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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 |
was obtained with the ACS on Aug. 24 and has finally been released [SN]. Still more MGS pics: NASA Release, Ast. Early Mars - frozen but habitable? AstroBio pts. 1 and 2. A movie of Opportunity heading for Mars - as seen from a RocketCam: APOD. The 2003/4 Mars landings: Science (sidebar). Keeping Mars landers clean: CSM. The 2005 Mars Reconnaissance Orbiter: JPL Feature, SC. Aurora mission design contracts: ESA Release, BBC. NASA's Mars future remains fuzzy: SC.
| Posted in part from the HQ of the European Southern Observatory in Garching, Germany, and the European Space Operations Centre of ESA in Darmstadt, Germany |
ESA's first lunar mission under way - ion engine worksIn a way it is two complete missions wrapped into one - and at a bargain price: The SMART-1 mission by the European Space Agency that began early on September 28 will first test an ion engine (which was already fired up briefly on Sept. 30) during a long and complicated journey to the Moon which also involves three gravity assists. And once in a safe orbit, in March 2005, SMART-1 will study the lunar surface with an array of instruments, some never used so close to the Moon. SMART-1 was one of three payloads on Ariane Flight 162: The generic Ariane-5 lifted off from the Guiana Space Centre, Europe's spaceport at Kourou, French Guiana, at 23:15 UTC on 27 September. 42 minutes after launch, all three satellites had been successfully released into a geostationary transfer orbit (742 x 36,016 km, inclined at 7 degrees to the Equator).SMART-1 quickly deployed its solar arrays and is currently undergoing initial checkout of its systems under control from ESA/ESOC. As the first mission in the new series of Small Missions for Advanced Research in Technology, SMART-1 is mainly designed to demonstrate innovative and key technologies for future deep space science missions. The first technology to be demonstrated on SMART-1 will be Solar Electric Primary Propulsion (SEPP), a highly efficient and lightweight propulsion system that is ideal for long-duration deep space missions in and beyond our solar system. SMART-1's propulsion system consists in a single ion engine fuelled by 82 kg of xenon gas and pure solar energy. This plasma thruster relies on the Hall effect to accelerate xenon ions to speed up to 16,000 km/hour. It is able to deliver 70 mN of thrust with a specific impulse 5 to 10 times better than traditional chemical thrusters and for much longer durations. |
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At first, the ion engine will fire almost continuously - stopping only when the spacecraft is in the
Earth's shadow - to accelerate the probe (at about 0.2 mm/s/s) and raise the altitude of its perigee
from 750 to 20,000 km. This manoeuvre will take about 80 days to complete and will place the spacecraft
safely above the radiation belts that surround the Earth. Once at a safe distance from Earth, SMART-1
will fire its thruster for periods of several days to progressively raise its apogee to the orbit of
the Moon. At 200,000 km from Earth, it will begin receiving significant tugs from the Moon as it
passes by. It will then perform three gravity-assist manoeuvres while flying by the Moon in late
December 2004, late January and February 2005. Eventually, SMART-1 will be captured and enter a
near-polar elliptical lunar orbit in March 2005. SMART-1 will then use its thruster to reduce the
altitude and eccentricity of this orbit. In April 2005 SMART-1 will begin the second phase of its mission, due to last at least six months and dedicated to the study of the Moon from a near polar orbit. The Advanced/Moon Micro-Imaging Experiment (AMIE) miniaturised CCD camera will provide high-resolution and high-sensitivity imagery of the surface, even in poorly lit polar areas. The highly compact SIR infrared spectrometer will map lunar materials and look for water and carbon dioxide ice in permanently shadowed craters. The Demonstration Compact Imaging X-ray Spectrometer (D-CIXS) will provide the first global chemical map of the Moon and the X-ray Solar Monitor (XSM) will perform spectrometric observations of the Sun and provide calibration data to D-CIXS to compensate for solar variability. The SPEDE experiment used to monitor Solar Electric Primary Propulsion interactions with the environment will also study how the solar wind affects the Moon. In addition to valuable lunar science, SMART-1's payload will be involved in the mission's technology demonstrations to prepare for future-generation deep space missions. For instance, the AMIE camera will be used to validate the On-Board Autonomous Navigation (OBAN) algorithm, which correlates data from sensors and star trackers to provide navigational data. It will also participate in a laser communication link experiment with ESA's optical ground station at the Teide Observatory in Tenerife, Canary Islands, trying to detect an incoming laser beam from the ground. Using both AMIE and KaTE hardware, the Radio Science Investigation System (RSIS) experiment will demonstrate a new way of gauging the interiors of planets and their moons by detecting the well-known tilting motion of the Moon. This technology can be used later by ESA planetary missions. |
