Books & Reports torque applied to the rocket due to SRB of freedom of the lens. The cell is placed Silicon-Germanium Voltage- nozzle movement. For calculation of in- onto a 3/8-in. (≈ 9-mm) ball bearing in Controlled Oscillator at ternal ballistics, Coriolis force, and the base of the housing, which provides 105 GHz torque computations, MATLAB soft- a pivot point for the rotations, and al- A group at UCLA, in collaboration ware was used. lows slight xand ytranslations (microns) with the Jet Propulsion Laboratory, has Coriolis force and torque were calcu- by allowing the cell to slide against it. designed a voltage-controlled oscillator lated and applied to Ares-1 during its as- Rotations are accomplished by 5 com- (VCO) created specifically for a com- cent. Two cases were considered: Corio- mercial picomotors that push on the cell pact, integrated, electronically tunable lis force and torque applied to the in 30-nanometer increments. Spring frequency generator useable for submil- rocket originating from gas movement plungers on the opposite side of the cell limeter-wave science instruments operat- in SRB, and Coriolis force and torque from the picomotors secure the cell in ing in extreme cold environments. The originating from exhaust gas movement the housing. VCO makes use of SiGe heterojunction in SRB nozzle. Coriolis force and torque The 410 stainless steel is used for the bipolar transistors (HBTs). The SiGe are the largest during the first 20 sec- cell, baseplate, and rails because it has a HBTs have a 0.13-micrometer emitter onds after the launch when rocket angu- low CTE (coefficient of thermal expan- width. A differential design was used lar velocity is large. SRB Coriolis force is sion) relative to most other metals. It is with two VCOs connected to form a about 5.4 times larger than nozzle Cori- used exclusively in the “growth path” of quadrature signal. A 2.5-V supply is re- olis force, and SRB Coriolis torque is the optical assembly so that when bulk quired to power the circuit. A cross-cou- about 2.8 times larger than the nozzle temperature changes occur in the lab, pled CMOS pair is used for emitter-de- Coriolis torque at the time t=10 seconds. the lenses will move a consistent amount generation of the SiGe HBTs, and the The inclusion of flexible rocket model apart from each other (which is a less design uses coupled load and base in- does not provide a significant change to sensitive factor in alignment), but will ductors. The circuit oscillates at 105 the results of Coriolis force and torque not tilt or rotate (alignment is very sensi- GHz. A linear superposition of VCOs has computations in comparison with a rigid tive to rotations). been designed to achieve four times the rocket model. This work was done by David W. Robinson oscillation frequency of the fundamen- This work was done by Ryan M. Mackey of Goddard Space Flight Center. Further infor- tal oscillator. and Igor K. Kulikov of Caltech; Vadim mation is contained in a TSP (see page 1). This work was done by Alden Wong, Tim Smelyanskiy and Dmitry Luchinsky of Ames GSC 15790-1 Larocca, and M. Frank Chang of UCLA , and Research Center; and Jeb Orr of BD Systems Lorene A. Samoska of Caltech for NASA’s Jet Inc. for NASA’s Jet Propulsion Laboratory. Propulsion Laboratory. Further information is Further information is contained in a TSP High-Precision Pulse contained in a TSP (see page 1).NPO-47116 (see page 1). Generator The software used in this innovation is A document discusses a pulse genera- available for commercial licensing. Please con- tor with subnanosecond resolution im- Estimation of Coriolis Force tact Daniel Broderick of the California Insti- plemented with a low-cost field-pro- and Torque Acting on Ares-1 tute of Technology at [email protected]. grammable gate array (FPGA) at low A document describes work on the ori- Refer to NPO-47326. power levels. The method used exploits gin of Coriolis force and estimating Cori- the fast carry chains of certain FPGAs. olis force and torque applied to the Ares- Prototypes have been built and tested in 1 vehicle during its ascent, based on an Null Lens Assembly for both Actel AX and Xilinx Virtex 4 tech- internal ballistics model for a multi-seg- X-Ray Mirror Segments nologies. In-flight calibration or control mented solid rocket booster (SRB). A document discusses a null lens as- can be performed by using a similar and The work estimates Coriolis force sembly that allows laser interferometry related technique as a time interval and torque applied to the vehicle dur- of 60° slumped glass mirror segments measurement circuit by measuring a pe- ing its ascent. Maveric flight simulation used in x-ray mirrors. The assembly riod of the stable oscillator, as the delays software was used to produce the re- consists of four lenses in precise align- through the fast carry chains will vary as quired angular velocity data for the ment to each other, with incorporated a result of manufacturing variances as Coriolis force and torque computa- piezoelectric nanometer stepping actu- well as the result of environmental con- tions. For the simulation of gas move- ators to position the lenses in six de- ditions (voltage, aging, temperature, ment in SRB, software was developed grees of freedom for positioning rela- and radiation). using a dynamical model of internal tive to each other. This work was done by Richard Katz and ballistics of the five-segmented SRB. Each lens is first installed and epoxied Igor Kleyner of Goddard Space Flight Center. Also included in the work are a study into a 410 stainless steel “cell.” The outer Further information is contained in a TSP and estimate of Coriolis force and housing is designed to allow five degrees (see page 1).GSC- 15831-1 NASA Tech Briefs, January 2011 41