Philae (spacecraft)

From Wikipedia, the free encyclopedia
  (Redirected from Philae lander)
Jump to: navigation, search
Philae
Philae lander (transparent bg).png
Illustration of Philae
Mission type Comet lander
Operator European Space Agency
COSPAR ID 2004-006C[1]
Website www.esa.int/rosetta
Mission duration Planned: 1-6 weeks
Actual: 64 hours
Spacecraft properties
Launch mass 100 kg (220 lb)[1]
Payload mass 21 kg (46 lb)[1]
Dimensions 1 × 1 × 0.8 m (3.3 × 3.3 × 2.6 ft)[1]
Power 32 watts at 3 AU[2]
Start of mission
Launch date 2 March 2004, 07:17 (2004-03-02UTC07:17Z) UTC
Rocket Ariane 5G+ V-158
Launch site Kourou ELA-3
Contractor Arianespace
End of mission
Last contact 15 November 2014, 00:36 (2014-11-15UTC00:36Z) UTC[3]
67P/Churyumov–Gerasimenko lander
Landing date 12 November 2014, 17:32 (2014-11-12UTC17:32Z) UTC[4]
Landing site Undetermined
Instruments

Philae (/ˈfli/[5] or /ˈfl/[6]) is a robotic European Space Agency lander that accompanied the Rosetta spacecraft[7][8] until its designated landing on comet 67P/Churyumov–Gerasimenko, more than ten years after departing Earth.[9][10][11] On 12 November 2014, the probe achieved the first-ever soft landing on a comet nucleus.[12][13] Its instruments obtained the first images from a comet's surface.[14] Philae is tracked and operated from the European Space Operations Centre (ESOC) in Darmstadt, Germany.[15] Several of the instruments on Philae made the first in situ analysis of a comet, sending back data that will be analysed to determine the composition of the surface.[16]

The lander is named after the Philae obelisk, which bears a bilingual inscription and was used along with the Rosetta Stone to decipher Egyptian hieroglyphics.

Mission[edit]

Video report by the German Aerospace Centre about Philae '​s landing mission. (10 min, English, in 1080p HD)

Philae '​s mission was to land successfully on the surface of a comet, attach itself, and transmit data about the comet's composition. An Ariane 5G+ rocket carrying the Rosetta spacecraft and Philae lander launched from French Guiana on 2 March 2004, 07:17 UTC, and travelled for 3,907 days (10.7 years) to Churyumov–Gerasimenko. Unlike the Deep Impact probe, which by design struck comet Tempel 1's nucleus on 4 July 2005, Philae is not an impactor. Some of the instruments on the lander were used for the first time as autonomous systems during the Mars flyby on 25 February 2007. CIVA, one of the camera systems, returned some images while the Rosetta instruments were powered down, while ROMAP took measurements of the Martian magnetosphere. Most of the other instruments need contact with the surface for analysis and stayed offline during the flyby. An optimistic estimate of mission length following touchdown was "four to five months".[17]

Scientific goals[edit]

The scientific goals of the mission focus on "elemental, isotopic, molecular and mineralogical composition of the cometary material, the characterization of physical properties of the surface and subsurface material, the large-scale structure and the magnetic and plasma environment of the nucleus."[18]

Landing and surface operations[edit]

Philae remained attached to the Rosetta spacecraft after rendezvousing with Churyumov–Gerasimenko on 6 August 2014. On 15 September 2014, ESA announced "Site J" on the smaller lobe of the comet as the lander's destination.[19] Following an ESA public contest in October 2014, Site J was renamed Agilkia in honour of Agilkia Island.[20]

A series of four Go/NoGo checks were performed on 11–12 November 2014. One of the final tests before detachment from Rosetta showed that the lander's cold-gas thruster was not working correctly, but the "Go" was given anyway, as it could not be repaired.[21][22] Philae detached from Rosetta on 12 November 2014 at 08:35 UTC SCET.[23][24]

Landing events[edit]

Philae '​s landing signal was received by Earth communication stations at 16:03 UTC after a 28 light-minute delay.[1][25] Unbeknownst to mission scientists at that time, the lander had bounced. It began performing scientific measurements while slowly moving away from the comet and coming back down, confusing the science team.[26] Further analysis showed that it bounced twice.[27][28]

Philae '​s first contact with the comet occurred at 15:34:04 UTC SCET.[29] The probe rebounded off the comet's surface at 38 cm/s (15 in/s) and rose to an altitude of approximately 1 km (0.62 mi).[28] For perspective, had the lander exceeded about 44 cm/s (17 in/s), it would have escaped the comet's gravity.[30] After detecting the touchdown, Philae '​s reaction wheel was automatically powered off, resulting in its momentum being transferred back into the lander. This caused the vehicle to begin rotating every 13 seconds.[29] During this first bounce, at 16:20 UTC SCET, the lander is believed to have struck a surface prominence, which slowed its rotation to once every 24 seconds and sent the craft tumbling.[29][31] Philae touched down a second time at 17:25:26 UTC SCET and rebounded at 3 cm/s (1.2 in/s).[29][28] The lander came to a final stop on the surface at 17:31:17 UTC SCET.[29] It sits in rough terrain apparently in the shadow of a nearby cliff or crater wall and is canted at an angle of around 30 degrees, but is otherwise undamaged.[32] Its final location has been determined within an accuracy of a few hundred meters by analysis of data from CONSERT in combination with the comet shape model based on images from the Rosetta orbiter.[33]

An analysis of telemetry indicated that the initial impact was softer than expected, that the harpoons had not deployed, and that the thruster had not fired.[34][35] The harpoon propulsion system contained 0.3 grams of nitrocellulose, which was shown by Copenhagen Suborbitals in 2013 to be unreliable in a vacuum.[36]

Final operations and communication loss[edit]

The primary battery was designed to power the instruments for about 60 hours.[37] ESA had hoped that a secondary rechargeable battery could be partially filled by the solar panels attached to the outside of the lander, but the limited sunlight (90 minutes per 12.4-hour comet day[38]) at the landing site is inadequate to maintain Philae '​s activities, at least in this phase of the comet's orbit.[39][40]

On the morning of 14 November 2014, the battery charge was estimated to be only enough for continuing operations for the remainder of the day. After first obtaining data from instruments whose operation did not require mechanical movement, comprising about 80% of the planned initial science observations, both the MUPUS soil penetrator and the SD2 drill were commanded to deploy. Subsequently, MUPUS data[41] as well as COSAC and Ptolemy data were returned. A final set of CONSERT data was also downlinked towards the end of operations. During the evening's transmission session, Philae was raised by 4 centimetres (1.6 in) and its body rotated 35 degrees to more favourably position the largest solar panel to capture the most sunlight in the future.[42][43] Shortly afterwards, electrical power dwindled rapidly and all instruments were forced to shut down. The downlink rate finally slowed to a trickle before coming to a stop.[38] Contact was lost on 15 November at 00:36 UTC.[3]

The German Aerospace Center's lander manager Stephan Ulamec stated:

Instrument results[edit]

Data from the SESAME instrument determined that, rather than being "soft and fluffy" as expected, Philae '​s first landing site held a large amount of water ice under a layer of dust. It found that the mechanical strength of the ice was high and that cometary activity in that region was low. At the third landing site, the MUPUS instrument was unable to hammer very far into the comet's surface, despite power being gradually increased. This area was also determined to have the consistency of solid ice.[44][45]

In the atmosphere of the comet, the COSAC instrument detected the presence of organic molecules, including carbon and hydrogen. However, soil elements could not be assessed because the lander was unable to drill into the comet surface, likely due to hard ice.[46] The SD2 drill went through the necessary steps to deliver a surface sample to the COSAC instrument,[44] but it was determined that nothing entered the COSAC ovens.[47]

Potential future reawakening[edit]

Philae appears to have lost all communication capability, but it is possible that by August 2015, when the comet has moved much closer to the Sun in its orbit, the lander's solar panels will receive enough solar energy for ESA to reawaken it.[38] Project manager Stephan Ulmanec said a few days of sunlight on the solar panels is all it would take to resume collecting data.[48]

Social media coverage[edit]

The landing was featured heavily in social media, with the lander having an official Twitter account portraying a personification of the spacecraft. The hashtag "#CometLanding" gained widespread traction. A Livestream of the control centres was set up, as were multiple official and unofficial events around the world to follow Philae '​s landing on Churyumov–Gerasimenko.[49][50]

Design[edit]

Rosetta and Philae

The lander was designed to deploy from the main spacecraft body and descend from an orbit of 22.5 kilometres (14 mi) along a ballistic trajectory.[51] It would touch down on the comet's surface at a velocity of around 1 metre per second (3.6 km/h; 2.2 mph).[52] The legs were designed to dampen the initial impact to avoid bouncing as the comet's escape velocity is only around 1 m/s (3.6 km/h; 2.2 mph),[53] and the impact energy would drive ice screws into the surface.[54] Philae would then fire a harpoon into the surface at 70 m/s (250 km/h; 160 mph) to anchor itself.[55][56] A thruster on top of Philae would fire to lessen the bounce upon impact and to reduce the recoil from harpoon firing.[21]

Communications with Earth used the Rosetta orbiter as a relay station to reduce the electrical power needed. The mission duration on the surface was planned to be at least one week, but an extended mission lasting months was considered possible.

The main structure of the lander is made from carbon fibre, shaped into a plate maintaining mechanical stability, a platform for the science instruments, and a hexagonal "sandwich" to connect all the parts. The total mass is about 100 kilograms (220 lb). Its exterior is covered with solar cells for power generation.[10]

It was originally planned to rendezvous with the comet 46P/Wirtanen. A failure in a previous Ariane 5 launch vehicle closed the launch window to reach the comet with the same rocket.[57] It resulted in a change in target to the comet 67P/Churyumov–Gerasimenko.[57] The larger mass of Churyumov–Gerasimenko and the resulting increased impact velocity required that the landing gear of the redesigned lander be strengthened, in order for the spacecraft and its delicate scientific instruments to survive the landing.[citation needed]

Spacecraft component Mass[18]:208
Structure 18.0 kg (39.7 lb)
Thermal control system 3.9 kg (8.6 lb)
Power system 12.2 kg (27 lb)
Active descent system 4.1 kg (9.0 lb)
Reaction wheel 2.9 kg (6.4 lb)
Landing gear 10.0 kg (22 lb)
Anchoring system 1.4 kg (3.1 lb)
Central data management system 2.9 kg (6.4 lb)
Telecommunications system 2.4 kg (5.3 lb)
Common electronics box 9.8 kg (22 lb)
Mechanical support system, harness, balancing mass 3.6 kg (7.9 lb)
Scientific payload 26.7 kg (59 lb)
Sum 97.9 kg (216 lb)

Power management[edit]

Philae '​s power management was planned for two phases. In the first phase, the lander operated solely on battery power. In the second phase, it was to run on backup batteries recharged by solar cells.[17]

The power subsystem comprises two batteries: a non-rechargeable primary 1000 watt-hour battery to provide power for the first 60 hours and a secondary 140 watt-hour battery recharged by the solar panels to be used after the primary is exhausted. The solar panels cover 2.2 square metres (24 sq ft) and were designed to deliver up to 32 watts at a distance of 3 AU from the Sun.[58]

Instruments[edit]

The science payload of the lander consists of ten instruments massing 26.7 kilograms (59 lb), making up just over one-fourth of the mass of the lander.[18]

Philae '​s instruments
APXS 
The Alpha Particle X-ray Spectrometer detects alpha particles and X-rays, which provide information on the elemental composition of the comet's surface.[59] The instrument is an improved version of the APXS on the Mars Pathfinder.
COSAC 
The COmetary SAmpling and Composition instrument is a combined gas chromatograph and time-of-flight mass spectrometer to perform analysis of soil samples and determine the content of volatile components.[60][61]
Ptolemy 
An instrument measuring stable isotope ratios of key volatiles on the comet's nucleus.[62][63]
CIVA 
The Comet Nucleus Infrared and Visible Analyser,[64] (sometimes given as ÇIVA[65]) is a group of seven identical cameras used to take panoramic pictures of the surface plus a visible-light microscope and an infrared spectrometer. The panoramic cameras (CIVA-P) are arranged on the sides of the lander at 60° intervals: five mono imagers and two others making up a stereo imager. Each camera has a 1024×1024 pixel CCD detector.[66] The microscope and spectrometer (CIVA-M) are mounted on the base of the lander, and are used to analyse the composition, texture and albedo (reflectivity) of samples collected from the surface.[67]
ROLIS 
The Rosetta Lander Imaging System is a CCD camera used to obtain high-resolution images during descent and stereo panoramic images of areas sampled by other instruments.[68] The CCD detector consists of 1024×1024 pixels.[69]
CONSERT 
The COmet Nucleus Sounding Experiment by Radiowave Transmission will use electromagnetic wave propagation to determine the comet's internal structure. A radar on Rosetta will transmit a signal through the nucleus to be received by a detector on Philae.[70][71]
MUPUS 
The MUlti-PUrpose Sensors for Surface and Sub-Surface Science instrument will measure the density, thermal and mechanical properties of the comet's surface.[72]
ROMAP 
The Rosetta Lander Magnetometer and Plasma Monitor is a magnetometer and plasma sensor to study the nucleus' magnetic field and its interactions with the solar wind.[73]
SESAME 
The Surface Electric Sounding and Acoustic Monitoring Experiments will use three instruments to measure properties of the comet's outer layers. The Cometary Acoustic Sounding Surface Experiment (CASSE) measures the way in which sound travels through the surface. The Permittivity Probe (PP) investigates its electrical characteristics, and the Dust Impact Monitor (DIM) measures dust falling back to the surface.[74]
SD2 
The Sampling, Drilling and Distribution system obtains soil samples from the comet and transfers them to the Ptolemy, COSAC, and CIVA instruments for analysis.[75] SD2 contains four primary subsystems: drill, ovens, carousel, and volume checker.[76][77] The drill system is capable of drilling to a depth of 230 mm (9.1 in), deploying a probe to collect samples, and delivering samples to the ovens.[78] There are a total of 26 platinum ovens to heat samples—10 medium temperature ovens at 180 °C (356 °F) and 16 high temperature ovens at 800 °C (1,470 °F)—and one oven to clear the drill bit for reuse.[79] The ovens are mounted on a rotating carousel that delivers the active oven to the appropriate instrument.[80] The volume checker determines how much material was deposited into an oven, and may be used to evenly distribute material on CIVA's optical windows.[81] Development of SD2 was led by the Italian Space Agency with contributions by prime contractor Tecnospazio S.p.A, Tecnomare S.p.A., Media Lario, and Dallara.[77] The instrument's principle investigator is Amalia Ercoli-Finzi.[82]

