The “egg drop experiment” is a staple of school physics classes that explains concepts such as gravity and impact resistance. Mark Rober (@markrober) Rober decided to take the experiment to the next level by dropping an egg from space. After three years of working on the ambitious project, Rober shared his journey in a video he posted in November 2022. The video has since gone viral, garnering over 106 million views.
Mark Robar, a former NASA engineer turned YouTuber with over 55 million subscribers, has worked with NASA’s Jet Propulsion Laboratory and Apple, and set out to create a device that would allow a raw egg to be dropped from as high as possible without cracking. He documented this ambitious experiment in his video “Eggs falling from space.”
His first idea was to drop an egg from the world’s tallest building, the Burj Khalifa in Dubai. “So my original plan was to drop an egg from the tallest building in the world with a device I made myself,” but then he realized that as humans continue to build taller buildings, he would need to go into space where the egg would fall faster than the speed of sound. Initially, he didn’t realize that this would be the most physically, financially and mentally exhausting video he’d ever attempted.
He detailed the plan: “The plan was to strap an egg to the tip of a rocket, attach the rocket to a weather balloon and carry it into space. Once in space, the weather balloon would release the egg, the rocket would accelerate under gravity alone until it exceeded the speed of sound, then autonomously adjust the four fins on its back to navigate to the target location, release the egg when it was 300 feet above the ground, and it would free fall onto a mattress on the ground. So far, it all seemed pretty simple.”
Working with a team of engineers, they broke the task down into small steps, starting with calculating the terminal velocity of the egg. Terminal velocity (TV) is: Science Directis “the constant speed reached by a falling object when gravity equals the drag and buoyancy forces acting on the object and the object falls uniformly at that speed.” Mark reveals that for humans, this value is about 120 miles per hour. He does the calculations and determines that for an egg, the TV would be 75 miles per hour.
They did the first test with a mattress to test if the egg would not crack at terminal velocity. The egg did not crack, he exclaimed excitedly. He then visited the town of Gridley, California, where he planned to set up a target mattress so that the egg would land in the middle of a field. The egg rocket to be launched had several complex mechanisms embedded in it. One was a “heated oven” that would freeze the egg and protect it from cracking during flight. Then there was the mechanism to release the egg and a GPS tracker attached to the back of the rocket. Everything was ready to drop the egg from the highest point. They had the world’s largest mattress and the eggs they had retrieved from the Gridley enclosure.
They began with a drill called a “flight characteristics test,” testing the rocket’s fins at a low altitude of 10,000 feet. Pre-launch preparations began early the next day at the launch site. To speed up the egg’s flight, they made a last-minute decision to add metal streamers to the back of the rocket to make it easier to follow with the eye. They also released helium from a weather balloon.
With dramatic music playing in the background, the footage showed the balloon rising into the air, and they tracked its movement on a computer. Suddenly, mid-flight, Finn sent the rocket into an uncontrollable death spiral, and the egg fell at high speed from 1,400 feet. “Check the mattress,” one of the men said. They followed the mattress and headed over to check on the egg. Sadly, it had cracked.
Undaunted, Mark sought advice from his friend Adam Steltzner, a Caltech PhD and lead engineer for NASA’s Perseverance spacecraft. Steltzner did indeed spot the error in the line of code and fixed it. “We still went to space with a weather balloon, but this time we put stationary fins on the rocket and tripled the length and quadrupled the weight to ensure we could get the egg down at supersonic speeds,” Mark said in the video.
He continued to explain, “Similar to how NASA separates their crew stage in the upper atmosphere and uses arrow braking to dissipate a lot of energy and velocity, we will separate the back half of the rocket after we break the sound barrier, about halfway down. Now that it’s significantly lighter, it will naturally error brake and slow down to a new, lower terminal velocity.”
Once again, they launched the egg rocket upward in a final attempt. Within two hours of launch, a twisted cord became tangled in the mechanism meant to lower the balloon. The entire shuttle began hurtling through space at 150 miles per hour. Luckily, the egg popped out of the balloon and landed on a mattress. Mark stepped forward and scooped up the egg, still intact. His experiment was a success.
