InSight Cruise Phase, Events during Mars transit prior to EDL |
  |
InSight Cruise Phase, Events during Mars transit prior to EDL |
 Nov 21 2018, 11:47 PM
Post
#76
|
|
 Senior Member  Group: Members Posts: 2425 Joined: 30-January 13 From: Penang, Malaysia. Member No.: 6853  |
QUOTE (djellison @ Nov 22 2018, 12:27 AM)  They have cameras. They'll be flying by Mars. Fingers crossed...there will be pics.  Fingers and Toes crossed  Thanks for the info Doug
|
 |
 
|
|
Nov 22 2018, 01:49 AM
Post
#77
|
|
|
Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
QUOTE (PaulH51 @ Nov 21 2018, 03:47 PM) Fingers and Toes crossed And then some...... Spoiler alert - I'm helping with planning and processing of pics from their tiny camera. Trying our best to estimate reasonable exposure times in the next 48hrs before committing on Sat AM.
|
|
|
|
|
Nov 22 2018, 03:19 AM
Post
#78
|
|
|
Senior Member Group: Members Posts: 2425 Joined: 30-January 13 From: Penang, Malaysia. Member No.: 6853 |
QUOTE (djellison @ Nov 22 2018, 09:49 AM) ...before committing on Sat AM. Excellent news indeed
|
|
|
|
| Guest_mcmcmc_* |
Nov 22 2018, 07:59 AM
Post
#79
|
|
Guests |
QUOTE (Gerald @ Nov 21 2018, 06:18 PM) Maybe this document, and the according server and directories could be a better point to start from. See also this LBL file together with this table. Yes, that table (and PHXPROFILES) is all I was able to find, but I think they do not match with that description. In this file you find the list of all fields: QUOTE PHXPROFILE.TAB contains the following items. Time (relative to reference time, seconds) UTC_TIME Radial distance (m) RADIAL_DISTANCE Areocentric latitude (degrees north) LATITUDE Areocentric longitude (degrees east) LONGITUDE X-component of position (m) X_POSITION Y-component of position (m) Y_POSITION Z-component of position (m) Z_POSITION Element 0 of quaternion (dimensionless) Q0 Element 1 of quaternion (dimensionless) Q1 Element 2 of quaternion (dimensionless) Q2 Element 3 of quaternion (dimensionless) Q3 X-component of velocity (m/s) X_VELOCITY Y-component of velocity (m/s) Y_VELOCITY Z-component of velocity (m/s) Z_VELOCITY Speed of spacecraft relative to atmosphere (m/s) VREL X-component of acceleration (m s^(-2)) X_ACCELERATION Y-component of acceleration (m s^(-2)) Y_ACCELERATION Z-component of acceleration (m s^(-2)) Z_ACCELERATION Angle of attack (degrees) ALPHA Axial force coefficient, CA (dimensionless) CA Normal force coefficient, CN (dimensionless) CN Mach number (dimensionless) MA Knudsen number (dimensionless) KN Density (kg m^(-3)) RHO Pressure (Pa) PRESS Temperature (K) TEMP QUOTE PHXCOMPACT.TAB contains the following items. Radial distance (m) MRADIAL_DISTANCE Altitude (km) MALTITUDE Density (kg m^(-3)) MRHO Pressure (Pa) MPRESS Temperature (K) MTEMP The description in my previous post says: QUOTE Spacecraft Clock count: Units = seconds Relative time from a defined entry state: Units = seconds The altitude of the spacecraft above the landing site: Units = seconds Planetocentric latitude of the spacecraft at the time of sample acquisition: Units = degrees Planetocentric east longitude of the spacecraft at the time of sample acquisition: Units = degrees Speed of the Phoenix entry probe at the given location: Units = m/s So I think they are different datasets. ------------------------- I got weird results while turning "angle of attack" data into something graphical, i.e. an image of the lander rotating as per AoA data, so then I analysed visually last seconds of the data and also plotted them, and they're weird: how can AoA become greater than 90°? (AoA is column 2x19=38 in PHXPROFILES.TAB). It also remaines greater than 90° after landing. Definition: QUOTE The angle of attack, namely the angle between the spacecraft symmetry axis and the vector velocity of the atmosphere relative to the spacecraft, was also determined using the assumption that the atmosphere rotates with the solid body of the planet. Translation: angle w.r.t ground. In the animation I obtained by rotating the image of spacecraft in realtime according to AoA (animation not yet online) it's clearly visible the effect of the engines being turned on (vibration of the lander), so one can assume that AoA>90° is due to backshell avoidance maneuver, but I expected AoA to become again 90° at landing, but it last value is 132°. |
|
|
|
| Guest_mcmcmc_* |
Nov 22 2018, 01:43 PM
Post
#80
|
|
Guests |
These links provide raw numerical data for MARCO-A (code "-65") and MARCO-B (code "-66") as per NASA Horizons site.