International contributions[edit]

Austria 
The Austrian Space Research Institute developed the lander's anchor and two sensors within MUPUS, which are integrated into the anchor tips.[83]
Belgium 
The Belgian Institute for Space Aeronomy (BIRA) cooperated with different partners to build one of the sensors (DFMS) of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument.[84][85]The Belgian Institute for Space Aeronomy (BIRA) and Royal Observatory of Belgium (ROB) provided information about the space weather conditions at Rosetta to support the landing of Philae. The main concern was solar proton events.[86]
Canada 
Two Canadian companies played a role in the mission. SED Systems located on the University of Saskatchewan campus in Saskatoon built three ground stations that were used to communicate with the Rosetta spacecraft.[87] ADGA-RHEA Group of Ottawa provided MOIS (Manufacturing and Operating Information Systems) software which supported the procedures and command sequences operations software.[88]
Finland 
The Finnish Meteorological Institute provided the Memory of the Command, Data and Management System (CDMS) and the Permittivity Probe (PP).[89]
France 
The French Space Agency together with some scientific laboratories (IAS, SA, LPG, LISA) provided the system's overall engineering, radiocommunications, battery assembly, CONSERT, CIVA and the ground segment (overall engineering and development/operation of the Scientific Operation & Navigation Centre).[citation needed]
Germany 
The German Space Agency (DLR) has provided the structure, thermal subsystem, flywheel, the Active Descent System (procured by DLR but made in Switzerland),[90] ROLIS, downward-looking camera, SESAME, acoustic sounding and seismic instrument for Philae. It has also managed the project and did the level product assurance. The University of Münster built MUPUS (it was designed and built in Space Research Centre of Polish Academy of Sciences [91]) and the Braunschweig University of Technology the ROMAP instrument. The Max Planck Institute for Solar System Research made the payload engineering, eject mechanism, landing gear, anchoring harpoon, central computer, COSAC, APXS and other subsystems.
Hungary 
The Command and Data Management Subsystem (CDMS) designed in the Wigner Research Centre for Physics of the Hungarian Academy of Sciences.[92] The Power Subsystem (PSS) designed in the Department of Broadband Infocommunications and Electromagnetic Theory at Budapest University of Technology and Economics.[93] CDMS is the fault tolerant central computer of the lander, while PSS assures that the power coming from the batteries and solar arrays are properly handled, controls battery charging and manages the onboard power distribution.
Italy 
The Italian Space Agency (ASI) has provided the SD2 instrument and the Photo Voltaic Assembly.[94]
Ireland 
Space Technology Ireland Ltd. at Maynooth University has designed, constructed and tested the Electrical Support System Processor Unit (ESS) for the Rosetta mission. ESS stores, transmits and provides decoding for the command streams passing from the spacecraft to the lander and handles the data streams coming back from the scientific experiments on the lander to the spacecraft.[95]
Netherlands
Moog Bradford (Heerle, The Netherlands) provided the Active Descent System (ADS) that is intended to provide the required impulse to ensure that Philae will descend towards the nucleus of Churyumov–Gerasimenko in 2014. To accomplish the ADS, a strategic industrial team was formed with Bleuler-Baumer Mechanik in Switzerland.[90]
Poland 
The Space Research Centre of the Polish Academy of Sciences built the Multi-Purpose Sensors for Surface and Subsurface Science (MUPUS).[91]
Spain 
The Instituto de Astrofísica de Andalucía and the Spanish National Research Council of Madrid have contributed to the mission of designing and manufacturing the ship's medium-gain antenna system, thermal control antennas and the Osiris camera,[96] while its centre in Tres Cantos (Madrid) has developed and manufactured the Star Tracker and the navigation camera control units. The GMV Spanish division has been responsible for the maintenance of the calculation tools to calculate the criteria of lighting and visibility necessary to decide the point of landing on the comet, as well as the possible trajectories of decline of the Philae module. SENER, a Spanish Aeronautics and Engineering Company, was responsible for the supply of two deployable masts, 15 shades of active thermal control and electronic control of all the Giada instrument unit, optical displays of attenuation of incident radiation on two navigation cameras and the two star trackers, and the driver of the filter wheel of cameras NAC and WAC of the Osiris instrument (the instrument onboard Rosetta ship to photographed the Comet), among other components. The Crisa group has provided the electronic unit from the star browser and navigation camera; a division of the Elecnor group Deimos Space, which has defined the path to reach the destination. Other important Spanish companies or educational institutions that have been contributed are as follows: INTA, Airbus Defence and Space Spanish division, other small companies also participated in subcontracted packages in structural mechanics and thermal control like AASpace (former Space Contact),[97] and the Universidad Politécnica de Madrid.[96]
Switzerland 
The Swiss Centre for Electronics and Microtechnology developed CIVA.[98]
United Kingdom 
The Open University and the Rutherford Appleton Laboratory (RAL) have developed PTOLEMY. RAL has also constructed the blankets that keep the lander warm throughout its mission. Surrey Satellites Technology Ltd. (SSTL) constructed the reaction wheel for the lander. It stabilises the module during the descent and landing phases.[96] Manufacturer e2v supplied the CIVA and Rolis camera systems used to film the descent and take images of samples, as well as three other camera systems.[99]
United States 
According to the Jet Propulsion Laboratory, NASA has contributed three instruments to Rosetta - ALICE, MIRO, and IES - plus a significant portion of the electronics package for another instrument, ROSINA. ALICE, MIRO, and IES will provide information about the dynamics of comet C-G: how it develops its coma and tails, and how its chemicals interact with each other, with radiation and with the solar wind.

