The Pioneer 10/11 spacecraft yielded the most precise navigation in deep space to date. However, their radiometric tracking data has consistently indicated the presence of a small, anomalous, Doppler frequency drift. The drift is a blue shift, uniformly changing with a rate of ~6 × 10-9 Hz/s and can be interpreted as a constant sunward acceleration of each particular spacecraft of aP = (8.74±1.33) × 10-10 m/s 2 (or, alternatively, a time acceleration of at = (2.92±0.44) × 10-18 s/s 2). This signal has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. We discuss the current state of the efforts to retrieve the entire data sets of the Pioneer 10 and 11 radiometric Doppler data. We also report on the availability of recently recovered telemetry files that may be used to reconstruct the engineering history of both spacecraft using original project documentation and newly developed software tools. We discuss possible ways to further investigate the discovered effect using these telemetry files in conjunction with the analysis of the much extended Pioneer Doppler data. In preparation for this new upcoming investigation, we summarize the current knowledge of the Pioneer anomaly and review some of the mechanisms proposed for its explanation. We emphasize the main objectives of this new study, namely (i) analysis of the early data that could yield the true direction of the anomaly and thus, its origin, (ii) analysis of planetary encounters, which should say more about the onset of the anomaly (e.g. Pioneer 11's Saturn flyby), (iii) analysis of the entire dataset, which should lead to a better determination of the temporal behavior of the anomaly, (iv) comparative analysis of individual anomalous accelerations for the two Pioneers with the data taken from similar heliocentric distances, (v) the detailed study of on-board systematics, and (vi) development of a thermal-electric-dynamical model using on-board telemetry. The outlined strategy may allow for a higher accuracy solution for the anomalous acceleration of the Pioneer spacecraft and, possibly, will lead to an unambiguous determination of the origin of the Pioneer anomaly.

A randomized parallel-group comparative trial with a 1-year follow-up period was performed. To compare the effect of a comprehensive functional restoration program involving intensive physical training, ergonomic training, and behavioral support (39 hours per week for 3 weeks) with the effect of outpatient intensive physical training (1.5 hours three times per week for 8 weeks). Nonrandomized studies conducted in the United States favor functional restoration for patients with chronic low back pain. Two previously reported randomized studies from the authors' Back Center in Copenhagen concur with this recommendation, although the positive effects in one of the studies had faded out after 2 years. Randomized functional restoration studies in Canada and Finland have failed to demonstrate any substantive effect. Initially, 138 patients with chronic low back pain were included in the current study. They then were randomized to either functional restoration (n = 64) or outpatient intensive physical training (n = 74). Of the initial 138 patients, 11 never started (5 and 6, respectively); 21 dropped out during treatment (8 and 13); and 7 of the graduates did not take part in the 1-year follow-up evaluation (3 and 4). The conclusions were drawn from the 99 patients (48 and 51, respectively) who graduated and participated in a 1-year follow-up evaluation. The median age of the patients was 42 years (range, 21-55 years) The female-to-male ratio was 68 to 31, and the median sick leave days during the preceding 3 years was 180 (range, 0-1080 days). The average back pain was rated 5.5 on a scale of 0 (no pain) to 10 (maximal pain). For these variables, there were no important differences between the groups. However, the functional restoration group tended to be more capable of work at baseline (58% vs 42%; P = 0.09). At the 1-year follow-up evaluation, overall assessment favored functional restoration. Otherwise, no significant differences were observed regarding work capability, sick leave for those at work, health care contacts,back pain, leg pain, or self-reported activities of daily living. Only in terms of overall assessment, the functional restoration program was superior to a comparatively short time-consuming outpatient physical training program. It may be that lower economic benefits during sick leave in the United States lead to favorable results from functional restoration programs, whereas greater benefits in Canada, Finland, and Denmark result in different conclusions. Finally, it may be that the difference in results across studies points simply to whether the studies were randomized.

Interior furnishings are consumer products found in various occupancies. They include furniture, bedding, curtains and drapes, surface finishes (wall, ceiling and floor coverings), and cabinetry. Among the features they have in common is the fact that they are rarely a single material, but that they generally involve various layers. This characteristic is important because it explains why testing of their individual components usually does not give adequate answers. A survey of the development of such fire tests, and of the present status, is presented here. Special focus will be placed on upholstered furniture tests. The flammability of upholstered furniture has been under a microscope since it was first discovered to be an important issue, in the late 1960s and early 1970s. However, relatively few tests have been developed and standardized, either in the United States or in other countries. The initial focus was on cigarette ignition and on component testing, resulting in tests such as the NBS mockups and the UFAC test (ASTM E 1352 or NFPA 261 and ASTM E 1353 or NFPA 262, respectively). This was followed by testing of entire chairs with cigarettes (CA TB 116). Eventually, composite component testing with small flames started, pioneered by British standard BS 5852. Parallel to this, material testing continued, using a variety of mostly small-scale tests (the most frequently used tests being CS 191-53 and CA TB 117). In the mid 1980s, tests started to appear for the flaming behavior of complete upholstered furniture items, CA TB 133 being among the most notable ones. The fire community has now understood that the most important fire property is the heat release rate, and this has been incorporated into contents and furnishings tests, as in ASTM E 1537. The next step is the attempt to predict the results of such tests with bench-scale heat release tests and fire models. This work is still in progress. Fire tests for other interior furnishings have also undergone a complex history, which is reviewed. Tests for the different products are in various stages of development. It would appear that the fire testing of furnishings and contents in the future will entail mostly finished products and heat release equipment. A flurry of activity is characterizing the present emphasis on furnishings. Moreover, the majority of the new tests being developed generate results that can be used as input for models to carry out fire hazard or fire risk assessments.

