| 1. |
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| 2. |
- Bamford, R. A., et al.
(författare)
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Minimagnetospheres above the lunar surface and the formation of lunar swirls
- 2012
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 109:8, s. 081101-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we will present the in-situ satellite data, theory and laboratory validation that show how small scale collisionless shocks and mini-magnetospheres can form on the electron inertial scale length. The resulting retardation and deflection of the solar wind ions could be responsible for the unusual "lunar swirl" patterns seen on the surface of the Moon.
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| 3. |
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| 4. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 5. |
- Grahn, Sven, et al.
(författare)
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History of human spaceflight
- 2013
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Ingår i: Human spaceflight and exploration. - Berlin, Heidelberg : Springer. - 9783642237256 - 9783642237249 ; , s. 11-63
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Bokkapitel (refereegranskat)abstract
- Over a period of about two centuries humans learned how to travel farther and farther from the surface of the Earth. However, we still have limited experience of flight in space. Progress was fast during the Cold War, when the competitive spirit between the United States and the Soviet Union drove both nations’ space engineers to work towards goals of ever increasing complexity. In this chapter the reader is taken through the early successes of the Russians, and then the early space programs of the United States. A number of space stations were built and flown by both countries in order to investigate how the human body coped with being weightless for long periods, and to carry out experimental microgravity research. The most advanced station to date is the ISS. China has recently begun to develop its space program, with plans for its own space station. Meanwhile space, which has traditionally been tackled by national and international projects, is having increased interest from the commercial sector. We are potentially at the brink of a change in direction in space travel, and may soon see an increase in the number of private individuals purchasing tickets for trips that are literally out of this world.
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| 6. |
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Human spaceflight and exploration
- 2013. - 1
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Samlingsverk (redaktörskap) (populärvet., debatt m.m.)abstract
- The book presents a unique overview of international activities in human spaceflight and exploration at a time of uncertainty regarding the direction of future development in the western world. It provides an introduction for the general public interested in space and would also be suitable for students at university. The contributors include a space physicist, two space engineers, a space-suit designer and two astronauts, who collectively have a broad experience of space activities.
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| 7. |
- Norberg, Carol, et al.
(författare)
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Active Dust Experiment in the Mesosphere
- 2008
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Ingår i: AIP Conference Proceedings vol. 1041. - : AIP. - 9780735405691 ; , s. 291-292
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The mesosphere stretches from an altitude of about 50 to 90 km above the Earth’s surface. Meteors entering the Earth’s atmosphere are believed to ablate and hence give rise to a thin layer of dust particles in the upper part of the Earth’s mesosphere. It seems that the dust is most dense in a layer that lies between 80 and 90 km. The dust particles are thought to have sizes of a few to tens of nanometers. Efforts have been made to measure these particles using rockets and radar techniques with limited success. We propose to release dust into the mesosphere over northern Sweden at a height of about 90 km and observe the released dust using the EISCAT radar system. The dust will be launched from the Swedish Space Corporation Esrange Space Centre on a single-stage Improved Orion rocket that will be launched so that its flight path will be in the radar field of view.
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| 8. |
- Norberg, Carol, 1963-
(författare)
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Hur går det med Marsresorna, egentligen?
- 2022
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Ingår i: Fysikaktuellt. - : Svenska fysikersamfundet. - 0283-9148 .- 2004-0059. ; :4, s. 12-13
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Det var en världsnyhet när de amerikanska astronauterna Neil Armstrong och Buzz Aldrin landade på månen den 20 juli 1969. Ytterligare månlandningar skapade förväntningar på att mänskligheten var i början av ett bredare utforskande av vårt solsystem och att nästa steg skulle bli att besöka Mars.
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| 9. |
- Norberg, Carol
(författare)
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Recent developments in space education in Kiruna, Sweden
- 2005
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Ingår i: 17th ESA Symposium on European Rocket and Balloon Programmes and Related Research. - Paris : European Space Agency. - 9290929014 ; , s. 61-62
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Konferensbidrag (refereegranskat)abstract
- The two most northern universities in Sweden, Lulea University of Technology and Umea University have formed a joint Department of Space Science located in Kiruna. The department is responsible for programmes covering a wide spectrum, practically oriented and more theoretical, leading to Bachelor's and Master's degrees in space engineering. In addition the universities have graduate education in space and atmospheric physics and space technology. Recent developments include the award by the European Commission of funding for an Erasmus Mundus Space Master Course, which is a cooperative project with five other European universities and an expansion of the department's summer programme to include a course in manned space flight.
