Destiny+ Dust Analyzer – Campaign & timeline preparation for interplanetary & interstellar dust observation during the 4-year transfer phase from Earth to Phaethon

2020 ◽  
Author(s):  
Maximilian Sommer ◽  
Harald Krüger ◽  
Ralf Srama ◽  
Takayuki Hirai ◽  
Masanori Kobayashi ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Interstellar Dust ◽  
Impact Ionization ◽  
Interplanetary Space ◽  
Dust Cloud ◽  
Dust Particles ◽  
Transfer Phase ◽  
Moon System ◽  
The Earth ◽  
The Impact

<p align="justify">The Destiny+ mission (Demonstration and Experiment of Space Technology for Interplanetary voyage Phaethon fLyby and dUst Science) has been selected as part of its M-class Space Science Program by the Japanese space agency JAXA/ISAS and is set to launch in 2023/2024. The mission target is the active asteroid (3200) Phaethon with a projected flyby in early 2028. The scientific payload consists of two cameras (the Telescopic Camera for Phaethon, TCAP, and the Multi-band Camera for Phaethon, MCAP), and the Destiny+ Dust Analyzer (DDA). DDA is the technological successor to the Cosmic Dust Analyzer (CDA) aboard Cassini-Huygens, which prominently investigated the dust environment of the Saturnian system. The DDA sensor is designed as a combination of impact ionization time-of-flight mass spectrometer and trajectory sensor, which will allow for the analysis of sub-micron and micron sized dust particles with respect to their composition (mass resolution m/Δm ≈ 100-150), mass, electrical charge, velocity (about 10% accuracy), and impact direction (about 10° accuracy).</p> <p align="justify">Besides attempting to sample the impact-generated dust cloud around Phaethon during the flyby, DDA will be actively observing the interplanetary & interstellar dust environment over the roughly four years spanning cruise phase from the Earth-Moon system through interplanetary space. After launch into a GTO-like orbit, Destiny+ will first employ its solar-electric propulsion system to spiral up to the lunar orbit within about 18 months, followed by a series of lunar swingbys and interim coasting phases in distant cislunar space, accumulating momentum to leave the Earth-Moon system at high excess velocity. The subsequent roughly 2-year interplanetary transfer to intercept Phaethon will be characterized by moderate orbital eccentricity of up to 0.1 and largely unpowered coasting phases.</p> <p align="justify">During these four years, the DDA sensor will benefit from a maximum pointing coverage range enabled by its dual-axis pointing mechanism and spacecraft attitude flexibility (during times of unpowered flight). This will allow for exhaustive mapping and analysis of the different interplanetary dust populations, as well as interstellar dust encountered in the region between 0.9-1.1 AU.</p> <p align="justify">Here, we give a progress report on the science planning efforts for the 4-year transfer phase. We present a tentative observation timeline that assigns scientific campaigns to different phases of the mission, taking into account results of various dust models, as well as operational and technical constraints.</p>

scholarly journals Mars Dust Counter on Board ISAS PLANET-B

1996 ◽  
Vol 150 ◽  
pp. 233-236 ◽  
Author(s):  
Eduard Igenbergs ◽  
Sho Sasaki ◽  
Georg Färber ◽  
Franz Fischer ◽  
Ralf Münzenmayer ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Interstellar Dust ◽  
Impact Ionization ◽  
Mass Range ◽  
Upper Atmosphere ◽  
Dust Particles ◽  
Velocity Range ◽  
The Earth ◽  
Elliptic Orbits ◽  
Dust Ring

AbstractPLANET-B is an ISAS spacecraft which will investigate the upper atmosphere and the surroundings of Mars between 1999 and 2001 To clarify the presence and characteristics of the Martian dust ring/torus, an impact ionization dust detector will be on board PLANET-B The detector (PLANET B Mars Dust Counter), which is an improved version of the Munich Dust Counters of HITEN and BREMSAT, will weigh only 630g with an aperture area 140cm2. The detectable mass range will be between 10-16g and more than 10-6g and the velocity range will be from 1km/s to more than 70km/s. Since PLANET-B executes retrograde elliptic orbits close to the zodiacal plane, our detector can investigate the spatial distribution of prograde dust particles from Phobos and Deimos with relative encounter velocity as large as or higher than 1km/s. PLANET-B MDC shall also measure the dust environment around the Earth and interplanetary and possibly interstellar dust particles.

