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By Daniel Fischer Every page present in Europe & the U.S.!
| Ahead | Awards 
The latest issue!
| An experimental German companion. Current mission news: MGS (latest pictures!) + Cassini + Galileo + NEAR |
SpaceViews, Space.com. Before the solution: CNN. SRTM had 9 extra hours: CNN, AP, Space.com, Fla. Today, SpaceViews. Status Reports # 20, 19, 18, 17 and 16. on a special TV channel for the SRTM on DFS-2 Kopernikus, 28.5 deg. East, 11.595 GHz V, analog PAL. There are daily half-hour programs from 14:30 UTC: details!
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"MPL" signals were probably interference - search endsMore theories about mission failure proposed: design error in descent system, explosion of gas hydrates in Martian soil blamedThe faint whisper heard from the direction of Mars with a big radio telescope two or three times after the arrival of the Mars Polar Lander (see Update # 170) had very much looked like emission from the lander's UHF antenna - the frequency, its temporal changes and so on had all fit deceivingly well. But as several intense observing campaigns with telescopes around the world since late January have come up empty, there is now a growing feeling that it wasn't Mars on the line after all: "Radio scientists at NASA's Jet Propulsion Laboratory have made a detailed analysis of data taken by a radio telescope at Stanford University on Jan. 4 and believe the suspect signal is more likely of terrestrial origin and not from Mars Polar Lander."Further analysis of data taken by radio telescopes in the Netherlands, Italy and at Stanford on Feb. 8 has not yielded any signal from MPL, though extensive analysis of all data taken during the last few weeks is ongoing. "We saw something in the Jan. 4 data that had all the earmarks of a signal and we felt we had to check it out," says Richard Cook, project manager for Mars Polar Lander at JPL: "In parallel, we started to perform analysis to determine if the signal came from Mars. Based on the latest results, it is unlikely that we will attempt to listen again." The main indication that the earlier signals were not from Mars but from Earth: They didn't fluctuate as one would expect for waves travelling long distance through the solar wind. Meanwhile more ideas have been voiced about what could have destroyed the MPL already on arrival. One technical explanation taken seriously in the community involves a possible design flaw of the lander system: The motion of the lander's legs in preparation for touchdown could have been misinterpreted by a sensor as contact with the ground - leading to the premature shutdown of the engines and the crash of the MPL. But there is also a chemical scenario that puts the blame on Mars itself: If there are gas hydrates in the Martian polar permafrost (like they are known in terrestrial ocean sediments and permafrost), the disturbance and heat induced by the incoming lander could have caused a fatal gas explosion. (van Groos & Guggenheim, Science of Feb. 11, p. 973) |
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Eros is a complex objectOnly a few days into the first close-up study of an asteroid, data from the Near Earth Asteroid Rendezvous mission already indicate that 433 Eros is no ordinary space rock: Observations made during NEAR's final approach and first days of orbit offer tantalizing glimpses of an ancient surface covered with craters, grooves, layers, house-sized boulders and other complex features. It is already certain that Eros' density is 2.4 grams per cubic centimeter, about the bulk density of Earth's crust and a near match of the estimates derived from NEAR's flyby of Eros in December 1998 (see Update #174 story 4): This asteroid a fairly solid object indeed and not a rubble pile like Mathilde (see Update # 51), the large asteroid NEAR passed and photographed in 1997.Even without in-depth analysis, pictures snapped with NEAR's Multispectral Imager offer several clues about Eros' age and geography. The large number and concentration of craters points to an older asteroid, uniform grooves across its craters and ridges hint at a global fabric and, perhaps, underground layers. In addition to numerous boulders, the digital camera has also captured brighter spots on the surface that NEAR scientists are anxious to study. NEAR's Near-Infrared Spectrometer has picked up variations in the asteroid's mineral composition, possibly the proportions of pyroxene and olivine, iron-bearing minerals commonly found in meteorites. For the next year, NEAR's instruments will continue to examine the potato-shaped asteroid's chemistry, geology, and evolutionary history. The mission also includes a radio science experiment to more precisely calculate Eros' density and mass distribution - clues critical to determining the asteroid's gravity and refining NEAR's orbit. NEAR's scientific capabilities expand soon, when its X-ray/Gamma-Ray Spectrometer and Laser Rangefinder are turned on within the next two weeks. The spectrometer will measure important chemical elements such as silicon, magnesium, iron, uranium, thorium and potassium; the laser scans will determine Eros' precise shape. |
