Search results for " Rocket"
showing 10 items of 17 documents
ZERODUR based optical systems for quantum gas experiments in space
2019
Abstract Numerous quantum technologies make use of a microgravity environment e.g. in space. Operating in this extreme environment makes high demands on the experiment and especially the laser system regarding miniaturization and power consumption as well as mechanical and thermal stability. In our systems, optical modules consisting of ZERODUR® based optical benches with free-space optics are combined with fiber components. Suitability of the technology has been demonstrated in the successful sounding rocket missions FOKUS, KALEXUS and MAIUS-1. Here, we report on our toolkit for stable optical benches including mounts, fixed and adjustable mirrors as well as polarization maintaining fiber …
Multistage rocket: integrational design of a prodrug-based siRNA delivery system with sequential release for enhanced antitumor efficacy.
2018
An integrated peptide-camptothecin prodrug (RSC) system was designed as a nano-sized multistage rocket for the efficient complexation and controlled sequential release of siRNA and anticancer drug under tumor-relevant reductive and esterase-enriched conditions, which facilitated the avoidance of negative interactions and maximized the synergistic effect.
Design of a compact diode laser system for dual-species atom interferometry with rubidium and potassium in space
2017
We report on a micro-integrated high power diode laser based system for the MAIUS II/III missions. The laser system features fiber coupled and frequency stabilized external cavity diode lasers (ECDL) for laser cooling, Bose-Einstein condensate (BEC) generation and dual species atom interferometry with rubidium and potassium on board a sounding rocket.
Controllable Solid Rocket Motor Nozzle Operations in Conditions of Limited-Amplitude Fluctuations
2009
A nonlinear multi scale analysis of a controllable solid rocket motor operating in conditions ranging from high-amplitude fluctuations in combustion chamber to conditions lying in limit cycle is presented and the motor behavior subsequent to some relevant nozzle operations is investigated. Effects of acoustic-vorticity-entropy wave coupling, wave steepening, rotational/viscous flow losses, steep-fronted wave losses are taken into account and oscillatory energy losses in pintle-nozzle, unsteady combustion and chamber geometry changes resulting from grain regression are included. The analysis provides evidence that the unsteady energy balance and the motor wave amplitude evolution are influen…
Baseline design of the thermal blocking filters for the X-IFU detector on board ATHENA
2014
ATHENA is an advanced X-ray observatory designed by a large European consortium to address the science theme "Hot and Energetic Universe" recently selected by ESA for L2 – the second Large-class mission within the Cosmic Vision science program (launch scheduled in 2028). One of the key instruments of the mission is the X-ray Integral Field Unit (X-IFU), an array of Transition Edge Sensor (TES) micro-calorimeters with high energy resolution (2.5 eV @ 6 keV) in the energy range 0.2÷12 keV, operating at the focal plane of a large effective area high angular resolution (5" HEW) grazing incidence X-ray telescope. The X-IFU operates at temperatures below 100 mK and thus requires a sophisticated c…
Zvaigžņotā Debess: 2000, Pavasaris (167)
2000
Contents: P.Müürsepp. B.Schmidt, Prominent Optician of 20th Century ; J.Miezis. Buildings on the Moon ; Z.Alksne, A.Alksnis. Stars Enshrouded in Envelopes ; A.Alksnis. Goals and Progress of the DENIS Program ; Z.Alksne. Shapley Supercluster – Playground of Clusters of Galaxies ; A.Alksnis. Wide Field Imager Discovers Distant Galaxies ; J.Jaunbergs. Roton SSTO: First Flight Tests ; M.Gills. Space Research 40 Years Ago – Chronicle ; I.Vilks. The Secret of Low-Probability Complexity in the Universe ; K.Bērziņš. On Friendly Terms with Cosmology: Development of Cosmological Views (concluded) ; A.Balklavs. Astronomy in the Internet (WWW) ; V.Flerov, A.Cēbers. Latvia 23rd Open Olympiad of Physics:…
Thrust Vector Controller Comparison for a Finless Rocket
2023
The paper focuses on comparing applicability, tuning, and performance of different controllers implemented and tested on a finless rocket during its boost phase. The objective was to evaluate the advantages and disadvantages of each controller, such that the most appropriate one would then be developed and implemented in real-time in the finless rocket. The compared controllers were Linear Quadratic Regulator (LQR), Linear Quadratic Gaussian (LQG), and Proportional Integral Derivative (PID). To control the attitude of the rocket, emphasis is given to the Thrust Vector Control (TVC) component (sub-system) through the gimballing of the rocket engine. The launcher is commanded through the cont…
Autonomous frequency stabilization of two extended cavity diode lasers at the potassium wavelength on a sounding rocket
2016
We have developed, assembled, and flight-proven a stable, compact, and autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during a sounding rocket flight by means of frequency modulation spectroscopy (FMS) of 39^K and offset locking techniques based on the beat note of the two ECDLs. The frequency stabilization as well as additional hard- and software to test hot redundancy mechanisms were implemented as part of a state-machine, which controlled the experiment completely autonomously throughout the entire flight mission.
Optical frequency combs for space applications
2016
Optical frequency comb-based high resolution laser spectroscopy has been demonstrated in space under micro-gravity on two sounding rocket based experiments. The comb has been used to simultaneously measure two different atomic transitions.
Controllable Solid Propellant Rocket Motor Stability: Deep and Rapid Variable Thrust Operations
2008
When flow and combustion processes couple with the acoustic modes of the combustion chamber, the solid rocket motors experience unsteady gas motion and associated thrust oscillation and motor vibration. The operations of the variable nozzle introduce relevant dynamic changes in the chamber flow and combustion. This article proposes a non-linear approach for the analysis of the effects of severe nozzle manoeuvres on the controllable solid rocket motor stability and provides the evidence that the acoustic wave amplitude evolution is influenced by the nozzle manoeuvre severity, shape and direction. The additional complexity in the problem of the combustion stability analysis introduced by the …