Introduction

The inventions can be successfully employed to support space missions for removing and de-orbiting debris such as failed spacecrafts or fragments . They are useful to estimate two fundamental parameters for planning rendezvous and  berthing maneuvers: location of the center of mass and angular rate. The estimation is just achieved by processing images taken from cameras placed on a chaser spacecraft

Technical features

A huge number of artificial satellites are nowadays orbiting at low altitudes (400-700 km) from the Earth’s surface . At the end of their life, or in  case of  failures, they become uncontrolled  and they clutter  orbits which are important from a commercial and scientific  point of view. Active spacecrafts and space stations are likely to collide with these objects, causing  fragmentation and then an increment in the number of  debris in low-Earth orbits. ESA e NASA are aware of the problem and in the last few years they organized conferences and projects to face it A possible solution consists in capturing  debris with chaser  spacecrafts with the idea of de-orbiting or, if it is the case, repairing them. Such a maneuver requires however the accurate knowledge of several parameters of the target such as center of mass location and angular rate. The proposed solution is able to measure  these data uniquely from the observation of the debris, without requiring any form of contacts. Such pools of systems, which are covered by 3 different patents, allow estimating the data exploiting passive sensors (cameras).

Possible Applications

• On-orbit repairing of failed or uncontrolled spacecrafts;
• On-flight refueling;
• Active space debris removal and de-orbiting.

Advantages

• Versatility: ease of use on-board of any kind of chaser spacecraft;
• Inferior cost and weight , but comparable accuracy of passive sensors with respect to active ones;
• Robust to temporary losses of measurement data (high reliability).