Jonathan's Space Report No. 543 2005 Jan 24, Somerville, MA ------------------------------------------------------------------------------- Greetings from the great northeast blizzard... Huygens on Titan ---------------- The European Space Agency's Huygens probe landed on Titan on Jan 14. The spacecraft reached the entry reference point at 1270 km above the surface at 0905:56 UTC, and entered the atmosphere protected by its heat shield. Relative to the target world, Huygens entered from an escape hyperbola with a periapsis 1100 km below the Titanian surface. By 0910:24 UTC the entry was complete and at about 160 km altitude the pilot parachute deployed, followed two seconds later by the aft cover and the main 8.3-meter diameter parachute. At around 0910:47 UTC the heat shield was jettisoned and the initial parachute descent began, ending at 0925:21 UTC when the main parachute was jettisoned and a smaller 3.0-meter diameter stabilizer parachute took over. The DISR camera snapped remarkable images of an apparent coastline during the ensuing slower 2-hour descent to the surface. The probe returned evidence of water-ice rocks and occasional liquid methane rain, with temporarily dry river channels draining into muddy basins. Touchdown on the Titanian surface was at 1138:11 UTC, at latitude 11 S longitude 192W. Huygens continued to transmit signals till at least 1448 UTC when the spacecraft set as seen by the Parkes radio telescope, which received the last bits of data 67 minutes later. Titan (Saturn VI) is one of the largest worlds in the solar system. I don't distinguish between 'moons' and 'planets' - it's more interesting to look at the physical nature of the world in question than which object it happens to be orbiting. After the gas giants, Earth and the larger terrestrial planets have densities of 3 to 5 grams per cubic centimeter - the rocky worlds; These are distinguished from Ganymede, Titan, Callisto, Triton and the other outer solar system worlds, which have densities of 2 grams per cubic centimeter or less and are considered icy worlds. Largest known worlds in the Solar System (radius > 750 km ) ---------------------------------------- Eq. Radius Gas giants: Jupiter 71492 km Saturn 60268 km Uranus 25559 km Neptune 24764 km Rocky and Icy worlds: Earth 6378 km Venus 6052 km Mars 3397 km Ganymede 2634 km (Jupiter III) Titan 2575 km (Saturn VI) Mercury 2440 km Callisto 2403 km (Jupiter IV) Io 1830 km (Jupiter I) Luna 1738 km (Earth I) Europa 1565 km (Jupiter II) Triton 1353 km (Neptune I) Pluto 1151 km Titania 789 km (Uranus III) Rhea 764 km (Saturn V) Oberon 761 km (Uranus IV) Sedna 750 km? (90377) Deep Impact ----------- The Deep Impact space probe was launched from Cape Canaveral on Jan 12 at 1847 UTC. The Boeing Delta 7925 rocket reached a 167 x 167 km x 29.7 deg parking orbit at 1856 UTC, and then restarted at 1911 UTC to enter a 163 x 4170 km orbit. The third stage separated and burned at 1914 UTC, and after separation at 1921 UTC there were four objects on an Earth escape trajectory: the PAM-D third stage, two despin weights, and the Deep Impact probe. By Jan 19 the probe was 1.9 million km from Earth and on track to enter a 0.981 x 1.628 AU solar orbit inclined 0.6 deg to the ecliptic. On 2005 Jul 3 the 601 kg flyby spacecraft will release the 372 kg impactor spacecraft and on Jul 4 the impactor will hit comet 9P/Tempel-1 at a relative velocity of 10.2 km/s. The experiment, carried out 7.5 light minutes from Earth, will make a crater and a plume of material, and observations by the flyby spacecraft and from the Earth will improve understanding of the composition and structure of cometary nuclei. Deep Impact is the Discovery-8 mission; the Discovery program was begun in the early 