Gallery[edit]

Philae '​s intended landing site Agilkia (Site J)

In popular culture[edit]

Vangelis composed the music for the trio of music videos released by ESA to celebrate the first ever attempted soft landing on a comet by ESA's Rosetta mission.[100][101][102]

On 12 November 2014, the search engine Google featured a Google Doodle of Philae on its home page.[103]

See also[edit]

References[edit]

  1. ^ a b c d e "Philae". National Space Science Data Center. Retrieved 18 November 2014. 
  2. ^ "Philae lander fact sheet" (PDF). DLR. Retrieved 28 January 2014. 
  3. ^ a b c Scuka, Daniel (15 November 2014). "Our Lander's Asleep". European Space Agency. Retrieved 15 November 2014. 
  4. ^ "Three Touchdowns For Rosetta's Lander". European Space Agency. 14 November 2014. Retrieved 15 November 2014. 
  5. ^ "philae". Dictionary.com Unabridged. Random House. Retrieved 13 November 2014. 
  6. ^ Ellis, Ralph (12 November 2014). "Space probe scores a 310-million-mile bull's-eye with comet landing". CNN. Retrieved 13 November 2014. 
  7. ^ Chang, Kenneth (5 August 2014). "Rosetta Spacecraft Set for Unprecedented Close Study of a Comet". The New York Times. Retrieved 5 August 2014. 
  8. ^ Editorial Board (23 November 2014). "In Pursuit of an Oddly Shaped Comet". New York Times. Retrieved 23 November 2014. 
  9. ^ Ulamec, S.; Espinasse, S.; Feuerbacher, B.; Hilchenbach, M.; Moura, D. et al. (April 2006). "Rosetta Lander—Philae: Implications of an alternative mission". Acta Astronautica 58 (8): 435–441. Bibcode:2006AcAau..58..435U. doi:10.1016/j.actaastro.2005.12.009. 
  10. ^ a b Biele, Jens (2002). "The Experiments Onboard the ROSETTA Lander". Earth, Moon, and Planets 90 (1–4): 445–458. Bibcode:2002EM&P...90..445B. doi:10.1023/A:1021523227314. 
  11. ^ Agle, D. C.; Cook, Jia-Rui; Brown, Dwayne; Bauer, Markus (17 January 2014). "Rosetta: To Chase a Comet". NASA. Retrieved 18 January 2014. 
  12. ^ Agle, DC; Webster, Guy; Brown, Dwayne; Bauer, Markus (12 November 2014). "Rosetta's 'Philae' Makes Historic First Landing on a Comet". NASA. Retrieved 13 November 2014. 
  13. ^ Chang, Kenneth (12 November 2014). "European Space Agency’s Spacecraft Lands on Comet’s Surface". The New York Times. Retrieved 12 November 2014. 
  14. ^ "Europe's Comet Chaser – Historic mission". European Space Agency. 16 January 2014. Retrieved 5 August 2014. 
  15. ^ ESOC at ESA website, retrieved 13 November 2014.
  16. ^ European Space Agency. "Pioneering Philae completes main mission before hibernation". 
  17. ^ a b Gilpin, Lyndsey (14 August 2014). "The tech behind the Rosetta comet chaser: From 3D printing to solar power to complex mapping". TechRepublic. 
  18. ^ a b c Bibring, J.-P.; Rosenbauer, H.; Boehnhardt, H.; Ulamec, S.; Biele, J. et al. (February 2007). "The Rosetta Lander ("Philae") Investigations". Space Science Reviews 128 (1–4): 205–220. Bibcode:2007SSRv..128..205B. doi:10.1007/s11214-006-9138-2. 
  19. ^ Bauer, Markus (15 September 2014). "'J' Marks the Spot for Rosetta's Lander". European Space Agency. Retrieved 20 September 2014. 
  20. ^ Kramer, Miriam (5 November 2014). "Historic Comet Landing Site Has a New Name: Agilkia". Space.com. Retrieved 5 November 2014. 
  21. ^ a b "Will Philae successfully land on comet? Thruster trouble heightens drama.". Christian Science Monitor. 12 November 2014. 
  22. ^ Baldwin, Emily (12 November 2014). "Rosetta and Philae Go for separation". European Space Agency. Retrieved 12 November 2014. 
  23. ^ "Rosetta to Deploy Lander on 12 November". European Space Agency. 26 September 2014. Retrieved 4 October 2014. 
  24. ^ Platt, Jane (6 November 2014). "Rosetta Races Toward Comet Touchdown". NASA. Retrieved 7 November 2014. 
  25. ^ "Probe makes historic comet landing". BBC News. 12 November 2014. Retrieved 12 November 2014. 
