A timeline of the most crucial activities related to separation, descent and landing on 11 and 12 November.

It has been compiled with inputs from the Flight Control Team at ESOC and the Science Operations Team at ESAC and is accurate as of now. PLEASE remember: many of these times are subject to change and confirmation, given the extremely dynamic nature of this delicate and complex operation. We’ll do our best to update this as we receive firm information, but on 12 November the live webcasts from ESA TV and ESA’s social media accounts (Twitter!) will be the best ways to get the latest information.

Admittedly, this timeline is a little dense, but we thought it better to provide more detail for those who – like us! – are extreme Rosetta & Philae fans (and you know who you are!). We’ll publish a lighter version in the main ESA website later today and there’s also a high-level version in the press kit (PDF; page 63 or in SlideShare here). And for those who wish, here is the opposite: an even more detailed version as a PDF, or also in Slideshare.

Review the notes/legend underneath for acronyms (no space mission can succeed without them!). There’s also a diagramme illustrating the delivery orbits.

ROSETTA AND PHILAE OPERATIONS TIMELINE AROUND COMET LANDING 11-12 NOVEMBER 2014



All times are subject to change and should not be assumed confirmed. Actual times may vary considerably. Please follow ESA TV, the Rosetta website, the Rosetta blog and ESA social media for the latest updates. All are linked via https://rosetta.esa.int

One-way light time (OWLT): 00h:28m:20s

Earth distance: 511 million km

CET/UTC offset: 01h:00m:00s

Updated 8.11.2014 to correct 12/11 04:28UTC event and add 01:00UTC event

Updated 12.11.2014 to indicate new GO/NOGO time for Philae lander, now at 02:35 UTC / 03:35 CET



Date UTC

on Earth CET

on Earth Event 11/11 01:48:49 02:48:49 BOT ESA New Norcia (NNO) 11/11 03:10:00 04:10:00 BOT NASA DSN Canberra 11/11 12:25:00 13:25:00 EOT Canberra 11/11 13:40:00 14:40:00 BOT DSN Madrid 11/11 13:58:05 14:58:05 BOT ESA Malargüe (MLG) 11/11 14:00:00 15:00:00 Flight Dynamics Team at ESOC begin orbit determination procedure to accurately fix Rosetta’s precise trajectory 11/11 14:30:17 15:30:17 EOT ESA NNO 11/11 18:33:20 19:33:20 Lander switch-on. Includes switching on Electrical Support System, which controls orbiter communication interface with the lander 11/11 19:05:20 20:05:20 Lander batteries and compartment heating

ADS Tank (Active Descent System – provides cold gas thrust upwards to avoid rebound upon landing) opening 11/11 19:25:20 20:25:20 Lander Primary Battery conditioning start; about 28 mins 11/11 19:00:00 20:00:00 EOT DSN Madrid 11/11 19:30:00 20:30:00 GO/NOGO1 – Last full orbit determination; ESOC Flight Dynamics confirms Rosetta trajectory is correct 11/11 20:03:00 21:03:00 Rosetta starts slew to pre-delivery manoeuvre attitude (expected loss of signal) 11/11 20:20:00 21:20:00 BOT DSN Goldstone 11/11 20:43:00 21:43:00 End of Rosetta slew 11/11 20:52:20 21:52:20 Start Lander flywheel operation – provides stability during descent 11/11 23:25:00 00:25:00 BOT DSN Goldstone 11/11 23:40:00 00:40:00 BOT DSN Canberra 12/11 00:00:00 01:00:00 EOT DSN Goldstone 12/11 00:00:00 01:00:00 GO/NOGO 2(a) – Confirm telecommands to control delivery sequence are ready

GO/NOGO 2(b) – ESOC confirms Rosetta is ready 12/11 01:00:00 02:00:00 ESOC uploads commands to control spacecraft for Lander delivery operations 12/11 01:03:20 02:03:20 Lander generates final telemetry (TM) on-board prior to GO/NOGO for SEP decision 12/11 01:35:00 02:35:00 (EXPECTED AT 02:35 UTC / 03:35 CET) GO/NOGO 3 – Confirm Philae is ready for landing 12/11 01:46:10 02:46:10 BOT ESA New Norcia 12/11 03:02:50 04:02:50 EOT ESA Malargüe 12/11 04:03:20 05:03:20 Lander – start of Separation, Descent & Landing (SDL) activities

Start switching Lander instruments ON; ROMAP first 12/11 04:28:20 05:28:20 Rosetta – Start executing on-board commands for delivery operations 12/11 04:34:20 05:34:20 Start heating Lander batteries to separation temperature 12/11 06:03:20 07:03:20 Rosetta – Earliest start pre-delivery manoeuvre (thruster burn)

Burn will be followed by loss of signal due to subsequent slew for separation

Manoeuvre expected to be about 0.46m/s & about 6 mins duration Date UTC

on Earth CET

on Earth Event 12/11 06:35:00 07:35:00 Earliest GO/NOGO 4 – final decision to go for landing 12/11 07:03:20 08:03:20 Rosetta – Latest start pre-delivery manoeuvre 12/11 07:35:00 08:35:00 Latest GO/NOGO 4 – final decision to go for landing – – Following MVR, ESOC Flight Dynamics Team conducts rapid assessment of MVR performance to verify burn results 12/11 07:49:20 08:49:20 Lander – Switch on MUPUS 12/11 07:52:20 08:52:20 Start MUPUS operation and switch-on CivaRolis