After the ASTM fire policy was first adopted in 1973, it was established that committee E5 would be responsible for developing fire hazard assessment and fire risk as- sessment standards. Since fire hazard is directly related to the type of occupancy involved, it was quickly recognized that a practice needed to use different criteria depending on the occupancy. Thus, a set of 23 occupancies was developed. The associated hazards were weighted based on empirical hazard ratings associated with issues such as (1) presence or absence of detection or suppression systems or both; (2) factors based on the fire, the occupants, or the type of ignition; and (3) the area available per occupant. A modified Delphi approach was used, based on ASTM committee members, to develop the numerical output. The result was a standard practice originally entitled “Assessment of Fire Risk by Occupancy Classification,” which was published as ASTM E 931, in 1985. This standard was generated well before proper techniques existed to carry out fire hazard or fire risk assessments. The technology of fire hazard and fire risk assessment has since become more quantitative, and subjective assessments now have insufficient validity. ASTM E5 has also now developed a standard guide for development of fire hazard assessment stan- dards, ASTM E 1546. The definitions of fire hazard and fire risk used by the fire science community have been improved, so that the real focus of the standard was discovered to have been fire hazard, rather than fire risk. Finally, it was discovered that there had been some transcription errors between the values calculated for ASTM E 931 and those actually printed in the standard. An attempt was made to correct the mislabeling (by replacing fire hazard for fire risk) to include the corrected tables and figures and thus develop a modified standard. This was rejected in June 1992 by ASTM subcommittee E5.15, even as an interim measure. A new standard practice, bearing the number ASTM E 931 and entitled “Classification of Occupancies for Their Relative Fire Hazard” will soon be published excluding all numerical values. Building codes and insurance companies often use occupancy classifications in order to compare the different threats to life or property inherent in the occupancy itself. Such codes control the use of materials, products, or assemblies in buildings. However, they often do not specifically address the potential threat posed by those furnishings or contents brought in by the consumer. The empirical practice described contains guidelines for rating the response of occupancies to a fire on the basis of the predicted threat to life. Thus, this paper was written to aid such potential users by ensuring ASTM archival maintenance of the correct results of the original work, which has had wide empirical use, rather than because the numbers have rigorous validity.

Approximately three minutes after the magnitude 7.4 Landers mainshock on 28 June 1992, a M5.7 aftershock occurred south of the mainshock epicenter, with a location of 34° 7.65′N, 116° 23.82′W. This aftershock was recorded on an array of portable digital seismic instruments deployed in Morongo Valley, 21 km southwest of the event. Although peak accelerations are found to differ by approximately 50% at stations with similar general site conditions within 500 m of each other, there is good coherence of arrivals across the array for frequencies ≤1 Hz. We use the recordings to determine the apparent phase velocity and azimuth of propagation across the array, and show that the event clearly ruptured to the south, with a rupture length of ∼11 km and a rupture velocity of approximately 3.0 km/s. Our results suggest that at least some of the mapped surface rupture south of the town of Yucca Valley (∼11 km in extent; maximum displacement of 20 cm) may have been associated with this aftershock. If this is the case, then the fault that produced the southern end of the Landers mainshock (the Johnson Valley fault) need not continue at depth across the active left‐lateral, east‐west trending Pinto Mountain fault.

Selecting an appropriate quantization table for Joint Photographic Exploitation Group (JPEG) data compression of a class of images can be an arduous task. We have designed a graphical user interface to study the effects of quantization on compression ratio and the resulting image quality. The tool calculates several measures of the difference between the original and lossy compressed image. Some of these measures are entropy, mean square error, and normalized mean square error. These measures aid the user in selecting the optimal quantization values with respect to image fidelity and compression ratio for a particular class of images.

The Navy Navigation Satellite System (NNSS) uses precision quartz crystal oscillators to provide time and frequency in the orbiting spacecraft. The frequency changes for multiple oscillators, which were observed for 28 years of operational service in the orbital environment, are discussed. The primary frequency changes are believed to be caused by mass transfer to and from the resonator, stress relief in the resonator mounting structure and electrodes, and ionizing radiation of the quartz resonator. Observations to a resolution of 10- 13 have been made from 1963 to 1991 on 20 operational satellites in near-Earth orbit. No oscillator failures have occurred during the entire program life of nearly 30 years. One oscillator provided continuous operational service for over 21 years, and several have served more than 15 years. No oscillator changed frequency more than two parts in 107 while in operational service. One of the best performing oscillators had a predictable drift rate of 9x10(-13)+/-1x10(-13) per day after three years of service.

Abstract The High Temperature Superconductivity Space Experiment (HTSSE) program, initiated by the Naval Research Laboratory (NRL) in 1988, is described. The HTSSE program focuses high temperature superconductor (HTS) technology applications on space systems. The program phases, goals and objectives are discussed. The devices developed for this program and their suppliers are enumerated. For HTSSE-I, 15 space-qualified, passive microwave devices were integrated onto a cryogenic cold bus as an experimental payload on a DoD spacecraft. The experiment payload and scientific data measurements systems, designed, developed, and built by NRL, are described.

Since its launch in February 1990, the Low-Power Atmospheric Compensation Experiment (LACE) satellite has been used as a space-based platform from which numerous observations have been carried out using the onboard Ultraviolet Plume Instrument (UVPI). UVPI consists of two pointable, co-aligned, intensified charged-coupled-device (ICCD) cameras sharing a common telescope mount. The instrument has obtained high spatial resolution near-UV/visible images of rocket plumes, and has observed aurorae, the Earth's limb, and other features of the Earth background. A description of the instrument, the data gathered, and some selected results are presented.