US4898347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for cleaning spacecraft critical surfaces
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1988-10-17
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Granted: 1990-02-06
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Expires: 2008-10-17
Abstract
Abstract Spacecraft components having critical surfaces which must arrive in outer space in a contamination-free, pristine state to assure their effecient operation over the entire spacecraft mission life are protected against contamination by applying to the surfaces a protective coating which sublimes away when exposed to the outer space environment, thereby exposing the surfaces in their pristine state to the environment.
Inventors
- 👤 Maurice P. Bianchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:27
CPC Classifications
B; B08; B08B; B08B17/00; B08B17/02; B08B17/04; G; G02; G02B; G02B1/00; G02B1/10; G02B1/14; Y; Y10; Y10S; Y10S136/00; Y10S136/291; Y10S136/292
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
In combination means having a pristine surface to be placed in an outer space environment, a protective coating on said pristine surface which sublimes in said outer space environment, whereby contaminants which would otherwise deposit on and contaminate said surface deposit instead on said coating, and wherein said protective coating and any contaminants thereon are eliminated from said surface in said outer space environment by sublimation of said coating, thereby to expose said surface in its pristine state to said outer space environment.
Claim 2
Dependent Claim
83 words
In combination means having a pristine surface to be placed in an outer space environment, a protective coating on said pristine surface which sublimes in said outer space environment, whereby contaminants which would otherwise deposit on and contaminate said surface deposit instead on said coating, and wherein said protective coating and any contaminants thereon are eliminated from said surface in said outer space environment by sublimation of said coating, thereby to expose said surface in its pristine state to said outer space environment.
Claim 3
Dependent Claim
39 words
The combination of claim 1 wherein, said means comprises a spacecraft component such as an optical sensor, mirror, solar cell, or other critical component having a surface to be exposed in its pristine state to said outer space environment.
Claim 4
Dependent Claim
19 words
The combination of claim 2 wherein said protective coating comprises a material which sublimes when exposed to a vacuum.
Claim 5
Dependent Claim
21 words
The combination of claim 3 wherein said protective coating is selected from the group consisting of camphor, naphthalene, biphenyl, benzonic acid.
Claim 6
Dependent Claim
37 words
The combination of claim 4 wherein, said protective coating contains a coloring additive which increases the solar absorptance-to emittance rates and thereby also the equilibrium temperature and sublimation rate of the coating when exposed to solar radiation.
Claim 7
Dependent Claim
20 words
The combination of claim 2 wherein said coloring additive is selected from the group consisting of carbon black, organic life.
Claim 8
Dependent Claim
19 words
The combination of claim 2 wherein said protective coating comprises a material which sublimes when exposed to ultraviolet radiation.
Claim 9
Dependent Claim
26 words
The combination of claim 7 wherein said protective coating is based on ultraviolet photolyzable polymers such as polyphthalaldehydes, polysilanes, polymethylisopropenyl, Ketone (PMIPR), polytertizrybutyl, isopropenyl, Ketone (PIBIPR).
Claim 10
Dependent Claim
22 words
The combination of claim 8 wherein said protective coating contains an ultraviolet sensitizing additive which increases the sublimation rate of the coating.
Claim 11
Dependent Claim
17 words
The combination of claim 9 wherein said sensitizing additive is selected from the group consisting of benzoquinone.
Claim 12
Dependent Claim
104 words
In combination a spacecraft to be launched into outer space and having at least one critical surface such as an optical sensor, mirror, solar cell or the like which is initially conditioned to a pristine state, a protective coating on said pristine surface which sublimes in outer space, whereby contaminants which would otherwise deposit on and contaminate said surface deposit instead on said protective coating, and wherein said protective coating and any contaminants thereon are eliminated from said surface in outer space by sublimination of said coating, thereby to expose said surface in its pristine state to outer space following launch of the spacecraft.
Claim 13
Dependent Claim
104 words
In combination a spacecraft to be launched into outer space and having at least one critical surface such as an optical sensor, mirror, solar cell or the like which is initially conditioned to a pristine state, a protective coating on said pristine surface which sublimes in outer space, whereby contaminants which would otherwise deposit on and contaminate said surface deposit instead on said protective coating, and wherein said protective coating and any contaminants thereon are eliminated from said surface in outer space by sublimination of said coating, thereby to expose said surface in its pristine state to outer space following launch of the spacecraft.
Claim 14
Dependent Claim
23 words
The combination of claim 11 wherein said protective coating comprises a material which sublimes when exposed to the hard vacuum of outer space.
Claim 15
Dependent Claim
25 words
The combination of claim 11 wherein said protective coating comprises a material which sublimes when exposed to the ultraviolet portion of the solar radiation spectrum.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-05 | 1993-08-07 | 1994-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-05 | 1997-08-07 | 1998-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-05 | 2001-08-07 | 2002-02-06 | $7700.00 | Window Closed / Lapsed |