SP -- INFORMATION SOUGHT ON MICROGRAVITY DISTURBANCES FOR VACUUM SERVICE VALVES The presence of a microgravity environment is the fundamental reason for conducting material experiments in space. However, there is currently little information available on the microgravity disturbances generated by various types of equipment (large mass translation devices, pumps, motors, fans, cold plates, valves) used in conducting those experiments. Knowing the microgravity disturbances of equipment early in a project is paramount to the success of the mission, because these disturbances will impact the design of the experiment as well as the operational procedures. There are numerous microgravity experiments being planned for the International Space Station in the coming years, and it is imperative that sources for flight qualified, low microgavity disturbance support hardware be developed and/or identified for potential requests for quotations in the future. The Government is seeking to obtain microgravity disturbance information regarding vacuum service valves. The valves are two position valves (open and close), electronically driven and remotely operated. Of particular interest are valves compatible with =" to 1 =" line sizes, that weigh 5 pounds or less, and have an open/close time of 30 seconds or less. The following documentation should be provided as part of the test results: 7 Mass of the test article and the test fixture 7 Limitations of the test fixture, such as fixture modes/resonances 7 Force or acceleration sensor manufacturer, model number, general specifications, and proof of current calibration 7 Facility calibration data, and description of signal conditioning and data processing 7 Effective data sample rate The preferred method of data collection is direct force measurements at the component mounting locations. If this method cannot be applied, acceleration measurements transformed to force using Newton's Second Law are acceptable. Components should use the table below as a target for disturbance produced during operation. This table represents an average allowable disturbance forthis type of component; the actual requirement for flight components could be more or less stringent. This table gives the force limit in terms of frequency, with the frequencies expressed in one-third octave bands. (Frequency (Hz) ;Force Limit (lbf)) (0.0089 ;0.0034) (0.0112 ;0.0042) (0.0112 ;0.0042) (0.0141 ;0.0053) (0.0141 ;0.0053) (0.0178 ;0.0067) (0.0178 ;0.0067) (0.0224 ;0.0085) (0.0224 ;0.0085) (0.0282 ;0.0107) (0.0282 ;0.0107) (0.0355 ;0.0134) (0.0355 ;0.0134) (0.0447 ;0.0169) (0.0447 ;0.0169) (0.0562 ;0.0212) (0.0562 ;0.0212) (0.0708 ;0.0268) (0.0708 ;0.0268) (0.0891 ;0.0337) (0.0891 ;0.0337) (0.1122 ;0.0424) (0.1122 ;0.0424) (0.1413 ;0.0534) (0.1413 ;0.0534) (0.1778 ;0.0672) (0.1778 ;0.0672) (0.2239 ;0.0846) (0.2239 ;0.0846) (0.2818 ;0.1065) (0.2818 ;0.1065) (0.3548 ;0.1341) (0.3548 ;0.1341) (0.4467 ;0.1688) (0.4467 ;0.1688) (0.5623 ;0.2125) (0.5623 ;0.2125) (0.7079 ;0.2676) (0.7079 ;0.2676) (0.8913 ;0.3369) (0.8913 ;0.3369) (1.122 ;0.4241) (1.122 ;0.4241) (1.413 ;0.5341) (1.413 ;0.5341) (1.778 ;0.6720) (1.778 ;0.6720) (2.239 ;0.8463) (2.239 ;0.8463) (2.818 ;1.0651) (2.818 ;1.0651) (3.548 ;1.3410) (3.548 ;1.3410) (4.467 ;1.6884) (4.467 ;1.6884) (5.623 ;2.1253) (5.623 ;2.1253) (7.079 ;2.6756) (7.079 ;2.6756) (8.913 ;3.3688) (8.913 ;3.3688) (11.22 ;4.2408) (11.22 ;4.2408) (14.13 ;5.3406) (14.13 ;5.3406) (17.78 ;6.7202) (17.78 ;6.7202) (22.39 ;8.4626) (22.39 ;8.4626) (28.18 ;10.6510) (28.18 ;10.6510) (35.48 ;13.4102) (35.48 ;13.4102) (44.67 ;16.8837) (44.67 ;16.8837) (56.23 ;21.2529) The information supplied will be used by the Government in developing future requirements for Space Station payloads. THIS IS NOT A SOLICITATION AND THE GOVERNMENT WILL NOT PAY FOR ANY INFORMATION PROVIDED. Questions regarding this announcement should be addressed to Earl Pendley/PS24-B/ (256) 544-2949/e-mail: george.pendley@msfc.nasa.gov or technical questions to John Lassiter (256-544-3022; email: john.lassiter@msfc.nasa.gov). Responses are requested by October 29, 1999. WEB: Click here for the latest information about this notice, http://nais.nasa.gov/EPS/MSFC/date.html#GEP2-92399. E-MAIL: George E. Pendley, george.pendley@msfc.nasa.gov. Posted 09/23/99 (D-SN383804).

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