1. Space News Update - April 25, 2011 - In the News Story 1: Story 1: Florida Braces for Huge Crowds for Friday's Space Shuttle Launch Story 2: Story 2: NASA Orbiter Reveals Big Changes in Mars' Atmosphere Story 3: Story 3: No ISS docking permission for SpaceX unless safety proven Says Roscosmos Departments The Night Sky ISS Sighting Opportunities Space Calendar NASA-TV Highlights Food for Thought Space Image of the Week

2. Florida Braces for Huge Crowds for Friday's Space Shuttle Launch

3. NASA Orbiter Reveals Big Changes in Mars' Atmosphere

4. No ISS docking permission for SpaceX unless safety proven Says Roscosmos

5. The Night Sky Monday, April 25 · In late twilight, have you been keeping an eye on bright Sirius in the southwest and Orion in the west? They're still in view but sinking lower daily. How much later in the season can you keep them in sight? Tuesday, April 26 · Sirius, the Dog Star, still twinkles low in the southwest right after dusk. High above it is Procyon, the Little Dog Star. Very far to Procyon's upper left is Regulus in Leo. Nearly halfway from Procyon to Regulus, look for a dim but distinctive asterism: the head of Hydra, the Sea Serpent. It's about the size of the end of your thumb at arm's length. Wednesday, April 27 · At the end of twilight this week, look for the Big Dipper tilting over very high in the northeast — almost overhead, depending on your latitude. This is also the time of year when, right after nightfall, the Little Dipper extends horizontally to the right from Polaris. Thursday, April 28 · A dawn challenge: Set the alarm to get up Friday morning well before your local sunrise time, grab binoculars or telescope, and get to a spot with a view of the eastern horizon by a half hour before sunrise. The waning crescent Moon will be hanging in the east. If the air is clear Venus should be easy to pick up far to its lower left. Try next for Mercury, Jupiter, and, for a real challenge, tiny Mars next to Jupiter, as shown here.your local sunrise time Friday, April 29 · Was it cloudy this morning at dawn? Set your alarm to try again Saturday morning for the Moon, Venus, Mercury, Jupiter, and Mars. This time the Moon is thinner and closer above Venus, as shown here. · Late tonight the large, 10.3-magnitude asteroid 7 Iris will occult (cover) an identically bright star in Cancer for up to 13 seconds as seen from a track running from northern Washington State through Iowa and Illinois to Virginia and North Carolina.

6. ISS Sighting Opportunities Sighting information for other cities can be found at NASA’s Satellite Sighting InformationSatellite Sighting Information For Denver: SATELLITELOCALDURATIONMAX ELEVAPPROACHDEPARTURE DATE/TIME(MIN)(DEG)(DEG-DIR) ISSMon Apr 25/10:11 PM< 11010 above NNE ISSTue Apr 26/10:34 PM< 11212 above NNW ISSWed Apr 27/09:24 PM< 11010 above N10 above NNE ISSThu Apr 28/09:48 PM11612 above NNW16 above NNE ISSFri Apr 29/08:38 PM< 11010 above N10 above NNE ISSFri Apr 29/10:13 PM< 12218 above NNW22 above NNW

7. NASA-TV Highlights April 25, Monday 2 p.m. - Signing Ceremony of a Formal Agreement Between NASA and the U.S. Agency for International Development (USAID) to Promote Collaboration on Scientific and Technological Solutions to Worldwide Problems - April 26, Tuesday 10 a.m. - STS-134 Countdown Preview Briefing (countdown begins at 2 p.m. EDT) 11 a.m. - Expedition 27 ISS Update - JSC (Public, HD and Media Channels) 12:15 p.m. - STS-134 Crew Arrival - KSC (All Channels) 1 p.m. - NASA Television Video File - HQ (Public, HD and Media Channels) April 27, Wednesday 10 a.m. - Expedition 27 ISS Update - JSC (Public, HD and Media Channels) 11 a.m. - STS-134 Prelaunch News Conference (follows completion of the L-2 day Mission Management Team meeting) - KSC (Public, HD and Media Channels) 12 p.m. - NASA Television Video File - HQ (Public, HD and Media Channels) April 28, Thursday 10 a.m. - STS-134 Countdown Status Briefing - KSC (Public, HD and Media Channels) 11 a.m. - Commercial Crew Development Briefing - KSC (Public, HD and Media Channels) 12 p.m. - NASA Television Video File - HQ (Public, HD and Media Channels) 1 p.m. - Space Science Update - The Voyager Spacecraft: Humanity’s Farthest Journey 2 p.m. - Alpha Magnetic Spectrometer Briefing - KSC (Public, HD and Media Channels) 6 p.m. - Ambassador of Exploration Award and 50th Anniversary Commemoration of Alan Shepard’s Flight on Freedom 7 - HQ (All Channels) 7 p.m. - Rotating Service Structure Retraction - KSC (All Channels) April 29, Friday 6:15 a.m. - STS-134 Fueling Coverage Begins - KSC (All Channels) 10 a.m. - ISS Progress 42 Docking Coverage (docking scheduled at 10:29 a.m. EDT) 10:30 a.m. - STS-134 Launch Coverage Begins (will begin as soon as ISS Progress 42 docking is confirmed) - KSC (All Channels) 3:47 p.m. - Launch of Endeavour on the STS-134 Mission - KSC (All Channels) 4:45 p.m. - Post-Launch News Conference - KSC (All Channels) Watch NASA TV on the Net by going to NASA website.NASA website.

8. Space Calendar · Apr 25 - Asteroid 2011 DV Near-Earth Flyby (0.100 AU) · Apr 26 - Asteroid 21 Lutetia Occults TYC 6873-00257-1 (8.6 Magnitude Star) · Apr 26 - Asteroid 2011 GR59 Near-Earth Flyby (0.035 AU) · Apr 26 - Asteroid 9342 Carygrant Closest Approach To Earth (1.610 AU) · Apr 27 -Progress M-10M Soyuz U Launch (International Space Station 42P) · Apr 27 - Asteroid 2011 GJ3 Near-Earth Flyby (0.020 AU) · Apr 27 - Asteroid 2008 UC202 Near-Earth Flyby (0.023 AU) · Apr 27 - Asteroid 2010 TU5 Near-Earth Flyby (0.090 AU) · Apr 27 - Asteroid 2410 Morrison Closest Approach To Earth (1.084 AU) · Apr 27 - Asteroid 11365 NASA Closest Approach To Earth (1.475 AU) · Apr 28 - Asteroid 2008 JV2 Near-Earth Flyby (0.059 AU) · Apr 28 - Asteroid 3350 Scobee Closest Approach To Earth (1.412 AU) · Apr 28 - Asteroid 770 Bali Closest Approach To Earth (1.509 AU) · Apr 28 - Asteroid 12820 Robinwilliams Closest Approach To Earth (2.047 AU) · Apr 29 STS-134 Launch, Space Shuttle Endeavour, International Space Station · Apr 29 - Cassini, Orbital Trim Maneuver #282 (OTM-282) · Apr 29 - Asteroid 1554 Yugoslavia Closest Approach To Earth (1.927 AU) · Apr 30 - Asteroid 38086 Beowolf Closest Approach To Earth (0.720) · Apr 30 - Asteroid 2362 Mark Twain Closest Approach To Earth (1.504 AU) · Apr 30 - Asteroid 2198 Ceplecha Closest Approach To Earth (2.092 AU) · Apr 30 - Kuiper Belt Object 90568 (2004 GV9) At Opposition (38.232 AU)

9. Food for Thought Asteroid or Planet? NASA Aims to Settle Vesta Debate

10. Space Image of the Week