  26. ^ Lakdawalla, Emily (12 November 2014). "Philae Has Landed! [Updated]". The Planetary Society. Retrieved 13 November 2014. 
  27. ^ Agle, D. C.; Brown, Dwayne; Bauer, Markus (13 November 2014). "Rosetta's Comet Lander Landed Three Times". NASA. Retrieved 13 November 2014. 
  28. ^ a b c "Three touchdowns for Rosetta's lander". European Space Agency. 14 November 2014. Retrieved 8 December 2014. 
  29. ^ a b c d e Baldwin, Emily (28 November 2014). "Did Philae graze a crater rim during its first bounce?". European Space Agency. Retrieved 8 December 2014. 
  30. ^ Wall, Mike (14 November 2014). "European Probe Survived Comet Landing with Luck and Great Design". Space.com. Retrieved 8 December 2014. 
  31. ^ Howell, Elizabeth (2 December 2014). "Philae’s Wild Comet Landing: Crater Grazing, Spinning And Landing In Parts Unknown". Universe Today. Retrieved 8 December 2014. 
  32. ^ Beatty, Kelly (15 November 2014). "Philae Wins Race to Return Comet Findings". Sky & Telescope. Retrieved 8 November 2014. 
  33. ^ Baldwin, Emily (21 November 2014). "Homing in on Philae's final landing site". European Space Agency. Retrieved 22 November 2014. 
  34. ^ Ellis, Ralph (12 November 2014). "Philae touches down on the surface of a comet". CNN. Retrieved 12 November 2014. 
  35. ^ Aron, Jacob (13 November 2014). "Problems hit Philae after historic first comet landing". New Scientist. Retrieved 13 November 2014. 
  36. ^ Djursing, Thomas (13 November 2014). "ESA skrev til danske raketbyggere om eksplosiv-problem på Philae". Ingeniøren (in Danish). Retrieved 13 November 2014. 
  37. ^ Amos, Jonathan (13 November 2014), "Rosetta: Battery will limit life of Philae comet lander", BBC News, retrieved 14 November 2014 
  38. ^ a b c Harwood, William (15 November 2014). "Loss of contact with Philae". Spaceflight Now. Retrieved 15 November 2014. 
  39. ^ Lakdawalla, Emily (13 November 2014). "Philae status, a day later". The Planetary Society. Retrieved 14 November 2014. 
  40. ^ Djursing, Thomas (13 November 2014). "Kometsonden Philae står skævt under en klippe og får for lidt sollys". Ingeniøren (in Danish). Retrieved 14 November 2014. 
  41. ^ Lakdawalla, Emily (14 November 2014). "Philae update: My last day in Darmstadt, possibly Philae's last day of operations". The Planetary Society. Retrieved 14 November 2014. 
  42. ^ Amos, Jonathan (15 November 2014). "Philae comet lander sends more data before losing power". BBC News. Retrieved 8 December 2014. 
  43. ^ Lakdawalla, Emily (15 November 2014). "Now Philae down to sleep". The Planetary Society. Retrieved 17 November 2014. 
  44. ^ a b "Churyumov-Gerasimenko – hard ice and organic molecules". German Aerospace Center. 17 November 2014. Retrieved 18 November 2014. 
  45. ^ Sinha, Kounteya (18 November 2014). "Philae reveals presence of large amount of water ice on the comet". The Times of India. Times News Network. Retrieved 18 November 2014. 
  46. ^ Gray, Richard (19 November 2014). "Rosetta mission lander detects organic molecules on surface of comet". The Guardian. Retrieved 18 December 2014. 
  47. ^ Hand, Eric (17 November 2014). "COSAC PI: Drill tried to deliver sample.". Twitter.com. Retrieved 8 December 2014. 
  48. ^ Jordans, Frank (17 November 2014). "Scientists 'confident' comet lander will wake up". Yahoo! News. Associated Press. Retrieved 18 November 2014. 
  49. ^ "Live updates: Rosetta mission comet landing". European Space Agency. 12 November 2014. 
  50. ^ "Call for Media Opportunities to follow Rosetta mission's historic comet landing". European Space Agency. 16 October 2014. 
  51. ^ Amos, Jonathan (26 September 2014). "Rosetta: Date fixed for historic comet landing attempt". BBC News. Retrieved 29 September 2014. 
