Rocket

About: Rocket is a research topic. Over the lifetime, 14018 publications have been published within this topic receiving 95852 citations. The topic is also known as: rockets.

Thermophysical Properties Measurements of Rocket Propellants RP-1 and RP-2

Abstract: The density, speed of sound, and viscosity of two rocket propellants (RP-1 and RP-2) have been measured. Densities were measured with two different instruments. Data at ambient atmospheric pressure were obtained with a rapid characterization instrument from 278.15 to 343.15 K that measured the speed of sound and density of the liquids in parallel. Adiabatic compressibilities derived from that data are included here. Densities of the compressed liquids were measured in an automated apparatus from 270 to 470 K and pressures to 40 MPa. Viscosities of the two liquids were measured in an open gravitational capillary viscometer at ambient atmospheric pressure from 293.15 to 373.15 K. The measurement results are consistent with compositional differences between the two samples. Correlations have been developed to represent the measured properties within the estimated uncertainties of the experimental data and to allow physically meaningful extrapolations beyond the range of the measurements.

Electron Echo Experiment 1: Comparison of observed and theoretical motion of artificially injected electrons in the magnetosphere

Abstract: On August 13, 1970, a sounding rocket launched from Wallops Island, Virginia, was used to successfully inject a controlled beam of energetic electrons into the trapping region of the earth's magnetosphere. The Aerobee 350 rocket carried a high-voltage electron gun, electron detectors, receivers to measure the electric field of waves generated by the experiment, and other apparatus to a peak altitude of 350 km. During a 10-min flight, more than 3000 16-ms-long 70-mA pulses of 35- to 43-keV electrons were injected into the magnetosphere with pitch angles within 25° of the local 90° mirror angle. The electrons, trapped in the geomagnetic field, bounced between the mirror point near the rocket and the southern conjugate point (−66° latitude, −82° longitude) while they were drifting eastward across field lines on a drift shell of constant McIlwain L parameter (2.56) under the gradient and curvature forces. Since Wallops Island conjugate mirror altitudes are at least 300 km lower than the injection altitudes, all returning electrons were backscattered from the atmosphere in the southern hemisphere. The rocket was launched eastward in an attempt to intercept the returning electrons, and for a 90-s interval about L apogee, electrons were detected returning from one, two, and in one case, three complete bounces to the southern hemisphere. The analyzed electron data agree well with echo patterns predicted from theoretical particle motion in models of the geomagnetic field combined with Monte Carlo studies of energy loss and diffusion in the conjugate point atmosphere. Observed bounce times, drift displacements, and cross L diffusion were in substantial agreement with theory. However, the returning flux was lower than predicted, and discrepancies between theory and experiment were observed at large diffusion distances. This experiment, Electron Echo 1, verified the concept of using controlled particle beams as magnetospheric probes, showing that such beams are sufficiently stable to be intercepted after bounces to the conjugate point and back.

The Shefex Flight Experiment - Pathfinder Experiment for a Sky Based Test Facility

Abstract: On Thursday, October 27th, 2005 the SHarp Edge Flight EXperiment SHEFEX has been successfully launched at the Andoya Rocket Range in northern Norway. The project, being performed under responsibility of the German Aerospace Center (DLR) flew on top of a two-stage solid propellant sounding rocket. One purpose of the experiment is the investigation of possible new shapes for future launcher or re-entry vehicles applying a shape with facetted surfaces and sharp edges and to enable the time accurate investi-gation of the flow effects and their structural answer during the hypersonic flight from 90 km down to an altitude of 20 km. Additionally, the SHEFEX project is a starting point for a series of experiments which enable the acquisition of important knowledge in hypersonic free flight experimentation and which are an excellent test bed for new technological concepts. The present paper gives an overview about the philosophy and the layout of ex- periment and introduces preliminary outcomes of the post-flight analysis.