The real-time simulation has 2,500 site views in the period of 35 to 9 hours prior to landing ... between 9 to 2.5 hours to landing, it's already been 5,500 visits. I'm too scared to look at the page views.
I managed to wake up, so that's good.
Stu, Fredk ... all that's missing is the view of Mars in the background of the script, isnt it :-(
Go Phoenix!

Mmm yes I have seen that too. The timing of the event in the timelist is about 1 hour off. It's supposed to be where Fgrav(Sun)=Fgrav(Mars). I need to review what happened, off-hand I suspect I either got rounded numbers or picked the wrong solution of that quadratic equation.

yes, 25 May 23:53 GMT is the Earth-Received landing time

Anything and everybody (every human, particle, planet ...) is an observer. So for Phoenix the landing happens at 23:38. So does it for Mars or any Martians watching. For the Sun the landing is perceived as happening at 23:52. Earth 23:53 etc. No piece of information can travel faster than light (not sure about the story of gravity 'information' and gravity waves, since that forms the space-time itself). So that's what relativity says.

Of course, once it happened on Mars, it will irreversably get to be perceived on Earth (unless the Universe ends in the meantime), so on a philospohical 'sphere' you can follow SCET or ERT. Or be like me, I follow both, so I can watch it twice!

Daniel

I think one of the old Soviet probes tried to release a balloon as they landed on Mars, if memory doesnt fail me (again). A ballooning mission (rather than a plane) is being thought about for a possible future mission to Titan as well

Well that depends if you are an ERT or SCET kind of guy. In any way, you will be munching peanuts in 24 hours ... either already, or still ...

Arrghh silly me ... that's just first grade trigonometry, now isnt it. Brain to mission control - need more coffee! Thanks Fred.
Daniel

Whilst I share the 'fear' that the landing may go wrong, I dont see how recent history should contribute to the fear. Unless I miss something major, only one landing of US spacecraft post the Vikings went wrong: MPL. The record is quite good once you get to Entry Interface. Mars Observer and Mars Climate Orbiter didnt attempt to land, though the cause for the demise of Mars Observer (fuel pressurization) is yet to come for Phoenix. I dont know how comparable the technology / systems / economics were for Beagle 2.

Daniel

Ah yes that one is hardcore Hollywood! Just watch the stars zip by in the cruise phase at Worp 5 I guess they gotta sell it to the masses ... most people probably dont get too hooked up on a 20 second lander separation discrepancy like us

Well if you drive to an event somewhere, just remember NOT to

• drive your car at a 13 degree angle after you pass the first speed restriction
• open the boot and think the parachute at the back of your car will slow you down in time for the second speed restiction
• open your fuel hatch after coming to a complete stop to vent helium
• call 1-800-ODYSSEY to tell your folks that you have arrived
• stay at the event after it is over because this is not a sample return mission

I agree ... be mindful of that EDL movie. It has lander separation at something like L - 25 secs, but according to the published nominal timeline, lander separation is at L - 45 secs or so, giving it twice as much time to stabilize and then topple over at the last instance anyway. The timeline shown is also shorter than the nominal timeline, but still within its +/-46 seconds of possible deviations.

Chance of success - well it's gonna be interesting. Given that so many things have to go right at the right time (cruise stage sep, attitude, parachute deploy, legs deploy, radar, lander sep, retro-rockets pulse firings, stabilization & attitude, retro-rockets cut-off, venting, solar panel deploy) ... well why shouldnt it work.

Daniel

SpaceListener, in addition to Emily's answer; Phoenix will switch off its radio one minute after touchdown and wait for the orbiters to be back in radio reach. Have a look at this: http://www.planetary.org/image/EDL_Geometry_8a.jpg

Announcement for those following the Phoenix Real-Time Simulation at http://www.dmuller.net/phoenix
Just in case anything goes wrong with the server, there is a backup / mirror site of the script at http://www.dmuller.com/phoenix
Enjoy watching the landing! Daniel

Announcement for those following the Phoenix Real-Time Simulation at http://www.dmuller.net/phoenix
Just in case anything goes wrong with the server, there is a backup / mirror site of the script at http://www.dmuller.com/phoenix
Enjoy watching the landing! Daniel

Announcement for those following the Phoenix Real-Time Simulation at http://www.dmuller.net/phoenix
Just in case anything goes wrong with the server, there is a backup / mirror site of the script at http://www.dmuller.com/phoenix
Enjoy watching the landing! Daniel


BTW thanks Skyrunner for the links. I have used the EDL HUD movie which is posted at the Phoenix website.

Daniel

The view of Mars as seen from Phoenix gets very blurry once you hit around 23:00 UTC on 25 May. Remember that the Solar System Simulator uses spacecraft event time, and please do not use it beyond 23:32:00 on landing day as Phoenix is shown to bounce off (or fly through Mars) and back into outer space! This is at 23:45 spacecraft event time: http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1


Unfortunately it's too late now to add, but I'll gladly include it for other missions once I get around coding them. BTW, what's the formula?


