History of the Delta Launch Vehicle
Frequently Asked Questions
Programs and Links
To Reach the High Frontier: A History of U.S. Launch Vehicles
Many other excellent books about spaceflight are recommended here.
Frequently Asked Questions
What about Delta IV?
Do you have, or know of, similar websites for the Titan and the Atlas launch vehicles?
I found your site during a search but can't find the information it quoted. Where is it?
What colour is the Delta II?
Can you explain how the stars in the Delta triangle insignia are determined?
The number of stars represents the highest number of consecutive launch successes attained by the Thor-Delta series (not including Delta III and Delta IV). Note that Boeing doesn't always get the number right every time. Part of the problem is that vehicles sometimes slip out of their planned launch sequence.
As of 25 June 2003, the Thor-Delta series is on its best ever winning streak, having performed its 52nd consecutive launch success with Delta 298 (MER-A). Delta 298 correctly carried 51 stars. Unfortunately, Delta 297 (which orbited GPS IIR-9 in March 2003) also had 51 stars, but should have had 50. This may have been because the SIRTF launch, originally planned to go before GPS IIR-9, slipped.
Here is a list of the Delta consecutive success streaks that seem to have determined the number of stars:
Delta 2-24, 1960-64, 22 successes
I think you'll find that many launch vehicle insignias were consistent with this list. For example, I've counted 49 stars on Deltas 239, 264, 271, 286, 291, 292, 294, and 295. I found 43 stars on Delta 210, etc.
As near as I can determine, the Delta star insignia first appeared sometime around 1966-67. Delta 51, for example, had 22 stars. Once the stars appeared, they were applied inside the triangle until sometime in 1982 when the number of successes exceeded 30 or so and stars began to be applied outside the triangle. By the time Delta 166 was launched in 1983, the number of stars inside the triangle had been fixed at 27 (it still is today). Delta 166 also had 4 additional stars outside the triangle, for a total of 31.
Thus ends the Delta insignia star mystery!
Many thanks to Tim Johnson for writing this excellent summary of the newsgroup discussion. In 2006, as the United Launch Alliance took over launch services from Boeing, the stars were discontinued; Delta 322 (the first ULA-directed launch) was the last to bear them.
As is apparent from Tim's research, given the occasional inconsistency in the insignia, your best bet for modelling a specific Delta flight—as in all scale modelling—continues to be to get lots of photo documentation. For flights from the eastern range, a good place to start is the NASA/KSC Multimedia Gallery.
How are the boosters on the Delta II numbered?
Booster 1 is centered on the downrange axis of the vehicle, as shown in the left-hand image. Boosters 8 and 6 flank the uprange axis, and the turbine exhaust pipe from the main engine is between them on the axis, though it's difficult to see in the right-hand image. (Also, the mission logo is always on the uprange side.) Therefore, the boosters go in this order, starting at the downrange axis and proceeding clockwise when viewed from above: 1, 4, 9, 3, 6, 8, 2, 5, 7.
I found this object (or piece of debris) and think it's part of a rocket. Do you know what it is?
How did you become interested in Delta?
From there, my interest quickly turned into a for-fun research project that took on a life of its own, aided substantially by excellent government documents and engineering libraries at Michigan State University. (Perhaps I also had a subconscious desire to crusade for a rocket that I feel deserves a great deal of the credit for success in the Space Age.) More recently, this site was the impetus for an invitation from NASA's then-Chief Historian to contribute to a book on U.S. launch vehicle development, which was published by the University Press of Kentucky in 2002 as To Reach the High Frontier: A History of U.S. Launch Vehicles.
Last update: 14 December 2009 CST
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