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Evidence mounts against single impact as cause for the K/TB mass extinctionSo far it's still a minority view, but some palaeontologists now read the geological record in a way that not a single big impact (at the famous Mexican Chicxulub site) doomed the dinosaurs and many other life forms 65 million years ago but that several impacts spread over hundreds of thousands of years were involved. Gerta Keller of Princeton University and a growing number of colleagues around the world are turning up evidence that, rather than a single event, an intensive period of volcanic eruptions as well as a series of asteroid impacts are likely to have stressed the world ecosystem to the breaking point. Although an asteroid or comet probably struck Earth at the time of the dinosaur extinction, it most likely was, as Keller says, "the straw that broke the camel's back" and not the sole cause.Perhaps more controversially, Keller and colleagues contend that the "straw" - that final impact - is probably not what most scientists believe it is. For more than a decade, the prevailing theory has centered on a massive impact crater in Mexico. In 1990, scientists proposed that the Chicxulub crater, as it became known, was the remnant of the fateful dinosaur-killing event. Keller has accumulated evidence, including results released this year, suggesting that the Chicxulub crater probably did not coincide with the K/T boundary. Instead, the impact that caused the Chicxulub crater was likely smaller than originally believed and probably occurred 300,000 years before the mass extinction. The final dinosaur-killer probably struck Earth somewhere else and remains undiscovered - and may well be hidden somewhere in Europe. Keller does not work with big fossils such as dinosaur bones commonly associated with paleontology. Instead, her expertise is in one-celled organisms, called foraminifera, which pervade the oceans and evolved rapidly through geologic periods. Some species exist for only a couple hundred thousand years before others replace them, so the fossil remains of short-lived species constitute a timeline by which surrounding geologic features can be dated. In a series of field trips to Mexico and other parts of the world, Keller has accumulated several lines of evidence to support her view of the K/T extinction. She has found, for example, populations of pre-K/T foraminifera that lived on top of the impact fallout from Chicxulub: These fossils indicate that this impact came about 300,000 years before the mass extinction. |
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Galileo is history as legendary orbiter plunges into JupiterThe Galileo spacecraft's 14-year odyssey came to an end on Sunday, Sept. 21, when the spacecraft passed into Jupiter's shadow, then disintegrated in the planet's dense atmosphere at 18:57 UTC. The Deep Space Network tracking station in Goldstone, Calif., received the last signal at 19:43:14 UTC; the delay was due to the time it takes for the signal to travel to Earth. Hundreds of former Galileo project members and their families were present at NASA's Jet Propulsion Laboratory in Pasadena, Calif., for a celebration to bid the spacecraft goodbye. Having traveled approximately 4.6 billion km, the hardy spacecraft endured more than four times the cumulative dose of harmful jovian radiation it was designed to withstand. During a previous flyby of the moon Amalthea in November 2002, flashes of light were seen by the star scanner that indicated the presence of rocky debris circling Jupiter in the vicinity of the small moon.Another measurement of this area was taken today during Galileo's final pass. Further analysis may help confirm or constrain the existence of a ring at Amalthea's orbit. The spacecraft was purposely put on a collision course with Jupiter because the onboard propellant was nearly depleted and to eliminate any chance of an unwanted impact between the spacecraft and Jupiter's moon Europa, which Galileo discovered is likely to have a subsurface ocean. Without propellant, the spacecraft would not be able to point its antenna toward Earth or adjust its trajectory, so controlling the spacecraft would no longer be possible. The possibility of life existing on Europa is so compelling and has raised so many unanswered questions that it is prompting plans for future spacecraft to return to the icy moon. |
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ISS UpdateThe next shuttle mission will not go before May or June 2004 - that's already official - or possibly October 2004. Science@NASA on ISS experiments and coverage of Oct. 1: FT. Sep. 30: FT, CNN, SC, ST, NZ. Sep. 29: BBC. Sep. 27: FT. Sep. 26: FT. Sep. 25: AP, FT, SC. Sep. 24: WP, AD, Dsc., ST. Sep. 23: BBC, AP, FT, AFP, ST, Welt, NZ. Sep. 21: SR. Sep. 19: BBC. Sep. 18: AIP FYI, FT, WP, BBC, ST. Sep. 17: FT, BBC, Dsc, AP, ST. Sep. 16: SN, FT 3, 2, 1, Rtr. |
OSP Level 2 Requirements released:
summary,
NASA Release,
FT,
ABC.
One less bidder for the OSP:
SC.
Lockheed, Northrop Grumman join forces for OSP:
Press Release,
ST.
Serious OSP questions remain:
SR.
