The structural stiffness of the both the main and top decks were improved multi-fold while using ~85 times less the material. The main deck was made larger allowing us to reduce the inclination of the legs with respect to the deck. This means more of the impact forces can be absorbed along the length by the honeycomb crush in the landing gear.

This is what the spacecraft looked like after these changes.

The spacecraft with crushable honeycomb landing gear and honeycomb structure decks.

This spacecraft design won us the GLXP milestone prize of $1 million to demonstrate our landing capabilities on the Moon.

The structure of the spacecraft plays an important role during the launch too. A lightweight and efficient design of the spacecraft allows for more payloads to be carried to the moon. Apart from the above changes, further refinements have been made that make the spacecraft lighter. Carbon fiber replaced aluminum strut in more places like the solar panel & thruster holders.

The Landing

The design progress doesn’t stop there. Landing on the moon is a tricky business as it is difficult to predict the type of terrain the spacecraft might land on.

The spacecraft might land on an uneven surface or an inclined plain. The landing gear footpad thus needs to adjust to the terrain below it. This is why our spacecraft had footpads which can change their orientation depending on angle it hits the surface.

Landing gear footpad can change angle based on the terrain below it.

The flat footpad structure has since been changed to a semi-spherical one and is allowed to move along all axes. The footpads were made lighter by substituting aluminum for carbon fiber.

Upon landing, the spacecraft will have both vertical and horizontal velocities. While the impact due to vertical velocity has been taken care of by our design, some horizontal velocity still remains, the forces of which need to be absorbed. If it is not absorbed, the orientation of the spacecraft cannot be assured to be sun-facing for the solar panels to function.

The solution? Make the secondary legs of the landing gear use honeycomb crush too. This will absorb the forces along the horizontal velocity component and prevent the spacecraft from pivoting post-touchdown.

Our final landing gear with a crushable honeycomb structure in both the primary and secondary legs to absorb maximum impact forces during the landing.

Conclusion

Our lander is thus capable of landing safely on a wide variety of terrains at the lunar landing site thanks to an incredible landing gear configuration. The structure of the spacecraft thus ensures the safety of the subsystems and the payloads during the landing.