Well the thing that created Gusev wasn't a light breeze either ... or a sand corn ...
And Astro0, glad you can still use Earthly units ... wonder if we'd all understood it if you'd said that the wind is blowing at 15.3 m/s
I myself been working (non-UMSF) until 4am on Sat, and will do so again on Sun, so I have a clear head to do the Dawn realtime simulation on Sunday in the day ...

Since there is much talk about the Dawn cruise, I have finally uploaded the Dawn Realtime simulation onto my website at http://www.dmuller.net/dawn

That's been 4 posts to this thread in 24 hours ... I'll give it a break now for a while

BTW, whilst getting the Dawn data from the Horizons system, I noticed the following description of the propulsion system. I particularly love the bold part, leaves every high-performance car lover drooling!

PROPULSION
Dawn uses 3 ion thrusters to reach Vesta once separated from the Delta II. It
will use the thrusters to spiral to lower altitudes on Vesta, leave Vesta,
cruise to Ceres, and spiral to a low altitude orbit at Ceres.

Weight : 8.9 kg each
Dimensions : 33 cm long, 41 cm diameter
Specific impulse : 3100 s
Thrust : 19-91 mN
Acceleration : 0-60 mph in 4 days
Operational time : 2000 days of thrust (entire mission)

Greg, if you have the Orbiter simulator (http://www.orbitersim.com) you can simulate this in Earth orbit. Get a scenario where your ship is docked to the ISS, set your Orbit display to PRJ ship and DST altitude (will look more or less like a circle), undock, hit "prograde", get your engines on the lowest thrust setting (i.e. press and hold "Ctrl" and then literally hit your "+" button on the Numpad as short as possible), speed up the simulation to 100x (unless you have a lot of time - but dont go over 100x), and watch the PeA (perigee altitude) and ApA (apogee altitude) increase ... everytime you nearly get a circle (circle: PeA = ApA), youl'll find the ApA running away, half an orbit later the PeA starts to catch up.

Greg, that does not seem to be the case. To start with, the original post-launch (pre-ion thrusting) was nowhere near a circle (150m km x 246m km). And the Mars flyby boosts both the periapsis and apoapsis quite a lot (as compared to the thrusting)

Again from Horizons:

My two cents worth:

Dawn is picking up speed from the flyby. As this happens halfway between periapsis (closest point to sun) and apoapsis (farthest point to sun), both are raised. It also rotates the apsises clockwise, so Dawn will be at periapsis shortly after the Mars encounter. By thrusting then, it efficiently raises the apoapsis further. It also increases the inclination from 1.9 to 6.5 degrees, which I think would be costly to do without a gravity assist.

I dont think it makes a difference whether the flyby is inbound or outbound, you gain speed w.r.t. sun as long as you fly behind Mars.

Horizons gives the following orbital elements w.r.t. solar system barycenter (Mars flyby as inferred from Horizons data is around Feb 12):

I will put it on the Space Outreach Library in due course, when I am a bit less busy.

Just out of curiosity ... would there be a "demand" for such large files to be available offline, i.e. burnt on CD and sent my snail mail, for a nominal fee of say US$x for 1 to 2 CDs to cover for postage & stationary & a bit extra for the time involved? This could be a service that the Space Outreach Library could offer, of course only with the approval of the authors of the files in question (I dont want to appear to be "selling" other people's work)

Would anybody have a detailed timeline of major events for the upcoming 3 months checkout & cruise science period? It would look good on my realtime simulation ...

Kwan, I'd love to link from my (ex-) Phoenix realtime simulation to your movie. Let me know once all the UMSFers have downloaded it and your website has bandwidth available for more visitors :-)

I saw the launch of the Shuttle carrying Ulysses at Cape Canaveral ... what a beautiful early morning that was. Was on holidays in Florida (lived in Europe at that time) and whilst we planned to visit KSC we didnt have a clue that a launch was on (in particular one that was about 10 years late). Ulysses is still (just) alive after all those year!

Then I was at the visitor center at the DSN in Canberra for the Phoenix landing. Watched the big dish dialing in on MRO, and I was looking into the big dish (it was at a very low angle) possibly at the time when the "Phoenix @ Heimdall Crater" image (see avatar) came down.

And ... somewhat related to umsf ... I visited the CERN some years back.

Better late than never, I have copied Emily's timeline into the realtime simulation

Glad to know!

Duplicate entry was the problem. Havent managed to recreate that in the testing environment yet

At last I have been able to release an early version of the Space Outreach Library at http://www.spaceoutreach.com

The library is meant to be a portal to information that, in some way, pertains to space outreach education. So if you have a website, presentation, images etc on this topic let the library know. At a later stage there should also be an option to host files on the library (email me if you desperately want to host a file there, it can be arranged manually).