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| 10. |
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| 11. |
- Norberg, Carol, et al.
(författare)
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Space Education in Kiruna, Sweden
- 2006
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Ingår i: Proceedings of a conference on Space Tourism: From Lofty Dreams to Commercial Reality. - 1 85768220 3
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Konferensbidrag (refereegranskat)
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| 12. |
- Norberg, Carol
(författare)
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Space exploration
- 2013
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Ingår i: Human spaceflight and exploration. - Berlin, Heidelberg : Springer. - 9783642237256 - 9783642237249 ; , s. 121-160
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Bokkapitel (refereegranskat)abstract
- Even before the first satellites were launched into Earth orbit scientists and engineers became interested in carrying out missions to the Moon and to the planets Venus and Mars. There have been many setbacks in their efforts, but also many successes. This chapter summarizes our exploration of the solar system using unmanned spacecraft, plus the science undertaken by the Apollo missions. The preparations for a renewal of human exploration beyond low Earth orbit must take into account both the physical and psychological challenges which human beings will face in making such journeys. Projects addressing the psychological challenges of isolation are described, such as the recently concluded Mars 500 simulation of a mission to Mars.
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| 13. |
- Norberg, Carol, Dr. 1963-
(författare)
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The space environment
- 2013
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Ingår i: Human spaceflight and exploration. - Berlin, Heidelberg : Springer. - 9783642237256 - 9783642237249 ; , s. 65-119
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Bokkapitel (refereegranskat)abstract
- The space environment is hostile to people and equipment. In this chapter the space environment is considered in terms of separate categories: gravity, neutral particles, vacuum, plasma, radiation, micrometeoroids, and space debris. The microgravity environment available in space is an interesting laboratory for researchers in many disciplines but as a workplace it poses physiological challenges to humans. Weightlessness can be produced for short periods of time in ground-based experiments in drop towers, parabolic flights on board aircraft, and sounding rockets. One of the most challenging aspects of a long-duration space mission for human exploration of the solar system is the susceptibility of both people and equipment to ionizing radiation consisting of relatively constant levels of galactic cosmic rays and sporadic high-energy solar particle events. Our current knowledge is insufficient to estimate with certainty the risk to astronauts from an extended period of exposure to this radiation. Since the space age began, spacecraft have been launched with little concern for the resulting pollution. As a result the most popular Earth orbits are littered with the debris of space missions, and this puts new missions at risk of potentially damaging collisions.
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| 14. |
- Norberg, Carol, 1963-
(författare)
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The Use of Space Data by Undergraduate Students to Predict and Analyse Auroral Displays in the Arctic
- 2021
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Ingår i: Proceedings of the International Astronautical Congress, IAC, 2021. - : International Astronautical Federation, IAF. - 9781713843177
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Konferensbidrag (refereegranskat)abstract
- Umeå University in Sweden offers a distance course in Arctic Science to Swedish and international undergraduates. Each year 70-80 students participate in the course which includes a field trip to Kiruna, a small town in the Arctic. A central activity in the course is an auroral observation exercise. Students use real-time data on the solar wind that is gathered by satellites at the L1 Lagrangian point to determine the status of the space weather close to the Earth. After a visit to the Swedish Institute of Space Physics to learn about the data gathered at the institute, they also use local ground-based observations of Earth's magnetic field and weather reports in order to plan outdoor observations. Students are able to access the necessary data from their mobile phones. Participants become deeply engaged in monitoring the space weather conditions to ascertain the chance of seeing an auroral display and acquire an understanding of the range of space-based data that is freely available to society at large. The students compare their own visual observations and photographs with data sets from space and the ground to acquire a deeper understanding of the interaction between the solar wind and the Earth's magnetosphere. The aurora exercise is carried out by small groups of students working together and written up in a report to promote teamwork and develop skills in academic writing. The aurora exercise has been run by Umeå University for over a decade and continues to evolve. At least partially cloud-free skies are needed in order to see the aurora from the ground. To maximise the chance of success an evening excursion to a location that is known to be often cloud free was introduced. Use of the aurora exercise has been extended to courses for PhD students and a teacher development course in space physics. Although the tantalising experience of standing outside surrounded by snow and looking up at an active colourful auroral display is confined to the planet’s auroral zones, by using all-sky camera data available on-line this activity can be adapted to a classroom at any location in the world. The online version has been tested out in 2021 since the course has been taken entirely online by some students due to the pandemic.
