More Bucks for the Bang: New Space Solutions, Impact Tourism and one Unique Science & Engineering Opportunity at T-6 Months and Counting

For now, the Planetary Defense Conference Exercise 2021's incoming fictitious(!) asteroid, 2021 PDC, seems headed for impact on October 20th, 2021, exactly 6 months after its discovery. Today (April 26th, 2021), the impact probability is 5%, in a steep rise from 1 in 2500 upon discovery six days ago. We all know how these things end. Or do we? Unless somebody kicked off another headline-grabbing media scare or wants to keep civil defense very idle very soon, chances are that it will hit (note: this is an exercise!). Taking stock, it is barely 6 months to impact, a steadily rising likelihood that it will actually happen, and a huge uncertainty of possible impact energies: First estimates range from 1.2 MtTNT to 13 GtTNT, and this is not even the worst-worst case: a 700 m diameter massive NiFe asteroid (covered by a thin veneer of Ryugu-black rubble to match size and brightness) would come in at 70 GtTNT. In down to Earth terms, this could be all between smashing fireworks over some remote area of the globe and a 7.5 km crater downtown somewhere. Considering the deliberate and sedate ways of development of interplanetary missions it seems we can only stand and stare until we know well enough where to tell people to pack up all that can be moved at all and save themselves. But then, it could just as well be a smaller bright rock. The best estimate is 120 m diameter from optical observation alone, by 13% standard albedo. NASA's upcoming DART mission to binary asteroid (65803) Didymos is designed to hit such a small target, its moonlet Dimorphos. The Deep Impact mission's impactor in 2005 successfully guided itself to the brightest spot on comet 9P/Tempel 1, a relatively small feature on the 6 km nucleus. And 'space' has changed: By the end of this decade, one satellite communication network plans to have launched over 11000 satellites at a pace of 60 per launch every other week. This level of series production is comparable in numbers to the most prolific commercial airliners. Launch vehicle production has not simply increased correspondingly - they can be reused, although in a trade for performance. Optical and radio astronomy as well as planetary radar have made great strides in the past decade, and so has the design and production capability for everyday 'high-tech' products. 60 years ago, spaceflight was invented from scratch within two years, and there are recent examples of fastpaced space projects as well as a drive towards 'responsive space'. It seems it is not quite yet time to abandon all hope. We present what could be done and what is too close to call once thinking is shoved out of the box by a clear and present danger, to show where a little more preparedness or routine would come in handy - or become decisive. And if we fail, let's stand and stare safely and well instrumented anywhere on Earth together in the greatest adventure of science

Voltage- and substrate-dependent interactions between sites in putative re-entrant domains of a Na(+)-coupled phosphate cotransporter

A common structural feature characterises sodium-coupled inorganic phosphate cotransporters of the SLC34 family (NaPi-IIa/b/c): a pair of inverted regions in the N- and C-terminal halves of the protein. These regions are hypothesised to contain re-entrant domains that associate to allow alternating access of the substrates from either side of the membrane. To investigate if these domains interact during the NaPi-II transport cycle, we introduced novel cysteines at three functionally important sites associated with the predicted re-entrant domains of the flounder NaPi-IIb for the purpose of fluorescent labelling and cross-linking. Single and double mutants were expressed in Xenopus oocytes and their function analysed using electrophysiological and real-time fluorometric assays. The substitution at the cytosolic end of the first re-entrant domain induced a large hyperpolarizing shift in the voltage dependence of steady-state and presteady-state kinetics, whereas the two substitutions at the external face were less critical. By using Cu-phenanthroline to induce disulfide bridge formation, we observed a loss of transport activity that depended on the presence of sodium in the incubation medium. This suggested that external sodium increased the probability of NaPi-IIb occupying a conformation that favours interaction between sites in the re-entrant domains. Furthermore, voltage-dependent fluorescence data supported the hypothesis that a localised interaction between the two domains occurs that depends on the membrane potential and substrate present: we found that the fluorescence intensity reported by a labelled cysteine in one domain was dependent on the side chain substituted at a functionally critical site in the opposed domain

Planetary Radar—State-of-the-Art Review

Planetary radar observations have provided invaluable information on the solar system through both ground-based and space-based observations. In this overview article, we summarize how radar observations have contributed in planetary science, how the radar technology as a remote-sensing method for planetary exploration and the methods to interpret the radar data have advanced in the eight decades of increasing use, where the field stands in the early 2020s, and what are the future prospects of the ground-based facilities conducting planetary radar observations and the planned spacecraft missions equipped with radar instruments. The focus of the paper is on radar as a remote-sensing technique using radar instruments in spacecraft orbiting planetary objects and in Earth-based radio telescopes, whereas ground-penetrating radar systems on landers are mentioned only briefly. The key scientific developments are focused on the search for water ice in the subsurface of the Moon, which could be an invaluable in situ resource for crewed missions, dynamical and physical characterization of near-Earth asteroids, which is also crucial for effective planetary defense, and a better understanding of planetary geology