Now all it needs is contents :-) (currently theres 10 test items in it) and heaps of feedback suggestions support and the like ...

It is a self-design and early release version, so please go slow on it and report any bugs you may find. Also there is no documentation and explanations available as yet ...

For feedback on the library, please post in here or email to space { at } spaceoutreach.com

Well I think in "kwan vs JPL Visualization" (sorry for putting it that way) we are talking about two different things.

Kwan's animation is amazing because it is scientifically and engineering-wise "correct", which is of great excitement for those interested in the science and engineering of it all (i.e. the majority on this forum).

The JPL Visualization's task, I can imagine, is to sell "space" and "spaceflight" to the masses (and hence guarantee funding etc). So that stuff has to look good. I somehow doubt that the big masses do get any excitement out of the big wobbles prior to parachute deploy, the resonances of leg deploy, the steadiness at constant velocity

Astro0: just makes me wonder what coffee flavors Starbucks would sell on Mars ... percloraccino? pink deimos dreaming? or just a simple "low-grav de-caf"

Well Rob, none of us would be able to do anything if you folks didn't put in that much hard and brilliant work in the first place ...

Question about the wobbling when PHX hangs on the parachute: does it pivot around the center of the spacecraft gravity (which seems to be what is animated) or would it pivot around the point where the parachute is attached to the backshell?

Wow ... genius! And the background music gives a nice comparison with the planned sequence of events (those of us who have disected that animation sec by sec or frame by frame would be very well versed in the meaning of the background music )


I should be able to host it for you at the Space Outreach Library. That would be an impressive first file for the library (which is coming soon, I promise ... it is well enough to host files at this moment)

I agree with earlier suggestions that the heatshield would have impacted before the lander touchdown and probably didnt quite trigger an impact that Phoenix would have registered.

I am also not sure if it's the 3rd leg touching down late. Vertical speed was 2.4 m/s, and that spike was .35 secs after landing, so one side of Phoenix would have tilted up 2.4 x .35 = 84cm which would be a tilt of 10% or so (assumes a Phoenix diameter of 5 meters)

If anybody is creating a very detailed timeline of EDL events, including possibly things like MRO MEX ODY activities, then I would be very grateful if you could share it ... I'd like to put it on my website where the realtime simulation used to be. I guess that'd be a fitting way to end the realtime simulation which incidentially still receives quite a number of hits.

If all else fails, I'll ultimately try and do it as well but that will be in the not-so-near future due to other commitments.

I notice one last peak of deceleration 0.35 seconds after landing ... did Phoenix bounce (a tiny little bit) on "impact"? To me the spike at L+0.35s does not seem to be part of a declining oscillations from the spacecraft vibrations

Glen, I am not a Celestia specialist and would not be able to answer your question on the fly, though it seems like a good idea.

There are quite a few Celestia spacecraft add-ons at http://www.celestiamotherlode.net/catalog/spacecraft.php I dont know how good they are. Some add-ons have an *.xyz file which seems to be the trajectory information consisting of four variables: time, x, y, z ... which is exactly the info I extract from JPL's Horizons system (need to find out which reference system Celestia is using). Thus it "should" be straight forward to plot a spacecraft trajectory in the solar system and pinpoint its position at any given time. However, I would not know (at this time) how to show additional information (events countdowns, distance to fly etc). A Celestia applet in the javascripts would be nice too, or remote controlling the viewing parameter of Celestia from a website, but I have no idea if it is possible.

On that note, I am itching to release the beta version of the Space Outreach Library, but I am still horribly busy at the moment :-(

BTW, is the CDSCC planning any event on 6 Oct for the Messenger Mercury flyby 2 (C/A is at something like 3:30pm Canberra time)

This "research" is to help improve the realtime simulations. For the Messenger Mercury Flyby 2 I plan to integrate "live" images from the solar system simulator (http://space.jpl.nasa.gov). Having read through various discussion boards, I noted that reference was made to that site being down during the Phoenix landing, and assuming that the same may occur on 6 Oct, it would probably be sensible to host time critical images on the same server as the realtime simulation. Hence my questions:

When did space.jpl.nasa.gov go down?
When did it come back up?

If anybody remembers, please let me know.

Thanks!

Alright, last but not least the first "draft" for the Messenger real-time simulation is up and running at http://www.dmuller.net/messenger

It's pretty preliminary, especially the timeline, but I'm mildly confident that total strangers would chip in and provide some timelines as happened for Phoenix and Rosetta. Unfortunately I am very busy with non-space work so I cant chip in heaps of research at the moment.

Dont forget Rosetta's flyby at Asteroid Steins on 5 Sep: http://www.dmuller.net/rosetta