Athena (spacecraft)


Mission typeAsteroid flyby
Mission duration2 years (planned)
Spacecraft properties
Launch mass≈ 182 kg (401 lb)
Start of mission
Launch date2022 (proposed)
Flyby of 2 Pallas
An ultraviolet image of Pallas showing its spherical shape, taken by the Hubble Space Telescope in 2007.

Athena is a proposed space mission that would perform a single flyby of asteroid 2 Pallas, the third largest asteroid in the Solar System.[1]

If Athena is funded, it would share the launch vehicle with the Psyche and Janus spacecraft and fly its own trajectory for a Mars gravity assist to slingshot into the asteroid belt. It would take about two years to reach Pallas.[1] The mission's principal investigator is Joseph O'Rourke, at Arizona State University.

The Athena spacecraft was examined in Category 1 of the 2018 NASA SIMPLEx competition and was eliminated before reaching Category 2; it will possibly be proposed at a later unknown time.[2] The Athena mission was beaten by other mission concepts such as the TransOrbital TrailBlazer lunar orbiter.[3]


The science goals and objectives include:[4]

  • to determine how differentiation varies on bodies with large proportions of ices and how they and evolved over time.
  • to determine how the current population of asteroids evolved in time and space.
  • to understand the role of water in the evolution of Pallas.
  • to constrain the dynamical evolution of Pallas and asteroids in the Pallas impact family.

Athena would conduct visible imaging of the geology of Pallas with a miniature color (RGB) camera. Also, a radio science experiment would use continuous antenna pointing to Earth for two-way Doppler tracking to enable the determination of the mass of Pallas with a precision of <0.05%.[4]


  1. ^ a b Dorminey, Bruce (10 March 2019). "Proposed NASA SmallSat Mission Could Be First To Visit Pallas, Our Third Largest Asteroid". Forbes. Retrieved 10 March 2019.
  2. ^ Athena: A SmallSat Mission to (2) Pallas
  3. ^ Finalists Selected for NASA’s SIMPLEx Program 24 June 2019
  4. ^ a b Athena: the first-ever encounter of (2) Pallas with a Smallsat. J. G. O'Rourke, J. Castillo-Rogez, L. T. Elkins-Tanton, R. R. Fu, T. N. Harrison, S. Marchi, R. Park, B. E. Schmidt, D. A. Williams, C. C. Seybold, R. N. Schindhelm, J. D. Weinberg. 50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132)