As everyday citizens of Earth, we’ve grown accustomed to hearing about new satellites launched into orbit.
Currently, several large corporations are engaged in a space race of sorts – trying to see who can launch the most satellites over the next decade. There are also plans to launch tens of thousands of them within that time frame.
However, we don’t seem to hear much about the retrieval of such satellites back to Earth. That’s because when they’ve completed their mission, most of them are left there. And it’s becoming a problem.
Space debris build-up
Depending on who you ask, it is estimated that more than one million objects are currently floating in Earth’s orbit – this includes satellites and various debris that got caught in Earth’s gravitation field.
While the majority of these objects are harmless, there are still some 20,000 or more that pose a threat to future space travel and the well-being of life on Earth.
Five dangerous objects that are a threat to Earth
The objects on this list have either died from malfunction or completed their respective missions, and they now present a serious threat to our planet. Let us examine them more closely.
The satellite Kosmos 1900 was initially launched in 1987 by the Soviet Union. It is referred to as a Controlled Active Satellite and was used originally for RORSAT (Radar Ocean Reconnaissance Satellite) missions. Right from the start, this satellite was hampered by several problems, and it even failed to reach its intended cruising orbit as designed.
A number of rocket boosts were attempted to correct its orbit, but to no avail, as the satellite proceeded to lose altitude. Even worse was the fact that its nuclear reactor didn’t reach its storage orbit.
Sometime before 1995, NASA surmised that a liquid radioactive cloud of material was emitted from the Kosmos 1900 satellite. NASA believed that a collision with another satellite likely caused the leak.
The Chinese government launched Tiangong-1 as a prototype space station in 2011. It was initially targeted for a two-year mission of testing space travel effects on astronauts and docking capabilities of various spacecraft.
While the mission got extended beyond its original end date, it had to be abandoned because operators and technicians in China could no longer maintain control of the space station. The most disturbing aspect of this failure is that the station weighs around 19,000 lbs.
Although it was reported that most of the space station had been incinerated in the atmosphere over the Pacific Ocean during reentry in April 2018, it is believed that its rocket engines were constructed of materials that wouldn’t burn up. Many experts fear that the intact pieces that remain from the station could cause enormous damage to Earth.
The United States launched the SNAP 10-A satellite into orbit from Vandenberg Air Force Base in 1965. As it stands, SNAP 10-A is the sole nuclear fission satellite that the United States has ever launched.
This satellite was created as an experimental nuclear spacecraft that could produce some 500 watts of electricity. Its primary objective was to observe how a nuclear fission reactor would operate and behave in space.
But its nuclear reactor only lasted 43 days, as the voltage regulator of its power supply malfunctioned. During the 1970s, the satellite began coming apart, which created around 50 pieces of debris.
Scientists fear that radioactive material was released into the atmosphere when the satellite began shredding. Currently, this nuclear reactor is orbiting Earth at an altitude of 700 nautical miles. It will continue its orbit for the next 4,000 years or so unless more random breakage occurs or it collides with another object.
As it turns out, the United States wasn’t the only one who believed launching nuclear reactors into orbit was a good idea. In 1987, the Soviet Union did the same thing when they launched Kosmos 1818, powered by a nuclear reactor known as TOPAZ 1.
Kosmos 1818’s objective was for naval surveillance. Unfortunately, its nuclear reactor operated for a mere five months before it shut down.
Since a 1978 incident when a similar satellite crashed into Earth and spread radioactive materials over Canada, the Kosmos 1818 was designed for a high orbit to prevent this from happening again. The only problem with this approach is that higher orbits also increases the probability of collisions.
As would be expected, the potential for a collision increases the likelihood of radioactive contamination on Earth.
In 2002, the European Space Agency (ESA) launched a large satellite called Envisat to monitor Earth’s geography and environment. Even though it operated some five years beyond its end date, ESA lost contact with the satellite in 2012.
Envisat now represents the greatest Kessler syndrome threat in Earth’s orbit. Astronomer Donald Kessler postulated in 1978 that a high density of objects in Earth’s lower orbit could create collisional cascading.
Considering Envisat’s mass of approximately 18,000 lb, any crash it would experience could be catastrophic and result in a massive debris field that would be virtually impossible to clean. Envisat’s wreckage would be so enormous that this potential chain reaction of collisions is a real danger to Earth.
It is expected that the satellite will remain in orbit for about 150 years before it crashes to Earth – thus significantly increasing the likelihood of a severe accident. However, it is encouraging that alternatives are being examined on how to remove Envisat from orbit.