Frequently Asked Questions
Programs and Links
To Reach the High Frontier: A History of U.S. Launch Vehicles
"A valuable contribution to the field of aerospace literature," this book includes an extensive overview of Delta history and development along with chapters on Atlas, Titan, Scout, Space Shuttle, and much more.
Many other excellent books about spaceflight are recommended here.
History of the Delta Launch Vehicle
Current Delta News
(What about Delta IV?)
30-Jan-15 | Delta II delayed again
The January 30 launch attempt for SMAP was postponed when some loose insulation was found on the first stage. This is a not-uncommon occurrence and is usually a quick patch job to repair. The next attempt is set for Saturday morning.
29-Jan-15 | Brief return
Yes, it has been an awfully long time since a fresh posting. This is the obvious consequence of 1) the Delta II program winding down to a very sporadic last few flights, and 2) me having paying gigs that take precedence over this labor of love. So, in brief:
Today’s launch of Delta flight 370 was scrubbed before release of the T-minus 4 minute hold due to upper level winds. A 24-hour turnaround is expected to have a 90% chance of favorable conditions. The United Launch Alliance two-stage Delta Med-Lite vehicle will carry NASA’s Soil Moisture Active Passive environmental monitoring satellite into a polar orbit from Vandenberg Air Force Base. As ever, SpaceflightNow.com will carry live coverage.
03-Oct-11 | Delta II reaches the on-ramp
NASA has announced the modification of its NASA Launch Services (NLS) II contract with United Launch Services, putting Delta II back on the menu. Parts for five Delta II vehicles have already been manufactured, and are now in storage; this contract modification will enable ULS to offer them to NASA for launch services between now and June 2020. [NASA Contract Release C11-044, 30-Sep-11]
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.
11-Sep-11 | Delta flight 356 – GRAIL
A Delta II-Heavy lifted off from Florida’s Cape Canaveral Air Force Station on Saturday, 10 September, sending NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission on its way to the Moon.
08-Sep-11 | Scrub!
A strong shear in the upper level wind conditions has led to a 24-hour turnaround for NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission to the Moon. The next launch opportunity is on Friday, 9 September, with two instantaneous launch windows at 12:33:25 and 13:12:31 UTC.
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%.
15-Aug-11 | Next launch
The next Delta II launch will send NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission toward the Moon. There, GRAIL will “create the most accurate gravitational map of the Moon to date, improving our knowledge of near-side gravity by 100 times and of far-side gravity by 1000 times.” This high-resolution map will help scientists to better understand the Moon’s internal composition. The twin spacecraft, GRAIL-A and GRAIL-B, completed their final inspections at the Astrotech facility on Tuesday, 9 August, and will be transported to Space Launch Complex 17 this week.
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.
01-Jul-11 | Mission round-up
In lieu of immediate Delta II action—the next launch will occur no earlier than September—here is a round-up of news about current missions that began with successful Delta II launches. More
10-Jun-11 | Delta flight 354 – SAC-D/Aquarius
A two-stage United Launch Alliance Delta II rocket lifted off into a thick fog early this morning, Friday, 10 June 2011, from California’s Vandenberg Air Force Base. Aboard was the SAC-D/Aquarius spacecraft, a joint mission of Argentina’s National Commission on Space Activities (CONAE) and NASA. The launch vehicle performed as expected, placing the spacecraft into a circular, sun-synchronous polar orbit some 56 minutes after launch. Official liftoff time was 14:20:13 UTC.
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.
07-Jun-11 | Next launch
Update for 8 June: Launch has been postponed for 24 hours due to a technical issue.
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.
With the last few Delta II missions already slated and no desire to cover the high cost of continuing that launch system, NASA now finds itself with a not-unexpected dilemma: no affordable means to get small- and medium-class spacecraft off the ground. Spaceflight Now has the full story.
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