Mars Science Lab (Curiosity) Entry-Descent-Landing Timelines

Mars Science Lab (Curiosity) Entry-Descent-Landing Timelines

Event times are relative to Event, and accurate to 1 second.

Calendar times are relative to August 5, 2012, Mountain Time, and accurate to 1 minute.

Calendar times of events correspond to when the communications signal reaches Earth.

This means the actual event happened 14 minutes earlier, because the signal travels at speed of light from Mars to Earth.

Mars Odyssey can relay event ‘tones’ and brief engineering data starting shortly after Entry Interface, as well as initial images from Mars surface, and ending about 15 minutes after touchdown.

Some key Events in calendar (Mountain) time:

9:24 pm, Final EDL navigation update

11:14 pm, Cruise Stage separation

11:28 pm, Supersonic Parachute deployment, Heatshield separation, Radar initiation

11:29 pm, Backshell separation, Powered approach, Thrusters throttle down to hover

11:30 pm, Rover separation from Sky Crane, Lower Rover to surface

11:31 pm, Touchdown, Bridal and Umbilical to Sky Crane release, Sky Crane fly away

11:40 pm, First touchdown pictures received

Timeline, start 9:24 pm MT

EI +/- / Event / Range / Relative Velocity
-02:00:00 / Final EDL Navigation Update / ~23,500km / ~3,996m/s
~-01:24:00 / MSL 'crosses' Orbit of Deimos
~-00:33:00 / MSL 'crosses' Orbit of Phobos
-13:30 / HRS Propellant Vent
Duration: 3 Minutes

Timeline, start 11:14 pm MT

EI +/- / Event / CSS +/-
-10:00 / Cruise Stage Separation / 00:00
-09:30 / Transition to EDL Communications: / +00:30
X-Band: Tones
UHF: 2kbps
-09:00 / Descent Stage Reaction Control System Enable / +01:00
De-Spin from 2rpm
Maneuver to Entry Attitude
Total Maneuver Duration: 3min 6sec
-05:49 / Entry Guidance Enable / +04:11
Achieve Center of Gravity Offset (Jettison 2 Weights)
Maneuver Duration: 30 Seconds
-5:19 / Quiescent Period / +04:41
Inertial Measurement Unit Calibration

Entry Interface 11:24 pm Mountain Time

Timeline, start 11:24 pm MT

EI +/- / Event / Altitude / Velocity
00:00 / ENTRY INTERFACE / ~125km / 5,900m/s
Pressurize Propulsion System
+01:25 / Peak Heating - 2,100°C
+01:36 / Peak Deceleration
+03:00 / Hypersonic Aero-Maneuvering
+03:50 / Eliminate Center Of Gravity Offset
Jettison 6 Inner Weights
Damp CG-Offset Elimination Transients

Timeline, start 11:28 pm MT

EI +/- / Event / Altitude / Velocity
+04:05 / Parachute Deployment / 11km / 450m/s
Reaction Control System Disabled
+04:06 / Mars Landing Engines to 1% Thrust
+04:34 / Heatshield Separation / 8km / 238m/s
Radar Initiation
Terminal Descent Sensor Activation
+04:39 / Begin Using Landing Radar Solutions
+05:05 / Prime Mars Landing Engines

Powered Descent Timeline, start 11:29 pm MT

~EI +/- / Event / BSS +/- / Altitude / Velocity
+05:15 / Backshell Separation / 00:00 / 2.0-1.6km / 120m/s
Mars Landing Engines at 1%
+05:15.8 / Mars Landing Engines at 20% / +00:00.8
+05:16 / Mars Landing Engines at Full Throttle / +00:01
+05:16.2 / Attitude Control Only / +00:01.2
Setup Turn Start
+05:19.4 / Powered Approach / +00:03.4 / ~1,620m / ~125m/s
Reduce Horizontal Velocity to 0m/s
Reduce Vertical Velocity to 20m/s
+05:50 / Constant Velocity Accordion / +00:35 / 105m / 20m/s
Duration: 0-5 Seconds
+05:52.5 / Constant Deceleration to 0.75m/s / +00:37.5 / 55m / 20m/s
+05:55 / Throttle down to 4 Mars Landing Engines / +00:40 / 21m / 0.75m/s

Sky Crane Timeline, start 11:30 pm MT

~EI +/- / Event / Release +/- / Rover Altitude / Velocity
+05:58 / Rover Separation / 00:00 / 18.6m / 0.75m/s
Deploy Front Rocker / 0.75m/s
+06:01 / Mobility Deploy / +00:03.0 / <13.0m / 0.75m/s
+06:03.5 / Release Bogie / +00:05.5 / 0.75m/s
+05:05 / Snatch / +00:07.0 / <8.8m / 0.75m/s
+06:07 / Enable Touchdown Logic / +00:09.0 / <3.0m / 0.75m/s
Differential Release / 0.75m/s
+06:09 / Touchdown / 0.00m/s

Touchdown 11:30 pm MT

Landing +/- / Event
00:00 / Touchdown
August 6, 2012 - 5:31 GMT
+00:01.7 / All Wheels Down/Bridle Offload
+00:02.7 / Touchdown Detection
Descent Stage Decel
Bridle Cut Command
+00:02.96 / Bridle Cut
+00:03.172 / Umbilical Cord Cut Command
+00:03.187 / Umbilical Cord Cut
Throttle Up
Fly Away Initiation
Fly Away Duration: Min: 4.0 Seconds
+00:07:187 / Earliest Cutoff Time
Descent Stage Impact

Wow, Successful Landing at Gale Crater!

Congratulations Curiosity, JPL, LMA, NASA!