Author: Nancy Atkinson

Europe’s Mars Express orbiter picked up the signal that Phoenix was transmitting as it descended to Mars’ surface on May 25. The data from the Mars Express Lander Communication system (MELACOM) tracked Phoenix and the signal was received on Earth soon after the Phoenix landing. The Mars Express Flight Control Team has now processed the signals, and the sounds of Phoenix descending are audible, loud and clear. ESA says the signal was tracked successfully, even during the expected transmission blackout window of the descent, until the lander was out of Mars Express’s view. The transmission blackout window is caused because of ionization around the probe, which builds up as the lander descends through the atmosphere and only very weak signals come through.

The closest Mars Express got to Phoenix was 1550 km. Then, as Mars Express flew away, the lander deployed its parachute, separated from it and landed. Then the signal from the lander was cut off.

Listening to the recording, you’ll notice the Doppler effect, which is very similar to what we hear when listening to the whistle of a passing train, of Phoenix and Mars Express getting closer and then farther away from each other.

Link to the sound recording.

The rest of the recording, the start and the end, contains background noise generated by Mars Express itself.

During the descent, all of the capabilities of Mars Express were focussed on tracking Phoenix with MELACOM. Unfortunately, the science observations carried out during the descent did not lead to the anticipated results.

Over the next few days, Mars Express will monitor Phoenix using MELACOM 15 more times; at least one of these will be used to demonstrate and confirm that the ESA spacecraft can be used as a data relay station for NASA, receiving data from the surface and transmitting test commands to the lander, which may be important if any issues remain with the communication troubles between Phoenix and the Mars Reconnaissance Orbiter.

Source: ESA

The UHF radio on the Mars Reconnaissance Orbiter that had gone into standby mode yesterday was successfully restarted. The orbiter was then able to receive information from the Phoenix Mars Lander late Tuesday evening and relay the transmission to Earth, which included images and other data collected by Phoenix during the mission’s second day after landing on Mars. The radio system used by the orbiter to communicate with the lander experienced an undetermined “transient event” early Tuesday and shut itself off. This prevented sending Phoenix any new commands from Earth on Tuesday. Instead, the lander carried out a backup set of activity commands that had been sent Monday, which included taking additional pictures of itself and the landing site. Above is one of the raw, unprocessed image the lander took of itself.

We’ve gotten used to the panoramic images of Mars from the Mars Exploration Rovers, and we can expect more of the same from Phoenix. Above is the beginnings of a panoramic view of the lander and its surroundings. The Surface Stereo Imager is in the process of taking multiple images, which the imaging team will process and piece together to form a a large color panorama.

And how do these raw, black and white images become colorful photos and panoramas? At left is a calibration target on Phoenix. It has grayscale and color dots. Before launch, the calibration targets are imaged and measured very accurately, so that the imaging team back on Earth knows what the colors and different shades of grey are.

Once on Mars, a picture is taken of the target. The picture will be processed through the software they use, and if it comes out looking the same as the pictures taken of the target before launch, the imaging team knows they have processed the picture correctly. They then use the same technique to process the images of Mars surface, and produce images that are as close as possible to the “real” colors on Mars.

Here’s one more raw image, the beginnings the panorama of the entire spacecraft, of the SSI camera looking down on the spacecraft itself.

Image Source: Phoenix Gallery

The UHF communications radio on board the Mars Reconnaissance Orbiter has switched to standby and was unable to relay instructions to the Phoenix lander for its activities for sol 2, which included unstowing its robotic arm. The problem arose at 0608 PDT on Tuesday. MRO did receive the sol 2 sequence from Earth – meaning the communications link between Earth and MRO continues to operate normally. But subsequently MRO reported that there had been a “problem with the handshake between MRO and Phoenix,” said Fuk Li, manager of NASA’s Mars Exploration Program. A ‘handshake’ is the set of signals the radios on the two spacecraft send each other to establish a data-communications link.

“All this is is a one-day hiccup in being able to move the arm around, so it’s no big deal,” said Ed Sedivy, Phoenix program manager at Lockheed Martin Space Systems.

The next opportunity to send commands to Phoenix will occur on Wednesday morning, when Mars Odyssey, the other spacecraft used to communicate with Phoenix, passes over the landing site. At that time, the commands that failed to reach the lander today will be transmitted. We’ll keep you posted.

Also, we’ll take this opportunity to share a couple of other tidbits about Phoenix. The image above was taken on sol 1, and shows Phoenix’s backshell off in the distance.

On board Phoenix is a weather station, contributed by the Canadian Space Agency and University of Aarhus in Denmark. The weather station was activated in the first hour after landing on Mars. Measurements are being recorded continuously. Skies were clear and sunny on Sol 1 on Mars. The temperature varied between minus 112 degrees Fahrenheit in the early morning and minus 22 degrees Fahrenheit in the afternoon. The average pressure was 8.55 millibars, which is less than a 1/100th of the sea level pressure on Earth.

This image shows the spacecraft’s robotic arm in its stowed configuration, with the a biobarrier, a shiny, protective film, that covers the arm on landing day, or Sol (Martian day) 0, and then the biobarrier was removed during lander’s first full day on Mars, Sol 1.

The “elbow” of the arm can be seen at the top center of the picture, and the biobarrier is the shiny film seen to the left of the arm.

The biobarrier is an extra precaution to protect Mars from contamination with any bacteria from Earth. While the whole spacecraft was decontaminated through cleaning, filters and heat, the robotic arm was given additional protection because it is the only spacecraft part that will directly touch the ice below the surface of Mars. After Phoenix landed, springs were used to pop back the barrier, giving it room to deploy.

These images were taken on May 25, 2008 and May 26, 2008 by the spacecraft’s Surface Stereo Imager.

News Sources: Astrobiology Magazine, JPL Phoenix News