Stardust Entry Reconstruction

An overview of the reconstruction analyses performed for the Stardust capsule entry is described. The results indicate that the actual entry was very close to the pre-entry predictions. The capsule landed 8.1 km north-northwest of the desired target at Utah Test and Training Range. Analyses of infrared video footage and radar range data (obtained from tracking stations) during the descent show that drogue parachute deployment was 4.8 s later than the pre-entry prediction, while main parachute deployment was 19.3 s earlier than the pre-set timer indicating that main deployment was actually triggered by the backup baroswitch. Reconstruction of a best estimated trajectory revealed that the aerodynamic drag experienced by the capsule during hypersonic flight was within 1% of pre-entry predications. Observations of the heatshield support the pre-entry estimates of small hypersonic angles of attack, since there was very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Stardust capsule entry were consistent with flight performance close to nominal pre-entry predictions. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated

Environmental protection requirements for scout/shuttle auxiliary stages

The requirements for enabling the Scout upper stages to endure the expected temperature, mechanical shock, acoustical and mechanical vibration environments during a specified shuttle mission were determined. The study consisted of: determining a shuttle mission trajectory for a 545 kilogram (1200 pound) Scout payload; compilation of shuttle environmental conditions; determining of Scout upper stages environments in shuttle missions; compilation of Scout upper stages environmental qualification criteria and comparison to shuttle mission expected environments; and recommendations for enabling Scout upper stages to endure the exptected shuttle mission environments

Experimental field estimation of organic nitrogen formation in tree canopies

The content of organic N has been shown in many studies to increase during the passage of rain water through forest canopies. The source of this organic N is unknown, but generally assumed to come from canopy processing of wet or dry-deposited inorganic N. There have been very few experimental studies in the field to address the canopy formation or loss of organic N. We report two studies: a Scots pine canopy exposed to ammonia gas, and a Sitka spruce canopy exposed to ammonium and nitrate as wet deposition. In both cases, organic N deposition in throughfall was increased, but only represented a small fraction (<10%) of the additional inorganic N supplied, suggesting a limited capacity for net organic N production, similar in both conifer canopies under Scottish summertime conditions, of less than 1.6 mmol Nm2 mth1 (equivalent to 3 kg N ha1 y1)

Reconstruction of the Genesis Entry

An overview of the reconstruction analyses performed for the Genesis capsule entry is described. The results indicate that the actual entry prior to the drogue deployment failure was very close to the pre-entry predictions. The capsule landed 8.3 km south of the desired target at Utah Test and Training Range. Analysis on infrared video footage (obtained from the tracking stations) during the descent estimated the onset of the capsule tumble at Mach 0.9. Frequency analysis on the infrared video data indicates that the aerodynamics generated for the Genesis capsule reasonably predicted the drag and static stability. Observations of the heatshield support the pre-entry simulation estimates of a small hypersonic angles-of-attack, since there is very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Genesis entry is consistent with flight performance that was close to the nominal preentry prediction. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated

Trajectory Reconstruction for the Genesis Entry

An overview of the reconstruction analyses performed for the Genesis capsule entry is described. The results indicate that the actual entry prior to the drogue deployment failure was very close to the pre-entry predictions. The capsule landed 8.3 km south of the desired target at Utah Test and Training Range. Analysis on infrared video footage (obtained from the tracking stations) during the descent estimated the onset of the capsule tumble at Mach 0.9. Frequency analysis on the infrared video data indicates that the aerodynamics generated for the Genesis capsule reasonably predicted the drag and static stability. Observations of the heatshield support the pre-entry simulation estimates of a small hypersonic angles-of-attack, since there is very little, if any, charring of the shoulder region or the afterbody. Through this investigation, an overall assertion can be made that all the data gathered from the Genesis entry is consistent with flight performance close to the nominal pre-entry prediction. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated

Reconstruction of the Stardust Entry

An overview of the reconstruction analyses performed for the Stardust capsule entry is described. The results indicate that the actual entry was very close to the pre-entry predictions. The capsule landed 8.1 km northwest of the desired target at Utah Test and Training Range. Frequency analysis on the infrared video data indicates that the aerodynamics generated for the Stardust capsule reasonably predicted the drag and static stability. Observations of the heatshield support the pre-entry simulation estimates of a small hypersonic angles-of-attack, since there is very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Stardust entry is consistent with flight performance close to the nominal pre-entry prediction. Consequently, the design principles and methodologies utilized for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated

Field-induced spin density wave in (TMTSF)2_2NO3_3

Interlayer magnetoresistance of the Bechgaard salt (TMTSF)$_2$NO$_3$ is investigated up to 50 teslas under pressures of a few kilobars. This compound, the Fermi surface of which is quasi two-dimensional at low temperature, is a semi metal under pressure. Nevertheless, a field-induced spin density wave is evidenced at 8.5 kbar above $\sim$ 20 T. This state is characterized by a drastically different spectrum of the quantum oscillations compared to the low pressure spin density wave state.Comment: to be published in Phys. Rev. B 71 (2005