SpaceShipOne: a progress report by SpaceRev. SS1 to use SpaceDev engine: Scaled and SpaceDev Press Releases, SC, ST. Shenzhou 5 likely to fly in mid-October, probably within a week after Oct. 10, reports from China now say: SD (earlier), AFP (earlier, still earlier), New Sci., VOA, BBC, CNN, SC, ST, Welt. |
U.S. Space Weather service in deep troubleThe Space Environment Center's financial situation has turned dire - for the coming fiscal year, the House Committee-recommended funding creates a huge shortfall, and the Senate Committee's recommendation implies no support for space weather service at all this year: SEC Statement, SC.NASA selects 2 Magnetospheric Multiscale Mission proposals for feasibility studies - MSM will explore fundamental plasma-physics processes of magnetic reconnection, particle acceleration and turbulence in the Earth's magnetosphere: NASA Release. TIMED mission extended: GSFC Release. Chandra spectroscopy of the MoonChandra observations of the bright portion of the Moon have detected X-rays from oxygen, magnesium, aluminum and silicon atoms - the X-rays are produced by fluorescence when solar X-rays bombard the Moon's surface: Chandra Press Release, Ast., SciAm, AFP, Dsc., SC.Swift launch to be delayed until next May or so because of instrument problems on the GRB observatory: S&T. Gravity Probe B launch planned for Dec. 6: ELV Status. What the SIRTF launch was like: CSM. Exploding star hunters make historyTwo British amateur astronomers have found more than 100 exploding stars, or supernovae - more than any other individuals: BBC.Harvesting supernova precursor stars - a big survey with the HST of numerous galaxies is underway, and if a supernova explodes eventually in one of them, we may have a picture of the precursor: ESA HST Release, Ast. Evidence for spinning black holes in the Milky Way may have been found by Chandra & Newton: CXO Press Release, graphics. First supernovae quickly seeded the Universe with heavy elementsSimulations show that high energy Population III supernovae should have expelled over 90% of the stellar metals into a region ~1 kpc across over a timescale of 3-5 Myr - due to this burst-like initial star formation episode, a large fraction of the universe could have been endowed with a metallicity floor at z > 15: a paper by Bromm & al., CfA Press Release, SC. Dark matter trouble? SF Gate. The lights go out in the cosmos: RAS PR, Ast., NSU, BBC, SC, BdW.Refining the properties of Dark Energy with supernovae of type Ia observed with the HST: a paper by Knop & al. and an LBL Press Release. Universe in a Black Hole? SC. Big rip again: Dsc. Multiverses: Guardian. China to join Galileo satellite navigation projectChina will play a role in Galileo, the European satellite navigation system designed to compete with GPS: EC, ESA Press Releases, New Sci., BBC, ST. |
Three more moons of Uranushave been found, two with Hubble and one with the Subaru telescope - they are about 12 to 16 km across and have eluded even Voyager 2; the total is now 25: HST and IfA Press Releases, Ast., FT, BdW, NZ, RP.Honduran Moon rock returned by NASA - presented in 1973 to the Honduran people, the Moon rock mysteriously disappeared but had been recovered in a sting operation in 1998: NASA Release, BBC, CollectSpace, AP. Are GRBs dangerous?Some theories suggest that anything caught in the beam, out to a distance of around 200 light years, will be vaporised: ESA News, NZ.One mass extinction blamed on a GRB, 443 million years ago: a paper by Melott and coverage by New Sci., NSU, BdW. The case V838 Mon - did a star swallow giant planets? One more attempt to explain the mysterious eruptions: Univ. Sydney PR, BBC, New Scientist, Ast. Explaining the "winking" of the star KH 15D: CfA PR, Ast., Rtr, BdW. "See-through" galaxy orbits AndromedaAstronomers have found another galaxy orbiting the Andromeda Galaxy - but don't bother trying to find it in your telescope as it's practically invisible against the bright disk of giant Andromeda: NOAO Press Release, Ast., SC, RP.Alien stars in the Milky Way, from the Sgr dwarf galaxy: Univ. VA PR [SN], pictures, APOD, S&T, BBC, Rtr, SC, BdW. Distant star bursts provide key to the origin of Galaxies - the biggest and most distant galaxies in the Universe were observed with the world's most sensitive submillimetre camera, SCUBA: PPARC PR. The 2nd Ed. of the USNO CCD Astrograph Catalog(UCAC2) has now been released - it comprises over 48 million stars with brightness ranges from 8th to a limit of 16th magnitude and covers about 85 percent of the entire sky and is he most astrometrically precise star catalog ever produced by ground-based instrumentation: USNO Press Release.JCMT gets a new sub-mm 'camera', SCUBA 2 with many more pixels: PPARC PR.
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All other historical issues can be found in the Archive.
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Compiled and written by Daniel Fischer
(send me a mail to [email protected]!), Skyweek