scholarly journals Boundary conditions for the formation of the Moon

2015 ◽  
Vol 95 (2) ◽  
pp. 131-139 ◽  
Author(s):  
M. Reuver ◽  
R.J. de Meijer ◽  
I.L. ten Kate ◽  
W. van Westrenen
Keyword(s):  
Angular Momentum ◽  
Boundary Conditions ◽  
Total Angular Momentum ◽  
Nuclear Explosion ◽  
Moment Of Inertia ◽  
The Moon ◽  
Moon System ◽  
Giant Impact ◽  
The Earth ◽  
The Impact

AbstractRecent measurements of the chemical and isotopic composition of lunar samples indicate that the Moon's bulk composition shows great similarities with the composition of the silicate Earth. Moon formation models that attempt to explain these similarities make a wide variety of assumptions about the properties of the Earth prior to the formation of the Moon (the proto-Earth), and about the necessity and properties of an impactor colliding with the proto-Earth. This paper investigates the effects of the proto-Earth's mass, oblateness and internal core-mantle differentiation on its moment of inertia. The ratio of angular momentum and moment of inertia determines the stability of the proto-Earth and the binding energy, i.e. the energy needed to make the transition from an initial state in which the system is a rotating single body with a certain angular momentum to a final state with two bodies (Earth and Moon) with the same total angular momentum, redistributed between Earth and Moon. For the initial state two scenarios are being investigated: a homogeneous (undifferentiated) proto-Earth and a proto-Earth differentiated in a central metallic and an outer silicate shell; for both scenarios a range of oblateness values is investigated. Calculations indicate that a differentiated proto-Earth would become unstable at an angular momentum L that exceeds the total angular momentum of the present-day Earth–Moon system (L0) by factors of 2.5–2.9, with the precise maximum dependent on the proto-Earth's oblateness. Further limitations are imposed by the Roche limit and the logical condition that the separated Earth–Moon system should be formed outside the proto-Earth. This further limits the L values of the Earth–Moon system to a maximum of about L/L0 = 1.5, at a minimum oblateness (a/c ratio) of 1.2. These calculations provide boundary conditions for the main classes of Moon-forming models. Our results show that at the high values of L used in recent giant impact models (1.8 < L/L0 < 3.1), the proposed proto-Earths are unstable before (Cuk & Stewart, 2012) or immediately after (Canup, 2012) the impact, even at a high oblateness (the most favourable condition for stability). We conclude that the recent attempts to improve the classic giant impact hypothesis by studying systems with very high values of L are not supported by the boundary condition calculations in this work. In contrast, this work indicates that the nuclear explosion model for Moon formation (De Meijer et al., 2013) fulfills the boundary conditions and requires approximately one order of magnitude less energy than originally estimated. Hence in our view the nuclear explosion model is presently the model that best explains the formation of the Moon from predominantly terrestrial silicate material.

scholarly journals The Cosmic Dust Analyzer: Experimental Evaluation of an Impact Ionization Model

1971 ◽  
Vol 13 ◽  
pp. 299-310
Author(s):  
J. F. Friichtenicht ◽  
N. L. Roy ◽  
D. G. Becker
Keyword(s):  
Mass Spectrometer ◽  
Relative Abundance ◽  
Microprobe Analysis ◽  
Impact Ionization ◽  
Time Of Flight ◽  
Cosmic Dust ◽  
Dust Particles ◽  
Flight Mass Spectrometer ◽  
Fractional Ionization ◽  
The Impact