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| 15. |
- Steimle, Hansulrich, et al.
(författare)
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Astronaut selection and training
- 2013
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Ingår i: Human spaceflight and exploration. - Berlin, Heidelberg : Springer. - 9783642237256 - 9783642237249 ; , s. 255-294
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Bokkapitel (refereegranskat)abstract
- In this chapter a review is given of astronaut selection campaigns carried out to date. The initial selections were undertaken in the United States and the Soviet Union. In the beginning the candidates were predominantly men having military backgrounds. Male engineers and doctors followed. With the exception of one occasion in the early 1960s, it was not until around 1980 that women were admitted as astronaut candidates. They have remained a minority. Nowadays Europe, Canada, Japan, and China also have corps of astronauts. The selection processes are long and thorough to ensure that the healthiest and most psychologically stable individuals are selected, with the potential to work well in a team while confined in a small space for extended periods of time. Having been selected, the candidates have a long and diverse training regime which requires flexibility and adaptability of both them and their families. The ultimate prize of a trip into space is not guaranteed, and the waiting period can be long. Intricate planning of space missions, which starts long before a mission occurs, produces detailed work schemes for the astronauts to follow when they are finally in space.
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| 16. |
- Vaverka, Jakub, et al.
(författare)
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Comparison of Dust Impact and Solitary Wave Signatures Detected by Multiple Electric Field Antennas Onboard the MMS Spacecraft
- 2018
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 123:8, s. 6119-6129
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Tidskriftsartikel (refereegranskat)abstract
- Dust impact detection by electric field instruments is a relatively new method. However, the influence of dust impacts on electric field measurements is not completely understood and explained. A better understanding is very important for reliable dust impact identification, especially in environments with low dust impact rate. Using data from Earth-orbiting Magnetospheric Multiscale mission (MMS) spacecraft, we present a study of various pulses detected simultaneously by multiple electric field antennas in the monopole (probe-to-spacecraft potential measurement) and dipole (probe-to-probe potential measurement) configurations. The study includes data obtained during an impact of a millimeter-sized object. We show that the identification of dust impacts by a single antenna is a very challenging issue in environments where solitary waves are commonly present and that some pulses can be easily misinterpreted as dust impacts. We used data from multiple antennas to distinguish between changes in the spacecraft potential (dust impact) and structures in the ambient plasma or electric field. Our results indicate that an impact cloud is in some cases able to influence the potential of the electric field antenna during its expansion.
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| 17. |
- Vaverka, Jakub, et al.
(författare)
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Detection of EMPs generated by meteoroid impacts on the MMS spacecraft and problems with signal interpretation
- 2017
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Ingår i: 2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS). - : IEEE. - 9789082598704
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Konferensbidrag (refereegranskat)abstract
- Signatures of hypervelocity dust impacts detected by electric field instruments are still not completely understood. We have used the electric field instrument onboard one of the MMS spacecraft orbiting the Earth since 2015 to study various pulses in the measured electric field detected simultaneously by multiple antennas. This unique instrument allows a detailed investigation of registered waveforms. The preliminary results shown that the solitary waves can generate similar pulses as dust impacts and detected pulses can easily by misinterpreted when only one antenna is used.
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| 18. |
- Vaverka, Jakub, et al.
