Fuel and thermal optimal spiral earth acquisition
US6076774A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1998 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Aug 12, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64G1/26
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A system and method for acquiring the Earth by a three-axis stabilized spacecraft in the presence of a significantly time-varying Sun-Earth angle including obtaining an Earth cone described by rotating the nadir vector about the Sun vector, slewing the spacecraft about an axis until the Earth sensor boresight touches an edge of the Earth cone, updating the Earth cone due to the changing Sun-Earth separation angle, performing a spiral coning maneuver about the updated Earth cone until the Earth sensor detects the Earth, and locking onto the Earth so as to hold the Earth sensor boresight coincident with the nadir vector. Additionally, the spacecraft may be rotated about the nadir vector so as to bring the spacecraft into a desired final attitude.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.