Characteristics of EMI generated by negative metal-positive dielectric voltage stresses due to spacecraft charging

Charging of spacecraft surfaces by the environmental plasma can result in differential potentials between metallic structure and adjacent dielectric surfaces in which the relative polarity of the voltage stress is either negative dielectric/positive metal or negative metal/positive dielectric. Negative metal/positive dielectric is a stress condition that may arise if relatively large areas of spacecraft surface metals are shadowed from solar UV and/or if the UV intensity is reduced as in the situation in which the spacecraft is entering into or leaving eclipse. The results of experimental studies of negative metal/positive dielectric systems are given. Information is given on: enhanced electron emission I-V curves; e(3) corona noise vs e(3) steady-state current; the localized nature of e(3) and negative metal arc discharge currents; negative metal arc discharges at stress thresholds below 1 kilovolt; negative metal arc discharge characteristics; dependence of blowoff arc discharge current on spacecraft capacitance to space (linear dimension); and damage to second surface mirrors due to negative metal arcs

Auroral rocket experiment 2 Final report

Detecting fluxes of energetic neutral hydrogen atoms in interplanetary medium by auroral rocket flight

Surge current and electron swarm tunnel tests of thermal blanket and ground strap materials

The results are described of a series of current conduction tests with a thermal control blanket to which grounding straps have been attached. The material and the ground strap attachment procedure are described. The current conduction tests consisted of a surge current examination of the ground strap and a dilute flow, energetic electron deposition and transport through the bulk of the insulating film of this thermal blanket material. Both of these test procedures were used previously with thermal control blanket materials

Hybrid, Subversive, and Skeptical Performances of Gender, Power, and Space in the Postcolonial Avant-Garde

In her one-woman play, Iraqi-American playwright and actress Heather Raffo performs the testimonies of nine resilient Iraqi women, emphasizing their diverse experiences of the American occupation and life under the Baathist regime. Near the end of the play, one of the soliloquies breaks down into incoherence: an instance of poetic rupture. There is revolutionary potential latent in this avant-garde technique, and by applying it to her urgent and immediate postcolonial context Raffo simultaneously enacts and demands a response of justice to the injustices attested to throughout. Through the poetic rupture of Layal’s textual/psychological breakdown, Raffo undermines the system that, by imposing norms and taboos, unjustly constructed and allotted power and privilege in the first place. To understand how the breakdown at the end of 9 Parts of Desire serves as a call to justice requires a journey through the connections between postcolonial, postmodern, gender, and spatial theories. Judith Butler, Susan Friedman, Chandra Mohanty, and Riverbend help elucidate the element of performed identity/feminism, and Simon Gikandi, Jacques Derrida, and Julia Kristeva reveal the revolutionary power latent in avant-garde texts. Butler argues that identity is always performed; Friedman, that we are all hybrid beings; Mohanty, that we must advocate for transnational feminism thoughtfully and critically; and Riverbend, that Iraqi feminism predates the American occupation. Gikandi highlights ways in which postcolonial texts adapt modernist avant-garde techniques; Derrida lays out the deconstructionist framework of différance from which Kristeva draws; and Kristeva unpacks the political rupture constituted by poetic deviations like Raffo’s. Raffo does not allow her audience to sit with the stereotypes, taboos, and norms that have been consciously established to enforce an oppressive agenda against Iraqi women, but rather breaks down the system in which they are stable

Properties of large 7079 aluminum alloy forgings in a cryogenic environment

Forged aluminum alloys for pump impeller and inducer applications in cryogenic liquid propellant rocket engine

Application of Alloy 718 in M-1 engine components

Alloy 718 applied to components of M-1 rocket engin

Implications of arcing due to spacecraft charging on spacecraft EMI margins of immunity

Arcing due to spacecraft charging on spacecraft EMI margins of immunity was determined. The configuration of the P78-2 spacecraft of the SCATHA program was analyzed. A brushfire arc discharge model was developed, and a technique for initiating discharges with a spark plug trigger was for data configuration. A set of best estimate arc discharge parameters was defined. The effects of spacecraft potentials in limiting the discharge current blowout component are included. Arc discharge source models were incorporated into a SEMCAP EMI coupling analysis code for the DSP spacecraft. It is shown that with no mission critical circuits will be affected