On October 31, China launched the second module of its new space station into orbit atop a Long March 5b booster rocket. The Long March 5b, or Changzheng 5, is purpose-built to boost large payloads into space, similar to SpaceX’s Falcon Heavy, ESA’s Ariane 5 and ULA’s Delta IV Heavy rocket used by NASA. The Long March 5b heavy lift booster rocket. Credit: Xiaojun Wang, China Academy of Launch Vehicle Technology (CC by 4.0) In the days after launch, the space community keeps a close eye on the depleted rocket. Once it delivered its payload into space, the booster went into an uncontrolled dive back toward Earth. While it’s fairly standard practice for spent rockets to fall back to Earth (SpaceX’s Falcon 9 and Falcon Heavy being an exception), this case was different. The trajectory of the booster was quite familiar. Each time it circled the Earth, it swung from 40 degrees north latitude to 40 degrees south latitude. That’s about as far north as Lake Erie, and down just south of Australia, which covers a large area of the planet. The problem was that no one knew exactly where in that area the rocket would eventually land! The best the space community could do is monitor each orbit and slowly narrow down which orbits were most likely to crash. Our latest re-entry forecast for rocket body #CZ5B is:🚀04 Nov 2022 11:20 UTC ± 3 hours Re-entry will be along one of the ground tracks shown here. It is still too early to determine a substantial debris footprint. Follow here for updates: pic.twitter.com/GlnE8C0Iok Our latest prediction for The Aerospace Corporation on Twitter: “Our latest prediction for #CZ5B rocket body re-entry is:🚀04 Nov 2022 11:20 UTC ± 3 hours Re-entry will be along one of the runways terrain shown here. It is still too early to determine a significant debris footprint. Follow here for updates: pic.twitter.com/GlnE8C0Iok / Twitter” Missile body re-entry is:🚀04 Nov 2022 11:20 UTC ± 3 hours H re-entry will be along one of the ground tracks shown here. It is still too early to determine a substantial debris footprint. Follow here for updates: The Aerospace Corporation on Twitter: “Our latest forecast for #CZ5B rocket body re-entry is:🚀04 Nov 2022 11:20 UTC ± 3 hours Re-entry will be along one of the ground tracks that are shown here. It is still too early to determine a meaningful debris footprint. Follow here for updates: pic.twitter.com/GlnE8C0Iok / Twitter” The Aerospace Corporation on Twitter: “Our latest forecast for #CZ5B missile body reentry is: 🚀04 Nov 2022 11:20 UTC ± 3 hours Re-entry will be along one of the ground tracks shown here. It is still too early to determine a significant debris footprint. Follow here for updates: pic.twitter.com/GlnE8C0Iok / Twitter” — The Aerospace Corporation (@AerospaceCorp) The Aerospace Corporation on Twitter: “Our latest forecast for #CZ5B rocket body re-entry is:🚀04 Nov 2022 11:20 UTC ± 3 hours Re-entry will be along one of ground tracks shown here. It is still too early to determine a substantial debris footprint. Follow here for updates: pic.twitter.com/GlnE8C0Iok / Twitter” On Friday morning, the US Space Administration confirmed that the booster re-entered the atmosphere around 7am. EDT (4 a.m. MDT). It apparently crashed in the south central Pacific Ocean. They later confirmed a second re-entry associated with the missile, in the northeast Pacific Ocean. Rockets are made of mostly light materials, which then burn up on re-entry into the atmosphere. However, there are some parts that can survive to reach the surface. Given the uncertainties involved in this incident, we are all fortunate that the missile did not land in a residential area. Both NASA and ESA criticized China’s National Space Administration on Friday for what they said was irresponsible behavior. “This is the [People’s Republic of China]its fourth uncontrolled re-entry since May 2020, and each of those re-entries was the longest in the past 30 years,” NASA Administrator Bill Nelson said in an emailed statement Friday. their space activities and follow established best practices, especially, for the uncontrolled re-entry of large missile body debris — debris that could well result in major damage or loss of life.” The head of the European Space Agency, Josef Aschbacher, added his own statement on Twitter, saying: “Today’s uncontrolled reentry of Long March 5B highlights the growing risk to critical infrastructure both in space and on the ground posed by unsustainable spaceflight practices ». Many types of rockets have the ability to push themselves down out of orbit. So they can make a controlled re-entry and usually launch into the South Pacific Ocean, in an area known as the “space graveyard”. Long March 5b rockets do not have this capability. Once spent, they rely solely on gravity and the pull of the atmosphere to pull them out of orbit. This makes their re-entry much more unpredictable. (Image thumbnail courtesy of CASC/Storyful)
