Harsh Environment Protective Housings

Dusty, dirty environments can be very tough on connectors. The abrasive nature of dust and dirt particles can rub and wear down connector surfaces through friction, and have a negative effect on coatings used on gaskets to seal equipment. Dust on umbilical connections can also make mating and de-mating electrical and fluid connections difficult, hazardous, and unreliable. NASA's Quick Disconnect (QD) design consists of columnar arrays of parallel filaments. All the pins of the electrical connector easily penetrate the barriers when the umbilicals are brought together. They are wiped clean of dust when they penetrate the barrier and mate cleanly and reliably. Likewise, the male end of a fluid connector penetrates the filament arrays of both connector ends. Since the filament arrays are oriented perpendicular to each other, the entire circumference of the connector is contacted by the filaments that stretch around, conform to, and sweep off dust from the mating surface ensuring a clean and secure connection.

Dusty, dirty environments can be very tough on connectors. The abrasive nature of dust and dirt particles can rub and wear down connector surfaces through friction, and have a negative effect on coatings used on gaskets to seal equipment. Dust on umbilical connections can also make mating and de-mating electrical and fluid connections difficult, hazardous, and unreliable. NASA's Quick Disconnect (QD) design uses the gas supplied by the umbilical to spray the connector surfaces prior to mating to remove dust and debris. The QD uses a novel dual-poppet design and springs that balance forces on umbilical components. This allows a controlled release of gas to clear away dust from the end of the connector before it it inserted in the supply umbilical. The connector assembly is capable of mating and de-mating under 3500 psi fluid/gas. One poppet seals the QD while de-mated and automatically cleans the front surface of the QD during mating. A second poppet seals the QD while de-mated and automatically cleans the cylindrical surface of the QD during mating. The internal cavity of the QD is specifically designed such that the pressure in the line is reduced from 3500 psi to 450 psi while surface cleaning occurs. Finally, all exterior connector surfaces are designed to minimize the entrapment of dust while in the de-mated position.

The Low Separation Force Quick Disconnect device uses an innovative seal arrangement and flow path to eliminate separation force from line pressure. A radial design ensures a low separation force regardless of line pressure. Ten holes around the internal seal cancel loads due to balanced pressure; thus, the central force exerted on the device is due to the springs fixed internally. The device also provides for additional optional characteristics including a self-aligning feature from a compliant mount and a self-sealing mechanism that keeps dust out of the device. The Low Separation Force Quick Disconnect device is designed to transport pneumatics and cryogenic fluid. Due to the low separation force and overall design, the system requires less heavy and high-strength support structures than conventional designs; the design permits lighter retention systems and reduces deflection variations. Aerospace specific uses of the invention include flight-to-ground, flight-to-flight and surface-system applications. Other uses of the invention include any mechanism in which fluid is being transferred from ground to a vehicle or another system, especially where a high line pressure is used.

Space and ground launch support related hardware often operate under extreme pressure, temperature, and corrosive conditions. When dealing with this type of equipment, it is frequently necessary to run wiring, tubes, or fibers through a barrier separating one process from another with one or both operating in extreme environments. Feedthroughs used to route the wiring, tubes, or fibers through these barriers must meet stringent sealing and leak tightness requirements. This affordable NASA feedthrough meets or exceeds all sealing and leak requirements utilizing easy-to-assemble commercial-off-the-shelf hardware with no special tooling. The feedthrough is a fully reconfigurable design; however, it can also be produced as a permanent device. Thermal cycling and helium mass spectrometer leak testing under extreme conditions of full cryogenic temperatures and high vacuum have proven the sealing capability of this feedthrough with or without potting (epoxy fill) on the ends. Packing material disks used in the construction of the device can be replaced as needed for rebuilding a given feedthrough for another job or a different set of feeds if potting is not used for the original feedthrough build. (Potting on one or both sides of the sleeve provides double or triple leak sealing protection). Variable Compression Ratio (VCR) connectors were adapted for the pressure seal on the feedthrough; however, any commercial connector can be similarly adapted. The design can easily be scaled up to larger (2" diameter) and even very large (12" or more) sizes.

In the development of this technology for the ISS, engineers had to pay careful attention to electrical draw efficiency, ease-of-use, mass reduction, production cost, and safety, as conducting scientific research under spacecraft stressors is an important requirement. To create a controlled environment within the science enclosure, engineers designed a ventilation system incorporating an external fan/blower that pulls air across a HEPA filter and diffuses it in a manner that creates an even laminar flow within the enclosure before exiting through the exhaust filter. The glove seal forms an airtight and liquid impervious seal. This novel design also allows the user flexibility to choose their own task-specific glove material, facilitates easy tool-free assembly and quick glove changes, and may be transferable to other types of enclosures. Another key feature is that a through-port can be quickly fitted to an empty glove port. Due to the science enclosure system intended application aboard the ISS, its electrical draw does not exceed 24V, thereby making it feasible to power it from a battery for terrestrial field use or other applications where accessing power is a challenge. The combination of its performance, portability, BSL 2 capability, and inexpensive production costs could position the science enclosure system and accompanying innovations to be valuable in the fields of education, research, clean rooms, hospitals, and disaster relief efforts.