  52. ^ Amos, Jonathan (25 August 2014). "Rosetta mission: Potential comet landing sites chosen". BBC News. Retrieved 25 August 2014. 
  53. ^ Dambeck, Thorsten (21 January 2014). "Expedition to primeval matter". Max-Planck-Gesellschaft. Retrieved 19 September 2014. 
  54. ^ Böhnhardt, Hermann (10 November 2014). "About the Upcoming Philae Separation, Descent and Landing". Max Planck Institute for Solar System Research. Retrieved 11 November 2014. 
  55. ^ Biele, J.; Ulamec, S.; Richter, L.; Kührt, E.; Knollenberg, J.; Möhlmann, D. (2009). "The Strength of Cometary Surface Material: Relevance of Deep Impact Results for Philae Landing on a Comet". In Käufl, Hans Ulrich; Sterken, Christiaan. Deep Impact as a World Observatory Event: Synergies in Space, Time, and Wavelength. ESO Astrophysics Symposia. Springer. p. 297. Bibcode:2009diwo.conf..285B. doi:10.1007/978-3-540-76959-0_38. ISBN 978-3-540-76958-3. 
  56. ^ Biele, Jens; Ulamec, Stephan (2013). "Preparing for Landing on a Comet – The Rosetta Lander Philae". 44th Lunar and Planetary Science Conference. 18–22 March 2013. The Woodlands, Texas. Bibcode:2013LPI....44.1392B. LPI Contribution No. 1719. 
  57. ^ a b "Why was 67P/Churyumov-Gerasimenko selected as the target comet instead of Wirtanen?". Rosetta's Frequently Asked Questions. European Space Agency. Retrieved 24 November 2014. The other options, including a launch to Wirtanen in 2004, would have required a more powerful launch vehicle, either an Ariane 5 ECA or a Proton. 
  58. ^ "Philae Lander Factsheets". DLR Public Relations. Retrieved 17 November 2014. 
  59. ^ "APXS". European Space Agency. Retrieved 26 August 2014. 
  60. ^ Goesmann, Fred; Rosenbauer, Helmut; Roll, Reinhard; Böhnhardt, Hermann (October 2005). "COSAC Onboard Rosetta: A Bioastronomy Experiment for the Short-Period Comet 67P/Churyumov-Gerasimenko". Astrobiology 5 (5): 622–631. Bibcode:2005AsBio...5..622G. doi:10.1089/ast.2005.5.622. PMID 16225435. 
  61. ^ "COSAC". European Space Agency. Retrieved 26 August 2014. 
  62. ^ Wright, I. P.; Barber, S. J.; Morgan, G. H.; Morse, A. D.; Sheridan, S. et al. (February 2007). "Ptolemy: An Instrument to Measure Stable Isotopic Ratios of Key Volatiles on a Cometary Nucleus". Space Science Reviews 128 (1–4): 363–381. Bibcode:2007SSRv..128..363W. doi:10.1007/s11214-006-9001-5. 
  63. ^ Andrews, D. J.; Barber, S. J.; Morse, A. D.; Sheridan, S.; Wright, I. P. et al. (2006). "Ptolemy: An Instrument aboard the Rosetta Lander Philae, to Unlock the Secrets of the Solar System". 37th Lunar and Planetary Science Conference. 13–17 March 2006. League City, Texas. 
  64. ^ Bibring, Jean-Pierre; Lamy, P; Langevin, Y; Souufflot, A; Berthé, J; Borg, J; Poulet, F; Mottola, S (2007). "CIVA". Space Science Reviews (Sprinter Netherlands) 138 (1–4): 397–412. doi:10.1007/s11214-006-9135-5. Retrieved 17 November 2014. 
  65. ^ Biele, J; Ulamec, S (1 July 2008). "Capabilities of Philae, the Rosetta Lander". Space Science Reviews (Springer Netherlands) 138 (1–4): 275–289. doi:10.1007/s11214-007-9278-z. Retrieved 17 November 2014. 
  66. ^ "Comet nucleus Infrared and Visible Analyser (CIVA)". National Space Science Data Center. Retrieved 15 November 2014. 
  67. ^ "ÇIVA". European Space Agency. Retrieved 26 August 2014. 
  68. ^ "ROLIS". European Space Agency. Retrieved 26 August 2014. 
  69. ^ "Rosetta Lander Imaging System (ROLIS)". National Space Science Data Center. Retrieved 28 August 2014. 
  70. ^ Kofman, W.; Herique, A.; Goutail, J.-P.; Hagfors, T.; Williams, I. P. et al. (February 2007). "The Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT): A Short Description of the Instrument and of the Commissioning Stages". Space Science Reviews 128 (1–4): 413–432. Bibcode:2007SSRv..128..413K. doi:10.1007/s11214-006-9034-9. 
