Next-generation spacecraft instruments are capable of producing data at rates of 108 to 1011 bits per second, and both their instrument designs and mission operations concepts are severely constrained by data rate and volume. SpaceCube™ enables these next-generation missions.
SpaceCube is a cross-cutting, in-flight, reconfigurable, Field Programmable Gate Array (FPGA)-based onboard hybrid science data processing system developed at Goddard Space Flight Center. The hybrid processing includes CPU, DSP, and FPGA logic. The goal of the SpaceCube program is to provide 10× to 100× improvements in onboard computing power while lowering relative power consumption and cost. The SpaceCube design strategy incorporates commercial radiation-tolerant Xilinx Virtex FPGA technology, and couples it with an integrated upset detection and correction architecture to provide reliable “order of magnitude” improvements in computing power over traditional fully radiation-hardened flight systems.
SpaceCube has demonstrated capabilities in onboard product generation, intelligent data volume reduction, autonomous docking/landing, direct broadcast products, and data-driven processing with the ability to autonomously detect and react to events. SpaceCube systems are currently being developed and proposed for platforms from small CubeSats, to larger-scale experiments on the International Space Station (ISS), and standalone free-flyer missions.
Applications for SpaceCube include real-time Lidar, SAR, and image processing; autonomous operations and robotic servicing; onboard data volume reduction; intelligent data compression; real-time calibration and correction; inter-platform collaboration; and real-time wavefront sensing and control.
3D Printing Computer Boards
As detector assemblies get smaller and denser — packed with electronic components that all must be electrically connected to sense and read signals — it’s becoming increasingly more challenging to design and manufacture these instrument devices.
Goddard researchers are investigating aerosol jet printing, or direct-write manufacturing, to produce new detector assemblies that are not possible with traditional assembly processes.
“If we succeed, aerosol jet technology could define a whole new way to create dense electronic board assemblies, and potentially improve the performance and consistency of electronic assemblies,” explained Goddard technologist Beth Paquette, who is leading the R&D effort that began last year. Aerosol jet printing promises to slash the time it takes to manufacture circuit boards, from a month to a day or two.
As with other 3D printing techniques, aerosol jet manufacturing builds components by depositing materials layer-by-layer following a CAD drawing; however, jet aerosol printing offers an important difference. Instead of melting and fusing plastic powder or other material in precise locations, aerosol jet printing uses a carrier gas and printer heads to deposit a fine aerosol of metal particles — including silver, gold, platinum, or aluminum — onto a surface. Aerosol jet printers also can deposit polymers or other insulators, and can even print carbon nanotubes.
The technique’s use isn’t limited to detector electronics. Instrument developers could one day use aerosol jet technology to print antennas, wiring harnesses, and other hardware directly onto a spacecraft.
Sampling and Control Circuit Board
Glenn Research Center has developed a circuit board that serves as a control and sampling interface to an inertial measurement unit (IMU). The board provides sampling and communication abilities that allow the IMU to be sampled at precise intervals. The data is minimally processed onboard, and returned to a separate processor for inclusion in an overall system.
For fast platform dynamics, it is necessary to sample the IMU at quick intervals in order to fulfill the Nyquist sampling theorem requirements. This can be difficult where low size, weight, and power are required, since a primary processor may already be saturated running the navigation algorithm or other system functions. The circuit operates using a universal serial bus (USB) or Bluetooth interface. A control command is sent to the circuit from a separate processor or computer that instructs the circuit how to sample data. Then, a signal is sent to trigger the circuit to perform automatic data collection from the IMU sensor. The technology addresses applications in navigation, robotics, process control, industrial automation, and instrumentation and measurement.
Goddard is also leading a team that’s building a new type of communications modem that will employ an emerging, potentially revolutionary technology that could transform everything from telecommunications and medical imaging, to advanced manufacturing and national defense.
The integrated-photonics modem will be tested aboard the International Space Station (ISS) beginning in 2020 as part of NASA’s Laser Communications Relay Demonstration (LCRD). The cellphone-sized device incorporates optics-based functions such as lasers, switches, and wires on a microchip, much like an integrated circuit.
Once aboard the ISS, the Integrated LCRD LEO (Low-Earth Orbit) User Modem and Amplifier (ILLUMA) will serve as a low Earth orbit terminal for NASA’s LCRD, demonstrating a capability for high-speed, laser-based communications. LCRD promises to transform the way NASA sends and receives data, video, and other information. It will use lasers to encode and transmit data at rates 10 to 100 times faster than today’s communications equipment, requiring significantly less mass and power.
ILLUMA incorporates an emerging technology — integrated photonics — that is expected to transform any technology that employs light. This includes everything from Internet communications over fiber optic cable, to spectrometers, chemical detectors, and surveillance systems.
The Goddard team will reduce the size of the terminal, now about the size of two toaster ovens — a challenge made easier because all light-related functions will be squeezed onto a microchip. Although the modem is expected to use some optic fiber, ILLUMA is the first step in building and demonstrating an integrated photonics circuit that ultimately will embed these functions onto a chip.
Although integrated photonics promises to revolutionize space-based science, it also has terrestrial uses; for example, in data centers. These costly, very large facilities house servers that are connected by fiber optic cable to store, manage, and distribute data. Integrated photonics would dramatically reduce the need for, and size of, these facilities — particularly since the optic hardware needed to operate them will be printed onto a chip.