Delta Rocket History - Part II - Legacy Of Thor - America's Most Successful Rocket

The Third part of my series one the Thor and Delta Rockets. At the start of the 1980's the Delta launch vehicle had managed to evolve from a small intermediate missile into a reliable launch vehicle that had carried hundreds of payloads over the last 2 decades. However, NASA was preparing to replace it with the Space Shuttle and it looked like it may be headed for retirement.
But when the Space Shuttle was unable to deliver on its promises of reliable low cost launch services Delta was there to pick up the slack and continue its career up to the present day... or maybe 2018, depending on what you consider delta to be.

A great deal of this research was compiled by Ed Kyle, thanks for his fantastic work.

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[mattcolver]

I had quite a few very busy years at McDonnell Douglas and then Boeing. I worked on the development team for the 10 ft Composite fairing for Delta II then went right into Delta III developing composite structures for it, fairing, payload adapter and interstage, then right into Delta IV developing fairings and payload adapters. I worked 7 years where Saturday was a regular work day. I was at the 1st launch of Delta III and was heart broken over the failure. I was at the 1st launch of Delta IV and it was a much better day. Then we became ULA. When Vulcan development was announced I assumed I'd be part of that development, but all composite structure design was subcontracted out to RUAG. So I grabbed a nice severance package and retired at the young age of 61. I had an enjoyable career.

[kerbalengineeringsystems]

Here's my thought process on Delta Nomenclature:
Once a major piece of hardware flies on a Delta, it becomes "Delta hardware, " thus making any future vehicles including it eligible for the Delta name. So once the Delta Cryogenic Upper Stage flew on Delta III (which was unquestionably a Delta rocket), it became part of the Delta family and can transfer the Delta name onto any rocket that flies it, thus making SLS Block I Delta V. Once the ICPS is retired for Block II, it's still a Delta family rocket, since by the same logic the SLS core stage has become Delta hardware, meaning that it can carry the Delta name to Block II. By this logic, then, SLS Block I is Delta V, and Block II is now Delta VI.
This is flawless logic and I'll be taking no further questions at this time.

[cosmicinsane]

Glad you mentioned that Delta II launch failure. That’s probably my favorite rocket explosion of all time for two reasons. First, it was seriously spectacular with the massive fireball and thousands of burning chunks of SRB falling all over the launch site. Second, the commentary on the launch had what was probably the best example of understatement in history “We have had an anomaly…”

[rosswarren]

Love it! "Delta" lives on a little longer. Can't argue with 700 missions for the "family". Guess that's as close as the U.S. will come to all the "Vostok/Soyuz" variants of the R7. I love the Falcon 9, but for many of us, when we think "rocket", that blue-green Delta II will always come to mind.

Just FYI: It took about 10 gallons of AkzoNobel's aerospace coating "Blue Fluid Resistant Primer" to cover a single Delta II. Between 1989 and 2018, 155 of the rockets flew.

Outside the space program, "Delta Blue" is formally known as Federal Standard 25193. Considered a shade of cyan, it is comprised of 36.47 percent red, 55.69 percent green and 58.82 percent blue.

Delta Blue has an approximate wavelength of 488.02 nanometers.

Pantone, known for its color matching system, identifies "Delta Blue" as simply "5483-C."

If you wanted to paint your rocket — or your room — Delta Blue then you could look for Dutch Boy's "Midnight Run, " Sherwin-Williams' "Mountain Stream" (no. 7162) or Valspar Paint's "Ocean Voyage." If you wanted to order your next car in Delta Blue, Chrysler's closest match is "Neptune Green, " General Motors' offers "Adriatic Turquoise" and at Ford it is just "Medium Turquoise."

To the McDonnell Douglas, Boeing and United Launch Alliance teams that worked on Delta II for three decades though, it was and continues to be "Delta Blue."

[frankgulla]

Scott, you are the man of the subtle irony. "SLS is a Delta" Fantastic. Thanks for this detailed history of a major launch vehicle.

[ethansigh]

The Delta II holds a very special place in my heart since I'm lucky enough that my cubesats flew on that final launch with Icesat2 in 2018! Thanks for such an awesome and informative video Scott!

[msudawg]

16:40 minor correction: At the time Boeing was developing Delta IV, the RS-68 was being developed by Rocketdyne. Which itself was also owned by Boeing. When Boeing bought McDAC they also around the same time bought Rocketdyne from NAA. It wasn't until many years later that UTC, who owned P&W, bought Rocketdyne from Boeing and created Pratt&Whitney-Rocketdyne (they went by PWR). I remember all of this fairly well as I worked for Rocketdyne at Stennis from June 1997 until Sep 2001. When I hired in we were being called Boeing North American as they were working out the logistics of combining the companies. It was some time after I left Rocketdyne for NASA in Sep 2001 that P&W bought them. So to the point, you could say the RS-68 was a Boeing engine at the time they developed D-IV.

As a side note, I supported the D-IV Common Booster Core testing at Stennis. My main job at the time was running SSME tests on A-2 test stand but I got to work LH2 fill of CBC during test. Those were fun days.

[dotydude]

My first job out of college (Parks College of Saint Louis University) was testing Delta II Second Stage bi-propellant valves with water at Aerojet. Once I mastered that task they let me hot-fire test the whole engine. It was very reliable and I never had a failure.

[stefanschneider]

"Down from 10 to 6 PER YEAR!" I first thought I misunderstood, but then I remembered: There were times before SpaceX, Rocketlab etc ... Great video as always, thanks Scott!

[deusexaethera]

It was an immensely stupid decision by NASA to not build a 5th version of the Delta rocket, named Delta V.

[joyl]

I love the Delta IV Heavy. It looks so awesome, plus it runs on hydrogen! Also, it just kicks butt that it lights itself on fire T-0. What a vehicle.

[matthewkubinec]

Considering SLS to be part of the Delta family because of the second stage makes sense when you remember from the first video that Delta was originally the name for the upgraded Thor second stage. So really, the common factor of a Delta rocket is the second stage lineage, not the first stage.

[simontanguay]

Very bold move adding SLS to the Delta family. But it's a bold move I can approve.

[Soacwiththaface]

Was at the last night launch of The Beast!!! Wont make it to port Canaveral this time but I'll be watching from 60 miles north.

[rockysgarage]

Thank you Scott!! Just adds another layer of love for the Delta 2/4 rocket.

[steffan]

Would love to see a series like this on the history of all the different Atlas variants leading into its retirement.

[rkornilo]

Great video as always, Scott. And I thought it was a classy decision not to show the actual explosion of Challenger.

[DroneDocs]

Super excited about the Delta V launch coming up this year Scott! 😉 Fly Safe

[elmofeneken]

Scott, what a detailed, highly researched, informative Part II of the Thor/Delta story. Thumbs up! Nobody could have done such a thorough job on this subject. You nailed it!

[minikawildflower]

This is such a great series - I've always been curious about what came before the Delta II, since you'd figure it was Delta I but it was really this long development of different models you've covered here. Thanks!