Work placement periods in university studies:recommendations on the planning, implementation and reporting of internships and other work placement periods – for students, universities and employers

Foreword An internship or other comparable work placement period plays an important role in a university degree – an internship can bridge theoretical knowledge with practical skills that are needed in working life. Particularly these days, as the pressure to shorten study times has increased, internships have become more important, because they offer students a chance to gain some work experience before graduation. A well-planned internship can benefit everyone: the student, the university, and the employer. At the moment, internship practices differ across universities and degree programmes, which can place students in different fields in unequal positions. Of course, each degree programme should be able to choose the internship model that best suits it. However, many aspects of internships could be harmonised, and developing the internship system would benefit students, universities and internship providers alike. This guide was written as part of the ESR funded TYYLI project (Työelämäjaksoja ja työssäoppimista yliopisto-opintoihin – Bridging the gap between university studies and working life). This guide maps out the strengths and weaknesses of current internship practices at Finnish universities and gives recommendations for areas of development and operating models, covering the different stages of the internship process and all the parties – the university, the student and the organisations that offer internship opportunities. This guide was commented on by a large and varied group of actors in the university sector, student unions, companies and employers’ associations, and we would like to thank everyone for their valuable contribution. Practice makes perfect

Työelämäjaksot yliopisto-opinnoissa:suosituksia harjoitteluiden sekä muiden työelämäjaksojen suunnitteluun, toteuttamiseen ja raportointiin — opiskelijalle, yliopistolle ja työnantajalle

Alkusanat Yliopisto-opintoihin sisältyvällä harjoittelulla tai muulla siihen rinnastettavalla työelämäjaksolla on merkittävä asema tutkinnossa, sillä harjoittelu sitoo usein teoreettisiksi miellettyjä opintoja käytännön työelämään. Etenkin nyt, kun opiskelijoiden valmistumisaikoja pyritään valtakunnallisesti lyhentämään, harjoittelun merkitys oman alan työkokemusta tarjoavana oppimiskokemuksena ennen valmistumista korostuu entisestään. Hyvin suunniteltu harjoittelu hyödyttää opiskelijoiden lisäksi myös yliopistoa ja työnantajia. Harjoittelukäytänteet eri yliopistoissa ja eri tutkinto-ohjelmissa ovat tällä hetkellä hyvin erilaisia ja osin jopa epätasa-arvoisia eri alojen opiskelijoiden välillä. On selvää, että jokaisessa tutkinto-ohjelmassa harjoittelu tulee toteuttaa sille parhaiten soveltuvalla tavalla. Monet harjoitteluun liittyvistä asioista ovat kuitenkin sellaisia, joita olisi mahdollista yhtenäistää ja joiden kehittäminen hyödyttäisi niin opiskelijoita, yliopistoa kuin harjoittelupaikkoja tarjoavia organisaatioitakin. Tämä opas on laadittu yliopistojen harjoittelukäytänteiden kehittämisen tueksi osana ESR-rahoitteista TYYLI (Työelämäjaksoja ja työssäoppimista yliopisto-opintoihin) -hanketta. Oppaassa kuvataan suomalaisten yliopistojen harjoittelukäytänteistä tunnistettuja vahvuuksia ja heikkouksia ja annetaan suosituksia kehittämiskohteiksi ja toimintamalleiksi harjoittelun eri vaiheisiin sekä yliopistolle, opiskelijalle että harjoittelupaikkoja tarjoaville organisaatioille. Oppaan kommentointiin ovat osallistuneet laajasti useat yliopistotoimijat, ylioppilaskunnat, yritykset ja työnantajajärjestöt, heille kaikille palautteista lämpimät kiitokset. Harjoittelu tekee mestarin

Light scattering model for small space debris particles

We have developed a scattering model allowing to study interaction of light with particles populating the near-Earth environment: satellite explosion remnants, collisional debris, particles detached from peeling paint surfaces, and ejecta resulting from micrometeorite bombardment. In its present configuration the model accounts for rough needles, grains, and plates as primary shape elements. More complex shapes are built upon combining them. The model is compared and validated against laboratory measurements. The studied samples include a set of space debris analogue samples obtained from the controlled MIRAD (Microparticle impact related attitude disturbances) experiment that collided solar cell panels with a projectile. The resulting samples are mostly carbon needles and curved aluminium sheets. We have both measured and modelled the scattering of light from a set of these samples. The model agrees rather well with the measurements. The shape and orientation of the particles are found to be the main contributor in how light is scattered, whereas the material dependence shows a weaker trend. Large amount of data with varying viewing and illumination angles are needed to allow for inversion of the target characteristics. The experimental results exploited in our study have significantly aided the model development. In the future, this work can be expanded to a real-mode in-orbit scattering model that can be utilised in Earth system and/or astronomical observations and space mission concept designs. Additional measurements with larger variety of samples and their expanded size range are required to extend and solidify the model for the full range of populations representing space particles