Phoenix Mars Scout UHF Relay-Only Operations

Abstract

The Phoenix Mars Scout Lander will launch in August 2007 and land on the northern plains of Mars in May of 2008. In a departure from traditional planetary surface mission operations, it will have no direct-to-Earth communications capability and will rely entirely on Mars-orbiting relays in order to facilitate command and control as well as the return of science and engineering data. The Mars Exploration Rover missions have demonstrated the robust data-return capability using this architecture, and also have demonstrated the capability of using this method for command and control. The Phoenix mission will take the next step and incorporate this as the sole communications link. Operations for 90 Sols will need to work within the constraints of Odyssey and Mars Reconnaissance Orbiter communications availability, anomalies must be diagnosed and responded to through an intermediary and on-board fault responses must be tolerant to loss of a relay. These and other issues pose interesting challenges and changes in paradigm for traditional space operations and spacecraft architecture, and the approach proposed for the Phoenix mission is detailed herein.

Mars to Earth communications through orbiters: Delay‐Tolerant/Disruption‐Tolerant Networking performance analysis

“…The Mars to Earth scenario considered is inspired by the case of the Phoenix lander exploration mission to Mars, with slight modifications to allow a broader investigation. The Phoenix mission started in 2007 and one aim was to make use of a relay network already available in order to improve the transmission efficiency achieved in the previous Spirit and Opportunity missions.…”

Mission design of the Phoenix Mars Scout mission

“…Because Phoenix has no direct‐from‐Earth (DFE) or direct‐to‐Earth (DTE) capability once it lands on Mars, the entire surface operations timeline is further constrained by relay latencies and potentially long delays in fault situations. Many of these challenges are described here, with the notable exception of the surface relay operations that are detailed by Lewicki et al [2006].…”

Autonomous access links using laser communications

“…Today such access links operate at UHF frequencies and have returned a bulk of the information received [1] from the Mars Exploration Rovers (Spirit and Opportunity) [2] and the recent Phoenix Mission [3]. The upcoming Mars Science Laboratory and other future lander/rover missions will rely on similar access links as a primary means for returning data to Earth.…”