The robotic arm's first movement was delayed by one day when, on May 27, 2008, commands from Earth were not relayed to the Phoenix lander on Mars.
The commands went to NASA's Mars Reconnaissance Orbiter as planned, but the orbiter's Electra UHF radio system for relaying commands to Phoenix temporarily shut off.
Without new commands, the lander instead carried out a set of backup activities.
On May 27 the Mars Reconnaissance Orbiter relayed images and other information from those activities back to Earth.

The robotic arm was a critical part of the Phoenix Mars mission.
On May 28, scientists leading the mission sent commands to unstow its robotic arm and take more images of its landing site.
The images revealed that the spacecraft landed where it had access to digging down a polygon across the trough and digging into its center.

The lander's robotic arm touched soil on Mars for the first time on May 31, 2008 (sol 6).
It scooped dirt and started sampling the Martian soil for ice after days of testing its systems.
The robotic arm's first movement was delayed by one day when, on May 27, 2008, commands from Earth were not relayed to the Phoenix lander on Mars. The commands went to NASA's Mars Reconnaissance Orbiter as planned, but the orbiter's Electra UHF radio system for relaying commands to Phoenix temporarily shut off. Without new commands, the lander instead carried out a set of backup activities. On May 27 the Mars Reconnaissance Orbiter relayed images and other information from those activities back to Earth.
The robotic arm was a critical part of the Phoenix Mars mission. On May 28, scientists leading the mission sent commands to unstow its robotic arm and take more images of its landing site. The images revealed that the spacecraft landed where it had access to digging down a polygon across the trough and digging into its center.
The lander's robotic arm touched soil on Mars for the first time on May 31, 2008 (sol 6). It scooped dirt and started sampling the Martian soil for ice after days of testing its systems.
Phoenix (spacecraft)