Mars Express Blog

Mars Express Blog http://webservices.esa.int/blog/blog/7 Mars Express is Europe’s first planetary mission. At launch, the mission consisted of an orbiter carrying seven instruments for remote sensing observations of the planet, and a lander (Beagle 2) for on-the-spot measurements of Martian rock and soil. Mars Express started science observations at the Red Planet in January 2004, and since then it has been delivering an incredible amount of scientific results. The ‘Express’ part of the name highlights the fact that the spacecraft was built more quickly than any other comparable planetary mission. In fact, it took only five years from mission approval to launch. In addition to global studies of the surface, subsurface and atmosphere of Mars with unprecedented spatial and spectral resolution, the unifying theme of the Mars Express mission from orbit is the search for water in its various states, everywhere on the planet by all its seven instruments using different techniques. danielscuka 2012-02-10T11:52:53Z Phobos flyby 9/01 - when can we expect first images? http://webservices.esa.int/blog/post/7/1303 On Sunday, 9 January, Mars Express will make its closest approach to Phobos, with the spacecraft passing just 111 km above the moon's centre at 14:09 UT (15:09 CET). Of course, we all know that science is about a lot more than pretty pictures; but we can’t help ourselves can we? The first question any of us ask when we hear about a new flyby is, "When do we get the images?" We want to see Phobos, and we want to see it now! While closest approach takes place this coming Sunday, Olivier Witasse, ESA Project Scientist for Mars Express, explains below that all things come to those who wait. I asked him when we can expect the first image? Olivier replied: <blockquote> We will have to be patient! The whole Phobos data set will be downloaded to Earth by Tuesday, 18 January. The HRSC team will then process the data, and we can expect a release of images (including a 3D view) on Friday, 21 January. </blockquote> Why wait for nine days after the closest approach? <blockquote> The reason is that besides this Phobos event, there are other camera observations of Mars and many observations by the other Mars Express instruments. <a href="http://www.esa.int/esaMI/ESOC/SEMYVF3XQEF_0.html" target="_blank">Software plans and optimises the data downlink</a> to make sure that no instruments lose any data, and it uses the biggest data storage on board (the one for the camera) to act as a buffer when downlink capabilities are scarce. This avoids overwriting valuable data! Once the other data are safely on the ground, then Mars Express sends the camera files. </blockquote> An interesting aspect of this story is that starting on 19 January, contact with Mars Express will be much reduced for five weeks. We will even loose contact for some days due to the solar conjunction, when the Sun will block our view of Mars and Mars Express. During this period, the spacecraft will be fully autonomous but perform no observations. Luckily, the Phobos close encounter occurs more than a week before and its images will be on the ground just in time! -- Stuart Note: To help pass the time, enjoy are a pair of recent images captured in March 2010 by the HRSC. <a id="res_20044" href="http://webservices.esa.int/blog/gallery/7/H7948_0005_SR2.png"> <div style="text-align: center"> <img src="http://webservices.esa.int/blog/gallery/7/previews-med/H7948_0005_SR2.gif" border="0" alt="Close view with the Super Resolution Channel of the HRSC camera ** Caption: This close-up of the surface of Phobos was taken on 16 March 2010 at a distance from the moon's centre of 660 km, with a spatial resolution of about 6 m/pixel. The image is available in the Planetary Science Archive. Credit: ESA/ DLR/FU Berlin (G. Neukum)." /> </div> </a>        <a id="res_20043" href="http://webservices.esa.int/blog/gallery/7/H7926_0011_SR2.png"> <div style="text-align: center"> <img src="http://webservices.esa.int/blog/gallery/7/previews-med/H7926_0011_SR2.gif" border="0" alt="Close view with the Super Resolution Channel of the HRSC camera ** Caption: This close-up of the surface of Phobos was taken on 10 March 2010 at a distance from the moon's centre of 278 km, with a spatial resolution of about 3 m/pixel. The image is available in the Planetary Science Archive. Credit: ESA/ DLR/FU Berlin (G. Neukum)." /> </div> </a>  <div align="center"> These close-ups of the