Position & speed are expressed w.r.t. Mars center. |
|
|
|
|
Nov 22 2018, 05:43 PM
Post
#81
|
|
 Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
QUOTE (djellison @ Nov 21 2018, 05:49 PM) And then some...... Spoiler alert - I'm helping with planning and processing of pics from their tiny camera.Just make sure you don't get your thumb or the camera strap in the images and you should be OK. -------------------- If Occam had heard my theory, things would be very different now.
|
|
|
|
| Guest_mcmcmc_* |
Nov 22 2018, 05:55 PM
Post
#82
|
|
Guests |
QUOTE (djellison @ Nov 22 2018, 02:49 AM) And then some...... Spoiler alert - I'm helping with planning and processing of pics from their tiny camera. Trying our best to estimate reasonable exposure times in the next 48hrs before committing on Sat AM.Don't forget the switch to turn the images upside-down (somebody said on july 20th, 1969...) ;-) |
|
|
|
|
Nov 22 2018, 08:09 PM
Post
#83
|
|
 Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Forum note: The EDL thread will go live at 0800 PST (1600 GMT) this Monday, 26 Nov, and discussion concerning that will happen there. Will post a link to it then.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
|
|
|
|
| Guest_mcmcmc_* |
Nov 22 2018, 09:15 PM
Post
#84
|
|
Guests |
Added manometers for deceleration and attack angle.
http://win98.altervista.org/space/explorat...-simulator.html It's cool to see even parachute oscillations and legs deployment in the "amplified" accelerometer! (first gauge) Paper says attack angle is unreliable after chute deployment, I don't know why. |
|
|
|
| Guest_mcmcmc_* |
Nov 23 2018, 09:44 AM
Post
#85
|
|
Guests |
QUOTE (mcmcmc @ Nov 22 2018, 10:15 PM) Paper says attack angle is unreliable after chute deployment, I don't know why. from official papers it results that even NASA does not why attack angle data are totally unreliable after parachute deployment, but i can't find any further update after 2010. There are 3 different issues on attack angle reconstruction: 1) discrepancies between predicted and re-constructed angles of attack addressed by Desai et al.(2008). 2) discrepancies (+/- 2° , which could be "explained" by a 300 m/s wind) between results from direct reconstruction from gyros and indirect reconstruction from accelerometers - "Results from the Phoenix Atmospheric Structure Experiment" Paul Withers and David Catling - 2010 3) nonsense values of angle attack at parachute deployment (46°) and after (up to 132°) - "Production of Reduced Data Records for the Phoenix Atmospheric Structure Experiment" - Paul Withers, D. C. Catlingb - From data it also appears that Phoenix touched ground... 1.2 km above ground ("Results from the Phoenix Atmospheric Structure Experiment" Paul Withers and David Catling - 2010). I'm not sure if they are talking about "above MOLA level" or "above ground level". MSL EDL data just stop at 12 km above surface. I've yet to examine EDL data for MPF, MER, and Schiaparelli, anyway last part of EDLs looks quite "mysterious" yet. Still a lot of work to do till safe manned capsule landing on Mars! Now I am very curious about what Insight EDL data will show. ---------------- I also found another interesting paper about an unexpected issue on Phoenix mission: descent radar locking on jettisoned heatshield and thus providing false values for altitude! "Phoenix Landing Radar Heatshield Anomaly" - J. Eric Belz, Curtis Chen, and Ben Cichy Together with high possibility of Phoenix cruise stage recontact with Phoenix lander during EDL, it's an issue I was totally unaware of till a week ago. |
|
|
|
| Guest_mcmcmc_* |
Nov 23 2018, 02:08 PM
Post
#86
|
|
Guests |
Just to better know what Insight is about to face:
Overview of the Phoenix Entry, Descent, and Landing System Architecture - Myron R. Grover III, Benjamin D. Cichy |
|
|
|
|
Nov 23 2018, 04:09 PM
Post
#87
|
|
 Member Group: Members Posts: 886 Joined: 15-June 09 From: Lisbon, Portugal Member No.: 4824 |
For the Google Mars community, here is a KMZ file with InSight's landing ellipse.
Unfortunately, Google Mars does not have any CTX registered for this area, so I suggest going to GE's left panel and in the Layers section, select under Global Maps the Daytime Infrared. This is the base map appearing, for instance, in landing ellipse image contained in the press kit. To install the file, download it to your favorite location and double click it. This should startup Google Earth, if not already opened, and initiate a switch to Google Mars (a pop-up will display). The globe should automatically rotate and position itself over the ellipse area. Acknowledgements, credits, and a short explanation are available on the file's help panel. To get to the panel select the file's name on GE's Places panel. The ellipse is approximated by a 180-sided polygon. I'd welcome information on any errors that may exist. Fernando 
InSight.kmz ( 4.74K )
Number of downloads: 244 |
|
|
|
| Guest_mcmcmc_* |
Nov 23 2018, 06:58 PM
Post
#88
|
|
Guests |
QUOTE (nogal @ Nov 23 2018, 05:09 PM) For the Google Mars community Damn!  If just you'd remebered me before about existence of Google Earth, I could have set up something better than this.... I totally forgot that I can create animations in google earth! This is the Phoenix EDL: http://win98.altervista.org/space/explorat...Phoenix-EDL.kmz It's even possibile to make the marker shape change depending on altitude, and shift whole trajectory to Insight site (just for fun, it's a simulator)... but I think it would require more time than remaining time to the event. :-( In case anybody has time/wish to help, this is the source code which converts EDL data into KML format: http://win98.altervista.org/space/explorat...t/crea-EDL.html Data are here: http://win98.altervista.org/space/explorat...ht/js/coords.js Taken as usual from PHXPROFILES.TAB . This line gets one sample every 200 to make things faster; change "200" to "1" for a realtime animation: CODE for (index = 0; index <= latLonAlt.length-1; index += 200) {
|
|
|
|
|
Nov 23 2018, 08:20 PM
Post
#89
|
|
|
Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
I believe that angle of attack information after chute deployment is irrelevant. The aeroshell is no longer providing any significant lift; it's all about the inflated chute at that point, which had better be normal to the flight path.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
|
|
|
|
| Guest_mcmcmc_* |
Nov 23 2018, 08:37 PM
Post
#90
|
|
Guests |
QUOTE (nprev @ Nov 23 2018, 09:20 PM) I believe that angle of attack information after chute deployment is irrelevant. Irrelevant for what? |
|
|
|
|
|
Lo-Fi Version | Time is now: 20th April 2024 - 01:51 AM |
|
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |
|
