How to get MARS2020/Perseverance EDL trajectory data from spice kernels?

Question

For MSL EDL it is available this answer: How to retrieve MSL EDL trajectory using Javascript and webgeocalc API?

How can I adapt it to MARS2020/Perseverance?

Answer 1

This folder contains SPICE kernels for MARS2020: https://naif.jpl.nasa.gov/pub/naif/MARS2020/kernels/spk/

These SPK kernels contain planned EDL trajectory (prepared before actual landing):

• https://naif.jpl.nasa.gov/pub/naif/MARS2020/kernels/spk/m2020_trajCEDLS-6DOF_ops_od020v1_AL23.bsp

  • Coverage: 2020-07-30 12:51:34 - 2021-02-18 23:43:42
  • Created by Monte 140.1 on 2020/08/18 23:34 UTC.
  • Contents: Mars 2020 Reference Trajectory
  • Mission phases: Cruise, entry, descent, landing, and surface
  • Created by: Mars 2020 Navigation Team Contact: Gerhard Kruizinga (gerhard.l.kruizinga AT jpl.nasa.gov)

• https://naif.jpl.nasa.gov/pub/naif/MARS2020/kernels/spk/m2020_FMAresponse_JEZ_20200717_P000.edl.bsp

  • Coverage: 2021-02-18 20:25:33 - 2021-02-18 20:32:16
  • Data source: Table 3.2 of D-95513_M2020_PCMD_RevC_190415_SIGNED.pdf
  • This SPK was provided by Julie Kangas, M2020 MD/NAV on 06/12/19.

• https://naif.jpl.nasa.gov/pub/naif/MARS2020/kernels/spk/m2020_edl_nom_jez_v2.bsp

  • Coverage: 2021-02-18 20:24:38 - 2021-02-18 20:31:15
  • Data source: Table 3.2 of D-95513_M2020_PCMD_RevB_180620_v0.pdf
  • This SPK was provided by Julie Kangas, M2020 MD/NAV on 08/16/18

Use following data to send a query to WebGeoCalc:

{
  "kernels": [
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/ground_stations_v0013.tm"
    },
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/solar_system_v0037.tm"
    },
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/latest_lsk_v0004.tm"
    },
    {
      "type": "KERNEL",
      "path": "MARS2020/kernels/spk/m2020_trajCEDLS-6DOF_ops_od020v1_AL23.bsp"
    }    

],
  "timeSystem": "UTC",
  "timeFormat": "CALENDAR",
     "intervals": [
       {
         "startTime": "2021-02-18 20:37",
         "endTime":   "2021-02-18 20:45"
       }
     ],
  "timeStep": 1,
  "timeStepUnits": "SECONDS",

  "calculationType": "STATE_VECTOR",

  "target" : "-168",
  "targetType": "OBJECT",

  "observer": "MARS",
  "observerType": "OBJECT",

  "referenceFrame": "IAU_MARS",
  "frameLocus": "OBSERVER",
  "aberrationCorrection": "NONE",
  "stateRepresentation": "PLANETOGRAPHIC"
}

Possible coordinates types:

• PLANETOGRAPHIC
• PLANETODETIC
• PLANETOCENTRIC
• RECTANGULAR

This will result in text data; if you want graphical representation of data, use graphical version of WebGeoCalc, and just manually add the proper MARS2020 EDL kernel; you will get something like this:

---

What about traverse map, i.e. the path of Perseverance on surface?

For MSL it is available the kernel msl_surf_rover_loc.bsp in SPK folder, updated twice a day with new data; following JSON object can be used to request text data for MSL/Curiosity; for Perseverance, change "-76" to "-168", and "MSL/kernels/spk/msl_surf_rover_loc.bsp" to Perseverance kernel once available.:

{
  "kernels": [
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/ground_stations_v0013.tm"
    },
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/solar_system_v0037.tm"
    },
     {
      "type": "KERNEL",
      "path": "pds/wgc/mk/latest_lsk_v0004.tm"
    },
    {
      "type": "KERNEL",
      "path": "MSL/kernels/spk/msl_surf_rover_loc.bsp"
    }    

],
  "timeSystem": "UTC",
  "timeFormat": "CALENDAR",
     "intervals": [
       {
         "startTime": "2021-02-10 20:37",
         "endTime":   "2021-02-18 20:45"
       }
     ],
  "timeStep": 1,
  "timeStepUnits": "MINUTES",

  "calculationType": "STATE_VECTOR",

  "target" : "-76",
  "targetType": "OBJECT",

  "observer": "MARS",
  "observerType": "OBJECT",

  "referenceFrame": "IAU_MARS",
  "frameLocus": "OBSERVER",
  "aberrationCorrection": "NONE",
  "stateRepresentation": "PLANETOGRAPHIC"
}

For the graphical version use Graphical Webgeocalc: