11. Orbital decay occurred on July 1, 2014.12. Spacecraft experience orbital decay due to drag. 13. A primary use of this model is to aid predictions of satellite orbital decay due to atmospheric drag. 14. Space stations typically require a regular altitude boost to counteract orbital decay ( see also orbital station-keeping ). 15. Orbital decay can occur due to tidal forces for objects below the synchronous orbit for the body they're orbiting.16. Some satellites with long conductive tethers can also experience orbital decay because of electromagnetic drag from the Earth's magnetic field. 17. Additionally, the orbital decay is caused not by atmospheric drag, but by solid body tidal forces not considered by Shklovsky. 18. The spacecraft carried 10 days of provisions to allow for survival and natural orbital decay in the event the retrorockets failed. 19. Even close orbiting planets can become disrupted, potentially leading to orbital decay and an increase in orbital eccentricity and tidal effects. 20. One of his many contributions while at NASA was conducting research to understand the dynamics of orbital decay of artificial Earth satellites.