Miniaturization and integration of accelerometers in standard integrated circuit (IC) processes has been the topic of extensive research. In most cases, accelerometer structures involve a solid proof mass that is allowed to move under accelerating conditions. This approach has many disadvantages....

NASA's Jet Propulsion Laboratory has developed a Hall thruster with a variable-area discharge chamber that improves the performance and lifetime of the thruster. Conventional Hall thrusters have poor ionization efficiency, which limits the thrust-to-power ratio...

Microprocessor-controlled exercise equipment that uses a servomotor has the capability to adjust the applied resistive load based on position, velocity, and acceleration. One method of applying the resistive load consists of applying a greater...

This technology allows one to test small-body surface mobility and sampling systems in the laboratory. It is capable of simulating a microgravity environment with relevant terrain. The magnitude of the gravity, the terrain properties, and the surface system being tested are all easily modified to allow for a broad range of...

There is an association between High-Intensity Long-Duration Continuous AE (HILDCAA) activity intervals and the acceleration of relativistic >1 MeV electrons in the magnetosphere. All of the HILDCAAs that occurred in solar cycle 23 (SC23) from 1995 to 2008 led to the acceleration of...

A general problem in spaceflight since its beginning is attitude guidance: how to turn a spacecraft — also called a slew — so as to point science instruments at their targets. The slew must be done while avoiding pointing sensitive science instruments (e.g., a...

The Magnetospheric Multiscale (MMS) mission is the fourth mission of the Solar Terrestrial Probes (STP) program. The MMS mission, consisting of four identically instrumented spacecraft, will use Earth’s magnetosphere as a laboratory to study magnetic reconnection, a...

Historically, parachutes have been load-tested by various methods including release from an aircraft, deploying in a wind tunnel, dragging through water, and shooting out of an air cannon. Each type of testing has its own advantages and drawbacks. Due to the loading mechanics particular to parachutes...

AJava software program was developed that provides a solar system simulation, demonstrating the application of calculus to understanding and modeling how the real universe operates. The program can be modified by the user to study various changes in physical properties, and software...

Typical spacecraft thruster configurations are often unable to provide full six-degree-of-freedom control and may have unwanted interaction between their attitude control and trajectory control functions, have undesirably high instantaneous electrical power demands, and use more thrusters...

This technique for compensating the gravitational attraction experienced by a test-mass freely floating onboard a satellite is new, and solves an important problem that all gravitational wave missions face. Its application to the geostationary Laser Interferometer Space Antenna (gLISA) mission concept...

A variable acceleration calibration system combines an innovative mechanical system and a statistical design of experiments to calibrate multi-axis force transducers. This system can reduce calibration time, allow for improved calibration of large-scale transducers, provide mobility for on-site...

Given the increased availability of small satellite opportunities either through CubeSats or the Air Force’s University Nanosat program, and the limited availability of larger platforms, it is challenging to develop new instrumentation that not only fits within the envelope of small...

Commercially available components are integrated into an assembly that can be used to measure the slosh dynamics of cryogenic liquids. The apparatus consists of a linear motion table that is properly instrumented to record high fidelity position, force, and acceleration measurements of all linear and rotation responses...

A prototype horizontal electromagnetic rail launcher has been demonstrated along with a corresponding theory. This system builds out of published work in augmented rail guns, but modifies this technology so that the motor can operate for seconds rather than...

Some vehicles use an internal measurement unit (IMU) system to determine the speed, acceleration, orientation, position, and/or direction of movement of the vehicle. Vehicles used for high-availability or life-critical systems may employ a fault-tolerant IMU design. Typically, such vehicles use three or more IMUs...