R. B. Perry

Visible and Near-Infrared Spectrophotometry of the Deep Impact Ejecta of Comet 9P/Tempel 1

Abstract We have obtained optical spectrophotometry of the evolution of Comet 9P/Tempel 1 after the impact of the Deep Impact probe, using the Supernova Integral Field Spectrograph (SNIFS) at the UH 2.2-m telescope, as well as simultaneous optical and infrared spectra using the Lick Visible-to-Near-Infrared Imaging Spectrograph (VNIRIS). The spatial distribution and temporal evolution of the “violet band” CN (0–0) emission and of the 630 nm [OI] emission was studied. We found that CN emission centered on the nucleus increased in the 2 h after impact, but that this CN emission was delayed compared to the light curve of dust-scattered sunlight. The CN emission also expanded faster than the cloud of scattering dust. The emission of [OI] at 630 nm rose similarly to the scattered light, but then remained nearly constant for several hours after impact. On the day following the impact, both CN and [OI] emission concentrated on the comet nucleus had returned nearly to pre-impact levels. We have also searched for differences in the scattering properties of the dust ejected by the impact compared to the dust released under normal conditions. Compared to the pre-impact state of the comet, we find evidence that the color of the comet was slightly bluer during the post-impact rise in brightness. Long after the impact, in the following nights, the comet colors returned to their pre-impact values. This can be explained by postulating a change to a smaller particle size distribution in the ejecta cloud, in agreement with the findings from mid-infrared observations, or by postulating a large fraction of clean ice particles, or by a combination of these two.

Preference and operational acceptability of Flightdeck Interval Management avionics

This study investigated the relative acceptance of different avionics implementations that present Flightdeck Interval Management (FIM) speeds and speed deviations to commercial pilots, and for indications of conditions that require action. Results indicate a clear preference for an Avionics condition where target speed information was provided in the primary flight display, relevant traffic information was provided in the navigational display, IM clearance information and conformance information was provided in the Multi-function Control Display Unit (MCDU), and the engine-indicating and crew-alerting system (EICAS) display showed conformance deviation alerts; and a condition in which all this information was presented only in an Electronic Flight Bag (EFB)-like display (with extended functionality) implemented under the side window for both pilots. Other Avionics conditions tested were less desirable. These were conditions in which the EFB was mounted aft of, and below the side window - with and without an auxiliary display that repeated speed target and conformance information in the primary field of view. Results also indicate a preference for aural indications to direct attention to new speed targets, as a reminder to enter these when not done in a timely manner, and to convey when the aircraft has deviated significantly from the calculated FIM speed profile. The aural indications, thresholds for reminders and conformance indications used in this study were found to be appropriate. In general FIM, as implemented in this study, was perceived as having no deleterious effect on workload or crew coordination; and, under some conditions, was reported to have improved situation awareness of arrival speeds and general conditions during approach and descent.

Technology development for NASA science missions: Challenges and potential opportunities

NASA has made tremendous progress in addressing critical questions about our solar system but often the knowledge gained raises new and more challenging questions. Future robotic space missions need to be endowed with more capable instruments, spacecraft subsystems and ground support to answer the new and more difficult questions that lay before us. Developing future instrument, spacecraft subsystem, or ground support technologies for robotic planetary missions is a complicated and challenging endeavor. Recognizing this, the Planetary Science Division (PSD) in NASAs Science Mission Directorate recently chartered a panel to review its current technology development programs and provide recommendations on process and policy improvements that will enable better utilization of technology resources. This paper discusses the work and findings of that panel, known as the Planetary Science Technology Review (PSTR) panel.