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DEVELOPER'S NOTES:

Here you will find notes from the Eyes on the Solar System developers regarding caveats, bugs, in-development features, etc. It will be updated as often as possible.


Compatability:

Platform
Although using the Unity 3D engine allows us cross-platform capabilities, it is still a challenge to get cross platform compatability to work smoothly in all situations. Firstly, the Unity 3D plug-in does not work on Linux systems. It is unfortunately compatible only with Windows and Mac OS X.

Browser
The program does make use of JavaScript for some initialization actions (such as loading a specific document or scene). This means that there is a dependence on what browser is used. We have found the best overall compatability using Firefox. Therefore, we highly recommend using Firefox when using Eyes on the Solar System. The program also works in Safari (for Mac or PC) and Internet Explorer. There are some unresolved issues with very specific Safari cases, but we hope these instances are rare. Although the program will run in Chrome, it is a bit choppy on Chrome for Mac OS X. Even worse, JavaScript compatibility is broken in Chrome, resulting in document launching links that do not work. As such, we suggest avoid Chrome for the moment until this issue can be resolved. Browsers beyond these four are not tested.


Recent Changes:

Added More Spacecraft (Apr. 28, 2011)
Added the following spacecraft based on DSN mission ephermis used to determine DSN pointing: ACE, Chandra, Cluster 1/2/3/4, GEOTAIL, INTEGRAL, Kepler, Lunar Reconnaissance Orbiter, Spitzer Space Telescope, STEREO Ahead/Behind, THEMIS B/C, Venus Express, WIND, and WMAP. Also updated SOHO trajectory data baesd on the same data source.

Added Sprites for Earth Orbiters (Mar. 18, 2011)
New sprites were added for many Earth orbiters that were previously unapproachable. A new spacecraft icon was also added for New Horizons.

Added MESSENGER Mercury Orbit Insertion (Mar. 16, 2011)
Added new predicted kernels for MESSENGER MOI (Mercury Orbit Insertion) which is set to start tomorrow around 8:30 pm Eastern, 5:30 pm Pacific. Ride along with the spacecraft as it performs orbit insertion around Mercury! See http://messenger.jhuapl.edu/orbit_insertion/stationkeeping.htm for more information. This addition includes a smoother system for changing object parents based on their trajectory data set. It also includes added functionality for sprites to act as a burn thrust effect.

Bookmarks and Descriptions (Mar. 14, 2011)
Added bookmark times for Mars missions, which were lacking before. The destination panel has also been reorganized. Description files were also added for many spacecraft that were missing theirs (resulting in the errors mentioned below).

Demoted Web Errors (Mar. 12, 2011)
Occasionally errors would show up in the console regarding failed downloads for description files. Errors in the console automatically bring up the console, which was detrimental to the user experience. These have been demoted to warnings so that the console remains hidden. The console can be brought up with the accent grave/tilde key.

New Models (Mar. 9, 2011)
Thanks to the hard work of our modeling team, we now have completed models for Ulysses, Juno, and New Horizons. The New Horizons trajectory has also been updated to use predictions extending the trajectory to just before Pluto encounter.

Mars Missions (Mar. 9, 2011)
We recently added trajectories for a number of Mars missions. These includes: Viking 1 and Viking 2 orbiters, Mars Global Surveyor, Mars Pathfinder, Mars Climate Orbiter, Mars Polar Lander, Mars Odyssey, Mars Reconnaissance Orbiter, Mars Express, Mars Exploration Rovers A/B, Phoenix, and Mars Science Laboratory.

More Earth Orbiters (Mar. 9, 2011)
Our pipeline for Earth orbiter data has been revamped to hopefully provide historical trajectories as well as the instantaneous ones provided by TLEs (two-line elements). This should keep our Earth orbiter trajectories more up-to-date since they can change daily. In addition to that, we've added a number of new Earth orbiters. These include: TDRS constellation, AIM, C/NOFS, ERBS, FGRST, GALEX, GP-B, HST (Hubble Space Telescope), LANDSAT 4, LANDSAT 5, RXTE, SWIFT, TIMED, TOPEX/POSEIDON, UARS, WISE, THEMIS A/D/E, and GRACE 2. Only the trajectories were added for these so you won't be able to go down and see a spacecraft model (with the exception of GRACE 2).

2005 YU55 (Mar. 1, 2011)
We've added the trajectory for asteroid 2005 YU55. This asteroid will come within eight-tenths of the Earth-Moon distance on November 8, 2011.


Caveats:

Shadows
No shadowing system has been implemented. This is planned for development in future releases.

Stuttering
You might have noticed that after a bit of data loading the program gets a bit stuttery. This is due to an unresolved issue involving the garbage collector. Since the program is still in development (thus the beta label) we plan on resolving this during a testing/optimization run in the future.


In Development:

Models
Our awesome modeling team is current working on a number of spacecraft models. In the near future, expect to see finished models of Phoenix (cruise), Mars Exploration Rovers (cruise), Mars Science Laboratory (cruise), Mars Odyssey, and Mars Express. There are many spacecraft in the pipeline, so be patient!


Frequently Asked Questions:

Is Eyes on the Solar System accurate enough to use for astronomy?
Eyes on the Solar System is a visualization first and foremost. Although accurate enough for simple star gazing, it should not be used for scientific purposes.

How accurate is Eyes on the Solar System?
The accuracy varies depending on the object. We process the data so that it is compatible for web streaming. This process introduces errors. For most objects, this error is on the order of 1 kilometer. At some points, the error is improved such as during encounters. In the end, it is dependent on the source data. Most of the orbit data is generated from NAIF SPICE kernels which can be found at http://naif.jpl.nasa.gov/. Some kernels are generated by the HORIZONs system. We also make use of some predicted scheduling kernels used by the Deep Space Network to track spacecraft. Earth orbiting satellites get their data from two-line elements (TLE) from http://celestrak.com/. These orbital states are then propogated by an SGP4 propagator.

Why does the sun get very bright when zooming out of the solar system?
When the solar system becomes so small that it dissapears, we show the sun's brightness relative to the other stars. When the solar system is visible, we decrease the sun's brightness so that objects in the solar system are visible.

From the Developers
Please keep in mind that these notes are from the developers and do not represent JPL, NASA, Caltech, or their respective outreach efforts.