Model analysis of the Skull

New Delhi: ISRO is approaching its human spaceflight programme in a more humane manner than other space programmes, by using a humanoid half-robot called Vyommitra to evaluate the safety of the Gaganyaan crew module before astronauts are launched into Earth Orbit using hardware primarily manufactured in India. Other space agencies used dogs and chimpanzees for the same purpose. Vyommitra is a robot resembling the top-half of a human, and can operate the Gaganyaan crew module, and respond to spoken commands from Earth.

For the demanding space applications, ISRO scientists opted for additive manufacturing or 3D printing using metals for realising the skull of Vyommitra. Vyommitra will be sent to Earth orbit in Gaganyaan hardware on an uncrewed flight, and is a precursor to future robotic space missions. The researchers designed the skull using Blender, an open source software, replicating the size and shape of a human head. The skull was designed to accommodate the face actuation mechanisms, keep the weight as low as possible, and strong enough to survive the rickety ride to Earth orbit.

Lattice Structure For Strength

The skull incorporates a lattice structure that allows for the required strength and rigidity to withstand the vibrations experienced during launch, while minimising weight as much as possible. The researchers used the Altair Inspire and Abaqus software for precisely designing the skull. Stress analysis was conducted on the structure as it was iteratively improved. Finally, the skull was 3D printed over the course of 50 hours. The 3D printed structure was sandblasted to obtain a better finish, and a 3-axis milling machine was used for finish machining of the skull, and remove stock material that was printed.

In all, the 3D printing approach allowed for the reduction of 20 per cent of the skull. A paper describing the process has been published in the Journal of The Institution of Engineers (India): Series C.

(ISRO, With Inputs From Agencies)