Interstellar Probe: Pushing the Frontier of Space Science

2020 ◽  
Author(s):  
Pontus Brandt ◽  
Kathleen Mandt ◽  
Elena Provoronikova ◽  
Casey Lisse ◽  
Kirby Runyon ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Kuiper Belt ◽  
Electrical Power ◽  
International Studies ◽  
The Sun ◽  
Gravity Assist ◽  
Trade Offs ◽  
First Time ◽  
Interstellar Probe

<p>An Interstellar Probe beyond our heliosphere in to the largely unexplored interstellar medium (ISM) would be the furthest and boldest step in robotic space exploration ever taken. A dedicated payload of in-situ and remote sensing instruments would uncover the new regime of physics at work in the heliospheric boundary region and offer the first external view of the global heliosphere that is currently missing in the family portrait of all other types of astrospheres observed. Beyond about 400 AU the Probe would reach the ISM and for the first time begin its sampling of the properties of the local interstellar cloud (LIC) that our Sun and neighboring star systems are immersed in.</p><p>An Interstellar Probe has been discussed since around 1960 in several NASA and international studies. The compelling science objectives have remained almost unchanged and are focused on understanding the plasma physics in the interaction region between the heliosphere and the ISM. Their importance have been amplified by the recent unexpected findings by the Voyager 1 and 2 spacecraft that are nearing their end of life at less than 150 AU from the Sun. Remote observations in Energetic Neutral Atoms (ENAs) by the NASA IBEX and Cassini missions have made the remarkable discoveries of ENA emission morphologies that have come as a complete surprise and still lack a satisfactory explanation. Hubble Space Telescope observations have now also made it clearer that the Sun is about to exit the LIC and perhaps already has, which is a unique event of astronomical scales that an Interstellar Probe could explore in-situ for the first time. In addition to these top-priority objectives, contributions of unprecedented science value to planetary sciences and astrophysics are possible including flybys of at least one Kuiper Belt Object, in-situ and remote observations of the dust debris disk, and the extra-galactic background light.</p><p>Here we review the outstanding questions and current state of understanding of the global heliosphere, the ISM and what planetary and astrophysics augmentations can offer. We summarize the compelling science case for an Interstellar Probe, including a range of possible science payloads and the associated operation scenarios. The results stem from the study of a Pragmatic Interstellar Probe currently underway, funded by NASA, and led by The Johns Hopkins University Applied Physics Laboratory with active participation from a large, international team of scientists and engineers. The study focuses on finding realistic mission architectures among a trade space of propulsion options, trajectories, risks and reliability challenges. The study considers operation out to 1000 AU, a survival probability of 85% over 50 years and electrical power of no less than 400 W at the beginning of mission. Over twice the speed of Voyager 1 (the fastest spacecraft currently) has already been achieved in the design using conventional propulsion, with a direct inject to Jupiter followed by a Jupiter Gravity Assist. In order to provide input requirements to the mission study, several possible payloads with different mass allocations and associated mission requirements, trade-offs and risks have been identified.</p>

Unique heliophysics science opportunities along the Interstellar Probe journey up to 1000 AU from the Sun

2021 ◽  
Author(s):  
Elena Provornikova ◽  
Pontus C. Brandt ◽  
Ralph L. McNutt, Jr. ◽  
Robert DeMajistre ◽  
Edmond C. Roelof ◽  
...  
Keyword(s):  
Space Mission ◽  
In Situ Measurements ◽  
Unique Determination ◽  
The Sun ◽  
Global Shape ◽  
Wide Range ◽  
First Time ◽  
Interstellar Probe ◽  
Probe Mission

<p>The Interstellar Probe is a space mission to discover physical interactions shaping globally the boundary of our Sun`s heliosphere and its dynamics and for the first time directly sample the properties of the local interstellar medium (LISM). Interstellar Probe will go through the boundary of the heliosphere to the LISM enabling for the first time to explore the boundary with a dedicated instrumentation, to take the image of the global heliosphere by looking back and explore in-situ the unknown LISM. The pragmatic concept study of such mission with a lifetime 50 years that can be implemented by 2030 was funded by NASA and has been led by the Johns Hopkins University Applied Physics Laboratory (APL). The study brought together a diverse community of more than 400 scientists and engineers spanning a wide range of science disciplines across the world.</p><p>Compelling science questions for the Interstellar Probe mission have been with us for many decades. Recent discoveries from a number of space missions exploring the heliosphere raised new questions strengthening the science case. The very shape of the heliosphere, a manifestation of complex global interactions between the solar wind and the LISM, remains the biggest mystery. Interpretations of imaging the heliosphere in energetic neutral atoms (ENAs) in different energy ranges on IBEX and Cassini/INCA from inside show contradictory pictures. Global physics-based models also do not agree on the global shape. Interstellar Probe on outbound trajectory will image the heliosphere from outside for the first time and will provide a unique determination of the global shape.</p><p>The LISM is a completely new area for exploration and discovery. We have a crude understanding of the LISM inferred from in-situ measurements inside the heliosphere of interstellar helium, pick-up-ions, ENAs, remote observations of solar backscattered Lyman-alpha emission and absorption line spectroscopy in the lines of sight of stars. We have no in-situ measurements of most LISM properties, e.g. ionization, plasma and neutral gas, magnetic field, composition, dust, and scales of possible inhomogeneities. Voyagers with limited capabilities have explored 30 AU beyond the heliosphere which appeared to be a region of significant heliospheric influence. The LISM properties are among the key unknowns to understand the Sun`s galactic neighborhood and how it shapes our heliosphere. Interstellar Probe will be the first NASA mission to discover the very nature of the LISM and shed light on whether the Sun enters a new region in the LISM in the near future.</p><p>In this presentation we give an overview of heliophysics science for the Interstellar Probe mission focusing on the critical science questions of the three objectives for the mission. We will discuss in more details a need for direct measurements in the LISM uniquely enabled by the Interstellar Probe.</p>

