Stabilization concepts for a spherical planetary entry probe configuration

1973 ◽  
Author(s):  
J. CASSANTO
Keyword(s):  
2020 ◽  
Author(s):  
Alena Probst ◽  
Linda Spilker ◽  
Tom Spilker ◽  
David Atkinson ◽  
Olivier Mousis ◽  
...  
Keyword(s):  

2009 ◽  
Vol 48 (6) ◽  
pp. 1109-1120 ◽  
Author(s):  
Robert Hruschka ◽  
Sean O’Byrne ◽  
Harald Kleine

2020 ◽  
Author(s):  
Alena Probst ◽  
Linda Spilker ◽  
Tom Spilker ◽  
David Atkinson ◽  
Olivier Mousis ◽  
...  

<p>In-situ probe measurements of planetary atmospheres add an immense value to remote sensing observations from orbiting spacecraft or telescopes, as highlighted and justified in numerous publications [1,2,3]. Certain key measurements such as the determination of noble gas abundances and isotope ratios can only be made in situ by atmospheric entry probes, but represent essential knowledge for investigating the formation history of the solar system as well as the formation and evolutionary processes of planetary atmospheres. Following the above rationale, a planetary entry mission to one of the outer planets (Saturn, Uranus and Neptune) has been identified as a mission of high priority by international space agencies. In particular, an entry probe mission proposal to Neptune has been selected as a flagship mission study in the next NASA decadal survey.</p><p>Within the scientific frame of atmospheric planetary sciences, a two- to three-year research study called IPED (<strong>I</strong>mpact of the <strong>P</strong>robe <strong>E</strong>ntry Zone on the Trajectory and Probe <strong>D</strong>esign) investigates the impact of the interplanetary and approach trajectories on the feasible range of atmospheric entry sites as well as the probe design, considering Saturn, Uranus and Neptune as target bodies. The objective is to provide a decision matrix for entry site selection by comparing several mission scenarios for different science cases.</p><p>In this presentation, the focus is on approach circumstances of the planetary entry probe upon arrival at a normalized, spherical planet. Science objectives are organised in four (planetocentric) latitude ranges: (1) low latitudes < 15°, (2) mid latitudes between 15° and 45°, (3) high latitudes between 45° and 75° and (4) polar latitudes of > 75°. The latitude ranges are considered as potential entry zones for the implementation. The implementation strategy will be explained and discussed. Astrodynamically accessible latitudes are presented as a function of the approach velocity  vector v<sub>∞ </sub>(both declination of the approach asymptote and magnitude). A roadmap is shown that explains the next implementation step to include the physical characteristics of the destination planet such as the planet’s size, rotation period, shape, ring geometries and obliquity.</p><p>The presented research was supported by an appointment to the NASA Postdoctoral Program (NPP) at the Jet Propulsion Laboratory (JPL), California Institute of Technology, administered by Universities Space Research Association (USRA) under contract with National Aeronautics and Space Association (NASA). © 2020 All rights reserved.</p><p>[1] Mousis, O. et al., Scientific Rationale for Saturn’s in situ exploration, Planetary and Space Science 104 (2014) 29-47.</p><p>[2] Mousis, O. et al., Scientific Rationale for Uranus and Neptune in situ explorations, Planetary and Space Science 155 (2018) 12-40.</p><p>[3] Hofstadter, M. et al., Uranus and Neptune missions: A study in advance of the next planetary science decadal survey, Planetary and Space Science 177 (2019) 104680.</p>


2021 ◽  
Author(s):  
Jack Ridderhof ◽  
Panagiotis Tsiotras
Keyword(s):  

2021 ◽  
Vol 217 (1) ◽  
Author(s):  
J. Simcic ◽  
D. Nikolić ◽  
A. Belousov ◽  
D. Atkinson ◽  
C. Lee ◽  
...  

AbstractTo date, a variety of different types of mass spectrometers have been utilized on missions to study the composition of atmospheres of solar system bodies, including Venus, Mars, Jupiter, Titan, the moon, and several comets. With the increasing interest in future small probe missions, mass spectrometers need to become even more versatile, lightweight, compact, and sensitive.For in situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, including 3He/4He, and other key isotopes like D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P; isotopes 13C/12C, 15N/14N, 18O/17O/16O; and disequilibrium species PH3, CO, AsH3, GeH4, and SiH4. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances.An inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled (gas, solid, or liquid) into the instrument interior, which operates at a vacuum level. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate for 1-2 hours over a range of atmospheric pressures, possibly covering 2 or more orders of magnitude, from the tropopause near 100 mbar to at least 10 bars, in an atmospheric layer of depth beneath the tropopause of about 120 km at Neptune and about 150 km at Uranus.The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS) is being developed to achieve all of these requirements. A compact, wireless instrument with a mass of only 7.5 kg, and a volume of 7 liters (7U), the JPL QITMS is currently the smallest flight mass spectrometer available for possible use on planetary descent probes as well as small bodies, including comet landers and surface sample return missions. The QITMS is capable of making measurements of all required constituents in the mass range of 1–600 atomic mass units (u) at a typical speed of 50 mass spectra per second, with a sensitivity of up to $10^{13}$ 10 13  counts/mbar/sec and mass resolution of $m/\Delta m=18000$ m / Δ m = 18000 at m/q = 40. (Throughout this paper we use the unit of m/q = u/e for the mass-to-charge ratio, where atomic mass unit and elementary charge are $1~\text{u} = 1.66\times 10^{-27}~\text{kg}$ 1 u = 1.66 × 10 − 27 kg and $1\text{e} = 1.6\times 10^{-19}$ 1 e = 1.6 × 10 − 19 C, respectively.) The QITMS features a novel MEMS-based inlet system driven by a piezoelectric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar.In this paper, we present an overview of the QITMS capabilities, including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation, especially suitable for ice giant atmospheres exploration.


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