Mars Recon naissance Orbiter: The History of Supporting the Phoenix Lander

The Mars Phoenix Lander arrived at Mars in May of 2008. Relying exclusively upon the Mars 2001 Odyssey spacecraft and the Mars Reconnaissance Orbiter to transmit operations data to and from Earth, the Phoenix project recently concluded a highly successful mission, having confirm ed the presence of water ice on the surface of Mars . Al most al l of the scientific and operational data acquired by the vehicle was relayed to Earth by the two orbiting assets. This report outlines some of the experiences of the Mars Reconnaissance Orbiter project in pr eparing for the arrival of Phoenix at Mars and the support provided to the lander after arrival. Strategies and lessons for successfully operating a relay network are iterated w ith discussion on the successes and failure s of the Mars Reconnaissance Orbite r project and the remainder of the “Mars Network” to implement them. Finally, results of the operational experience are tabulated and discussed. I. The 2008 Mars Relay Network URING the middle of 2008 , there w ere six spacecraft at Mars that could communica te with each other in a “relay network,” as in Fig . 1. The twin Mars Exploration Rovers ( MERs ), Spirit and Opportunity, arrived at Mars in January 2004, and they have been relaying data to Earth via the Mars 2001 Odyssey orbiter since that time. The Mars Express Orbiter has been in orbit at Mars since just before the arrival of the rovers and has performed several relay tests with the m, but has not served as a primary relay asset. The Mars Reconnaissance Orbiter (MRO) arrived at Mars in 2005 and has rece ntly concluded its primary science mission , but it has not to date been providing primary relay support for either of the rovers . Most recently, the Phoenix lander arrived in May of 2008 and utilized both Odyssey and MRO for primary relay operations durin g its five month mission . This paper outlines the experience of the MRO project as it relates to preparing for the arrival of the Phoenix lander at Mars, recording data as transmitted from the lander during its entry, descent, and landing (EDL) on Mars; an d serving as a relay asset to Phoenix throughout its surface mission. The challenges of clearly defining the interface s between the projects, the test strategy and schedule for ensuring these interfaces, and the actual support plans will be outlined. In addition, the as -flown experience of supporting the Phoenix lander during its mission, along with technical issues that were encountered and addressed will be discussed. Interspersed throughout this paper are lessons that were initially documented shortly after Spirit and Opportunity landed on Mars about ways to improve relay operations. The reader is encouraged to review that earlier report (see Ref. 2) to learn more about the context in which the lessons were generated. This paper will comment on those lessons with an eye towards further improvement for future Mars relay network activities. Finally, several new lessons that were learned from the 2008 experience will be outlined.