surface of Phobos were taken on 10 March 2010 at a distance from the moon's centre of 278 km, with a spatial resolution of about 3 m/pixel. The images are available in the Planetary Science Archive. Credit: ESA/ DLR/FU Berlin (G. Neukum). </div> <div align="center">   </div> <div align="center">   </div> General ESTRACK Science Phobos Fly-by 2011 2011-01-07T15:16:44Z stuartclark ESA's 35m deep space antenna Cebreros swings into action http://webservices.esa.int/blog/post/7/1066 A short video clip recorded 9 March 2010, 19:50 CET, showing ESA's giant 35m deep space antenna at Cebreros station (Spain) - part of the Agency's ESTRACK network - swinging into position to start a ground station pass. The weather tonight in central Spain is crystal clear and cold (below freezing) - perfect! CEB was used last week to track Mars Express during Phobos closest approach... -- Daniel <object type="application/x-shockwave-flash" width="400" height="326" data="http://www.motionbox.com/external/hd_player/type%253Dhd%252Caffiliate_name%253Dpro%252Cvideo_uid%253D7c99dfb51913ebc5f4" id="ltVideoGoogleVideo"> <param name="movie" value="http://www.motionbox.com/external/hd_player/type%253Dhd%252Caffiliate_name%253Dpro%252Cvideo_uid%253D7c99dfb51913ebc5f4" /> <param name="wmode" value="transparent" /> <param name="allowScriptAcess" value="sameDomain" /> <param name="quality" value="best" /> <param name="bgcolor" value="#FFFFFF" /> <param name="FlashVars" value="playerMode=embedded" /> </object> General ESTRACK 2010-03-09T23:25:44Z danielscuka An experiment that extends over 117.5 million kilometres! http://webservices.esa.int/blog/post/7/1009 <img src="http://imagine.gsfc.nasa.gov/YBA/cyg-X1-mass/images/doppler.gif" alt="Johaan Christian Doppler 1803-1853" width="90" height="109" align="left" />Greetings again to all Phobos and Mars aficionados! Christian Andreas Doppler (29 November 1803 – 17 March 1853) The closest-ever flyby of Phobos to date will be dedicated to an experimental method called 'radio sounding'. The way radio sounding works is that we place the object (think a celestial body) we want to investigate close to the trajectory of a moving vehicle (think a spacecraft) equipped with a very stable and precise radio transmitter. We also need a very sensitive receiver equipped with measurement devices to record the received signal (think ground stations). The transmitter  on the moving vehicle sends out a continuous unmodulated signal (meaning no actual data will be transmitted - just an 'empty' carrier signal). The receiver receives the signal and then sends that signal to the measurement equipment, which will record the famous Doppler shift of the received signal's frequency (access more details under the 'Full story' link below) -- Hannes. As the transmitter on the moving vehicle moves past our object of interest, its velocity will be influenced by the object's gravity. This influence can be picked up by the measurement equipment on the receiving end as a minute variation in the Doppler shift as compared to an undisturbed trajectory. By calculating the expected Doppler shift and comparing this with that actually recorded, the effect due to gravity of the object on the moving vehicle can be isolated and interpreted. The resulting velocity profile lets scientists compute the 'shape' of the gravitational field of the object, which in turn yields information about the interior mass distribution of the object. Combining this information with spectrometer readings, subsurface sounding radar data and visual images will provide clues to the object's origin and formation process. The object of interest in this case is - you already guessed right - Phobos. Our moving vehicle is Mars Express - equipped with a precision transmitter - and on the receiving end we have the finest receiver that the world has to offer: NASA's mighty 70m deep space tracking station in Madrid (<a href="http://webservices.esa.int/blog/post/7/1006">read Daniel's previous post here about DSN stations</a>). To enhance the signal stability of the transmitter on board Mars Express, we will send an even more precise signal up to the spacecraft, which it locks on to it. To isolate other influences on the signal propagation, we will have Mars Express transmit in two different radio bands. So what we are doing with this closest-ever flyby is actually setting up an experiment that ranges across the inner Solar System and spans a whopping 117.5 million kilometres! To