Easily claiming the title of most impressive ground station in the world, DSS-63 is one of only three 70m antennas on the planet. Taking 3 years to build the original antenna (64m) was finished in 1973 to support early JPL Mars missions. In the 1980s the upgrade to 70m was made to support the Voyager extended mission. With this upgrade these dishes became the largest ground stations in the world, communicating with spacecraft at the edge of our solar system. Credit: Thomas Ormston http://www.flickr.com/photos/thomas_ormston/2571785802/in/set-72157605571353325/NASA's Deep Space Network (DSN) will play a critical role in the central science activity for the 3 March flyby.

The American space agency's giant 70m station at Robledo, Spain (DSS-63), will be enlisted to track ESA's Mars Express during Phobos flyby to record extremely precise Doppler data - which in turn will enable Mars Express scientists to obtain the best-ever measurements of Phobos gravity and hence mass (click on 'Full story' for more details). -- Daniel

Yes, ESA's own 'giant' 35m Deep Space Antenna, DSA-2 at Cebreros station, also in Spain, will be involved - for telecommanding, telemetry receipt and as back-up for the radio science tracking. Yes, the flyby could still be done using only ESA's Cebreros station, but the radio science data quality will be greatly improved by the use of the NASA 70m antenna - like listening with a much bigger ear!

35m Cebreros antenna, ESA DSA-2. While not as big as the 70m dish at DSN Madrid, the 35m ESA dish was still a sight to behold. Credit: Thomas Ormston

  DSA-2: ESA's 35m station at Cebreros, Spain

The practical effect of using the bigger NASA dish is that we'll improve the signal-to-noise ratio - i.e. we'll hear the spacecraft signal more clearly over the background 'noise'. This lets us better detect the subtle changes in the radio signal that will be caused by Phobos. As Mars Express passes Phobos, the Martian moon will change our spacecraft's velocity and this will result in a change in the frequency of the signal sent by Mars Express back to Earth (through the Doppler effect - like the change in tone of an ambulance siren as it passes).

Easily claiming the title of most impressive ground station in the world, DSS-63 is one of only three 70m antennas on the planet. Taking 3 years to build the original antenna (64m) was finished in 1973 to support early JPL Mars missions. In the 1980s the upgrade to 70m was made to support the Voyager extended mission. With this upgrade these dishes became the largest ground stations in the world, communicating with spacecraft at the edge of our solar system. Credit: Thomas Ormston http://www.flickr.com/photos/thomas_ormston/2571785802/in/set-72157605571353325/
  DSS-63: NASA's 70m station at Robledo, Spain

"We're grateful to NASA for giving us the time on this dish because there are only three stations like this in the world and they're understandably very busy supporting all sorts of missions in far flung parts of the Solar System," said Michel Denis, Mars Express Spacecraft Operations (SOM) Manager here at ESOC.

There are some great Flickr image sets taken by Mars Express Spacecraft Operations Engineer (and one of the contributors to this blog!) Thomas Ormston:

http://www.flickr.com/photos/thomas_ormston/sets/72157605571353325/
The first show DSS-63 - one of only three 70m antennas on Earth. After three years of construction, the original antenna (64m) was finished in 1973 to support early JPL Mars missions. In the 1980s, the upgrade to 70m was made to support the Voyager extended mission.

http://www.flickr.com/photos/thomas_ormston/sets/72157605579459793/
The next set of images show the MDSCC (Madrid Deep Space Communications Complex) control centre at Robledo - run by Spanish contractor INTA on behalf of NASA.

http://www.flickr.com/photos/thomas_ormston/sets/72157605576298784/
Finally, a couple sets showing ESA's own 35m antenna at Cebreros

... and ESA's Cebreros Operations Centre
http://www.flickr.com/photos/thomas_ormston/sets/72157605581422127/

Like all stations in ESA's global ESTRACK station network, Cebreros is remote-controlled from the ESTRACK Control Centre at ESOC here in Darmstadt; the industrial support engineers on site take care of regular maintenance and do go 'on-console' for critical operations - like Phobos flyby.

More on ESTRACK: http://www.esa.int/SPECIALS/Operations/SEM8YCSMTWE_0.html

Cebreros webcam: http://www.esa.int/SPECIALS/Operations/SEM26DSMTWE_0.html