Why in News?

A 500 kg fragment of the Soviet Kosmos 482 spacecraft, launched on March 31, 1972, is expected to crashed in Indian Ocean, west of Jakarta.

Originally intended to land on Venus, the mission failed, and while most parts re-entered Earth within a decade, this particular piece remained in orbit. Till the very end, experts could not determine the exact time or location of its re-entry.

What’s in Today’s Article?

• Kosmos 482 Mission
• Kosmos 482: Mission Failure Explained
• Kosmos 482's Uncontrolled Re-entry
• Frequency of Space Debris Re-entry

Kosmos 482 Mission

• Kosmos 482 was part of the Soviet Union's Cold War-era effort to explore Venus and showcase scientific dominance.
• The mission aimed to study Venus’s surface and atmosphere.
• Background
  • Launched under the Venera Program (1961–1984), the Soviet Union sent 28 spacecraft to Venus.
  • Of these, 13 entered the atmosphere and 10 landed successfully, but extreme conditions limited their survival to 23 minutes–2 hours.
• Mission Details
  • Kosmos 482 lifted off on March 31, 1972, just days after its twin mission, Venera 8, which landed on Venus 117 days later.
  • Kosmos 482 carried instruments to measure temperature, pressure, wind speed, visibility, atmospheric gases, and rock composition, and was designed to transmit data back to Earth.
• Outcome
  • The mission failed to leave Earth orbit due to a malfunction, preventing it from reaching Venus.

Kosmos 482: Mission Failure Explained

• Cause of Malfunction
  • A critical error occurred shortly after launch when the upper rocket stage shut off prematurely due to an incorrectly set timer.
  • This stage was responsible for propelling the spacecraft out of Earth’s orbit.
• Immediate Consequence
  • The spacecraft failed to escape Earth’s orbit and became stranded. The lander module separated from the main body of the spacecraft as a result.
  • The main spacecraft, being large and heavy, eventually burned up upon re-entering Earth's atmosphere.
  • The smaller lander module remained in orbit for decades.
• Current Status
  • The lander module is now gradually being pulled toward Earth by atmospheric drag.

Kosmos 482's Uncontrolled Re-entry

• The lander module's return to Earth was uncontrolled.
• After 53 years in space, it lacked systems like aerobraking, parachutes, or internal cooling, making it reliant solely on atmospheric friction to slow down.
• Material and Speed Concerns
  • The module was made of titanium, which melts at around 1,700°C—hotter than typical re-entry temperatures (~1,600°C).
  • Therefore, it was unlikely to burn up completely and may survive re-entry.
  • It was traveling at over 17,000 miles per hour.
• Potential Impact Zone
  • Its orbit covers a wide area between 52°N and 52°S latitudes, including regions in Africa, Australia, the Americas, and large parts of Europe and Asia.

Frequency of Space Debris Re-entry

• The crash of Kosmos 482 is not unusual.
• According to the European Space Agency, over 2,400 man-made objects re-entered Earth’s atmosphere in 2022 alone—a record high.
• Most of these objects either burned up or landed in the ocean.
• Why Scientists Are Not Alarmed
  • Because such re-entries are common and typically harmless, scientists were not particularly concerned about Kosmos 482’s lander module crashing.
• Human Risk Remains Extremely Low
  • There has been no recorded human fatality due to space debris.
  • ESA states that the annual risk of an individual being injured by falling space debris is less than 1 in 100 billion.
  • In contrast, a person is 65,000 times more likely to be struck by lightning.