It took SpaceX years to successfully pull off the first vertical landing for its reusable Falcon 9 rocket. Since then, model rocket designers have attempted to recreate the feat—with Joe Barnard’s BPS.space accomplishing the milestone in 2022 after 7 years of work. The latest model to achieve a vertical landing, however, comes from a high schooler.
In a video uploaded to YouTube on July 5 under his company’s account, JRD Propulsion, Kapoor describes first setting out in August 2021 to design a model rocket capable of handling a propulsive landing. Three years of “development, testing, and many failures” later, it all reportedly came together on May 25 after four previous launch tries.
Unlike Barnard’s iteration, Aryan Kapoor’s rocket is also an original design instead of a scale replica of a SpaceX. As Hackaday notes, Kapoor’s model relies on a stack of two solid-propellant motors—one for liftoff and one for its descent and soft landing. One of the most striking aspects of Kapoor’s rocket is its overall design, which ditches stability fins for thrust-vector controls using a 3D-printed gimbal mount. The inclusion of two servo motors allows the stack to pivot plus and minus 7 degrees in two directions. All of this is then controlled through a custom computer array, inertial measurement unit, and barometric altimeter. In his video, Kapoor says creating the thousands of lines of software code proved to be “by far” the most complicated step during his multiyear trials and errors.
[Related: SpaceX’s Starship may mess up the moon’s surface.]
After a successful liftoff, the altimeter lets the rocket’s computer know when to eject the first propellant and switch over to the second motor for its controlled descent. To stick the landing, Kapoor attached much longer legs than a standard model—with some creative adaptations. Each leg is rigged with a repurposed syringe and rubber bands that serve as shock absorbers, enabling the rocket to further dampen its landing.
Interestingly, Kapoor’s rocket nailed its first successful landing even in spite of some internal issues. During its ascent, the system failed to eject its first spent propellant stack, which added unintended extra weight during the controlled descent. This caused the model’s springy legs to bounce it slightly back upward after first touching down, technically meaning it landed upright not once—but twice.
