Search results for "avaruus"

Aalto-1, multi-payload CubeSat: Design, integration and launch

2021

The design, integration, testing, and launch of the first Finnish satellite Aalto-1 is briefly presented in this paper. Aalto-1, a three-unit CubeSat, launched into Sun-synchronous polar orbit at an altitude of approximately 500 km, is operational since June 2017. It carries three experimental payloads: Aalto Spectral Imager (AaSI), Radiation Monitor (RADMON), and Electrostatic Plasma Brake (EPB). AaSI is a hyperspectral imager in visible and near-infrared (NIR) wavelength bands, RADMON is an energetic particle detector and EPB is a de-orbiting technology demonstration payload. The platform was designed to accommodate multiple payloads while ensuring sufficient data, power, radio, mechanica…

Black Hole Shadow Drift and Photon Ring Frequency Drift

2021

The apparent angular size of the shadow of a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as the redshift drift - all redshift-dependent quantities acquire a time-dependence, and a fortiori so do black hole shadows. We find a mathematical description of the black hole shadow drift and show that the amplitude of this effect is of order $10^{-16}$ per day for M87$^{\star}$. While this effect is small, we argue that its non-detection can be used to constrain the accretion rate around supermassive black holes, as well as a novel probe of the equivalence principle. If general relativity is assumed, we infer from the data obtaine…

Gendering multi-voiced histories of the North American space industry: the GMRD White women

2019

Purpose The authors focus on “writing women into ‘history’” in this study, embracing the notion of cisgender and ethnicity in relation to the “historic turn”. As such, the authors bring forward the stories of the US Pan American Airway’s Guided Missile Range Division (GMRD) and the White women who worked there. The authors ask what has a Cold War US missile division to tell us about present and future gendered relationships in the North American space industry. Design/methodology/approach The authors apply Foucault’s technology of lamination, a form of critical discourse analysis, to both narrative texts and photographic images in the GMRD’s in-house newsletter, the Clipper, dating from 19…

The apparatgeist of the moon landing

2019

Cyberspace from the hybrid threat perspective

2013

Hybrid threats use conventional and unconventional means to achieve their goals. This paper explores the cyber threats as one possible aspect of hybrid threats. It describes three ways of approaching cyberspace (operations) from the hybrid threats perspective: supporting conventional operations, exploiting non-military systems, and exploring the opportunities provided by this environment. In particular, it highlights the aspects that are or likely will be relevant to the military community. peerReviewed

Failure Estimates for SiC Power MOSFETs in Space Electronics

2018

Silicon carbide (SiC) power metal-oxide-semiconductor field effect transistors (MOSFETs) are space-ready in terms of typical reliability measures. However, single event burnout (SEB) due to heavy-ion irradiation often occurs at voltages 50% or lower than specified breakdown. Failure rates in space are estimated for burnout of 1200 V devices based on the experimental data for burnout and the expected heavy-ion linear energy transfer (LET) spectrum in space. peerReviewed

On the aestheticization of technologized bodies : a portrait of a cyborg(ed) form of agency

2017

Discussions revolving around cyborgs seldom include aesthetics, let alone propose aesthetics as an inextricable part of the phenomenon of the cyborg. Rather, the term “cyborg”, a contraction of “cybernetic organism”, evokes a figure of the (hu)man- machine. In the field of social and political sciences, the cyborg is designated a human-machine hybrid, a metaphor of humans becoming machinelike, or a portrait of (political) agency in an era of high technology. These approaches promote a figure of technologized bodies, that is, the cyborg as a figure of technologically dominated and altered bodies. I will sustain that the cyborg contributes to our understanding of agency in the age of high tec…

Technology Impact on Neutron-Induced Effects in SDRAMs : A Comparative Study

2021

International audience; This study analyses the response of synchronous dynamic random access memories to neutron irradiation. Three different generations of the same device with different node sizes (63, 72, and 110 nm) were characterized under an atmospheric-like neutron spectrum at the ChipIr beamline in the Rutherford Appleton Laboratories, UK. The memories were tested with a reduced refresh rate to expose more single-event upsets and under similar conditions provided by a board specifically developed for this type of study in test facilities. The board has also been designed to be used as a nanosatellite payload in order to perform similar tests. The neutron-induced failures were studi…

High-Energy Electron-Induced SEUs and Jovian Environment Impact

2017

We present experimental evidence of electron-induced upsets in a reference European Space Agency (ESA) single event upset (SEU) monitor, induced by a 200-MeV electron beam at the Very energetic Electronic facility for Space Planetary Exploration in harsh Radiation environments facility at CERN. Comparison of experimental cross sections and simulated cross sections is shown and the differences are analyzed. Possible secondary contributions to the upset rate by neutrons, flash effects, and cumulative dose effects are discussed, showing that electronuclear reactions are the expected SEU mechanism. The ESA Jupiter Icy Moons Explorer mission, to be launched in 2022, presents a challenging radiat…

Electron-Induced Upsets and Stuck Bits in SDRAMs in the Jovian Environment

2021

This study investigates the response of synchronous dynamic random access memories to energetic electrons and especially the possibility of electrons to cause stuck bits in these memories. Three different memories with different node sizes (63, 72, and 110 nm) were tested. Electrons with energies between 6 and 200 MeV were used at RADiation Effects Facility (RADEF) in Jyvaskyla, Finland, and at Very energetic Electron facility for Space Planetary Exploration missions in harsh Radiative environments (VESPER) in The European Organization for Nuclear Research (CERN), Switzerland. Photon irradiation was also performed in Jyvaskyla. In these irradiation tests, stuck bits originating from electro…