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Radar mapping can go the full 9 daysPropellant conservation measures have paid off and Endeavour's crew could be notified on Feb. 17th that the mapping operations will continue for the full nine days as planned prior to launch. Several fuel-saving steps have been implemented, including a change in the way excess water is dumped overboard, and allowing more flexibility in holding Endeavour and the 61-meter mast in the proper attitude. The final conservation measure will be the deletion of the eighth trim burn, which controllers believe can safely be deleted by adjusting the sixth and seventh burns without a disruption to data collection.Until early on Feb. 18th, the Shuttle Radar Topography instruments aboard Endeavour had mapped 83 percent, or almost 100 million square kilometers, of the target area once, an area larger than the Americas, Africa and Australia combined. More than 50 percent of the target area, over 60 million square kms, has been mapped with two or more passes. Endeavour images 100000 square kilometers of land every minute, a rate that would allow the Shuttle to map the state of Alaska in 15 minutes. And while the radar mapping continues, a student-operated camera mounted in one of Endeavour's windows also has set a record pace. So far this EarthKAM has sent down almost 1400 photos of Earth to middle school students.
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IRDT experiment a success in principle - but capsule came down too fastThe first-ever test of the new reentry system called IRDT (Inflatable Reentry and Descent Technology) has been declared a success, now that the smaller of the two experimental objects to be returned with this innovative technology (see Update # 172 story 5), a sensor-equipped demonstrator, has finally been recovered - with some damages, though. The Fregat upper stage of the Russian Soyuz rocket and the much smaller demonstrator have both landed in the Russian steppe on the 9th at 7:59 UTC, but at that time the correct working of their respective IRDT systems could only be determined by radar tracking. The search for the Fregat upper stage, which carried a larger version of the same IRDT, will be continued.Due to unfavorable weather conditions and locator transmitter failures on both objects, the recovery of the demonstrator was delayed by several days. First inspection of it confirmed that the reentry as such was successful: No signs of burn were found on the heat shield. However, there had been deviations during the flight phase after reentry: It appears as if the calculated rate of fall had been exceeded so that the demonstrator was deformed on impact. The cause of increased rate of fall can only be clarified after detailed examination to be undertaken by Lavochkin in Moscow, where the IRDT technology was developed. The outstanding feature of the innovative heat shield is its low weight. Like a liferaft used in aircraft or ships, the shield is folded up and safely stored in the space transportation system. The IRDT will inflate shortly before reentry of atmosphere and then act as a drag parachute. As the heat shield can be launched in a small package in contrast to other reentry systems so far in use (e.g. the Space Shuttle or capsules), space, weight and transportation costs can be saved. A wealth of IRDT applications could be possible in the future, for example automatic and considerably cost-effective transports of samples and cargos from the International Space Station back to Earth. Or rocket upper stages could be re-used on a routine basis. |
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NASA's next comet spacecraft: CONTOUR construction begins!NASA's Comet Nucleus Tour, or CONTOUR, mission this month took a giant step closer to its launch when the project received approval to begin building the spacecraft. Planned for a July 2002 launch, CONTOUR is expected to encounter Comet Encke in November 2003 and Comet Schwassmann-Wachmann 3 in June 2006. The mission has the flexibility to include a flyby of Comet d'Arrest in 2008 or an as-yet undiscovered comet, perhaps originating from beyond the orbit of Pluto. Such an unforeseen cometary visitor to the inner solar system, like Comet Hale-Bopp discovered in 1995, would present a rare opportunity to conduct a close-up examination of these mysterious, ancient objects which normally reside in the cold depths of interstellar space. |