scholarly journals Solar Orbiter’s first Venus flyby: observations from the Radio andPlasma Wave instrument

2021 ◽  
Author(s):  
Lina Hadid ◽  
Keyword(s):  
Plasma Waves ◽  
Bow Shock ◽  
The Sun ◽  
Gravity Assist ◽  
Tail Region ◽  
Plasma Properties ◽  
In Situ Observations ◽  
Orbit Geometry ◽  
High Cadence

<p>On December 27, 2020, Solar Orbiter completed its first gravity assist manoeuvre of Venus. While this flyby was performed to provide the spacecraft with sufficient velocity to get closer to the Sun and observe its poles from progressively higher inclinations, the Radio and Plasma Wave (RPW) consortium, along with other operational in-situ instruments, had the opportunity to perform high cadence measurements and study the plasma properties in the induced magnetosphere of Venus. In this work we present an overview of the in situ observations performed by RPW, inside the induced magnetosphere of Venus, during this first encounter of Solar Orbiter.<br />These data allowed conclusive identification of various waves at low and higher frequencies than previously observed and detailed investigation regarding the structure of the induced magnetosphere of Venus. Furthermore, noting that prior studies were mainly focused on the magnetosheath region and could only reach 10-12 Venus radii (RV) down the tail, the particular orbit geometry of Solar Orbiter’s VGAM1, allowed the first investigation of the nature of the plasma waves continuously from the bow-shock to the magnetosheath, extending to ∼ 70 R V in the far distant tail region.</p>

Interstellar Probe: Humanity's Journey Into Interstellar Space Begins

2020 ◽  
Author(s):  
Pontus Brandt ◽  
Elena Provornikova ◽  
Kirby Runyon ◽  
Carey Lisse ◽  
Abigail Rymer ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Planetary Science ◽  
Space Physics ◽  
Global Structure ◽  
Interstellar Space ◽  
Gravity Assist ◽  
Quantum Leap ◽  
Global Nature ◽  
Interstellar Probe

<p>The global nature of the interaction of the heliosphere and the Local Interstellar Medium (LISM) is among one of the most outstanding space physics problems of today. Ultimately, our magnetic bubble is upheld by the expanding solar wind born in the solar corona that is now accessible by Parker Solar Probe. At the other extreme boundary, a completely new regime of physical interactions is at work that shape the unseen global structure of the entire heliosphere. Voyager 1 and 2 are soon nearing their end of operations inside of 170 AU and their payloads dedicated to planetary science have uncovered a region of space that defies our understanding. At the same time, IBEX and Cassini have obtained complementary “inside-out” ENA images of the heliospheric boundary region that cannot be fully explained.</p> <p>An Interstellar Probe through the heliospheric boundary, in to the LISM would be the first dedicated mission to venture into this largely unexplored frontier of space. With a dedicated suite of in-situ and remote-sensing instrumentation, such a probe would not only open the door for a new regime of space physics acting at the boundary and in other astrospheres, but would also obtain the very first images from the outside of the global structure of the heliosphere that, in context with the in-situ measurements would enable a quantum leap in understanding the global nature of our own habitable astrosphere. Beyond the Heliopause, the Interstellar Probe would offer the first sampling of the properties of the Local Interstellar Cloud and interstellar dust that are completely new scientific territories. Relatively modest contributions across divisions would offer historic science returns, including a flyby of one or two Kuiper Belt Objects, first insights in to the structure of the circum-solar dust disk, and the first measurements of the Extra-galactic Background Light beyond the obscuring Zodiacal cloud. In summary, an Interstellar Probe would represent humanity’s first step in to the galaxy and become the farthest space exploration ever undertaken.</p> <p>The idea of an Interstellar Probe and a Solar Probe shares a common beginning as two of the “Special Probes” that the Simpson Committee carried forward in their Interim Report to the Space Studies Board in 1960. Since then, an Interstellar Probe has scientifically been highly rated in the Solar and Space Physics Decadal Surveys, but the lack of propulsion technologies and launch vehicles have presented a stumbling block for its realization. However, this bottleneck is now being removed with the development of the Space Launch System (SLS) Block 2 with first launch projected to end of the 2020’s.</p> <p>A study funded by NASA is now progressing towards its third year of developing realistic mission architectures for an Interstellar Probe using technology ready for launch beginning 2030. An SLS Block 2, with an Atlas Centaur 3<sup>rd</sup>stage, a Star 48 4<sup>th</sup> stage  could propel a spacecraft up to about 8.5 AU/year, which would be more than twice the fastest escaping spacecraft (Voyager 1 at 3.6 AU/year). The scenario would use a direct inject to Jupiter followed by a Jupiter Gravity assist powered by the 4<sup>th</sup> stage. The mission trade space is bound by requirements to be able to operate out to 1000 AU, 600 W of power beginning of mission, and survive up to 50 years.</p> <p>Here, we discuss the outstanding science questions that could be addressed by a mission to the LISM, notional science payload and report on realistic mission architectures, design concepts and trades, enabling technologies, and programmatic challenges.</p>

