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Dallmann, Nicholas

Publications and source records attributed to Dallmann, Nicholas.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

System for multiple burns from a rocket motor

A system for multiple burns from a solid fuel rocket motor may extinguish rocket fuel after the rocket has been ignited. The motor may be extinguished via rapid decompression of the combustion chamber. The fuel may then be reignited by a suitable igniter, and the process of extinguishing and reigniting may be repeated, enabling multi-burn maneuvers. A decompressive extinguishing plug nozzle may extinguish solid rocket fuel after the rocket has been ignited and/or keep a rocket in a disarmed (zero thrust) state until the rocket is to be armed. The nozzle may include a plug that mostly impedes the opening of the nozzle and an outer cowl that is movable to rapidly decompress the combustion chamber. This rapid decompression extinguishes the solid rocket fuel. In some aspects, the fuel can be reignited and extinguished multiple times.

Dallmann, Nicholas↗
DOE OSTI2023

Streaming authentication and multi-level security for communications networks using quantum cryptography

Message authenticators for quantum-secured communications facilitate low-latency authentication with assurances of security. Low-latency message authenticators are especially valuable in infrastructure systems where security and latency constraints are difficult to satisfy with conventional non-quantum cryptography. For example, a message transmitter receives a message and derives an authentication tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message transmitter outputs the message and its authentication tag. A message receiver receives a message and authentication tag for the message. The message receiver derives a comparison tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message receiver checks whether the message is authentic based on a comparison of the authentication tag and the comparison tag. In example implementations, the authenticator uses stream-wise cyclic redundancy code operations.

Hughes, Richard J.↗
DOE OSTI2023

Energy Characterization of the UMD Electron Accelerator

Multiple different groups at Los Alamos National Laboratory have a cited interest in understanding the effects of ionizing radiation in materials. Of especial interest to the ISR division is understanding the effects in materials that are used in the space environment, where radiation is omnipresent and impossible to fully shield from. Development is under way to simulate the effects of radiation damage in detectors and electronics, primarily with particle transport codes such as Geant4 and RAMPART, a code that provides a user friendly interface to Geant4. However, these simulations need benchmarking to experimental tests, some of which have been performed at a variety of small electron accelerator facilities. One of these facilities is the Linear Electron Accelerator at the University of Maryland Radiation Facilities. This facility can provide electron beams on the order of 100 mA delivered in tight macropulse bunches, which allows for experiments where the behavior of electronics is monitored as a function of pulse number. While the beam rates per macropulse of this accelerator is monitored during an experiment via a current pick-off connected to a large graphite beamstop, the energy distribution of this electron beam is not measured during the experiment and has not been well characterized. The energy distribution of the beam is pertinent for these types of experiments, since dose is directly related to energy deposited in a medium. Further, these experiments are performed in open air and sample placement in the room can dictate what dose rate they receive per macropulse. We have created simulated dosemaps for the UMD vault room, but these simulations assume a given energy of the beam, both for calculating the dose and to simulate how much the beam diverges in the air. There have been two attempts now to characterize this accelerator beam energy with a plate type spectrometer, including the most recent experiment earlier this year to quantify the beam energy distribution. These results will also be compared to a dosimetry experiment performed by collaborators at the UMD facility, the details of which are described in Reference. Understanding the electron beam energy is important for future experiments, because the energy directly impacts the dose and radiation damage given to a sample and is important for properly simulating the electron beam when comparing simulation to experiment.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Space-based quantum networks are an essential component of future architecture for distributed quantum computers and quantum-enhanced secure communication

Space-based quantum links show great promise for connecting and communicating between quantum computers over ultra-long distances without the high loss incurred through fiber. A successful US quantum satellite would require large investment, national priority, and a diverse set of expertise. But, it would deliver US-owned quantum links that would allow for quantum-enhanced secure communications and the ability to connect quantum computers over long distances.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

Tag that enhances vehicle radar visibility of objects

A tag enhances vehicle radar visibility of objects by increasing the effective radar cross-section of the object, allowing detection at longer ranges and providing the vehicle/driver with more time to avoid a collision. The tag may include a receive antenna and a bandpass filter configured to receive a signal from the receive antenna and to allow a portion of the frequency range of the signal from the receive antenna through. The tag may also include an amplifier configured to receive and amplify the signal with the portion of the frequency range from the bandpass filter. The tag may further include a transmit antenna configured to transmit the amplified signal. The receive antenna, the transmit antenna, and the amplifier may be configured such that antenna-to-antenna isolation between the receive antenna and the transmit antenna is greater than a gain of the amplifier.

42 ENGINEERING↗
DOE OSTI2021

Space vehicle system and payload interposer (PIP) board

A payload interposer (PIP) board provides an interface for hosting payloads on a space vehicle platform. Payload development may be performed via the PIP board in a manner that “abstracts” the hardware of the space vehicle from the payload developer. The PIP board may include a host side payload interface connector that connects to a space vehicle and a payload side payload interface connector that connects to a payload. Power, CDH, and other space vehicle functionality may thus be provided to the payload from the space vehicle via the PIP board.

Proicou, Michael↗
DOE OSTI2021

Vehicle Tracking

The detection and tracking of vehicles moving at hypersonic speeds (> Mach 5) at altitudes of ~100 km has been of growing interest due to the ongoing development of hypersonic glide vehicles (HGVs) by the U.S., Russia and China. This challenge is notably different from traditional ballistic missile systems whose re-entry vehicles move at hypersonic velocities but at much higher altitudes on a ballistic course. Hypersonic glide vehicles are also designed to be able to make sudden turns along their flight path making prediction of their trajectories difficult. Their ability to maneuver, combined with their high velocity and altitude make them difficult to track. The combination of these characteristics presents a challenge for anyone attempting to defend against a hypersonic glide vehicle attack by generally shortening the time available to react. That reaction can involve moving potential targets or attempting to detect the hypersonic glide vehicle and intercept it before it reaches the intended target. Figure 1 compares the trajectory of hypersonic vehicles compared to that of a traditional ballistic missile.

