Launch visibility update from the LCROSS Flight Director's Blog Kaf Note: The flight director's comments regarding Perth, Australia as being favored for the initial launch track discusses only the first few hours of flight and not the subsequent trans lunar orbit trajectory through flight hour 30. Generate a Horizons ephemeris for an extended prediction across several days. The LCROSS-Centaur may be visible for up to the first 30 hours of its outbound flight by scopes of 10-12 inches of aperture. Source: http://wiki.nasa.gov/cm/blog/lcrossfdblog LCROSS Flight Director Paul D. Tompkins Posted on Jun 18, 2009 02:21:32 AM Paul.D Tompkins ============================= <snip> 3. Finally, one of my readers suggested a really great idea. He wanted to know if our Centaur would be venting gas as part of its sequence. The reason he asked is that under the right lighting conditions, the sunlight high above Earth can actually illuminate the vented gases, making them visible from the ground. He said he was able to observe this effect as a kid right after the Apollo 14 launch. Cool! So, I've tracked this down, and our Navigation team has provided some data for those of you with enough experience might be able to use to predict LCROSS's early-mission trajectory. Here is the information and some figures (attached). Best for our friends in the Southeast...and by that I mean Australia, Indonesia, Singapore and Thailand...enjoy...and thank you for such a great idea! From our extended Navigation team: -------------------------------- "I have used the P10 trajectory for 18 Jun in SOAP to assess visibility starting at separation from LRO. Attached are two SOAP screen shots showing links to some major cities. The yellow line running NNW to SSE is the terminator. Locations sufficiently to the left of this line (preferably with Sun elevation less than -12 degree though this limit occurs early) would be best situated to observe the blowdown event assuming it occurs before the sky gets too bright. Perth is most favored, with Sun El -6 degree at 22:49 UTC, almost an hour after LRO separation. The red line is the ground track (leading part only). The yellow line extending to the right is the link to the Sun (LCROSS in sunlight). The time ticks on the trajectory line (lower left, gray; upper right, light blue) are spaced at five minutes. There is also a light blue link from LCROSS to the current position of the ground track. We have posted the LCROSS trajectory on the JPL Horizons system (18 Jun P10): telnet horizons.jpl.nasa.gov 6775 lcross Availability of the LCROSS trajectory on Horizons has been announced on Seesat-L (where those interested in observing fuel dumps from Centaur rockets have been known to gather): www.satobs.org/seesat/Jun-2009/0077.html Horizons can be used to generate topocentric ephemeris data." -------------------------------- =============================