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Beirut Blast Ranks Among History’s Most Powerful Accidental Explosions

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One of 16 videos of the Beirut blast used in the new study.
Gif: Borzou Daragahi/Twitter/Gizmodo

By analyzing videos uploaded to social media, scientists have calculated the strength of the blast that devastated the city of Beirut in August, finding it to be among the biggest non-nuclear explosions in human history.

When a warehouse at the Port of Beirut in Lebanon exploded this past summer, it released the equivalent of 500 tons of TNT and possibly as much as 1.12 kilotons of TNT, according to new research published in the scientific journal Shock Waves. That’s somewhere between 3% and 7% of the yield produced by the atomic bomb detonated at Hiroshima, which packed a blast yield equal to 15 kilotons of TNT. Accordingly, the explosion in Beirut now ranks among the 10 biggest accidental non-nuclear explosions of all time.

Around 2,750 tons of ammonium nitrate stored at Beirut’s port exploded on August 4, 2020, resulting in 200 deaths and over 6,000 injuries. The resulting shockwave damaged buildings and homes across a wide swath, leaving nearly 300,000 people homeless.

To calculate the explosive yield, a team led by Sam Rigby from the Blast and Impact Engineering Research Group at the University of Sheffield tracked the speed of the blast as it tore through the city. They did so by analyzing over a dozen videos uploaded to social media, all of which captured a reasonably clear view of the blast and visible landmarks.

A preliminary study from the same team estimated the blast yield at somewhere between 1.0 and 1.5 kilotons TNT, but that was based on a limited set of videos. The new study is more comprehensive, as it includes 16 high-quality videos that met the team’s criteria, namely a direct line-of-sight view of

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After lengthy delays, ULA’s most powerful rocket poised to launch classified spy satellite

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After many weeks of delays due to faulty equipment and bad weather, the United Launch Alliance is set to launch its most powerful rocket from Cape Canaveral, Florida, lofting a classified spy satellite for the National Reconnaissance Office. The mission is finally ready to fly a full month after the rocket’s first launch attempt, which was aborted just three seconds before liftoff.

The rocket going up on ULA’s mission is the Delta IV Heavy, a giant vehicle that consists of three rocket cores strapped together to provide extra thrust. It’s one of the most powerful rockets in the world, though it falls short of the power packed into SpaceX’s Falcon Heavy. ULA doesn’t fly the Delta IV Heavy very often, as it’s an expensive vehicle to make, but the company uses the rocket for large, heavy satellites headed to super-high orbits.

The rocket’s payload is NROL-44, and like all NRO missions, its purpose is cloaked in secrecy. The office simply notes that “NROL-44 supports NRO’s overall national security mission to provide intelligence data to the United States’ senior policymakers, the Intelligence Community and Department of Defense.” ULA has already launched 29 missions for the NRO, many of which have required the Delta IV Heavy.

ULA was all set to launch NROL-44 in the wee hours of the morning on August 29th. ULA counted all the way down to just seconds before liftoff, with the Delta IV Heavy’s main engines briefly igniting. But the engines quickly shut off and the rocket remained fixed on the launchpad. ULA later learned a piece of ground equipment had failed, prompting the abort. It took the company a few weeks to replace the faulty equipment.

Further problems with equipment on the launchpad pushed back the launch time again, but ULA is hoping to get off