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By Daniel Fischer Every page present in Europe & the U.S.!
| Ahead | Awards 
The latest issue!
| A German companion - only available here! Current mission news: MGS (latest pictures!) + Cassini + Stardust |
Up to one-tenth of the stars in the Milky Way galaxy lie in a habitable zone that would permit their planets to harbor life - and most of them are on average 1 Gyr older than the Sun, allowing much more time, in theory, for any life to evolve: New Sci., Guardian, Telegr., ST, NZ, BdW, RP. Planet formation processes - why some grow big: CfA Release.
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Stardust's comet visit a smashing success: lots of dust captured and measured - and the sharpest pictures of a nucleus everSeveral dusty jets seen and felt, but the Whipple shields held / 250 km minimum distance closest ever for a »seeing« spacecraft / Pictures & data still trickling inThe flyby of comet Wild 2 by NASA's Stardust spacecraft on January 2nd has been a huge success: shielded well by its »Whipple bumpers« it made it safely through the inner coma, shooting great pictures of the comet's nucleus and measuring and collecting lots of dust particles. To the mission team's surprise the coma did not have a smooth density profile but was dominated by several dense dusty jets: those were easily seen by the navigation camera - now doubling as a science instrument - and also felt directly als distinct bursts of data from the dust instruments when Stardust passed through the jets. No harm was done, though, and the scientific output will only be all the greater. The dust counters e.g. should have provided detailled space profiles for different particle masses.The huge count rates in the dust detectors alone provide ample proof that the aerogel collectors should now be well loaded with precious comet stuff. And the return of the sample capsule to Earth has already been practised - without problems - last summer when Stardust was at exactly the same location along its orbit. The arrival of the small container in the Utah desert almost exactly two years from now will allow all laboratory techniques one can think of - and many not even on the drawing boards yet - to be applied to this supposedly very primordial material from the earliest times of the solar system. But the in-situ science performed by Stardust is already now turning the mission into a »smashing« success, while the downlink is still trickling in via the spacecraft's small HGA and won't be complete until the morning of January 4th. The 5 (of 72) pictures seen so far show a surprisingly spherical nucleus (perhaps just an artefact of perspective), with lots of small depressions: These are not impact craters but in all likelyhood locations where the cometary ice is sublimating into gas which is then dragging dust with it. Thus those are »very sublime pictures,« according to lead scientist Don Brownlee, both in the poetic sense and w.r.t. the physical change of state. At least five distinct dust jets can be discerned in the early images, and some of them can be linked directly to specific vents - something that was not so clear in the cases of Halley and Borrelly, the only other comet nuclei imaged from close-up. Stardust's roughly 250 km minimum distance has set a new record for a »seeing« spacecraft, by the way: Giotto came a bit closer to Grigg-Skjellerup in 1992 but then its camera had long been killed by Halley's dust.
As Mars Express changes orbit to polar,
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In the narrowing polar orbit, the orbiter will fly directly over the landing site at an altitude
of 315 km on 7 January 2004, at 12:13 UTC. The reduced distance, the ideal angle of overflight
and originally foreseen communication interfaces between the 'mother' and 'baby' will increase
the probability of catching signals from the ground - all attempts by Mars Odyssey and Jodrell
Bank (which can no longer be used) have been futile to date. Meanwhile, further scenarios of
what could have happened to Beagle 2 are being discussed, including the remote probability of
Beagle 2 having landed in a 1 km crater, which has been recently discovered within the landing
ellipse by Mars Global Surveyor. However, the chance of Beagle 2 landing in this exact spot is
thought to be very low and this is just one of the areas that is being currently investigated.