Determination of the elemental composition of cosmic dust particles by means of an impact ionization time-of-flight mass spectrometer has been investigated at several institutions. In most configurations, the instrument supplies the identity of ion groups of both target and particle materials extracted from the impact plasma and the number of ions contained in each group. Experiments have shown that the fractional ionization of a given species is not constant with impact velocity nor is the fractional ionization the same for different kinds of atoms. A model of the impact ionization effect developed at TRW involves an equilibrium plasma condition with the consequence that the fractional ionization for an arbitrary atomic species can be specified by the Saha equation if the plasma volume (V) and temperature (T) are known. It follows that T can be determined by taking the ratio of the Saha equations for two elements present in the target in known concentration. (Taking the ratio negates the requirement of knowing V.) Given T, the procedure can be reversed to yield the relative abundance of elements contained in the impacting particle. To test the model, a PbZrO3-PbTiO3 target was bombarded with high velocity Fe, MoB, and NiAl particles and the number of Pb, Ti, and Zr ions was determined in a time-of-flight mass spectrometer. For each event, the relative abundance of Ti to Pb was taken as known (from electron microprobe analysis) and T was determined from the Ti-Pb measurement. The Zr to Pb ratio was found to be in good agreement with the microprobe analysis (0.38 calculated mean value compared to 0.34 actual). The result was valid for all particle materials and for a velocity range 17<v<47 km/s. T ranged from 3300 to 11 500° K and was only mildly velocity dependent.

scholarly journals A Comparison of Contact Charging and Impact Ionization in Low Velocity Impacts: Implications for Dust Detection in Space

2020 ◽  
Author(s):  
Tarjei Antonsen ◽  
Ingrid Mann ◽  
Jakub Vaverka ◽  
Libor Nouzak ◽  
Åshild Fredriksen
Keyword(s):  
Impact Ionization ◽  
Interplanetary Space ◽  
Dust Particles ◽  
Low Velocity ◽  
Charge Generation ◽  
Earth’S Atmosphere ◽  
Contact Charging ◽  
Metal Metal ◽  
Dust Detection ◽  
Earth's Atmosphere

Abstract. We investigate the generation of charge during collision of projectiles with sizes below ~ 1 μm and metal surfaces at speeds ~ 0.1 km/s. This corresponds to speeds above the elastic limit and well below speeds where volume ionization can occur. The conditions that we consider apply to dust particles naturally occurring in space and in Earth's upper atmosphere and their direct impacts on rockets, spacecraft, and impacts of secondary ejecta. We introduce a model of capacitive contact charging in which we allow for projectile fragmentation upon impact, and show that this model describes measurements of metal-metal impacts in the laboratory and in-situ measurements of dust in the Earth's atmosphere well. We have considered the utilization of our model for different scenarios in interplanetary space and in Earth's atmosphere. From this discussion we find it likely that our work can be employed in a number of situations where impact velocities are relatively small. Furthermore, we have discussed the thermodynamics of the low velocity solution of shock wave ionization, and conclude that the impurity charging effect utilized in the much used model of Drapatz and Michel (1974) does not sufficiently describe charge generation at impact speeds below a few kilometers per second. Consequently, impact charging at low speeds cannot be described with a Saha-solution.

scholarly journals The Contribution of Kuiper Belt Dust Grains to the Inner Solar System

1996 ◽  
Vol 150 ◽  
pp. 163-166
Author(s):  
Jer-Chyi Liou ◽  
Herbert A. Zook ◽  
Stanley F. Dermott
Keyword(s):  
Solar System ◽  
Interstellar Dust ◽  
Numerical Study ◽  
Kuiper Belt ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Dust Grains ◽  
Zodiacal Light ◽  
Interplanetary Dust Particles ◽  
The Earth

AbstractThe recent discovery of the so-called Kuiper belt objects has prompted the idea that these objects produce dust grains that may contribute significantly to the interplanetary dust population at 1 AU. We have completed a numerical study of the orbital evolution of dust grains, of diameters 1 to 9 μm, that originate in the region of the Kuiper belt. Our results show that about 80% of the grains are ejected from the Solar System by the giant planets while the remaining 20% of the grains evolve all the way to the Sun. Surprisingly, these dust grains have small orbital eccentricities and inclinations when they cross the orbit of the Earth. This makes them behave more like asteroidal than cometary-type dust particles. This also enhances their chances to be captured by the Earth and makes them a possible source of the collected interplanetary dust particles (IDPs); in particular, they represent a possible source that brings primitive/organic materials from the outer Solar System to the Earth.When collisions with interstellar dust grains are considered, however, Kuiper belt dust grains larger than about 9 μm appear likely to be collisionally shattered before they can evolve to the inner part of the Solar System. Therefore, Kuiper belt dust grains may not, as they are expected to be small, contribute significantly to the zodiacal light.