scholarly journals 2.1.2 Preliminary Results of the Micrometeoroid Experiment on Board Helios A

1976 ◽  
Vol 31 ◽  
pp. 159-163
Author(s):  
E. Grün ◽  
J. Kissel ◽  
H. Fechtig ◽  
P. Gammelin ◽  
H.-J. Hoffmann
Keyword(s):  
Interplanetary Dust ◽  
Strong Increase ◽  
The Sun ◽  
Impact Rate ◽  
M 10 ◽  
Large Particles ◽  
The Impact ◽  
First Time ◽  
Measured Particle

AbstractFor the first time in situ measurements of interplanetary dust have been performed between 0.3 AU and 1 AU from the sun by the micrometeoroid experiment on board Helios A. The measured particle masses are between 10−15 g and 10−8 g and their measured speeds are between 2 km/sec and 20 km/sec. Particle impacts are identified by the time-of-flight spectra of the ions released upon impact. 15 large particles (m ≥ 10−12 g) were detected from Dec. 15, 1974 to Sept. 5, 1975. They show a strong increase of the impact rate (appr. a factor of 10) between 1 AU and 0.3 AU. The directions from which they impacted the sensor are concentrated between the solar direction and the apex direction of the Helios spacecraft.

scholarly journals Exploiting White-Light Observations to Improve Estimates of Magnetic Connectivity

2021 ◽  
Vol 8 ◽  
Author(s):  
Nicolas Poirier ◽  
Alexis P. Rouillard ◽  
Athanasios Kouloumvakos ◽  
Alexis Przybylak ◽  
Naïs Fargette ◽  
...  
Keyword(s):  
White Light ◽  
Solar Wind Plasma ◽  
Magnetic Polarity ◽  
Model Parameters ◽  
The Sun ◽  
Heliospheric Observatory ◽  
Practical Applications ◽  
One Year ◽  
First Time

The Solar Orbiter (SolO) and Parker Solar Probe missions have opened up new challenges for the heliospheric scientific community. Their proximity to the Sun and their high quality measurements allow us to investigate, for the first time, potential sources for the solar wind plasma measured in situ. More accurate estimates of magnetic connectivities from spacecraft to the Sun are required to support science and operations for these missions. We present a methodology to systematically compare coronal and heliospheric models against white-light (WL) observations. WL images from the SOlar and Heliospheric Observatory (SoHO) are processed to unveil the faint structures of the K-corona. Images are then concatenated over time and are projected into a Carrington synoptic map. Features of interest such as the Streamer Belt (SB) are reduced to simplified geometric objects. Finally, a metric is defined to rank models according to their performance against WL observations. The method has been exploited to reproduce magnetic sectors from WL observations. We tested our results against one year of in situ magnetic polarity measurements taken at near one AU from the Advanced Composition Explorer (ACE) and the Solar TErrestrial RElations Observatory (STEREO-A). We obtained a good correlation that emphasizes the relevance of using WL observations to infer the shape of the sector structure. We show that WL observations provide additional constraints to better select model parameters such as the input photospheric magnetic map. We highlight the capability of this technique to systematically optimize coronal and heliospheric models using continuous and near-real-time WL observations. Several relevant practical applications are discussed, which should allow us to improve connectivity estimates.

