HiRISE captures Phoenix descent
BY DR EMILY BALDWIN
ASTRONOMY NOW
Posted: May 28, 2008

The HiRISE camera onboard NASA’s Mars Reconnaissance Orbiter (MRO) captured Phoenix hanging from its parachute during its descent through the Martian atmosphere, and imaged the lander after it had safely landed in the north polar region of Mars.

MRO was about 760 kilometres away from the Phoenix spacecraft when it pointed the HiRISE camera obliquely towards the lander, seizing the moment that Phoenix glided in front of the 10 kilometre wide crater Heimdall (image below). In the full image, Phoenix is just a few pixels wide, but a zoomed in image reveals the fully inflated 30 metre wide parachute, and even the cords that attach the aeroshell containing the lander to the parachute.

Phoenix glides past a 10 kilometre wide crater on its way down to the Martian surface. Image: NASA/JPL-Caltech/University of Arizona.

HiRISE has since located and imaged Phoenix and its trail of discarded landing equipment at its landing site (image below). The parachute (lower left) is easy to see because it is bright, and the backshell is still attached to the parachute chords. The double dark marking at the right is consistent with the impact and bouncing of the heat shield, which fell from a height of roughly 10 kilometres. Phoenix, with its wings spread, is clearly identifiable in the upper left.

This montage of enhanced colour images from HiRISE shows the Phoenix landing area as viewed from orbit, including its discarded heat shied and parachute. Image: NASA/JPL-Caltech/University of Arizona.

Since landing on the Martian surface over two days ago, Phoenix has snapped many pictures of its surrounds. Phoenix principal investigator Peter Smith of the University of Arizona is delighted with the new images. "The workspace is ideal for us because it looks very diggable," he says. "We're very happy to see just a few rocks scattered in the digging area."

The mission scientists are now keen to unfurl Phoenix’s robotic arm, which will dig the icy terrain and perform in situ experiments to study the composition and habitability potential of this unexplored Martian environment. Although the commands to perform this operation were sent to the lander on Tuesday 27 May, due to a transient glitch with a radio onboard the Mars Reconnaissance Orbiter, the command was not received. The commands will be resent today, but the day on Mars was certainly not wasted: Phoenix executed stored commands to snap additional pictures of its surroundings, and sent back a weather report revealing temperatures at the landing site that range from a biting -30 to an even chillier -80 degrees Celsius. The average pressure was less than 1 percent of the sea level pressure on Earth and the wind below across the lander at 32 kilometres per hour.

This image shows the American flag and mini-DVD on Phoenix's deck, about one metre above the Martian surface. The DVD contains a message to future Martian explorers, science fiction stories and art inspired by the red planet, and the names of over a quarter million earthlings! Image: NASA/JPL-Caltech/University of Arizona.

“We're very proud to be making such progress," Smith said. "We're already getting a good sense of what the space is around our lander. We're really feeling very positive about this mission and can't wait to start interacting with the soil and doing our scientific investigations."