Kodiak 3D Lidar

NASA Goddard Space Flight Center has developed a low cost, modular, and flexible space flight laser range finder consisting of optics, electronics, and interfaces for satellite servicing missions (i.e. Restore-L) using customized optics. Built upon previous NASA technologies, the system also consists of a high dynamic range receiver and adjustable laser for a wide range of measurements (i.e. multiples of km to sub-meter).

The Client Berthing System (CBS) was originally designed for NASA’s On-orbit Servicing, Assembly, and Manufacturing 1 (OSAM-1) spacecraft, which will grapple and refuel the LandSat 7 satellite. After the OSAM-1 spacecraft has rendezvoused with LandSat 7, a robotic arm equipped with a gripper tool will autonomously grapple the satellite’s Marman ring (launch separation ring) and affix it to the CBS in the appropriate refueling position. The CBS is comprised of three posts protruding from the servicing satellite, each with integrated berthing mechanisms, distributed in a radial pattern of 120° along the client’s Marman ring diameter. Each berthing mechanism includes a rotary clamping jaw with a drawdown and radial contact portion. The clamping jaws are actuated by a motor-driven leadscrew and guided by recirculating linear ball bearings. After the servicing spacecraft’s robotic arm has placed the client satellite Marman ring into the CBS berthing box, the clamping jaws simultaneously move radially inward towards the center of the ring. The lead-in features of the jaws exert downward pressure on the ring, driving it towards the jaw palms as the lead-in portion rises over the surface of the ring flange. Once the flange is drawn down such that it contacts the radial clamp surface of the jaws, force is exerted causing the jaws to pivot, driving the underside of the lead-in surfaces into contact with the upper flange surface. As the jaw mechanisms continue to drive, increased axial load squeezes the ring flange between the lead-in-feature and palm of the jaws, stabilizing the connection. At a predetermined load, brakes are engaged, and system motors shut off. A NASA-developed Marman ring location detection system is employed to guide the berthing process. NASA has developed a suite of cutting-edge technologies that can help your business develop robust satellite servicing offerings. For additional information, please see the NASA Satellite Servicing Technologies Available for Licensing link provided.

In addition, the higher the level of abstraction that developers can work from, as is afforded through the use of scenarios to describe system behavior, the less likely that a mismatch will occur between requirements and implementation and the more likely that the system can be validated. Working from a higher level of abstraction also provides that errors in the system are more easily caught, since developers can more easily see the big picture of the system. This technology is a technique for fully tractable code generation from requirements, which has an application in other areas such as generation and verification of scripts and procedures, generation and verification of policies for autonomic systems, and may have future applications in the areas of security and software safety. The approach accepts requirements expressed as a set of scenarios and converts them to a process based description. The more complete the set of scenarios, the better the quality of the process based description that is generated. The proposed technology using automata learning to generate possible additional scenarios can be useful in completing the description of the requirements.

The Miniaturized Astrometric Alignment Sensor advances satellite capabilities for astrophysical measurements, necessary for formation flying, relative navigation, and virtual telescope capabilities. The sensor is a single assembly consisting of a small, low powered camera assembly. The sensor detects stellar objects from which both stellar and object tracking are performed. The sensors components consist of a low power camera assembly, interchangeable lenses, camera power supply, and image processing software and algorithms. The system functions by searching and identifying objects in the camera's field of view and tracking the objects against a selected star pattern with a central body of interest in the sensor's field of view. The Miniaturized Astrometric Alignment Sensor makes it possible to measure a spacecrafts altitude and orientation with respect to known stellar objects. The instrument takes an image of a patch of sky, identifies the stars in that field of view, and compares the field view with a stored star map. The data is processed with a dedicated processor attached to the instrument to spell out the attitude and orientation of a spacecraft.

To enable it to acquire GPS signals very quickly and also track weak signals, the radiation-hardened Navigator receiver utilizes a bank of hardware correlators, a ColdFire microprocessor, and a specialized fast acquisition module (see figure 1). The hardware is implemented in VHSIC Hardware Description Language (VHDL) to target radiation-hardened Field Programmable Gate Arrays (FPGA) rather than Application-Specific Integrated Circuits (ASIC), in order to maintain flexibility for growth and design modifications. The Navigator was designed to operate autonomously to enable the use of GPS for onboard navigation in high altitude space missions. With the exception of GPS signals, Navigator requires no external data (e.g., current time estimate, recent GPS almanac, or converged navigation filter estimate of the receiver dynamics). By double buffering data up front in 1ms blocks, data can be processed as it is acquired. A discrete Fourier transform (DFT) is used to calculate the 1ms correlations, significantly reducing computing time. Computational efficiency is optimized and tradeoffs among sampling rate, data format, and data-path bit rate are carefully weighed in order to increase performance of the algorithm. In addition, the Navigators hardware-independent receiver software includes both a hardware interface to perform low-level functions as well as basic navigation. Onboard orbit determination and accurate state estimation/propagation during periods with no GPS access are accomplished by integration with the GPS Enhanced Onboard Navigation System (GEONS). Exploiting the properties of Fourier transform in a massively parallel search for the GSP signal, the Navigator has been tested and proven capable of acquiring signals at 25dB-Hz and below.