scholarly journals SIRTF: A Unique Opportunity for Probing the Zodiacal Cloud

1996 ◽  
Vol 150 ◽  
pp. 159-162
Author(s):  
Sumita Jayaraman ◽  
Stanley F. Dermott ◽  
Michael Werner
Keyword(s):  
Thermal Emission ◽  
Dust Cloud ◽  
Thermal Characteristics ◽  
Dust Particles ◽  
Infrared Telescope ◽  
The Earth ◽  
Telescope Facility ◽  
Asteroidal Dust ◽  
Infrared Telescope Facility ◽  
Dust Ring

AbstractThe Space Infrared Telescope Facility (SIRTF) is planned for launch by NASA in 2001 in a heliocentric orbit at 1.01 AU The spacecraft will drift away from the Earth slowly, reaching a distance of 0.3 AU behind the Earth at the end of its 2.5 year mission. This implies that SIRTF will spiral through the Earth's resonant dust ring (Wright et al., 1995) and, in particular, that it will traverse the dust cloud in the ring that trails the Earth in its orbit. We have used a dynamical model of the ring (Dermott et al., 1994) followed by simulation of the SIRTF orbit to predict the variations in the zodiacal thermal emission due to the trailing dust cloud as seen by SIRTF. Because the dust ring is inclined to the ecliptic, the latitude of peak flux of the trailing cloud will have yearly oscillations about the ecliptic. The amplitude of the oscillations will increase as SIRTF approaches the cloud, reaching a maximum of 20 during the mission. The magnitude of the flux variations can be as high as 4 – 5% or 2–3 MJy/Sr, SIRTF's measurements of these effects will allow us to model the number density and thermal characteristics of asteroidal dust particles near the Earth.

scholarly journals Physical Modeling of the Zodiacal Dust Cloud

2001 ◽  
Vol 204 ◽  
pp. 17-34 ◽  
Author(s):  
Leonid M. Ozernoy
Keyword(s):  
Solar System ◽  
Physical Modeling ◽  
Interstellar Dust ◽  
Extrasolar Planets ◽  
Dust Cloud ◽  
Interplanetary Dust ◽  
Asteroid Belt ◽  
Dust Particles ◽  
Resonant Structure ◽  
Zodiacal Light

This review is based on extensive work done in collaboration with N. Gorkavyi, J. Mather, and T. Taidakova, which aimed at physical modeling of the interplanetary dust (IPD) cloud in the Solar System, i.e., establishing a link between the observable characteristics of the zodiacal cloud and the dynamical and physical properties of the parent minor bodies. Our computational approach permits one to integrate the trajectories of hundreds of particles and to effectively store up to 1010–11 positions with modest computer resources, providing a high fidelity 3D distribution of the dust. Our numerical codes account for the major dynamical effects that govern the motion of IPD particles: Poynting-Robertson (P-R) drag and solar wind drag; solar radiation pressure; particle evaporation; gravitational scattering by the planets; and the influence of mean-motion resonances. The incorporation of secular resonances and collisions of dust particles (both mutual and with interstellar dust) is underway. We have demonstrated the efficacy of our codes by performing the following analyses: (i) simulation of the distribution of Centaurs (comets scattered in their journey from the Kuiper belt inward in the Solar System) and revealing the effects of the outer planets in producing ‘cometary belts’; (ii) detailed inspection of a rich resonant structure found in these belts, which predicts the existence of gaps similar to the Kirkwood gaps in the main asteroid belt; (iii) a preliminary 3-D physical model of the IPD cloud, which includes three dust components – asteroidal, cometary, and kuiperoidal – and is consistent with the available data of Pioneer and Voyager dust detectors; (iv) modeling of the IPD cloud, which provides a zodiacal light distribution in accord, to the order of 1%, with a subset of the COBE/DIRBE observations; and (v) showing that the resonant structure in dusty circumstellar disks of Vega and Epsilon Eridani is a signature of embedded extrasolar planets. Further improvements of our modeling and their importance for astronomy and cosmology are outlined.

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