By George Studor, NASA’s Johnson Space Center, Houston, TX
Every ounce of weight brought to the lunar surface costs 40 to 60 times that in fuel needed at liftoff from the Earth. Part of that weight penalty is due to wires, but the cost of wires is much more than weight. Wired connectivity drives up the price of design from the beginning: it drives the cost of the many systems and structures; it drives inspection, troubleshooting, maintenance, and upgrade costs; as well as the cost of making system changes. Future vehicles that can reduce the effects and limitations of wires will not be without risk or a lot of work, but the effort has begun.
The Space Shuttle has been using wireless instrumentation for over 10 years now. In fact, during every mission, we listen for impacts to the critical wing leading edge using a wireless standalone data acquisition system. Aerospace avionics and instrumentation is undergoing a process similar to the move to wireless phones, wireless computers, video games, and other devices around the home; the industry replacement of barcode labels with RFID tags; and now our cars, which have wireless systems we enjoy every day. Even commercial airlines are reducing costs and adding functions and redundancy with wireless devices. So it makes sense that NASA sees a need for wireless systems in each of NASA’s mission directorates.
In one sense, the technology has to buy its way into each program by the evaluation of each application from the bottom-up. We are developing policies and performance measures that more accurately reflect the choices we now have in today’s world — to buy the item with the cord or the item without it, considering all the costs and risks. Elements that NASA is focusing upon are:
- System engineering approaches to reliably reduce cables & connectors.
- Accommodations, such as modularity and accessibility, in the vehicle architectures.
- New technologies and capabilities to provide alternatives to wired connectivity.
What Technologies Does NASA Need?
We need truly wireless sensors that can operate in earth-bound, airborne, and space environments. We need very smart, small, and low-power standalone wireless systems for data acquisition, processing, and storage. We need to be able to connect avionics boxes with few or no wires/connectors. We need vehicle designs that easily accommodate the evolving technologies as they mature. We need more testing of RF devices in appropriate environments to make improvements and allow certification. We need supporting technologies that enable standalone power through longlife batteries or scavenging from its environment. We need robust RF systems with miniature antennas. We need design provisions in vehicle and ground test architectures to optimize the use of wireless and less-wire technologies.