do that, we have to manoeuvre the spacecraft into a position close to the moon Phobos - the closer the better - and record the spacecraft's signal starting from several hours before the encounter to several hours after. This is necessary to precisely know the trajectory before and after the encounter. The first orbit manoeuvre to place Mars Express onto the correct trajectory was completed successfully a few days ago (<a href="http://webservices.esa.int/blog/post/7/1000">see my earlier blog post</a>). Two days ago, I finished the final planning for the second manoeuvre to be conducted next week and my Mars Express team mates in charge of implementing these are checking everything as I write these lines. Once my colleague who is working on the mission planning computer system right now lets me have it back, I will start preparing the final plans for the actual flyby and related events. In preparation for closest approach, two proficiency tests have been scheduled for this coming Monday and Wednesday (22 & 24 February). These tests will give ground station personnel and spacecraft controllers the opportunity to rehearse the appropriate steps and settings that will have to be made to properly record the spacecraft's radio signal. We will, in effect, simulate the flyby as if it were for real using Mars Express, with the only exception being that Phobos will actually not pass by. Stay tuned as we buckle up for the second orbit manoeuvre and get in shape to unlock yet another clue to the secret of Solar System formation! -- Hannes PS: Excellent NASA article on Doppler <a href="http://imagine.gsfc.nasa.gov/YBA/cyg-X1-mass/Doppler.html" target="_blank">http://imagine.gsfc.nasa.gov/YBA/cyg-X1-mass/Doppler.html</a>   Phobos Fly-By 2010 ESTRACK 2010-02-19T11:40:17Z hagriebel Phobos flyby radio science supported by NASA's Big Dish http://webservices.esa.int/blog/post/7/1006 <a id="res_11815" href="http://webservices.esa.int/blog/gallery/7/2571785802_5a9c5a4fb3_b.jpg"><img src="http://webservices.esa.int/blog/gallery/7/previews/2571785802_5a9c5a4fb3_b.gif" border="0" alt="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/" align="left" /></a>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! <a id="res_11816" href="http://webservices.esa.int/blog/gallery/7/2573190449_2a9b576be1_b.jpg"> <div style="text-align: center"> <img src="http://webservices.esa.int/blog/gallery/7/previews-med/2573190449_2a9b576be1_b.gif" border="0" alt="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" /> </div> </a>   <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605576298784/" target="_blank">DSA-2: ESA's 35m station at Cebreros, Spain</a> 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). <a id="res_11815" href="http://webservices.esa.int/blog/gallery/7/2571785802_5a9c5a4fb3_b.jpg"> <div style="text-align: center"> <img src="http://webservices.esa.int/blog/gallery/7/previews-med/2571785802_5a9c5a4fb3_b.gif" border="0" alt="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/" /> </div> </a>  <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605571353325/" target="_blank">DSS-63: NASA's 70m station at Robledo, Spain</a> "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: <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605571353325/" target="_blank">http://www.flickr.com/photos/thomas_ormston/sets/72157605571353325/</a> 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. <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605579459793/" target="_blank">http://www.flickr.com/photos/thomas_ormston/sets/72157605579459793/</a> 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. <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605576298784/" target="_blank">http://www.flickr.com/photos/thomas_ormston/sets/72157605576298784/</a> Finally, a couple sets showing ESA's own 35m antenna at Cebreros ... and ESA's Cebreros Operations Centre <a href="http://www.flickr.com/photos/thomas_ormston/sets/72157605581422127/" target="_blank">http://www.flickr.com/photos/thomas_ormston/sets/72157605581422127/</a> 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: <a href="http://www.esa.int/SPECIALS/Operations/SEM8YCSMTWE_0.html" target="_blank">http://www.esa.int/SPECIALS/Operations/SEM8YCSMTWE_0.html</a> Cebreros webcam: <a href="http://www.esa.int/SPECIALS/Operations/SEM26DSMTWE_0.html">http://www.esa.int/SPECIALS/Operations/SEM26DSMTWE_0.html</a> Phobos Fly-By 2010 ESTRACK 2010-02-17T12:23:25Z danielscuka