PHILAE LANDER

'Philae' (previously known as 'RoLand') is the name of the lander that accompanies the Rosetta spacecraft. It is designed to land on a comet (67P/Churyumov-Gerasimenko) shortly after arrival. ^[1]
[2]

Contents

Design

Instruments

Name

Mission

External links

References

Design

The lander is designed to touch down on the comet’s surface after detaching itself from the main spacecraft body and “falling” towards the comet along a ballistic trajectory. It also will deploy harpoons to anchor itself to the surface, and the legs are designed to dampen the initial impact to avoid bouncing. Communications with Earth will use the orbiter spacecraft as a relay station to reduce the electrical power needed on board the Lander. The mission duration on the surface is planned to be at least one week, but an extended mission that lasts months is possible.
The main structure of the Lander is made from carbon fiber, shaped into a plate maintaining mechanical stability, a platform for the science instruments, and a hexagonal “sandwich” to connect all the parts. The total weight of the Lander is about 100 kg. Its “hood” is covered with solar cells for power generation.
The higher mass and therefore stronger gravitational force of the new target comet 67P/Churyumov-Gerasimenko compared to 46P/Wirtanen made changes in the landing gear necessary.^[3]

Instruments

★ 'APXS' (Alpha Proton X-ray Spectrometer) APXS analyses the chemical element composition of the surface below the lander. The instrument is an improved version of the APXS of the pathfinder mission on mars.

★ 'COSAC' (The COmetary SAmpling and Composition) The combined gas chromatograph and time of flight mass spectrometry will perform analysis of soil samples and determin the content of volatile components.^[4]

★ 'Ptolemy' ^[5][6]

★ 'ÇIVA'

★ 'ROLIS' (Rosetta Lander Imaging System)

★ 'CONSERT' (COmet Nucleus Sounding Experiment by Radio-wave Transmission)

★ 'MUPUS' (MUlti-PUrpose Sensors for Surface and Sub-Surface Science)

★ 'ROMAP' (Rosetta Lander Magnetometer and Plasma Monitor)

★ 'SESAME' (Surface Electrical, Seismic and Acoustic Monitoring Experiments)

★ 'SD2' (The sampling, drilling and distribution subsystem)

Name

The Philae Lander is named an island in the nile river where an obâelisk was found that was used to translate the Rosetta stone.

Mission

The mission of The Philae Lander is to land successfully on the surface of a comet, and transmit data from the surface about the comet's composition. Unlike the Deep Impact probe which was an impactor. Some of the instruments and the lander were first time used as autonomous system during the Mars fly-by on February 25, 2007. The camera system ÇIVA produced some pictures while the Rosetta instrument were powered down. Also the ROMAP instrument produced some measurements of the Martian magnetosphere. Most of the other instruments need contact to the surface for analysis and stayed offline during the fly-by.

External links

★ Rosetta website

★ Rosetta Lander an article by Andrew J Ball, 1997.

★ Philae site at gwdg.de

★ Experiments German page with all onboard experiments.

References

1. Rosetta Lander—Philae: Implications of an alternative mission, S. Ulameca, S. Espinasseb, B. Feuerbachera, M. Hilchenbachc, D. Mourad, H. Rosenbauerc, H. Scheuerlea, R.Willneckera, , , Acta Astronautica, 2006
2. The Experiments Onboard the ROSETTA Lander, J. Biele, , , Journal Earth, Moon, and Planets, 2002
3. Rosetta Lander - Philae: Implications of an alternative mission, Ulamec S, Espinasse S, Feuerbacher B, Hilchenbach M, Moura D, Rosenbauer H, Scheuerle H, Willnecker R, , , Acta Astronautica, 2006
4. COSAC onboard Rosetta: A bioastronomy experiment for the short-period comet 67P/Churyumov-Gerasimenko, Gosmann F., Rosenbauer H., Roll R., Bohnhardt H., , , Astrobiology, 2005
5. Ptolemy – an Instrument to Measure Stable Isotopic Ratios of Key Volatiles on a Cometary Nucleus, Wright, I. P.; Barber, S. J.; Morgan, G. H.; Morse, A. D.; Sheridan, S.; Andrews, D. J.; Maynard, J.; Yau, D.; Evans, S. T.; Leese, M. R.; Zarnecki, J. C.; Kent, B. J.; Waltham, N. R.; Whalley, M. S.; Heys, S.; Drummond, D. L.; Edeson, R. L.; Sawyer, E. C.; Turner, R. F.; Pillinger, C. T., , , Space Science Reviews, 2006
6. Ptolemy: An Instrument aboard the Rosetta Lander Philae, to Unlock the Secrets of the Solar System., D. J. Andrews, S. J. Barber, A. D. Morse, S. Sheridan, I. P. Wright, G. H. Morgan,, , , Lunar and Planetary Science, 2006