[X] My Assistant

[dmuller]

I am in the midst of programming a rather simple javascript to keep track of Phoenix's progress (and later EDL) together with a timeline of events. The current version is online at www.dmuller.net/phoenix, but if anybody has more details, I would greatly appreciate any input, in particular of upcoming events and their anticipated timing, as well as details during the atmospheric flight (altitude, speed, downrange). For all times, it would also be great to know their timezone and whether they are SCET or ERT. The "positions" information is calculated based on data downloaded from the SSD Horizons system, which is available right up to the Entry Interface.

Naturally, I also welcome any suggestions on what other information could be added to the script.

I can also provide an off-line version of the script (does not require php) e.g. for public display in a visitor center.

Please post any information / feedback / requests either here or send me an email through my public profile on this board. I may not respond for a couple of days as I will not have internet access.

Thanks a lot to everybody!

Phoenix Entry Interface in 41 days 22 hours. Distance to fly: 79.7 million km. Altitude above Mars: 9.6 million km

[dmuller]

An update with 22 days and 5 million kilometers to go ...

First my thanks to Emily for mentioning the simulation on her Planetary Society blog. It attracted a large crowd (avg 100 visits/day) and by now I get a steady stream of visitors to the simulation from people who have bookmarked the site. Great!

As for the script, all functionality is now included, including DSN coverage, virtual commentary during landing and a bigger font for the numbers. At the moment, the script is in "Spacecraf Event Time", and "Earth Received Time" will be enabled shortly.

The challenge now is to fine-tune the data during the first part of the atmospheric flight, in particular from Entry Interface to Parachute deployment. Therefore, again, if anybody has information on the following, please share them with me ... pretty please ...

(1) Precise timing for TCMs 4, 5, 6 and 6X

(2) Anticipated nominal altitude as a function of time and speed as a function of time (time being from Entry Interface or landing). Trajectory reconstructions for Spirit, Opportunity or Beagle-2 would be welcomed too ... I saw references made to them on the net, but havent actually found one :-( I did, however, find a neat one for the Huygens landing on Titan

Piecing together the snippets of interviews found on youtube just doesnt give the whole picture.

Also, if you manage / work for / represent etc a spaceflight educational outreach position (and dont have internet access there), I can create an offline version of the script. At last count, it's already heading that way to 3 such organizations on 3 continents.

[kwan3217]

...The challenge now is to fine-tune the data during the first part of the atmospheric flight, in particular from Entry Interface to Parachute deployment. Therefore, again, if anybody has information on the following, please share them with me ... pretty please ...

(2) Anticipated nominal altitude as a function of time and speed as a function of time (time being from Entry Interface or landing). Trajectory reconstructions for Spirit, Opportunity or Beagle-2 would be welcomed too ... I saw references made to them on the net, but havent actually found one :-( I did, however, find a neat one for the Huygens landing on Titan

http://trs-new.jpl.nasa.gov/dspace/bitstre...8/1/05-2473.pdf "Landing on Mars" with a velocity vs altitude chart for all the past and current entry phase stuff. You could integrate it somehow to get downrange vs time, then the things you want.

http://ntrs.nasa.gov/archive/nasa/casi.ntr..._2008012906.pdf "2007 Mars Phoenix EDL Simulation and Modeling Analysis" Another velocity vs altitude chart.

http://trs-new.jpl.nasa.gov/dspace/bitstre...7/1/95-0980.pdf "Mars Pathfinder Atmospheric Entry Trajectory Design" includes an altitude and acceleration as function of time from entry interface. For Mars Pathfinder, so not particularly relevant.

All of these references say that Phoenix is similar to MER entry trajectory, which is very well documented (search ntrs.nasa.gov).

http://starbrite.jpl.nasa.gov/pds-explorer...ume=merimu_1001 Mars Exploration Rover EDL accelerometer record

I've seen acceleration and velocity vs time from entry interface charts, but I can't locate them again.

I'm working on a Phoenix model for Orbiter http://orbitersim.com and it looks like I have a valid aerodynamic and atmosphere model, since it is hitting exactly 9.2G peak on entry. I'll be able to get an extraordinarily complete log of my model's entry. I plan on publishing the model before the real thing does its entry.

[dmuller]

Thanks Kwan for the links. Interesting reading, and please do make the orbitersim.com Phoenix model available for public use :-)

Meanwhile, the following animation has been put up at http://phoenix.lpl.arizona.edu/videos.php#edl_hud, very useful for my project, and impressive as is:

Phoenix EDL Animation - This animation featuring a heads-up display shows second-by second the entry, descent and landing of the Phoenix Mars Lander on May 25, 2008. The animation was created by NASA's Jet Propulsion Laboratory's Solar System Visualization Project.
Low Bandwidth English Units (5.7 MB)
Low Bandwidth Metric Units (5.7 MB)
High Bandwidth English Units (47.3 MB)
High Bandwidth Metric Units (42.9 MB)

I will still use your references for the time from Entry Interface to plasma blackout.

Daniel