42 ENGINEERING↗
DOE OSTI2021

Compact star-field sensor (SFS)

A compact SFS may can be deployed in small space vehicles. The SFS may have a small size, weight, and low power requirements. The hardware, software, catalogs, and calibration algorithm of the SFS provide highly accurate attitude information that can be used for pointing. For instance, accurate attitude determination may be provided that supports pointing of a deployable high gain helical antenna. A full “lost in space” attitude solution, accurate to about an arcminute, may be accomplished in under a minute. The SFS may be fully reprogrammable on orbit, allowing continued algorithm development and deployment after launch.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

Cubesat system

Small cubesat systems may be available for a lower cost, have a higher reliability, and be much simpler to use than conventional cubesats. A complete turnkey system solution may be provided, including the ground station and remote field units. The satellite, ground station, and field unit may be provided separately as kits that are ready to go out-of-the-box as soon as they arrive. This enables universities, researchers, and hobbyists to obtain and deploy their own functional satellites. Furthermore, theoretical designs and functionality may be rapidly prototyped and demonstrated, which allows for proof-of-concept without needing to build a larger, more expensive satellite system and hope that the new design or functionality works as intended.

Judd, Stephen↗
DOE OSTI2021

Space vehicle with customizable payload and docking station

A “black box” space vehicle solution may allow a payload developer to define the mission space and provide mission hardware within a predetermined volume and with predetermined connectivity. Components such as the power module, radios and boards, attitude determination and control system (ADCS), command and data handling (C&DH), etc. may all be provided as part of a “stock” (i.e., core) space vehicle. The payload provided by the payload developer may be plugged into the space vehicle payload section, tested, and launched without custom development of core space vehicle components by the payload developer. A docking station may facilitate convenient development and testing of the space vehicle while reducing handling thereof.

Judd, Stephen↗
DOE OSTI2020

Payload interposer (PIP) system and control software

A payload interposer (PIP) system and its control software provide an interface between a space vehicle and a payload. The PIP board facilitates power and communications between a command and data handler (CDH) of the space vehicle and the payload. A microcontroller of the PIP board may control operation of the payload, format messages between the space vehicle and the payload, and extract data from the payload for downlink via the space vehicle.

42 ENGINEERING↗
DOE OSTI2020

Streaming authentication and multi-level security for communications networks using quantum cryptography

Message authenticators for quantum-secured communications facilitate low-latency authentication with assurances of security. Low-latency message authenticators are especially valuable in infrastructure systems where security and latency constraints are difficult to satisfy with conventional non-quantum cryptography. For example, a message transmitter receives a message and derives an authentication tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message transmitter outputs the message and its authentication tag. A message receiver receives a message and authentication tag for the message. The message receiver derives a comparison tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message receiver checks whether the message is authentic based on a comparison of the authentication tag and the comparison tag. In example implementations, the authenticator uses stream-wise cyclic redundancy code operations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Modular space vehicle boards, control software, reprogramming, and failure recovery

A space vehicle may have a modular board configuration that commonly uses some or all components and a common operating system for at least some of the boards. Each modular board may have its own dedicated processing, and processing loads may be distributed. The space vehicle may be reprogrammable, and may be launched without code that enables all functionality and/or components. Code errors may be detected and the space vehicle may be reset to a working code version to prevent system failure.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Compact readout of large CLYC scintillators with silicon photomultipler arrays

Compact readout of a large (5 x 5 x 5 cm 3) CLYC scintillator was demonstrated with a 8 x 8 array of 6mm silicon photomultipliers (SiPMs, specifically, a SensL ArrayJ-60035-64P) and an optimized amplification and summing circuit. Read out by the SiPM array, the crystal yielded an energy resolution of 5.5% at 662 keV and a figure of merit of 3.5, equivalent to the performance achieved with a 3-inch Hamamatsu R6233-100 PMT. To reduce channel count and avoid individual amplification of each SiPM in the array, the standard outputs of 16 SiPMs were passively summed then amplified. A current feedback amplifier was used for each channel to provide the required fast response time. The four amplified channels were then passively summed resulting in a single signal channel. A custom laboratory setup, based on the PSD8C ASIC, was used to capture the output and provide time-gated integration for PSD computation. We conclude the compact volume, low bias voltage, and reduced mass of the SiPM array readout are desirable for space and national security applications.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Attitude determination and control system (ADCS), sun sensor, and star tracker

An ADCS module may be configured to use coordinate data from 2D photodiodes in one or more sun sensors to determine a sun vector. The ADCS module may then use the sun vector in reference to its own body faced (BF) coordinate system to calculate a change in the orientation of the space vehicle. The change in orientation mechanism may be accomplished by reaction wheels, ion thrusters, or other orientation altering mechanisms. A miniature, intelligent star tracker may be included that improves satellite attitude determination and pointing accuracy. An improved reaction wheel assembly may be included that is more robust and suitable for inclusion in small space vehicles.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Space vehicle chassis

A modular space vehicle chassis may facilitate convenient access to internal components of the space vehicle. Each module may be removable from the others such that each module may be worked on individually. Multiple panels of at least one of the modules may swing open or otherwise be removable, exposing large portions of the internal components of the space vehicle. Such chassis architectures may reduce the time required for and difficulty of performing maintenance or modifications, may allow multiple space vehicles to take advantage of a common chassis design, and may further allow for highly customizable space vehicles.

42 ENGINEERING↗