also noted the following during the inspection:

[B]efore noticing the growing deposit of liquid coolant, Kononenko reported seeing a myriad of small holes on the surface of the radiator’s panels. “The holes have very even edges, like they’ve been drilled through,” Kononenko radioed to the flight controllers working in Moscow Mission Control. “There are lots of them. They are spread in a chaotic manner.”

In the past year similar coolant leaks have occurred on both a Progress freighter and a Soyuz manned capsule, with the leak location in almost the exact same spot, suggesting an intentional cause, not a random micrometeorite hit. This coolant leak in Nauka is on equipment that was launched to ISS in 2010. If it was also drilled, whoever did it did so a long time ago, which implies Russia has a long standing saboteur within its operations.

This conclusion however remains wild speculation. In the dozen-plus years since launch, this radiator has been stored on the outside of ISS, where it could easily have been hit by micrometeorites that would cause those holes and this leak.

The plan is to consider some repair operation on future spacewalks. In the 1980s the Russians did something similar, with astronauts doing six spacewalks to replace a section of fuel line that was leaking on its Salyut-7 station. They cut open its hull and installed a second section of line so that the valves could remove leaking section from operations.

Frank Rubio’s flight to ISS will exceed a year, setting a new American record

Frank Rubio
Frank Rubio

Initially, Frank Rubio’s first flight in space was intended to be a standard six month mission on ISS. Launched on September 21, 2022 on a Soyuz-2 rocket inside a Soyuz capsule, the plan was for him and his two crewmates to return in March, 2023.

Then their Soyuz capsule developed a leak in its coolant system in December 2022. Not knowing if it was safe to use this capsule with humans inside, a replacement unmanned Soyuz capsule was launched by the Russians to ISS in February 2023, with the leaking Soyuz capsule brought back unmanned earlier this week.

The Russians however decided that this new capsule, designed for a six month mission, would stay in orbit for six months, so that it would be used to its planned capability. This decision also hinged on the lack of a new crew arriving on this new capsule. If it brought Rubio and his crew home earlier, ISS would be short three crew members for at least several months.

The planned return date, September 27, 2023, now means that Rubio’s mission will be at least 371 days long, making him the first American to fly a full year in space. Previously NASA falsely touted Scott Kelly’s 340-day mission as a year-long mission, when it never was. Later, Mark Vande Hei’s mission, also launched on a Soyuz, was extended to 355 days, still just short of a year, because the Russians wanted to send a film crew to ISS and return them on the capsule which Vande Hei was intended to come home on.

Whether Rubio truly does spend a year in space however remains uncertain. Two different Russian spacecraft — the Soyuz and a Progress freighter — have developed this coolant leak in the past three months. If this problem is a systemic manufacturing error, which Russia is now investigating, the decision might be to return the new capsule sooner than planned, out of fear it will develop its own leak. We shall likely find out sometime in the next three months.

If Rubio does end up in space for a full year, however, it will likely be a dream come true, having become an astronaut in 2017 but waiting six years for his first flight.

Russia considering bringing Soyuz launched on February 23rd home earlier

According to unnamed sources in the Russian press, Roscosmos officials are considering bringing the Soyuz capsule launched on February 23rd to ISS back to Earth in June rather than September, while moving up the launch of the next Soyuz manned mission.

As noted by space journalist Anatoly Zak:

The existence of such plans indicated that specialists had still been concerned about the possibility of a critical leak in the thermal control system of the fresh crew vehicle similar to those that hit two previous transport ships. Such change in schedule would also debunk the official explanation of previous two accidents by Roskosmos and NASA as caused by meteors rather than production defects.

The two previous coolant leaks occurred about three months after launch. Bringing the Soyuz home in June would get it home in about three and a half months, suggesting the Russians are no longer confident their Soyuz and Progress spacecraft can withstand six months in space.

If this plan is adopted it will also put less strain on the crew slated to come home on that Soyuz. Their mission has been planned for six months. Extending it to a full year without any prior preparation risks serious health issues.

First picture of hole that occurred on Soyuz in December

Hole in First picture of hole that occurred on Soyuz in December

Russia has now released an image taken using the robot arm on ISS of the leak that occurred on its Soyuz capsule docked to ISS in December.

The picture to the right, cropped and reduced to post here, is that image. This is not the coolant leak hole on the Progress freighter on February 11th, this past weekend. As of now no image of that hole has ever been released.

No interpretation of this hole and the stain around it has as yet been released. However, Russia has now postponed the launch of the next Soyuz capsule from February 19th until early March in order “to give investigators time to rule out similar issues in the upcoming mission.” This Soyuz was to launch unmanned to replace the Soyuz that leaked in December and provide the astronauts that launched on that leaking Soyuz a safe lifeboat that they could come home on.

Meanwhile, all communications with ISS have now been shifted to the private channels, so the public cannot hear them.

All these actions strongly suggest that both the Russians and Americans are now seriously considering the possibility of sabotage or damage to the coolant systems on all Russian spacecraft, before they leave the factory and are launched.

ISS as of February 11, 2023

To clarify the situation, the image to the right shows all the spacecraft presently docked to ISS. Progress 82 is the spacecraft that experienced a leak in its coolant system on February 11th. Soyuz-MS22 experienced a leak in its coolant system in December. At the moment the only safe vehicle for returning the seven astronauts on ISS is Crew-5 Dragon, SpaceX’s Endurance spacecraft. Should a major catastrophe occur requiring an immediate evacuation of the station, the plan right now is for five astronauts to come home on Endurance, and two Russians to come home on the damaged Soyuz. (The thinking is that having only two men on board will prevent too much of a temperature rise during the return to Earth because of the lack of its coolant system.)

With the delay in the launch of the replacement Soyuz lifeboat, this emergency plan will be in place for at least three weeks longer.

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.

A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

Construction workers in space: A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

A slight 1.5-pound-per-year leak in the channel 2B cooling system has been present since 2007 and during a shuttle visit last year, two spacewalking astronauts added eight pounds of ammonia to the reservoir to boost it back up to a full 55 pounds. The plan at that time was to top off the system every four years or so to “feed the leak,” replacing the lost ammonia as required.

But over the past few months, engineers saw the leak rate suddenly quadruple, either because something changed at the original leak site or, more likely, because another leak developed somewhere else in the system.

Whether the leakage was caused by space debris or a component failure of some sort is not yet known. But the result is: If the leak continues at its current rate, the coolant will drop below a 40-pound safety limit and the system will shut down by the end of the year or shortly thereafter, taking power channel 2B down with it. While the space station can operate without the full complement of power channels, the loss of channel 2B would force flight controllers to power down equipment, eliminating redundancy and reducing the amount of research the crews could carry out.