Electra, more formally the Electra Proximity Payload, is a software-defined radio defined and implemented by the Jet Propulsion Laboratory for use between spacecraft. It is typically used by a lander to communicate with an orbiter that can then communicate with Earth. From the JPL description:
Many exploration platforms, such as balloons, gliders, airplanes, penetrators, and small landers, are severely constrained in mass, volume, power, and energy. For such missions, the high energy-per-bit required for direct-to-earth communications, as well as the operational complexity of pointing a high-gain antenna, are prohibitive. Such mission concepts are enabled by the possibility of relay communications to a nearby orbiter, via simple omnidirectional relay communications links.
The use of such a relay increases the amount of data that can be returned by two to three orders of magnitude.
- Mars Reconnaissance Orbiter
- Mars Express
- Mars Exploration Rovers Spirit and Opportunity.
- Mars Science Laboratory, which uses a new version of Electra, Electra-lite.
- Charles D. Edwards, Jr., Thomas C. Jedrey, Eric Schwartzbaum, and Ann S. Devereaux, Ramon DePaula, Mark Dapore, Thomas W. Fischer. "The Electra Proximity Link Payload for Mars Relay Telecommunications and Navigation".
- Edgar Satorius, Tom Jedrey, David Bell, Ann Devereaux, Todd Ely, Edwin Grigorian, Igor Kuperman, and Alan Lee. "The Electra Radio".. This is chapter 2 from the book Autonomous Software-Defined Radio Receivers for Deep Space Applications.
- Dale J. Mortensen, Daniel W. Bishop, David Chelmins. "Space Software Defined Radio Characterization to En able Reuse"..