Real-time position estimation for a descent lander is a critical technological need for many planned NASA missions. In particular, it enables the ability to land precisely and safely in a scientifically promising but hazardous site and is a key technology to be demonstrated by NASA in the next decade. The primary question of pinpoint landing is how to localize the lander by recognizing landmark...

Ideally, when a pilot approaches a runway on their final approach for landing, they must maintain a constant trajectory, or glideslope, of typically 3°-4°. If pilots misperceive their glideslope and alter their flight path accordingly, they are likely to overshoot or undershoot their desired touch down point on the runway. This experiment examined the accuracy of passive glideslope perceptions ...

Introduction: Combined lander-rover modeling is the transformational means for developing high resolution, color, three-dimensional representations of planetary features such as cave entrances and skylights. Lander-rover modeling combines registered overflight imagery with rover-based surface imaging techniques to build highly accurate co-registered models. The models produced by this approach ...

Many recent studies on autonomous spacecraft landing use computer vision methods to improve the accuracy of the state estimates used for landing. Typically, these studies integrate the vision module with other exteroceptive sensors such as laser or radar altimeters. This is a sensible approach for the main landing system of a large spacecraft. However, for a backup emergency system or for much ...

Internal tibial rotation with the knee close to full extension combined with valgus collapse during drop landing generally results in non-contact anterior cruciate ligament (ACL) injury. The purpose of this study was to investigate the relationship between internal rotation of the knee and muscle activity from internal and external rotator muscles, and between the internal rotation of knee and ...

Military static-line parachuting is a highly tactical and hazardous activity, with a well-documented injury risk. Due to the high impact forces and rapid rate of loading when a parachutist lands, injuries most frequently occur to the lower limbs and the trunk/spine, with ankle injuries accounting for between 30 and 60 % of all parachuting injuries. Although military static-line parachuting inju...

Human running at low and intermediate speeds is characterized by a greater average force exerted after 'landing', when muscle-tendon units are stretched ('hard landing'), and a lower average force exerted before 'takeoff', when muscle-tendon units shorten ('soft takeoff'). This landing-takeoff asymmetry is consistent with the force-velocity relation of the 'motor' (i.e. with the basic property ...

CONTEXT Control of the trunk segment in landing has been implicated as a contributing factor to the higher incidence of anterior cruciate ligament injuries in females than in males. Investigating the sex-specific abdominal activation strategies during landing lends insight into mechanisms contributing to control of the trunk segment. OBJECTIVE To examine the abdominal activation strategies us...