ÇIVA and ROLIS are imaging systems; ÇIVA makes panoramic images, ROLIS looks down 12/11 07:55:20 08:55:20 Start CivaRolis operation and switch-on SESAME (dust sensor) 12/11 08:04:20 09:04:20 Start SESAME operation 12/11 08:46:20 09:46:20 Start MSS (Mechanical Support System), which executes the mechanical separation from the Orbiter 12/11 08:46:20 09:46:20 Separation Motors ON 12/11 08:49:20 09:49:20 Start CONSERT Orbiter operation 12/11 08:50:20 09:50:20 Start CONSERT Lander operation 12/11 08:51:20 09:51:20 Start MSS sequence – internal autosequence to prepare for landing 12/11 08:53:20 09:53:20 Lander now on internal battery power 12/11 – – Screws in Separation Motors start to rotate and impart deployment speed to push Lander away, retrograde .21 m/s 12/11 09:03:20 10:03:20 PHILAE SEPARATION (Forecast; 94-sec window)

Separation confirmation received on ground via ESA’s NNO New Norcia station 12/11 09:04:12 10:04:12 Lander (ÇIVA) obtains first images of Orbiter (FAREWELL1) 12/11 09:06:17 10:06:17 Lander (ÇIVA) obtains seconds images of Orbiter (FAREWELL2) 12/11 09:12:17 10:12:17 Lander / Orbiter separation distance now ~100m

Earliest autodeployment of landing gear and ROMAP boom antenna 12/11 09:25:50 10:25:50 Lander starts rotation of 14 degrees to stable landing orientation 12/11 09:43:20 10:43:20 Rosetta performs post-delivery manoeuvre

Burn will be followed by loss of signal due to subsequent slew back to nominal pointing

Manoeuvre magnitude to be determined on 12/11 12/11 09:47:17 10:47:17 Lander completes all post-separation activities 12/11 10:53:20 11:53:20 Acquisition of signal (AOS) from Rosetta

Expected AOS; link with Rosetta now re-established 12/11 11:59:20 12:59:20 Start of stored data downlink from Rosetta & Philae 12/11 12:20:00 13:20:00 EOT DSN Canberra 12/11 13:15:00 14:15:00 BOT DSN Madrid 12/11 13:55:00 14:55:00 BOT ESA MLG 12/11 14:27:00 15:27:00 EOT NNO 12/11 14:58:57 15:58:57 Lander – switch-on Anchor & CivaRolis Date UTC

on Earth CET

on Earth Event 12/11 15:01:57 16:01:57 Lander – start imaging landing site and switch on ADS (Active Descent System) 12/11 15:07:02 16:07:02 ROLIS begins imaging 12/11 15:17:15 16:17:15 On board Lander, systems conduct final pre-touch-down operations 12/11 15:22:20 16:22:20 Start of Lander touch-down window 12/11 16:02:20 17:02:20 EXPECTED LANDING and receipt of signal (Forecast; 40 min variability) 12/11 – – Upon landing – start post-touch-down operations including:

* ADS thruster fires for ~15 sec to avoid rebound

* Harpoons (X2) fire to secure Lander to surface

* Flywheel off 12/11 16:07:12 17:07:12 ÇIVA-P panoramic imaging on

Lander obtains first images of surface and transmits same (forecast; depends on landing time) 12/11 16:07:14 17:07:14 Separation, Descent & Landing (SDL) science observations continue: Ptolemy & COSAC begin science gathering; data collected during descent and initial surface observations will be uploaded 12/11 16:39:39 17:39:39 Lander completes SDL operations; upload of science data 12/11 17:49:07 18:49:07 Lander begins First Science Sequence (FSS) Block 1; runs about 7 hours 12/11 19:00:00 20:00:00 EOT DSN Madrid 12/11 19:03:00 20:03:00 End of Lander/Orbiter first communication window 13/11 01:43:00 02:43:00 BOT ESA NNO 13/11 02:59:00 03:59:00 EOT ESA MLG

Keen for more details? Download the extended version of this timeline here.

Notes:

BOT Begin of track EOT End of track NNO ESA – ESTRACK 35m New Norcia tracking station, Australia MLG ESA – ESTRACK 35m Malargüe tracking station, Argentina LDR Philae Lander ROS Rosetta Orbiter LCC Lander Control Centre, DLR/Cologne ESOC Rosetta Control Centre, ESA/Darmstadt ROLIS Rosetta Lander Imaging System (ROLIS): CCD imager designed to return images of the landing site before and after Philae has landed ADS Active Descent System (ADS) – this system emits cold gas thrust at touchdown to avoid rebound. BOT Indicates when station is pointing & ready. Actual acquisition of signal may come only afterwards DSS 25 NASA – DSN 34m Goldstone tracking station, California, USA DSS 45 NASA – DSN 34m Canberra tracking station, Australia DSS 55 NASA – DSN 34m Madrid tracking station, Spain DSS 54 NASA – DSN 34m Madrid tracking station, Spain MVR Manoeuvre – a thruster burn to change direction and/or speed MSS (Mechanical Support System) is the lander side of Philae which executes the mechanical separation from the orbiter. ESS ESS (Electrical Support System) is the orbiter part of the lander. The ESS controls the orbiter communication interface with the lander. ESS itself operates as usual as power and data interface to the Orbiter.

Link to Lander science instruments via https://www.esa.int/Our_Activities/Space_Science/Rosetta/Lander_Instruments

CIVA, CONSERT, COSAC, PTOLEMY, MUPUS, ROLIS, ROMAP, SD2, SESAME