1990s as the planetary counterpart to the Explorer missions. One mission (CONTOUR) failed soon after launch and another (Genesis) had a rough landing but may still return results; NEAR, Mars Pathfinder and Lunar Prospector were very successful and the remaining missions are still in play. Mission Launched Name Mission Status Discovery-1 1996 Feb 17 NEAR Shoemaker Eros orbiter Landed Eros 2001 Discovery-2 1996 Dec 4 Mars Pathfinder Mars lander Landed Mars 1997 Discovery-3 1998 Jan 7 Lunar Prospector Moon orbiter Impacted Moon 1999 Discovery-4 1999 Feb 7 Stardust Comet flyby Utah landing due 2006 Discovery-5 2001 Aug 8 Genesis L1 mission Crashed in Utah 2004 Discovery-6 2002 Jul 3 Contour (Comet flybys) Destroyed 2002 Discovery-7 2004 Aug 3 Messenger Mercury orbiter In solar orbit Discovery-8 2005 Jan 12 Deep Impact Comet impact In solar orbit Discovery-9 - Dawn Asteroid orbiter Under construction Discovery-10 - Kepler Planet hunter Under construction Genesis ------- After the Genesis capsule slammed into Earth last Sep 8, the Genesis bus was left on a deep Earth orbit. It reached apogee at 1.28 million km on Oct 7, and fell back in to a 60670 km perigee on Nov 6 when its orbit was tweaked to ensure departure from the Earth-Moon system on Nov 17. It is now in a 0.896 x 0.990 AU orbit around the Sun inclined 0.28 deg to the ecliptic, according to data on JPL's Horizons system. SMART-1 ------- ESA's SMART-1 lunar probe entered lunar orbit on Nov 15 in a 4962 x 51477 km x 81.1 deg orbit. Its ion engine has now lowered the orbit to 1014 x 5204 km x 87.9 deg. Kosmos-2414 ----------- The Russian Defense Ministry's Kosmos-2414 satellite was launched on Jan 20 by a Kosmos-3M rocket from Plesetsk. The satellite is in a 912 x 966 km orbit, somewhat lower than the usual Parus navigation satellite launches - corresponding to a small underspeed of about 27 m/s. The satellite was launched into the same plane as Kosmos-2239, orbited in 1993. A 30 kg student satellite for radiation studies, "Universitetskiy", was ejected from Kosmos-2414. The satellite was built by students at MGU (Moskovskiy Gosudarstvenniy Universitet) for the university's 250th anniversary, and is nicknamed 'Tatyana' since the university's anniversary day is St. Tatyana's day (Thanks to Tony Vitek for this information). The MGU web page indicates that a second microsatellite called 'Kompass-2/Tatyana' is also planned. Table of Recent Launches ----------------------- Date UT Name Launch Vehicle Site Mission INTL. DES. Dec 17 1207 AMC 16 Atlas 521 Canaveral SLC41 Comms 48A Dec 18 1626 Helios 2A ) Ariane 5G+ Kourou ELA3 Imaging 49A Parasol ) Remote sen. 49G Nanosat ) Tech 49B Essaim 1 ) Sigint 49C Essaim 2 ) Sigint 49D Essaim 3 ) Sigint 49E Essaim 4 ) Sigint 49F Dec 21 2150 Demosat ) Delta 4H Canaveral SLC37B Test 50A 3CS-1 ) Imaging 3CS-2 ) Imaging Dec 23 2219 Progress M-51 Soyuz-U Baykonur LC1 Cargo 51A Dec 24 1120 Sich-1M ) Tsiklon-3 Plesetsk LC32 Remote sen. 52A MK-1TS Mikron ) Imaging 52C Dec 26 1353 Kosmos-2411 ) Proton-K/DM-2 Baykonur LC81/23 Navigation 53A Kosmos-2412 ) Navigation 53B Kosmos-2413 ) Navigation 53C Jan 12 1847 Deep Impact Delta 7925 Canaveral SLC17B Comet probe 01A Jan 20 0300 Kosmos-2414 ) Kosmos-3M Plesetsk PL132/1 Navigation 02A Universitetskiy ) Tech 02C .-------------------------------------------------------------------------. | Jonathan McDowell | phone : (617) 495-7176 | | Somerville MA 02143 | inter : jcm@host.planet4589.org | | USA | jcm@cfa.harvard.edu | | | | JSR: http://www.planet4589.org/jsr.html | | Back issues: http://www.planet4589.org/space/jsr/back | | Subscribe/unsub: mail majordomo@host.planet4589.org, (un)subscribe jsr | '-------------------------------------------------------------------------'