Results 121 to 130 of about 90,052 (317)

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Rotational motion control of a spacecraft

IEEE Transactions on Automatic Control, 2003
The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested.
Wisniewski, Rafal, Kulczycki, P.
openaire   +3 more sources

Visible, near‐, and thermal infrared spectra of asteroid Bennu samples: Relationship to and implications for remote sensing of carbonaceous asteroids

Meteoritics &Planetary Science, EarlyView.
Abstract Remote spectroscopy is used to characterize the mineralogy and infer the history of planetary bodies. Carbonaceous asteroids, such as B‐type (101955) Bennu, represent the earliest stages of planet formation. B types have a blue (negative) spectral slope and comprise <5% of asteroids.
V. E. Hamilton, E. A. Cloutis, R. E. Milliken, P. Haenecour, D. R. Golish, K. J. Domanik, T. J. McCoy, L. P. Keller, A. A. Simon, H. H. Kaplan, C. A. Goodrich, S. A. Sandford, D. Applin, T. Hiroi, D. H. Hill, N. G. Lunning, F. M. McCubbin, S. A. Eckley, C. J. Snead, E. H. Blumenfeld, J. E. Aebersold, C. Schultz, N. Bowles, K. A. Shirley, S. S. Russell, J. J. Barnes, T. J. Zega, D. N. DellaGiustina, A. J. Ryan, D. P. Glavin, J. P. Dworkin, H. C. Connolly Jr., D. S. Lauretta   +32 more
wiley   +1 more source

The role of composition in the spectral evolution of carbonaceous asteroids as informed by Bennu sample return

Meteoritics &Planetary Science, EarlyView.
Abstract Near‐Earth rubble‐pile asteroids Bennu and Ryugu are part of the carbonaceous taxonomic complex (C‐complex), and samples returned from both bodies resemble the most aqueously altered carbonaceous chondrites. However, telescopic and spacecraft visible–near infrared (VIS–NIR) reflectance spectra of Ryugu exhibit a red (positive) spectral slope ...
Ralph E. Milliken, Takahiro Hiroi, Victoria E. Hamilton, Cody D. Schultz, Ed A. Cloutis, Hannah H. Kaplan, Melissa K. Kontogiannis, Nathalia Vega‐Santiago, Dani N. DellaGiustina, Harold C. Connolly Jr., Dante S. Lauretta   +10 more
wiley   +1 more source

Designs of multi-spacecraft swarms for the deflection of apophis by solar sublimation

, 2009
This paper presents two conceptual designs of multi-spacecraft swarms used for deflecting Apophis. Each spacecraft is equipped with a solar concentrator assembly, which focuses the solar light, and a beaming system that projects a beam of light onto the ...
Vasile, M., Maddock, Christie, Summerer, Leopold, Radice, Gianmarco, McInnes, C.R.   +4 more
core  

Nanoscale space weathering features in mature lunar soil revealed by TEM and APT

Meteoritics &Planetary Science, EarlyView.
Abstract Space weathering significantly alters the optical, chemical, and structural properties of lunar regolith at micro‐ and nanoscales; yet detailed nanoscale variability within individual soils remains underexplored. Here we apply transmission electron microscopy (TEM) and atom probe tomography to four mineral grains (olivine, ilmenite, and two ...
Jennika Greer, Alexander M. Kling, Luke Daly, Dieter Isheim, David N. Seidman, Michelle S. Thompson, Philipp R. Heck   +6 more
wiley   +1 more source

Spacecraft tracking with the SKA

New Astronomy Reviews, 2004
6 pages, 4 figures, to appear in "Science with the Square Kilometer Array", eds. C. Carilli and S. Rawlings, New Astronomy Reviews (Elsevier: Amsterdam)
openaire   +2 more sources

Modular testbed for spinning spacecraft

, 2019
The ground verification of a spacecraft control algorithm is commonly done via air bearing facility. Air bearing testbeds are frequently developed for testing a three-axis stabilized spacecraft control algorithm but hardly for a spin-stabilized ...
Si, J, Gao, Yang, Chanik, Abadi
core   +1 more source

An eye on long‐duration spaceflight: Controversies, countermeasures and challenges

Experimental Physiology, EarlyView.
Abstract Space flight‐associated neuroocular syndrome (SANS) is a consequence of long‐duration space flight and is detected in two‐thirds of astronauts. In‐flight, this can cause a change in the refraction of the eyes, requiring graded hypermetropic ‘superfocus adjustable’ glasses, optic nerve head oedema and choroidal folds.
Vincent Wing Sum Ng, Susan Patricia Mollan   +1 more
wiley   +1 more source

Uncontrolled spacecraft formations on two-dimensional invariant tori

, 2012
Within the class of natural motions near libration point regions quasi-periodic trajectories evolving on invariant tori are studied. Those orbits prove beneficial for relative spacecraft configurations with large distances among satellites. In this study
Vasile, Massimiliano, Duering, Marcel, Landgraf, Markus   +2 more
core