公开(公告)号：US20080023587A1

公开(公告)日：2008-01-31

申请号：US11782407

申请日：2007-07-24

Applicant: James Head ,  Gregory Hoppa ,  Thomas Gardner ,  Karen Tsetsenekos ,  Stephen Dolfini ,  Tomas Svitek ,  Karleen Seybold

Inventor： James Head ,  Gregory Hoppa ,  Thomas Gardner ,  Karen Tsetsenekos ,  Stephen Dolfini ,  Tomas Svitek ,  Karleen Seybold

IPC: B64G1/10 ,  B64G1/24 ,  B64G1/40 ,  G01C21/00 ,  G05D1/00

CPC classification number: G01C21/24 ,  B64G1/10 ,  B64G1/62 ,  B64G2001/1071

Abstract: An autonomous unmanned space flight system and planetary lander executes a discrete landing sequence including performing an initial velocity braking maneuver to remove velocity at altitude, coasting during which the planet surface is imaged and correlated to reference maps to estimate cross-track and along-track navigation errors and one or more lateral braking maneuvers are performed to reduce cross-track navigation error, and performing a terminal velocity braking maneuver(s) to reduce the along-track braking maneuver and remove the remainder of the velocity just prior to landing. A bi-propellant propulsion system provides a very high T/M ratio, at least 15:1 per nozzle. Short, high T/M divert maneuvers provide the capability to remove cross-track navigation error efficiently up to the maximum resolution of the reference maps. Short, high T/M terminal velocity braking maneuver(s) provide the capability to remove along-track navigation error to a similar resolution and remove the remaining velocity in a very short time window, approximately 3-15 seconds prior to touchdown. The propulsive efficiency frees up mass which can be allocated to a fuel to remove the unknown navigation errors, perform hazard avoidance and/or relocate the lander by flying it to another site or be allocated to additional payload.

Abstract translation: 自主无人空中飞行系统和行星着陆器执行离散的着陆序列，包括执行初始速度制动操纵以去除高度上的速度，在行星表面成像期间惯性滑行，并将其与参考图相关，以估计交叉轨道和沿轨道导航 执行错误和一个或多个横向制动操纵以减少交叉轨道导航误差，以及执行终端速度制动操纵以减少沿轨道制动操纵并且在着陆之前移除其余速度。 双推进剂推进系统提供非常高的T / M比，每个喷嘴至少15：1。 短，高T / M转向机动能够有效地去除跨轨道导航错误，直到参考地图的最大分辨率。 短，高T / M终端速度制动机动能够将沿轨道导航误差移除到相似的分辨率，并在触地之前约3-15秒在非常短的时间窗内消除剩余速度。 推进效率释放了可以分配给燃料的质量，以消除未知的导航错误，通过将着陆器飞到另一个站点或分配给另外的有效载荷来执行危险回避和/或重新定位着陆器。