Detection of radio interference in the UHF amateur radio band with the Serpens satellite

High packet losses when uplinking commands to small satellites have been reported in the UHF amateur band (430–440 MHz) since late 2013. Measurements of the uplink radio environment have shown high levels of in-band interference in previous works, but public measurement results are limited. Average interference levels are usually measured over some time to build heat maps. In this paper, the analysis is focused on sustained interference over a 24 ms time window using a maximum-minimum method. New heat maps and interference power distributions over Europe, Africa, the Middle East and the Americas were obtained using this method on measurements from the Serpens satellite. One of the missions of Serpens was to test an in orbit store-and-forward communication system to exchange short messages with ground sensors for disaster monitoring. The satellite operators had difficulties commanding the satellite due to interference, causing bit errors in uplink packets. Interference power of up to −70 dBm was detected during in-orbit measurements over Europe and North America, while expected received power from the ground stations was not more than −80 dBm. High power space-object tracking radars on the ground operating in the 420–450 MHz band could be the cause, but further measurements are required to verify this. Characterizing this interference can help develop mitigation techniques for future satellite communication systems

RoboCrane: a system for providing a power and a communication link between lunar surface and lunar caves for exploring robots

Lava caves are the result of a geological process related to the cooling of basaltic lava flows. On the Moon, this process may lead to caves several kilometers long and diameters of hundreds of meters. Access to lava tubes can be granted through skylights, a vertical pit between the lava tube and the lunar surface. This represents an outstanding opportunity for long-term missions, for future permanent human settlements, and for accessing pristine samples of lava, secondary minerals and volatiles. Given this, the ESA launched a campaign through the Open Space Innovation Platform calling for ideas that would tackle the many challenges of exploring lava pits. Five projects, including Robocrane, were selected. Solar light and direct line of sight (for communications) with the lunar surface are not available inside lava tubes. This is a problem for any robot (or swarm of robots) exploring the lava tubes. Robocrane tackles both problems by deploying an element (called the Charging head, or CH) at the bottom of the skylight by means of a crane. This CH behaves as a battery charger and a communication relay for the exploring robots. The required energy is extracted from the crane’s solar panel (on the surface) and driven to the bottom of the skylight through an electrical wire running in parallel to the crane hoisting wire. Using a crane allows the system to deal with unstable terrain around the skylight rim and protect the wires from abrasion from the rocky surface and the pit rim. The charger in the CH is wireless so that the charging process can begin as soon as any of the robots get close enough to the CH. This avoids complex and time-consuming docking operations, aggravated by the skylight floor orography. The crane infrastructure can also be used to deploy the exploring robots inside the pit, reducing their design constraints and mass budget, as the robots do not need to implement their own self-deployment system. Finally, RoboCrane includes all the sensors and actuators for remote operation from a ground station. RoboCrane has been designed in a parametric tool so it can be dynamically and rapidly adjusted to input-variable changes, such as the number of exploring robots, their electrical characteristics, and crane reach, etc.Agencia Estatal de Investigación | Ref. RTI2018-099682-A-I0

Post-Franco Theatre

In the multiple realms and layers that comprise the contemporary Spanish theatrical landscape, “crisis” would seem to be the word that most often lingers in the air, as though it were a common mantra, ready to roll off the tongue of so many theatre professionals with such enormous ease, and even enthusiasm, that one is prompted to wonder whether it might indeed be a miracle that the contemporary technological revolution – coupled with perpetual quandaries concerning public and private funding for the arts – had not by now brought an end to the evolution of the oldest of live arts, or, at the very least, an end to drama as we know it

Benito Pérez Galdós

In Galdós\u27 time, the tensions between such diverse phenomena as coins and credit, free trade and protectionist tariffs, factory work and domestic economy, masculine and feminine, and private and public exacerbated friction among peoples—those of pueblo and rural origins, whose voices rasped and whose bright colors raked the eye, and a nascent, insecure bourgeosie who, fearful of the masses, strove to imitate the aristocracy. Old and new converged also with the question of suffrage and citizenship to aggravate social malaise and political upheavals—Carlist wars, palace intrigues, the Revolution of 1868 and overthrow of Queen Isabel, the brief reign of Amadeo of Savoy, the aborted First Republic and the Bourbon Restoration (1875-1885), which reached Spain from England in the imported person of Alfonso XII. These turbulent events undergird the cultural, historical, and political events of the novels by Benito Pérez Galdós (1843–1920) to be discussed in this chapter. Galdós is the author of seventy-seven novels, twenty-six original plays, and numerous occasional pieces, written between 1867 and 1920. These divide into two main categories: the historical and the contemporary social novels, now more appropriately described as novels of modernity The forty-six historical novels, called Episodios nacionales, make up five series, each consisting of ten interconnected novels, except the fifth series, left unfinished. The thirty-one novels of modernity, published between 1870 and 1915, also divide into two groups: Novelas de la primera época ( Novels of the Early Period, 1870–1879) and Las novelas de la serie contemporánea ( The Contemporary Social Novels, 1881–1915). The novels of the early period comprise Galdós\u27 first attempts at novel writing, as well as four so-called thesis novels : Doña Perfecta (1876), the sequel Gloria (1876–1877), Marianela (1878), and La familia de León Roch ( The Family of León Roch, 1878–1879). The next group of novels represents what Galdós called his segunda manera —his second style, a different kind of writing ... a more sophisticated and varied mode of narrative presentation