| 摘要 |
A method of solar occultation, and in particular solar coronagraphy, employing a spacecraft 200 is disclosed. The spacecraft is controlled to achieve a position within a target zone relative to a celestial body, such as the Moon, such that the celestial body occults the Sun, allowing observations of the Sun or the space around the Sun, and in particular the Sun's corona, to be made from the spacecraft. The spacecraft has an orbit 40 around the Earth in a plane S, which like the Moon's orbit 20 in plane M, is inclined relative to the ecliptic plane E. Once inside the target zone, the spacecraft's orbit is controlled such that it remains in the target zone for longer than it would otherwise. This is achieved through the orbit within the target zone being at least partly non-Keplerian, when the orbit is under the influence of spacecraft translational thrust for example. The invention also extends to a method of controlling a spacecraft, to a spacecraft, and to a solar coronagraph comprising a spacecraft and a celestial body. |
