Konoplev O.A.,Science Systems And Applications Inc. |
Chiragh F.L.,Pinnacle Engineering Management Solutions |
Vasilyev A.A.,Trident Vantage Systems LLC. |
Edwards R.,Fibertek, Inc. |
And 8 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016
We present the results of a three-year operational-aging test of a specially designed prototype flight laser operating at 1064 nm, 10 kHz, 1ns, 15W average power and externally frequency-doubled. Fibertek designed and built the q-switched, 1064nm laser and this laser was in a sealed container of dry air pressurized to 1.3 atm. The external frequency doubler was in a clean room at a normal air pressure. The goal of the experiment was to measure degradation modes at 1064 and 532 nm separately. The external frequency doubler consisted of a Lithium triborate, LiB3O5, non-critically phase-matched crystal. After some 1064 nm light was diverted for diagnostics, 13.7W of fundamental power was available to pump the doubling crystal. Between 8.5W and 10W of 532nm power was generated, depending on the level of stress and degradation. The test consisted of two stages, the first at 0.3 J/cm2 for almost 1 year, corresponding to expected operational conditions, and the second at 0.93 J/cm2 for the remainder of the experiment, corresponding to accelerated optical stress testing. We observed no degradation at the first stress-level and linear degradation at the second stress-level. The linear degradation was linked to doubler crystal output surface changes from laser-assisted contamination. We estimate the expected lifetime for the flight laser at 532 nm using fluence as the stress parameter. This work was done for NASA's Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) LIDAR at Goddard Space Flight Center in Greenbelt, MD with the goal of 1 trillion shots lifetime. © 2016 COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
Chamorro E.,Andrés Bello University |
Melin J.,ASRC Federal Space and Defense
Journal of Molecular Modeling | Year: 2015
We present a critical discussion related to the recent definition of the intrinsic reactivity index, IRI, (Tetrahedron Lett. 2013, 54, 339-342; Tetrahedron 2013, 69, 4247-4258) formulated to describe both, electrophilicity (charge acceptance) and nucleophilicity (charge donation) reactivities. We here stress that such an IRI model, based on the quantity μ/η, should be properly related to theoretical approximations associated to the change in the global electronic energy of a given chemical system under interaction with a suitable electron bath (Gazquez JL et al. J Phys Chem A 2007, 111, 1966-1970). Further, the limitations of the IRI model are presented by emphasizing that the intrinsic relative scales of electrophilicity and nucleophilicity within a second-order perturbation approach must account for the further stabilization of the two interacting species (Chamorro E et al. J Phys Chem A 2013, 117, 2636-2643).[Figure not available: see fulltext.] © 2015, Springer-Verlag Berlin Heidelberg.
Berg M.D.,ASRC Federal Space and Defense |
Berg M.D.,NASA |
Kim H.S.,ASRC Federal Space and Defense |
Phan A.D.,ASRC Federal Space and Defense |
And 3 more authors.
IEEE Transactions on Nuclear Science | Year: 2013
We apply a model and heavy-ion cross section data to predict the potential that one single event upset (SEU) will induce multiple bit errors (MBEs) by the next clock-cycle of a synchronous design. © 2013 IEEE.
Jhabvala C.A.,NASA |
Benford D.J.,NASA |
Brekosky R.P.,Stinger Ghaffarian Technologies Inc. |
Costen N.P.,Stinger Ghaffarian Technologies Inc. |
And 11 more authors.
Journal of Low Temperature Physics | Year: 2016
We have demonstrated in the laboratory multiple, fully functional, kilopixel, bolometer arrays for the upgraded instrument, the High-resolution airborne wideband camera plus (HAWC+), for the stratospheric observatory for infrared astronomy (SOFIA). Each kilopixel array consists of three individual components assembled into a single working unit: (1) a filled, Transition Edge Sensor (TES) bolometer array, (2) an infrared, back-termination, and (3) an integrated, two-dimensional superconducting quantum interference device (SQUID) multiplexer readout. Kilopixel TES arrays are directly indium-bump-bonded to a 32 (Formula presented.) 40 SQUID multiplexer (MUX) circuit. In order to provide a fully superconducting pathway from the TES to the SQUID readout, numerous superconductor-to-superconductor interfaces must be made. This paper focuses on the fabrication techniques needed to create the superconducting path from the TES, out of the detector membrane, through the wafer, and to the SQUID readout. © 2016 Springer Science+Business Media New York (outside the USA)
Ajluni T.,ASRC Federal Space and Defense |
Everett D.,NASA |
Linn T.,Lockheed Martin |
Mink R.,NASA |
And 2 more authors.
IEEE Aerospace Conference Proceedings | Year: 2015
This paper addresses the technical aspects of the sample return system for the upcoming Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission. The overall mission design and current implementation are presented as an overview to establish a context for the technical description of the reentry and landing segment of the mission. The prime objective of the OSIRIS-REx mission is to sample a primitive, carbonaceous asteroid and to return that sample to Earth in pristine condition for detailed laboratory analysis. Targeting the near-Earth asteroid Bennu, the mission launches in September 2016 with an Earth reentry date of September 24,2023. OSIRIS-REx will thoroughly characterize asteroid Bennu providing knowledge of the nature of near-Earth asteroids that is fundamental to understanding planet formation and the origin of life. The return to Earth of pristine samples with known geologic context will enable precise analyses that cannot be duplicated by spacecraft-based instruments, revolutionizing our understanding of the early Solar System. Bennu is both the most accessible carbonaceous asteroid and one of the most potentially Earth-hazardous asteroids known. Study of Bennu addresses multiple NASA objectives to understand the origin of the Solar System and the origin of life and will provide a greater understanding of both the hazards and resources in near-Earth space, serving as a precursor to future human missions to asteroids. This paper focuses on the technical aspects of the Sample Return Capsule (SRC) design and concept of operations, including trajectory design and reentry retrieval. Highlights of the mission are included below. The OSIRIS-REx spacecraft provides the essential functions for an asteroid characterization and sample return mission: • attitude control • propulsion • power • thermal control • telecommunications • command and data handling • structural support to ensure successful rendezvous with Bennu • characterization of Bennu's properties • delivery of the sampler to the surface, and return of the spacecraft to the vicinity of the Earth • sample collection, performed by the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), to acquire a regolith sample from the surface • Earth re-entry and SRC recovery Following sample collection, OSIRIS-REx drifts away from Bennu until the Asteroid Departure Maneuver is commanded on March 4, 2021, sending OSIRIS-REx on a ballistic return cruise to Earth. No additional large deterministic maneuvers are required to return the SRC to Earth. During the cruise, tracking and trajectory correction maneuvers (TCMs) are performed as necessary to precisely target the entry corridor. As OSIRIS-REx approaches Earth, the reentry plans are reviewed starting about a year before arrival, and preparations begin. The spacecraft is targeted away from the Earth until 7 days before entry. The final two trajectory correction maneuvers bring the spacecraft on target toward the Utah Test and Training Range (UTTR), with sufficient time for contingency resolution. The SRC releases 4 hours prior to atmospheric entry interface and, using the Stardust capsule heritage design, employs a traditional drogue and main parachute descent system for a soft touchdown. © 2015 IEEE.