The announcement means that the Delta II era might last beyond the launch of NPP, currently slated for 27 October. Of course, since the production line is out of commission, these five vehicles will be the last—but at least they have a chance to serve their purpose, rather than gather dust. Any remaining Delta II launches are expected to take place at Vandenberg’s SLC-2W.

A first attempt on Thursday was scrubbed due to upper level wind shear, and Saturday’s launch had to contend with much the same issue: a wind shear at 15–22,000 ft altitude, right around the transsonic region of the Delta II flight path, when the vehicle would be most vulnerable. Fortunately the shear was less severe than Thursday’s and flight controllers were able to work around it, targeting the second of two instantaneous launch windows. The official range liftoff time was 09:08:52.775 EDT.

The twin spacecraft of GRAIL will take nearly four months to reach the Moon, using a circuitous path through the Earth-Sun Lagrange point 1 to help refine and synchronize their orbits to each other. The long cruise will also allow the spacecraft to eliminate any outgassing that could be mistaken for gravitational effects. This will enable them to make highly accurate gravimetric measurements of the Moon in order to map its complete internal structure for the first time in over 50 years of lunar exploration.

According to Jonathan’s Space Report, the Aerojet-built second stage ended up in a 0.88 x 1.05 AU x 0.01 deg heliocentric orbit, with a period of around 347 days. Based on that approximation, the stage could sail past Earth again in 19 years.

The two-stage launch vehicle, with its oversized GEM-46 booster motors marking it as a “Heavy” model, extended the Delta II reputation for reliability, now standing at 95 consecutive successful launches. One Delta II launch—next month’s NPP from Vandenberg—remains on the schedule. United Launch Alliance continues to seek customers for the final 5 Deltas in storage.

Update: Friday’s attempt has been postponed “to allow additional time to review propulsion system data from Thursday’s detanking operation.” Launch windows for Saturday, 10 September, are 12:29:45 and 13:08:52 UTC. The weather report for that day gives a 60% chance of conditions favourable for launch, an improvement over Thursday and Friday’s 40%.

The two-stage Delta II Heavy launch vehicle has been stacked on pad 17B since 20 May, and pre-launch testing has been in work since then. The launch period opens on 8 September.

Dawn (Delta 327) will arrive at Vesta on 16 July. It will remain in orbit for several months to study the asteroid before moving on to Ceres. (JPL Press Release, 23 June 2011)

Studies of samples returned to Earth in 2004 by Genesis (Delta 287) suggest that the Sun and inner planets “may have formed differently than previously thought.” (JPL Press Release, 23 June 2011)

MESSENGER (Delta 307) attained orbit around Mercury in March 2011, and so far its science return has been spectacular. Co-Investigator Scott Murchie of the Johns Hopkins University Applied Physics Laboratory (APL) will be awarded the NASA Distinguished Public Service Medal at a ceremony later this month. (MESSENGER Mission News, 22 June 2011)

And finally, one piece of Delta-related news: NASA is considering purchase of one or more of the five remaining Delta II vehicles for use of future missions, according to Space News. The loss of two NASA spacecraft to failures of the Taurus XL vehicle is a factor in the move. No word on how negotiations with United Launch Alliance are proceeding.

Satelite de Aplicaciones Cientificas-D, the second SAC spacecraft to launch aboard a Delta II, is festooned with several Earth-sensing scientific instruments supplied by different countries. Primary among these is NASA’s Aquarius sensor, which will gauge ocean surface salinity levels. Data from Aquarius is expected to fundamentally impact our understanding of the world’s oceans in terms of circulation, climate, and water cycle.

This was the 94th consecutive successful launch by Delta II, a world-record series of successes dating back to May 1997. It was the first of three planned launches for Delta II this year—all of them for NASA, and the final flights on the schedule. Five Delta II vehicles remain in storage, complete and awaiting assignment.

The first of three Delta II launches slated for 2011 is on schedule for departure on Thursday, 9 June. The 5-minute window opens at 07:20:13 PDT at Vandenberg Air Force Base, where a two-stage Delta II 7320 stands ready to put the SAC-D/Aquarius spacecraft into orbit for the Argentina National Commission on Space Activities and NASA. The Flight Readiness Review was completed on 2 June, and loading of the Delta II second stage with hypergolic propellants was performed a day later.

The launch of COSMO-SkyMed 4, from Vandenberg AFB on Friday evening local time (02:20 UTC on 6 November 2010), went off without issue after three previous attempts were scrubbed, two for main engine compartment heating systems, one for a low voltage reading in the second stage battery. As usual, Justin Ray provided a complete play-by-play in Spaceflight Now’s Mission Status Center.

This was the only Delta II launch for 2010, and the final scheduled commercial flight for the venerable rocket. Three flights for NASA are slated for 2011, and five vehicles remain unassigned. Boeing hopes to find commercial customers for those remaining rockets.