  71. ^ "CONCERT". European Space Agency. Retrieved 26 August 2014. 
  72. ^ "MUPUS". European Space Agency. Retrieved 26 August 2014. 
  73. ^ "ROMAP". European Space Agency. Retrieved 26 August 2014. 
  74. ^ Seidensticker, K. J.; Möhlmann, D.; Apathy, I.; Schmidt, W.; Thiel, K. et al. (February 2007). "Sesame – An Experiment of the Rosetta Lander Philae: Objectives and General Design". Space Science Reviews 128 (1–4): 301–337. Bibcode:2007SSRv..128..301S. doi:10.1007/s11214-006-9118-6. 
  75. ^ Di Lizia, Pierluigi (9 April 2014). "Introducing SD2: Philae’s Sampling, Drilling and Distribution instrument". European Space Agency. Retrieved 24 December 2014. 
  76. ^ "Philae SD2". Politecnico di Milano. Retrieved 11 August 2014. 
  77. ^ a b Marchesi, M.; Campaci, R.; Magnani, P.; Mugnuolo, R.; Nista, A. et al. (2001). "Comet sample acquisition for ROSETTA lander mission". 9th European Space Mechanisms and Tribology Symposium. 19-21 September 2001. Liège, Belgium. Bibcode:2001ESASP.480...91M. 
  78. ^ "Drill Box". Politecnico di Milano. Retrieved 24 December 2014. 
  79. ^ "Ovens". Politecnico di Milano. Retrieved 11 August 2014. 
  80. ^ "Carousel". Politecnico di Milano. Retrieved 24 December 2014. 
  81. ^ "Volume Checker". Politecnico di Milano. Retrieved 24 December 2014. 
  82. ^ "Rosetta, anche l'Italia sbarca sulla cometa". La Repubblica (in Italian). 12 November 2014. Retrieved 24 December 2014. 
  83. ^ "Rosetta". Institut für Weltraumforschung. 8 June 2014. Retrieved 1 December 2014. 
  84. ^ Christiaens, Kris (6 November 2014). "België mee aan boord van Rosetta kometenjager". Belgium in Space.be (in Dutch). Retrieved 13 November 2014. 
  85. ^ Christiaens, Kris (19 July 2009). "Rosetta". Belgium in Space.be (in Dutch). Retrieved 13 November 2014. 
  86. ^ "Space weather report for Rosetta". ESA rocket science blog. 12 November 2014. Retrieved 19 November 2014. 
  87. ^ "Two Canadian Firms Play Small but Key Roles in Comet Landing". Maclean's. Retrieved 16 November 2014. 
  88. ^ "ADGA Media Release". Retrieved 16 November 2014. 
  89. ^ "Lander successfully touches down on the comet surface". Finnish Meteorological Institute. 12 November 2014. Retrieved 23 November 2014. 
  90. ^ a b "Active Descent System". Moog Inc. Retrieved 11 November 2014. 
  91. ^ a b "The MUPUS Instrument for Rosetta mission to comet Churyumov-Gerasimenko". Laboratorium Mechatroniki i Robotyki Satelitarnej. 2014. Retrieved 6 August 2014. 
  92. ^ "12 November, 2014 A Space Probe landed on the Surface of a Comet for the first time in Space Research". 
  93. ^ Kocsis Gábor. "References". 
  94. ^ "Rosetta Mission: Italy’s decisive technological contribution". Italian Ministry of Foreign Affairs and International Cooperation. 13 November 2014. Retrieved 20 November 2014. 
  95. ^ "Maynooth University scientists play key role in historic Rosetta mission". Maynooth University Maynooth, County Kildare, Ireland. 12 November 2014. Retrieved 20 November 2014. 
  96. ^ a b c "IAA-CSIC is co-managing an instrument that will orbit around the Sun on board the Solar Orbiter mission ESA". Instituto de Astrofísica de Andalucía. 2014. Retrieved 11 November 2014. 
  97. ^ "Presentacin de PowerPoint - SPACE ACTIVITIES". 
  98. ^ "CIVA Project". 2014. Retrieved 7 November 2014. 
  99. ^ Alan Tovey (11 November 2014). "UK space industry behind Rosetta comet mission". The Telegraph. 
  100. ^ "Arrival" by Vangelis on YouTube
  101. ^ "Philae's journey" by Vangelis on YouTube
  102. ^ "Rosetta's waltz" by Vangelis on YouTube
  103. ^ Solon, Olivia (12 November 2014). "Philae: Google Doodle marks Rosetta's historic comet landing". Mirror. Retrieved 12 November 2014. 

Further reading[edit]

External links[edit]

Media