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Space opens for business with signing of Mir lease - station could become a hotel ...RKK Energiya, the privatized Russian company that built and operates the Russisn space station, has signed an agreement granting Amsterdam-based MirCorp rights for commercial use - e.g. as the ultimate hotel - for the rest of the station's life, while ownership of the station remains with the Russian government, and Energiya will still operate it: BBC, Spaceflight Now, SPIEGEL, AP, SpaceViews.Earlier stories: Space.com, AP, Space Daily, Fla. Today, AvNow. Mir now 14 years in orbit: RP. Mir movie plans continue: AP. NASA approves additional mission to the ISS - there will be STS-101 before and STS-106 after the arrival of Zvezda: ISS Status, Spaceflight Now, Discovery, SpaceViews. Hearing on the ISS problems - tough questions asked to NASA chief: SpaceRef, SpaceViews, Fla. Today. Starshine has reenteredon Feb. 18th around 14:30 UTC - no reports of observations yet: Reentry Page, previews from SpaceScience, Discovery and Space.com.Galileo's closest Io flyby on Feb. 22ndThe Galileo spacecraft is trying to go "three for three" as it attempts its third and closest flyby of Jupiter's fiery moon Io, the most volcanic body in the solar system - the spacecraft will dip to only 200 kilometers above Io's surface 14:32 UTC on February 22nd: JPL Release, SPIEGEL, Space.com, SpaceViews stories.Mushy magma below Io's crust? An old idea about the interior of Jupiter's volcanic moon, which had fallen out of favor for a decade or two, makes a comeback: PSR Discoveries. The first Far UV image of a meteorhas been obtained by the Global Imaging Monitor of the Ionosphere (GIMI) instrument on board the DoD Space Test Program's Advanced Research and Global Observation Satellite (ARGOS). The image was taken on November 18, 1999, during the last Leonid maximum: Space Daily, BBC, Space.com.Deep NIR looks into the Universehave been produced with the Very Large Telescope as part of an attempt to locate very distant galaxies that have so far escaped detection in the visual bands - the first results are very promising and some concentrations of galaxies at very large distances were uncovered: ESO Press Release, RP story. |
Coronal Mass Ejection heading towards Earth!On Feb. 17th a medium-sized solar flare erupted from a sunspot group near the middle of the solar disk, accompanied by a coronal mass ejection (CME) that appears to be headed directly for our planet. There's no cause for alarm, but this CME could trigger beautiful aurorae and other geomagnetic activity when it passes by our planet around February 20th: SpaceScience and ESA Science News, BBC and Space.com = EZ stories. A geomagnetic storm happened on Feb. 12th: Discovery story. Watch Today's Space Weather!A quasar with a redshift of 5.5has set a new distance record for these extremely bright galactic nuclei (but galaxies are known with much higher z values such as 6.7 - see Updates # 104 and 172): a paper, JPL and U.FL Press Releases and BBC story (which first got it wrong - "Most distant object in Universe found" - but has since corrected it).Every 3rd astronomer wanted XMM timeThe European X-ray observatory XMM-Newton is extremely popular: Requests from 2500 astronomers, 30% of the 'total population', for observing time had been received. Only 250 proposals could be selected for the first 18 months of regular observations, starting this June - and only the scientific value, not where the scientists were from, was the criterion. ESA has only funding for 2 1/2 years of operation, which costs 10 million Euros/year, while the satellite should be good for at least 10 years... (Space News Feb. 21)One of the first XMM spectra, of the double star HR1099: Columbia Press Release. XMM's mini-camera spots the Earth - one of the two Small Visual Monitoring Cameras (VMC): ESA Science News. U.S. detector lost with Astro-E was originally planned for Chandra: The super-cooled X-ray spectrometer that flew on the ill-fated Japanese satellite was part of the original large NASA satellite AXAF - which in 1992 was split into two missions, one of which eventually was launched as Chandra. The other satellite was later cancelled, but the detector of a new type (that will also be used in future missions) was invited to Astro-E... (Space News Feb. 21) Astro-E leaves a void: Space Daily. Chandra spectroscopy of gas near a galactic center demonstrates the existence of a blanket of warm gas that is expanding rapidly away from the central engine of NGC 5548: MSFC Press Release, NASA Science News version.
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Compiled and written by Daniel Fischer
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