(författare)
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Detection of meteoroid hypervelocity impacts on the Cluster spacecraft : First results
- 2017
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Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 122:6, s. 6485-6494
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Tidskriftsartikel (refereegranskat)abstract
- We present the first study of dust impact events on one of the Earth-orbiting Cluster satellites. The events were identified in the measurements of the wide band data (WBD) instrument on board the satellite operating in monopole configuration. Since 2009 the instrument is operating in this configuration due to the loss of three electric probes and is therefore measuring the potential between the only operating antenna and the spacecraft body. Our study shows that the WBD instrument on Cluster 1 is able to detect pulses generated by dust impacts and discusses four such events. The presence of instrumental effects, intensive natural waves, noncontinuous sampling modes, and the automatic gain control complicates this detection. Due to all these features, we conclude that the Cluster spacecraft are not ideal for dust impact studies. We show that the duration and amplitudes of the pulses recorded by Cluster are similar to pulses detected by STEREO, and the shape of the pulses can be described with the model of the recollection of impact cloud electrons by the positively charged spacecraft. We estimate that the detected impacts were generated by micron-sized grains with velocities in the order of tens of km/s.
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| 19. |
- Vaverka, Jakub, et al.
(författare)
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Potential of Earth Orbiting Spacecraft Influenced by Meteoroid Hypervelocity Impacts
- 2017
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Ingår i: IEEE Transactions on Plasma Science. - 0093-3813 .- 1939-9375. ; 45:8, s. 2048-2055
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Tidskriftsartikel (refereegranskat)abstract
- Detection of hypervelocity impacts on a spacecraft body using electric field instruments has been established as a new method for monitoring of dust grains in our solar system. Voyager, WIND, Cassini, and STEREO spacecraft have shown that this technique can be a complementary method to conventional dust detectors. This approach uses fast short time changes in the spacecraft potential generated by hypervelocity dust impacts, which can be detected by monopole electric field instruments as a pulse in the measured electric field. The shape and the duration of the pulse strongly depend on parameters of the ambient plasma environment. This fact is very important for Earth orbiting spacecraft crossing various regions of the Earth's magnetosphere where the concentration and the temperature of plasma particles change significantly. We present the numerical simulations of spacecraft charging focused on changes in the spacecraft potential generated by dust impacts in various locations of the Earth's magnetosphere. We show that identical dust impacts generate significantly larger pulses in regions with lower electron density. We discuss the influence of the photoelectron distribution for dust impact detections showing that a small amount of energetic photoelectrons significantly increases the potential of the spacecraft body and the pulse duration. We also show that the active spacecraft potential control (ASPOC) instrument onboard the cluster spacecraft strongly reduces the amplitude and the duration of the pulse resulting in difficulties of dust detection when ASPOC is ON. Simulation of dust impacts is compared with pulses detected by the Earth orbiting cluster spacecraft in the last part of Section III.
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| 20. |
- Vaverka, Jakub, et al.
(författare)
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Spacecraft potential influenced by meteoroid hypervelocity impacts
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Detection of hypervelocity impacts on a spacecraft body using electric field instruments has been established as a new method for monitoring of dust grains in our solar system. Voyager, WIND, Cassini, and STEREO spacecraft have shown that this technique can be a complementary method to conventional dust detectors. This approach uses fast short time changes in the spacecraft potential generated by hypervelocity dust impacts, which can be detected by monopole electric field instruments as a pulse in the measured electric field. The shape and the duration of the pulse strongly depend on parameters of the ambient plasma environment. This fact is very important for Earth orbiting spacecraft crossing various regions of the Earth's magnetosphere where the concentration and the temperature of plasma particles change significantly. We present the numerical simulations of spacecraft charging focused on changes in the spacecraft potential generated by dust impacts in various locations of the Earth's magnetosphere. We show that identical dust impacts generate significantly larger pulses in regions with lower electron density. We discuss the influence of the photoelectron distribution for dust impact detections showing that a small amount of energetic photoelectrons significantly increases the potential of the spacecraft body and the pulse duration. We also show that the active spacecraft potential control (ASPOC) instrument onboard the cluster spacecraft strongly reduces the amplitude and the duration of the pulse resulting in difficulties of dust detection when ASPOC is ON. Simulation of dust impacts is compared with pulses detected by the Earth orbiting cluster spacecraft in the last part of Section III.
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