US3780966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Attitude sensor
Assignee: National Aeronautics and Space Administration
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Filing: 1972-09-14
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Granted: 1973-12-25
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Expires: 1992-09-14
Abstract
Abstract The invention consists essentially of two light sensors on a spacecraft that are mounted beneath a baffle which divides the light from a light source such as the sun or a star. The divided light reflects off of two reflective surfaces onto the two light sensors. When the spacecraft assumes its normal attitude the baffle divides the light from the light source into two equal parts cuasing the two light sensors to produce equal outputs. An electrical circuit containing the two sensors produces a zero voltage output when the outputs of the two light sensors are equal thereby indicating that the spacecraft is in its normal attitude relative to the light source. While the spacecraft is not in its normal attitude relative to the light source the two light sensors produce unequal outputs causing the electrical circuit to produce an output voltage. The amplitude and polarity of this output voltage are indicative of the attitude of the spacecraft and can be applied to the controls of the spacecraft to return it to its normal attitude.
Inventors
- 👤 A Newcomb
- 👤 A Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:17
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/24; B64G1/36; B64G1/361; B64G1/363
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
248 words
An attitude sensor on a spacecraft for sensing the attitude of the spacecraft about an axis relative to a light source such as a star or the sun comprising: housing means attached to said spacecraft with an aperture in one of its ends, the aperture being pointed in the direction of siad light source while the spacecraft is in its normal attitude; two reflective surfaces located inside said housing means at its other end and fixed relative to the housing means; a single baffle means located inside said housing means between said aperture and said two reflective surfaces for dividing into two parts the light that passes through said aperture from said light source such that one part of the light strikes one of the reflective surfaces and the other part of the light strikes the other reflective surface, said baffle means being positioned such that only while said spacecraft is in its nOrmal attitude the baffle means divides the light from said light source into equal parts; two light sensor means for sensing the light reflected by said two reflective surfaces, respectively; and electrical circuit means including said two light sensor means for producing an electrical signal indicative of the difference between the outputs of said two light sensor means whereby the amplitude of said electrical signal is indicative of the difference between the attitude of the spacecraft and its normal attitude and the polarity of said electrical signal is indicative of the direction of the difference.
Claim 2
Dependent Claim
248 words
An attitude sensor on a spacecraft for sensing the attitude of the spacecraft about an axis relative to a light source such as a star or the sun comprising: housing means attached to said spacecraft with an aperture in one of its ends, the aperture being pointed in the direction of siad light source while the spacecraft is in its normal attitude; two reflective surfaces located inside said housing means at its other end and fixed relative to the housing means; a single baffle means located inside said housing means between said aperture and said two reflective surfaces for dividing into two parts the light that passes through said aperture from said light source such that one part of the light strikes one of the reflective surfaces and the other part of the light strikes the other reflective surface, said baffle means being positioned such that only while said spacecraft is in its nOrmal attitude the baffle means divides the light from said light source into equal parts; two light sensor means for sensing the light reflected by said two reflective surfaces, respectively; and electrical circuit means including said two light sensor means for producing an electrical signal indicative of the difference between the outputs of said two light sensor means whereby the amplitude of said electrical signal is indicative of the difference between the attitude of the spacecraft and its normal attitude and the polarity of said electrical signal is indicative of the direction of the difference.
Claim 3
Dependent Claim
16 words
An attitude sensor according to claim 1 wherein said two reflective surfaces are two flat surfaces.
Claim 4
Dependent Claim
16 words
An attitude sensor according to claim 1 wherein said two reflective surfaces are two integrating spheres.
Claim 5
Dependent Claim
18 words
An attitude sensor according to claim 1 wherein said two light sensor means are two photo-resistive light sensors.
Claim 6
Dependent Claim
25 words
An attitude sensor according to claim 1 wherein said two light sensor means are attached to the side of said baffle away from said aperture.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |