This report describes what an HST observer must do to activate a Target of Opportunity proposal and the steps taken by STScI after the request is received. ... In the request the PI identifies which visit (or visits) to activate and supplies all the information needed to implement and schedule the observation on-board HST. ... If the activation request is not approved, you may re-request it at a later time, until the end of the observing cycle when unexecuted ToO observations are withdrawn. ...

... The science from both these missions contributed to three of the Nobel Prizes ­ Giacconi (2002), Mather, and Smoot (2006) - awarded for NASA-based science. ... We encourage NASA to seek new launch capabilities to fill this strategic gap in moderate lift rockets to enable the Explorer program to continue launching missions with significant science payoff but reduced costs and timescales compared to large strategic missions. ... 18 Appendix B: Explorer Missions 1989-present (From PILMSS) No . ...

ST-ECF Instrument Science Report ACS-2006-03 Wavelength and Flux calibration of the ACS/HRC PR200L prism S. S. Larsen, J. Walsh and M. KЭmmel, March 2006 ABSTRACT Wavelength- and flux calibrations are presented for the ACS/HRC PR200L slitless spectroscopy mode. ... Wavelength solutions for the PR200L prism. ... Wavelength. ... 12 ST-ECF Instrument Science Report ACS-2006-03 Figure 7: Comparison of the aXe-extracted prism spectra of the two flux standards with the reference spectra. ...

... 70 · Winter 2007 www.astrosociety.org/uitc © 2007, Astronomical Society of the Pacific 390 Ashton Avenue, San Francisco, CA 94112 Hubble Observations of Ceres and Pluto: A Closer Look at the "Ugly Ducklings" of the Solar System by Max Mutchler Space Telescope Science Institute Introduction regret that my 4th Grade teacher, Mrs. Hadley, doesn't know that she provided me with the very first astronomy book that I ever read, because it had a profound impact on me. ... Planet count 7 6 7 11 12 13 8 9 9? ...