Augmentation Options for Enhanced Landing Success

courtesy of NASA

There are several options for augmenting the descent and landing phases in order increase the safety margin, including:

• a three-lobe radar altimeter

• a man-in-the-loop

• an onboard vision-based navigation system experiment.

The 'man-in-the-loop' option of introducing manual/computer- assisted ground support and intervention into the navigation loop, based on visual information from onboard wide-angle camera(s), is particularly interesting as it would allow:

• navigation based on visual identification of lunar surface features (landmark recognition), during the Lander's descent

• precise obstacle avoidance during the landing (hovering).

Timewise, ground intervention during the navigation process certainly seems possible, given that closure of the navigation loop (based on visual landmark recognition) would take only 5-10 seconds.

All image processing would be carried out on the ground, providing an excellent opportunity for the public to share in the high drama of the actual landing. A hovering phase, lasting about 2 minutes, might also be envisaged during the descent from 100 m to touchdown, to further facilitate obstacle avoidance.

The possibility of including a 'hopping' capability is also being considered as a fuel-efficient means of changing the landing spot should a hazard be found at the original target site.