I always wondered what settings to use to make it appear as seen by someone sitting on Phoenix. My knowledge of optics is really zero, I might just as well be theoretically blind

Daniel

http://www.unmannedspaceflight.com (?)



Everything Phoenix related is getting busier ... frantic preparations for the weekend (Monday morning in Australia, so convenient!), emails, questions, testing, ... Just look at the site visits to the real-time simulation: anybody else seeing a "trend"?

I'll be making the 4 hour trip to the next town, which happens to be the Canberra DSN station (well, 45 mins out of Canberra). Hope to catch the landing there, but if I run late, I'll be watching it from a friends house in Canberra on the way to the DSN and go to the DSN for the first image.

On that note, can anybody tape / record the NASA TV stream (media stream preferred)?

Daniel

Hello again Tanjent ... I had a nice strong cup of coffee and fixed the display issue

Thanks for letting me know! I dont have such a device, but now I know anyway what column widths to use for any future scripts to make it work ... mmm call it iUMSF

Hi Tanjent ... good spotting! no worries, it's all a display issue, but it got me scratching my head as well some time ago. Programming decimals in javascript is a bit of a headache and the way I do it causes the sixth decimal to be dropped if it happens to be a zero. Combine that with the right-side alignment and you have the following display problem:


_0.000038
_0.000039
__0.00004
_0.000041
_0.000042



The formula BTW is (acceleration) = (gravitational constant) x (mass of Mars) / (square of distance to center of Mars) and it is independent of the mass of Phoneix


Daniel

Kwan3217, I did some of that work as well for the real-time simulation. I noticed the problems after landing separation as well, in my case it manifested in the altitude being higher than the distance remaining to fly (which I based on speed). But more importantly, it seems to follow an older version of the timeline, with lander separation something like 25 secs before landing BUT according to the latest landing events posted on http://www.nasa.gov/mission_pages/phoenix/...dingevents.html this event now takes place around 45 secs before landing.

Nevertheless, it remains the best and most scientific landing animation I've ever seen.

Daniel

Hmm well memory failed me again and I seem to have mixed up the Earth and Sun terminator lines on that map :-( Anyway, at midnight local Phoenix time it's not gonna be all that bright compared to midday. Any unfortunate tilt in the lander attitude may make it even worse. Does Phoenix ground ops get affected by that? Do they schedule certain activities (other than recharging batteries) only in the day for power reasons?

With 4 1/2 days to landing, and after 3,500 website visits (a lot for a website of mine) I can announce that the final version of the real-time simulation is now online at http://www.dmuller.net/phoenix. I do not intend to make further changes unless the entry interface and/or nominal landing times change "significantly". Such changes can be made as late as just after TCM 6. Some important information:

Download Speed: I would expect the simulation to take longer to load on May 25. At the moment, all position data is correct on an hourly basis and interpolated in between, but soon this will change to a minute-by-minute basis and requires more data to be loaded into the simulation. Starting from about 30 minutes before landing, all the remaining trajectory information will be loaded into the script when it does its auto-reload, or is accessed for the first time. This may take a while longer than usual, but avoids having to reload the script during the crucial EDL phase. Be patient :-)

Mirror Site: In case anything goes pear-shaped, the simulation is also running at http://www.dmuller.com/phoenix. You can use this site if the main page goes down or becomes too slow. I will not be able to attend to the script or server issues in the last 24 hours before landing as I wont be home, and the server sits in the US where there is a long weekend. On that note: could anybody record the NASA TV feed for me (preferably the one without commentary) ... I'll paypal for postage etc?

Beyond Phoenix: given the interest in the script and feedback I have received, I will create similar scripts in due course. However, I do need to catch up on my "proper", space-unrelated :-( work a bit before continuing (as a freelancer it's easy to 'scale back' work for other more interesting activities, but unfortunately the bank account starts to hurt a month later ...). Top of the list will be New Horizons (because I like that mission) and Messenger (for the upcoming Mercury flyby 2). Updates will be posted to where the Phoenix script sits at the moment. I will also look into creating a spaceflight (& related) outreach online library, so if anybody has any suggestions, you know where to find me.

8.5 million km to go. Good luck Phoenix, we're all waiting to hear from you from the surface of Mars.

Go, Phoenix!


Daniel

Aaah relativity ... so we should not look at all as we might kill Schroeder's cat, errrr NASA's Phoenix


but but we dont want the landing to simply "occur", we want to make it happen! So I'll be watching 15 mins 20 secs ahead of SCET because that's the last time we could make changes

Gee I'm glad I studied Economics after all. Relativistic theory with a pinch of salt is so much more fun.

Daniel