Philae lander makes historic touchdown on comet

Philae lander makes historic touchdown on comet

Rosetta is a cornerstone mission to chase, go into orbit around, and land on a comet. It is studying the Jupiter-family comet 67P/Churyumov-Gerasimenko with a combination of remote sensing and in situ measurements. The spacecraft arrived at the comet on 6 August 2014 following a 10-year journey through the Solar System. Between August and November, the spacecraft has been orbiting the comet and gathering data to characterise the environment and the comet nucleus. On 12 November 2014, Rosetta's lander Philae will be deployed to the surface. Philae carries a suite of instruments for imaging and sampling the comet nucleus. The Rosetta orbiter will track the comet through perihelion (August 2015), examining its behaviour before, during and after.

The mission was first considered in the late 1970s and developed from a sample-return plan to the plan for a lander. It was approved in November 1993 by ESA’s Science Programme Committee. The original mission target had been comet 46P/Wirtanen, but this was changed to 67P/Churyumov-Gerasimenko when it was clear that the launch would take place in 2004.

The spacecraft was launched from Kourou aboard an Ariane 5G+ on 2 March 2004. It required four gravity assists for its journey, one by Mars and three by Earth. Rosetta had already flown by the asteroids 2867 Steins (in 2008) and 21 Lutetia (in 2010), before entering deep space hibernation in June 2011.

The spacecraft was launched from Kourou aboard an Ariane 5G+ on 2 March 2004. It required four gravity assists for its journey, one by Mars and three by Earth. Rosetta had already flown by the asteroids 2867 Steins (in 2008) and 21 Lutetia (in 2010), before entering deep space hibernation in June 2011.

Rosetta has achieved major milestones in 2014. Following a planned exit from hibernation on 20 January, all of the spacecraft's instruments were checked as it continued on its journey to 67P/Churyumov-Gerasimenko. The first science results were obtained even before the spacecraft arrived at the comet on 6 August 2014. On 12 November 2014, Rosetta's lander Philae will be deployed to the surface.

Here are the key dates of the Rosetta mission:

PHILAE'S INSTRUMENTS (WHITE BACKGROUND)

Date: 02 January 2014
Satellite: Rosetta
Depicts: Philae Lander
Copyright: ESA/ATG medialab

Rosetta will deploy the Philae lander to the surface of comet 67P/Churyumov-Gerasimenko for in situ analysis with its 10 instruments:

APXS: Alpha Proton X-ray Spectrometer (studying the chemical composition of the landing site and its potential alteration during the comet's approach to the Sun)

CIVA: Comet Nucleus Infrared and Visible Analyser (six cameras to take panoramic pictures of the comet surface)

CONSERT: COmet Nucleus Sounding Experiment by Radiowave Transmission (studying the internal structure of the comet nucleus with Rosetta orbiter)

COSAC: The COmetary SAmpling and Composition Experiment (detecting and identifying complex organic molecules)

PTOLEMY: Using MODULUS protocol (Methods Of Determining and Understanding Light elements from Unequivocal Stable isotope compositions) to understand the geochemistry of light elements, such as hydrogen, carbon, nitrogen and oxygen

MUPUS: MUlti-PUrpose Sensors for Surface and Sub-Surface Science (studying the properties of the comet surface and immediate sub-surface)

ROLIS: Rosetta Lander Imaging System (providing the first close-up images of the landing site)

ROMAP: Rosetta Lander Magnetometer and Plasma Monitor (studying the magnetic field and plasma environment of the comet)

SD2: Sampling, drilling and distribution subsystem (drilling up to 23 cm depth and delivering material to onboard instruments for analysis)

SESAME: Surface Electric Sounding and Acoustic Monitoring Experiment (probing the mechanical and electrical parameters of the comet), comprising: CASSE (Comet Acoustic Surface Sounding Experiment), DIM (Dust Impact Monitor), and PP (Permittivity Probe).

  

Event	Nominal date
Launch	2 March 2004
First Earth gravity assist	4 March 2005
Mars gravity assist	25 February 2007
Second Earth gravity assist	13 November 2007
Asteroid Steins flyby	5 September 2008
Third Earth gravity assist	13 November 2009
Asteroid Lutetia flyby	10 July 2010
Enter deep space hibernation	8 June 2011
Exit deep space hibernation	20 January 2014
Rendezvous manoeuvres begin	7 May 2014
Arrive at comet	6 August 2014
Start global mapping	10 September 2014
Lander delivery	12 November 2014
Perihelion passage	13 August 2015
End of mission	31 December 2015