If the lander software is running as planned, and according to the initial timing dictated by the onboard clock, a number of the programmed communication sessions have already passed, without the slightest hint of a signal being received. One possible explanation that has been raised for the apparent silence is the potential for incompatibility between the systems on board Beagle and those used by Mars Odyssey. The Beagle team has been in constant contact with JPL where scientists are checking whether there may be any problems with the transmitters and receivers aboard Odyssey. It is important to note that neither of the communication routes attempted so far has ever been tested: Therefore it is possible that the best opportunity for successful communication may arise when Mars Express achieves its final orbit and can take part in the search for Beagle. ESA certains sees it so, too, and thus won't give up on Beagle 2 anytime soon (see last update). A backup has been built into the communication schedule such that if 10 scheduled sessions pass unsuccessfully then Beagle 2 will switch to an emergency mode 'search mode 1', and if a further 10 communication sessions are unsuccessful, Beagle will then switch to 'search mode 2' which involves the production of a signal throughout the martian day. With two 'search mode 1' sessions taking place each day, the adoption of search mode 2 would, in theory, begin on January 5th - soon after the date when Mars Express is first available for communication. A further explanation for the lack of contact between Beagle and the Earth is that the onboard clock may have been corrupted during the entry, descent, and landing stage of the mission: It is possible that Beagle 2 is signalling correctly but not at a time when Mars Odyssey is passing or when Jodrell Bank can 'see' Mars. Consequently, when Beagle assumes 'search mode 1' and begins signaling more regularly it may be possible for Odyssey or Jodrell to pick up the 'additional' transmissions. In order to address the potential problems associated with an incorrect clock setting on Beagle 2 right now, a 'blind command' was transmitted by Mars Odyssey during the pass over the landing site during session 5 on the morning of Dec. 27: The hope is that Beagle may be able to receive such signals, but is not currently able to transmit. The effect of this command would be to reset the onboard clock with the aim of resynchronising the process and prompting an opportunity for successful communication. 'Blind commands' can also be used by the 'Lander Operations Control Centre' to control other processes onboard Beagle 2 that may have prevented it from talking to Earth so far, without the requirement for two-way communication. Meanwhile the Mars Express orbiter is in a stable and precise orbit around Mars. The essential Mars Orbit Insertion (MOI) manoeuvre had been completed on 25 December at 2:47 UTC. This brought the spacecraft as close as 400 kilometres to the surface of Mars. Afterwards, the spacecraft went into a highly elliptical orbit, going as far as 188,000 kilometres away from the planet. The most essential part of the Mars Express mission is performing very well, and on 27 December the mission control team at ESOC prepared the next steps to turn Mars Express from a near-equatorial orbit into a polar orbit: A series of manoeuvres will start with a major move on 30 December, when the main engine will be fired again for three minutes. These key manoeuvres will allow the spacecraft to get even closer to Mars: That will not only allow more frequent overflights of the Beagle 2 landing area, but also ensure the beginning of the orbiter's science mission. |
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On the Horizon for 2004: coming attractions in space
January 4 + 25 | Landings of the Mars Exploration Rovers Spirit + Opportunity | Homepage |
February 26 | Launch of Rosetta, the most complex comet mission yet, on Ariane 5 | Homepage |
April ? | Launch of Cosmos 1, the first solar sail in orbit, privately financed | Homepage |
April 20 | Launch of Gravity Probe-B, a long-delayed NASA mission to test General Relativity. | Homepage |
May 11 | Launch of MESSENGER, a NASA satellite to orbit Mercury | Homepage |
Early to mid-May | Two potentially bright comets peak, first NEAT, then LINEAR | Analysis of visibility conditions |
June ? | Launch of the Lunar Trailblazer, the first commercial Moon orbiter | Homepage |
June | Launch of the TC-2, the 2nd Double Star satellite | Homepage |
June 8 | Transit of Venus in front of the Sun - the first time since 1882! | One of many portals |
June 20 | Launch of Aura, the next EOS environmental satellite | Homepage |
July 1 | Arrival of Cassini at Saturn and orbit insertion | Homepage |
July 15 | Launch of Swift, a NASA satellite to hunt for GRBs | Homepage |
August 12 | Perseid meteor shower peaks, with possible outbursts | IMO Shower calendar entry |
August 30 | Launch of Lunar-A, a much delayed Japanese mission | NSSDC entry |
September 8 | Genesis returns with samples of the solar wind. | Homepage |
September 12 | Earliest return-to-flight date for the shuttle, with mission STS-114 to the ISS | RTF Homepage |
September 27 | First launch of the ATV, ESA's ISS cargo truck | Homepage |
October 14 | Deep partial solar eclipse in Alaska and Siberia | Map |
November 2 | MESSENGER flyby at Venus on the way to Mercury | Homepage |
December | SMART-1 reaches the Moon and starts settling into orbit | Homepage |
December 30 | Launch of the Deep Impact mission that will send a big mass into the nucleus of comet Tempel 1 | Homepage |
First Chinese-European "Double Star" satellite successfully launchedOn December 29 at 19:06 UTC the Chinese National Space Administration (CNSA) successfully launched TC-1, the first of two scientific satellites known as Double Star. The spacecraft, called "Tan Ce 1" which in Chinese means "Explorer 1," took off from the Chinese launch base in Xichang, in Sichuan province, on board a Long March 2C launcher. The European Space Agency has contributed to the Double Star mission by providing eight on-board scientific instruments. Double Star follows the footsteps of ESA's Cluster mission and will study closely the interaction between the solar wind and the Earth's magnetic field.In 1997, the CNSA had invited ESA to participate in Double Star, a two-satellite mission to study the Earth's magnetic field, but from a perspective which is different from that of Cluster and complementary to it. An agreement to develop this joint mission was signed on 9 July 2001: ESA's contribution to the mission includes eight scientific instruments, of which seven are spares from the Cluster mission, and support to the ground segment for four hours each day via ESA's satellite tracking station in Villafranca, Spain. The instruments on board Double Star are the first ever European ones to be flown on a Chinese satellite. The 2nd Double Star will follow next summer. |
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All other historical issues can be found in the Archive.
The U.S. site of this Cosmic Mirror has been visited
since it was issued (the German site has no counter).
Compiled and written by Daniel Fischer
