The Electra Proximity Link Payload for Mars Relay Telecommunications and Navigation

Abstract

To support the coming decade of Mars exploration, NASA is establishing a telecommunications relay and navigation infrastructure in Mars orbit, supporting increased science data return, providing energy-efficient relays for small scout-class mission concepts, gathering engineering telemetry during critical mission events, and providing in situ radiobased navigation. A key element of this vision is the Electra Proximity Payload, a telecommunications and navigation payload that will fly on each Mars orbiter, beginning with the 2005 Mars Reconnaissance Orbiter (MRO) and with subsequent flight on the 2009 Mars Telecommunications Orbiter (MTO). We present here the functional requirements, design characteristics, and implementation status of the Electra Payload and its role as a telecommunications node in an evolving Mars orbital infrastructure.

Telecommunications relay support of the Mars Phoenix Lander mission

“…MRO incorporates the Electra UHF transceiver, a new transceiver design based on a software-defined radio architecture that allows significant evolution of protocols and signal processing capabilities even after launch [13]. While Electra offers frequency-agile operations and a wider range of data rates, for Phoenix support operations were constrained to the fixed frequencies and limited data rates available in the Phoenix CE-505 transceiver.…”

Integrated network architecture for sustained human and robotic exploration

“…These arrays will provide 10 to 100 times the receive performance of existing 70-m DSN stations. Given that these antennas would be built in large quantities, there 5 The lunar brightness temperature of 230 K significantly reduces return rates when the moon is in view of the ground antenna. The system noise temperature contribution due to lunar blackbody brightness temperature depends on link frequency.…”

“…One region of the spectrum is sent to a modified Electra proximity radio [5], which can receive and store data to spacecraft memory via the Command & Data Handling (C&DH) subsystem. Another region of the received spectrum is downconverted to another region of the S-band spectrum and sent back through the same antenna to the lunar surface to support real-time over-the-horizon communications.…”

“…MRO will add a new Electra reprogrammable UHF relay radio [5] and a K a -band deep space link [6] to the Mars Network. JPL is also managing the development of Mars Telecommunications Orbiter (MTO), the first interplanetary mission whose principal function is to support other missions [7].…”

Transforming the deep space network into the Interplanetary Network

“…This initial Mars telecommunications infrastructure is being established by including a standardized proximity link relay payload on each science orbiter (1996Mars Global Surveyor, 2001Mars Odyssey, 2003 Mars Express, and 2005 Mars Reconnaissance Orbiter) [8]. By adopting a standard link layer protocol [9], these orbiters offer interoperable telecommunications relay services for future Mars landers.…”