• → European Space Agency

      • Space for Europe
      • Space News
      • Space in Images
      • Space in Videos
    • About Us

      • Welcome to ESA
      • DG’s blog
      • For Member State Delegations
      • Business with ESA
      • Law at ESA
      • ESA Exhibitions
      • ESA Publications
      • Careers at ESA
      • ESAshop
    • Our Activities

      • Space News
      • Observing the Earth
      • Human and Robotic Exploration
      • Space Transportation
      • Navigation
      • Space Science
      • Space Engineering & Technology
      • Operations
      • Telecommunications & Integrated Applications
      • Preparing for the Future
    • Careers at ESA

    • For Media

      • Media
      • ESA TV
      • Videos for professionals
      • Photos
    • For Educators

    • For Kids

    • ESA

    • ESA Science

    • Mars Express

    • Europe goes to Mars

      • Europe reclaims a stake in Mars exploration
      • Space age transforms our knowledge about Mars
    • About Mars Express

      • Mars Express mission facts
      • Mars Express instruments
      • The mission
      • The spacecraft
      • The launcher
    • About Mars

      • Geography of Mars
      • Water on early Mars?
      • Facts about Mars
    • Meet the team

      • International collaboration
      • Mission team
      • Operations
      • Industry
    • Multimedia
    • Mars Express images
    • Mars Express videos
    • Services
    • Frequently asked questions
    • Follow us
    • ESA Sci on Twitter

    ESA > Our Activities > Space Science > Mars Express

    Auspicious orbit marks run-up to Phobos flyby

    Phobos
    29 January 2010

    On 26 January, Mars Express completed its 7777th orbit around the Red Planet, an auspicious milestone as the satellite is readied for the closest-ever flyby of Phobos, scheduled for just a few weeks from now.

    Mars Express has been in orbit since 25 December 2003, returning a wealth of scientific information and some of the most stunning high-resolution imagery of the Red Planet ever. Its data have allowed scientists to measure the abundance of water ice and vapour in the martian subsurface, surface and the atmosphere, as well as previously unknown methane in the atmosphere.

    This week, the orbiter completed 7777 circuits of the planet and continues to operate flawlessly. Currently, each orbit takes 6 hours and 54 minutes. The spacecraft is following a polar orbit, and at closest approach passes just 350 km above the surface of Mars and, at farthest approach, 10 300 km.


    Closest-ever Phobos flyby

    This highly elliptical orbit will enable Mars Express, on 3 March, to conduct the closest flyby and examination of Phobos, Mars’ largest moon. The flyby, at a planned altitude of just 50 km, will collect very precise radio Doppler data to help determine the moon’s gravity field more accurately than ever.

    Mars Express imaged the martian moons Phobos and Deimos together on 5 November 2009

    This close flyby will be bracketed by similarly close passages, which will be used for other scientific investigations including radar sounding and imaging.

    Knowing the gravity field will help scientists to understand the distribution of mass inside the moon, which is another step in the quest to discover the origin of Phobos.

    None of the other spacecraft now orbiting Mars can fly as close to Phobos. While Mars is the mission’s primary target, this flyby is an excellent opportunity for additional scientific investigation of the Mars system, and will boost overall science return.

    This Phobos flyby is combined with a sequence of precise orbit manoeuvres planned in February and March. They will increase the orbit duration to almost exactly 7 hours, in order to improve the Sun illumination of the ground track pictured by the spacecraft for many years to come.

    Mars Express is scheduled to operate until 2012; a further extension to 2014 will be assessed this year.

    Mars Express Orbit 7777

    Mars Express
    Mars Express
    • Mars Express completes one orbit of the Red Planet in just under 7 hours
    • Mars Express carries a suite of 7 scientific instruments
    • The spacecraft is in its 7th year of operation

    Rate this

    Views

    Share

    • Currently 0 out of 5 Stars.
    • 1
    • 2
    • 3
    • 4
    • 5
    Rating: 0/5 (0 votes cast)

    Thank you for rating!

    You have already rated this page, you can only rate it once!

    Your rating has been changed, thanks for rating!

    1140
    Tweet
    • Mars Express blog
    • Looking at Mars
    • Mars Express on YouTube
    • Traces of Martian life
    • Mars Webcam
    • Related articles
      • Phobos flyby success
        • Mars Express heading for closest flyby of Phobos
          • Phobos flyby season starts again
            • Auspicious orbit marks run-up to Phobos flyby
              • Craters young and old in Sirenum Fossae
                • Pioneering images of both martian moons
                  • Mars Express acquires sharpest images of martian moon Phobos
                    • ESA closes in on the origin of Mars’ larger moon
                      • Chaotic terrain between Kasei Valles and Sacra Fossae
                        • Lava flows in Daedalia Planum
                        • More information
                        • Mars Express in-depth
                          • Mars Express operations
                            • New Norcia - DSA 1
                              • Cebreros - DSA 2
    • App Store
    • Subscribe
    • mobile version
    • FAQ

    • Site Map

    • Contacts

    • Terms and conditions