The Comet Interceptor Mission

2021 ◽  
Author(s):  
Geraint H. Jones ◽  
Colin Snodgrass ◽  
Cecilia Tubiana ◽  
Keyword(s):  
Surface Composition ◽  
The Sun ◽  
Solar Wind Interaction ◽  
Space Agency ◽  
Short Period ◽  
Interplanetary Trajectory ◽  
In Situ Observations ◽  
First Time ◽  
Coma Region

<div>Comet Interceptor was selected in 2019 as the European Space Agency's next planetary mission, to which the Japanese space agency, JAXA, will make a major contribution. The mission is ESA's first Fast (F) project, and its primary science goal is to characterise, for the first time, a long period comet, preferably dynamically-new, or an interstellar object. An encounter with one of these objects for the first time will provide valuable data to complement that from all previous comet missions, which have by necessity studied short-period comets that have evolved during their time orbiting near the Sun from their original condition. Planned measurements of the target include its surface composition, shape, and structure, its dust environment, and the composition of the gas coma. A unique, multi-point ‘snapshot’ measurement of the comet- solar wind interaction region is to be obtained, complementing single spacecraft observations made at other comets. The spacecraft will be delivered to Sun-Earth Lagrange Point L2 with the ESA Ariel mission in 2029, a relatively stable location suitable for later injection onto an interplanetary trajectory to intersect the path of its target. A suitable new comet would be searched for from Earth prior to launch, and after launch if necessary, with short period comets serving as a backup destinations. With the advent of powerful facilities such as the Vera Rubin Observatory, the prospects of finding a suitable comet nearing the Sun are very promising. The possibility may exist for the spacecraft to encounter an interstellar object if one is found on a suitable trajectory. When approaching the target, two sub-spacecraft – one provided by ESA, the other by JAXA, would be released from the primary craft. The main spacecraft, which would act as the primary communication point for the whole constellation, would be targeted to pass outside the hazardous inner coma, making remote and in situ observations on the sunward side of the comet. The two sub-spacecraft will be targeted closer to the nucleus and inner coma region. We shall describe the science drivers, planned observations, and the mission’s instrument complement, to be provided by consortia of institutions in Europe and Japan.</div>

Notes from the Polar Night

2020 ◽  
Vol 9 (4) ◽  
pp. 35-43
Author(s):  
Chris Ingraham
Keyword(s):  
Global Warming ◽  
The Sun ◽  
Polar Night ◽  
Academic Scholarship

Drawing from in situ fieldwork in Longyearbyen, Svalbard, the northernmost settlement on Earth, these notes bring out the affective, ambient, and atmospheric power of extended darkness during the polar night, when the sun does not appear above the horizon for several months at a time. Each entry is composed of 113 words to reflect the number of days without light in Longyearbyen during the winter of my visit. Through a mixture of ethnographic observations, researched academic scholarship, and some endeavors of poetic worldmaking, these notes attempt to evoke the ineffable force of global warming by performing the sort of acutely observed and felt attentiveness to planetary being that is needed for our time.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

scholarly journals Engineered Phage Endolysin Eliminates Gardnerella Biofilm without Damaging Beneficial Bacteria in Bacterial Vaginosis Ex Vivo

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Christine Landlinger ◽  
Lenka Tisakova ◽  
Vera Oberbauer ◽  
Timo Schwebs ◽  
Abbas Muhammad ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Bactericidal Activity ◽  
High Selectivity ◽  
Ex Vivo ◽  
Vaginal Microbiome ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Promising Alternative ◽  
First Time

Bacterial vaginosis is characterized by an imbalance of the vaginal microbiome and a characteristic biofilm formed on the vaginal epithelium, which is initiated and dominated by Gardnerella bacteria, and is frequently refractory to antibiotic treatment. We investigated endolysins of the type 1,4-beta-N-acetylmuramidase encoded on Gardnerella prophages as an alternative treatment. When recombinantly expressed, these proteins demonstrated strong bactericidal activity against four different Gardnerella species. By domain shuffling, we generated several engineered endolysins with 10-fold higher bactericidal activity than any wild-type enzyme. When tested against a panel of 20 Gardnerella strains, the most active endolysin, called PM-477, showed minimum inhibitory concentrations of 0.13–8 µg/mL. PM-477 had no effect on beneficial lactobacilli or other species of vaginal bacteria. Furthermore, the efficacy of PM-477 was tested by fluorescence in situ hybridization on vaginal samples of fifteen patients with either first time or recurring bacterial vaginosis. In thirteen cases, PM-477 killed the Gardnerella bacteria and physically dissolved the biofilms without affecting the remaining vaginal microbiome. The high selectivity and effectiveness in eliminating Gardnerella, both in cultures of isolated strains as well as in clinically derived samples of natural polymicrobial biofilms, makes PM-477 a promising alternative to antibiotics for the treatment of bacterial vaginosis, especially in patients with frequent recurrence.

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