The Unreported Abnormalities of the ISS and a Surge in Serious Incidents

In August, a malfunction occurred in Boeing’s new spacecraft, Starliner, and two crew members are still stranded on the ISS (International Space Station), which was widely reported. In fact, the ISS, which has been under construction for 27 years, has frequently experienced a number of serious incidents (situations leading to accidents).

In April of this year, 1.7 kg of air per day leaked inside the ISS at four times the normal rate, and as of September the leakage had been reduced to one-third, but the ISS risk level has been raised to Level 5, the highest level. This has been a regular occurrence since 1919, and no clear solution has been found yet,” said NASA’s Office of the Inspector General.

Most of the ISS troubles are on the Russian side.

The ISS, which consists of multiple modules (components), is roughly divided into an American compartment at the nose and a Russian compartment at the rear. However, the cracks are minute and the exact location has not been identified.

In fact, most of the ISS’s troubles occur on the Russian segment. And they are not only occurring on aging, but also on newly-built spacecraft. The most critical accident occurred in July 2009. Russia launched the new multi-purpose module “Nauka” and docked it to the ISS, but three hours later, Nauka’s thrusters (attitude control system) suddenly activated. The abnormal thrusts could not be stopped by remote control from the ground station, and the ISS began to rotate, raising its nose as if in a backflip,” said a Science magazine editor.

In response to this unprecedented situation, NASA declared a state of emergency. The rotation finally came to a halt when NAUKA ran out of fuel. It did not deviate far from its orbit. The rotational motion was caused by the fact that Nauka’s connection port was off the ISS’s center of gravity, but if it had docked at a port closer to the center of gravity, the ISS hull would have been dragged down toward the Earth for a long time.

The rotation caused the direction of the communication antenna to shift, and communication with the ground was disrupted twice during this emergency. If the rotation had continued for a long time, the sun would not shine on the solar panels, and the system might have stopped due to power loss. Also, even in zero-gravity, the aircraft would be subjected to G-forces as it rotated, and the high rate of rotation could have ruptured vulnerable parts of the system.

In the event of an emergency, the crew would board the spacecraft and stand by for immediate return to Earth, but it would be impossible to undock the spacecraft while the ISS itself was spinning.

This situation is clearly the biggest incident on the ISS in history, but it was hardly reported on TV or in newspapers.

The U.S. does not want China to gain hegemony over the ISS.

Troubles caused by Russian equipment have continued to occur frequently since then. In December 2010, a coolant leak from the Soyuz MS-22 spacecraft docked to the ISS resulted in the aircraft being returned to Earth unmanned, and the crew returned in the MS-23, which followed.

Two months later, in February 2011, coolant also leaked from the Progress “MS-21,” an unmanned resupply vehicle. Furthermore, in October of the same year, a similar leak occurred in Nauka. Why, then, do they continue to operate the ISS in its aging and dangerous state?

Russia, which has been subject to economic sanctions from various countries since its invasion of Crimea in 2002 and the outbreak of the war in Ukraine, has been unable to secure sufficient funds to maintain the ISS. Therefore, Russia hopes to scrap the ISS as soon as possible. The ISS was originally scheduled to be in operation until 2003, but the U.S. has been pushing it back to 20, 24, and 30 years.

Four commercial space station replacements for the ISS are currently being developed and manufactured, but their schedules have been delayed as well. If the ISS is scrapped without a replacement being put into orbit, the Chinese space station will be the only one in Earth orbit. For the U.S., which wants to maintain its space supremacy, it is necessary to avoid such a situation.

However, Russia is not confident about the future operation of the ISS, and has only pledged to cooperate until the year 2008. Therefore, if further problems arise in the future, the hatch leading to the Russian module may be closed, and the Russian compartment may be operated in a dead space. If this happens, the U.S. would ultimately be on its own to drop the ISS into the Pacific Ocean.

The total mass of the ISS is 450 tons. It is quite huge, about the same size as a soccer court (108.5m wide). At present, it is scheduled to be dropped into the Pacific Ocean in ’31, but anxiety has not been dispelled at all.

Most of the ISS will burn up in the atmosphere, but some of its hard parts such as iron and titanium (so-called “space debris”) will not burn up and fall to the surface. For this reason, the ISS is planned to be dropped into “Point Nemo” (Latin for “uninhabited”), an area of the South Pacific Ocean that is the farthest from any land.

All of the components that fell into the habitable zone were separated from the orbit similar to that of the ISS.

The ISS travels at an altitude of 410 km from the surface of the Earth at an orbit of about 7.7 km per second. Dropping the ISS into the restricted waters of Point Nemo requires extremely sophisticated control technology: over a period of three years, the orbital altitude is gradually lowered and the accuracy of the drop is improved, but if the timing of the drop is off even slightly, metal parts could fall on the habitation site.

Everyone thinks that with NASA’s technology, the possibility of debris falling to the habitat should be low, but accidents in which debris falls to the ground have occurred frequently even in recent years. In other words, it continues to be possible for debris to fall anywhere.

In March ’24, a 2.6-ton used battery pack dumped into orbit from the ISS failed to burn up in the atmosphere, and part of it crashed through the roof of a house in Florida. No casualties were reported, but NASA is responding to claims for compensation at this time.

Also in ’22, on a farm in Australia, and in May ’24, on a farm in Canada. The following month, parts of SpaceX’s Crew Dragon spacecraft also fell in the mountains of North Carolina, USA. All of them were separated from the airframe that was going to and from the ISS, i.e., the airframe that was traveling on an orbit (inclination angle) similar to that of the ISS.

It will be six and a half years until the moment when the ISS is brought down to Earth, but until then, the ISS will remain above our heads as a “crisis in the present.