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NASA鈥檚 Phoenix lander has successfully completed the deployment of its robotic arm, putting it on track to start digging into the Martian soil within a few days. But first, the arm will use its built-in camera to peek under the lander鈥檚 body and make sure its feet are planted stably on the surface.

Phoenix touched down in Mars鈥檚 north polar region on Sunday and quickly started beaming back images of its surroundings.

Now, the lander鈥檚 robotic arm has finished freeing itself from its restraints, a crucial step along the way to sampling the Martian soil and ice.

Two pins held the arm in place and prevented it from being damaged by vibrations during Phoenix鈥檚 launch and landing. NASA commanded the arm to start the process of freeing itself on Wednesday morning PDT (Wednesday afternoon GMT).

The arm has now completely freed itself from the pins and a sterile wrapping called the biobarrier, which prevented the arm from being contaminated with Earth microbes prior to launch, the Phoenix team reported at a press briefing on Thursday.

鈥淥ur arm was cooped up in our restraints for 14 months,鈥� Phoenix team member Matthew Robinson of NASA鈥檚 Jet Propulsion Laboratory (JPL) in Pasadena, California, US, said during the briefing. 鈥淚t was raring to go, it鈥檚 busted loose now, and we鈥檙e ready to go 鈥� we鈥檙e excited.鈥�

Practice digs

The Phoenix team hopes to start doing some practice digs into the surface in the early to middle part of next week in preparation for the eventual collection of samples of soil and ice for analysis by the robot鈥檚 onboard instruments.

But the robotic arm鈥檚 first mission will be to reach underneath the lander and take some images with a camera mounted on its wrist.

One of the lander鈥檚 three feet is out of view of the Surface Stereo Imager (SSI), which sits atop a mast on the lander鈥檚 back. The Phoenix team wants to make sure the lander is stable, with all three feet planted firmly on the ground before ordering any digging.

Before moving under the lander, the arm will take a look from the side to make sure there are no large rocks in its way.

In another milestone, the lander has now acquired a full 360掳 view of its surroundings (not including the ground out of view beneath it), showing a surface that is mostly free of large rocks, which should make for easier digging.

Weather station

鈥淛ust look at that workspace,鈥� said Phoenix project manager Barry Goldstein of JPL. 鈥淚t couldn鈥檛 be better. . . . I鈥檓 really looking forward over the next 90 sols [90 Martian days] for some major scientific breakthroughs.鈥�

Goldstein noted that the mission so far had gone better than even the team鈥檚 most optimistic predictions and played down the importance of the few problems that have cropped up, such as Tuesday鈥檚 radio communication glitch.

鈥淓verything that we faced over the course of these last 4 sols on the surface of Mars has been rather benign,鈥� he said. 鈥淭his has been in some regards very, very easy.鈥�

The team also reported that the Canadian-built weather station on Phoenix has started making measurements, showing temperatures that climb to -30掳 C during the day and plunge to -80掳 C at night at Phoenix鈥檚 location in the northern plains of Mars. A laser instrument that makes up part of the weather station has measured surface dust that has been blown 3.5 kilometres above the surface.

Mars Rovers 鈥� Mars is full of surprises, learn more in our continually updated .