Description
SPICE is a NASA-built planet ephemeris library which can compute coordinates, including positions, velocities, rotations and harmonic oscillations of celestial bodies at a range of epochs. The SPICE interface, although not exposed to the user, manages the data flow between the Universe system and the SPICE kernels loaded. When a user requests a new planet, the interface loads the planet in the buffer and on the update call receives the new data from the kernel. It is publicly available and has been flight tested by internationally-made space vehicles.
Example Use Cases
- All orbits require the use of SPICE. It is in-built and always available.
- Modelling interplanetary orbits and trajectories between planetary bodies.
Module Implementation
The SPICE interface simply acts as a data barrier between the Universe planets and the loaded kernels. Model implementation can be found on the NASA NAIF website. NAIF
Assumptions/Limitations
- SPICE data reads extremely precise ephemeris data, which is compared with JPL’s Horizons data. Depending on the celestial body, the accuracy may vary.
- The kernels in the NAIF directory must be loaded correctly for SPICE to work.
- The latest Epoch that can be entered is the year 2560. No simulation can be run after this year due to the incomplete SPICE kernels.
References
[1] Acton, C.H.; “Ancillary Data Services of NASA’s Navigation and Ancillary Information Facility;” Planetary and Space Science, Vol. 44, No. 1, pp. 65-70, 1996. DOI 10.1016/0032-0633(95)00107-7
[2] Charles Acton, Nathaniel Bachman, Boris Semenov, Edward Wright; A look toward the future in the handling of space science mission geometry; Planetary and Space Science (2017); DOI 10.1016/j.pss.2017.02.013