Talk:Delta IV Heavy

Launches

                                 Date:         Payload
* Delta IV Heavy                 21.12.2004    Demosat / 3CS 1 / 3CS 2
* Delta IV Heavy                 11.11.2007    DSP 23 
* Delta IV Heavy                 18.01.2009    Orion 6 
* Delta IV Heavy                 21.11.2010    Orion 7 
* Delta IV Heavy                 20.01.2011    KH-11 15 
* Delta IV Heavy                 29.06.2012    Orion 8 
* Delta IV Heavy                 28.08.2013    KH-11 16 
* Delta IV Heavy                 05.12.2014    Orion EFT-1

— Preceding unsigned comment added by Telecineguy (talk • contribs) 20:13, 19 December 2015 (UTC)

Source for payload masses?

@Nergaal: Thanks for adding the payload masses for various missions. Could you please add the source(s) for this information? — JFG ^talk 09:53, 12 July 2018 (UTC)

Individual pages at http://space.skyrocket.de/doc_lau/delta-4.htm and whatever numbers I saw here in our D4 launches lists. Nergaal (talk) 10:42, 12 July 2018 (UTC)

1st Stage Thrust is Misleading

I noticed that the thrust for the first stage is listed as "3,140 kN (710,000 lbf)" which is true of a single one of the three first stage cores. As there are three of them, it may make sense to either denote that with something similar to "3,140 kN (710,000 lbf) x3" or perhaps just do the multiplication for the reader. I was made aware of this mistake while CEO Tory Bruno tweeted (https://twitter.com/torybruno/status/1260754475259740160?s=20) that Delta IV Heavy had 2.1Mlbf of thrust, which is not what the wiki showed. I went to find another source for the thrust level and found this from ULA's site: https://www.ulalaunch.com/docs/default-source/rockets/delta-iv-heavy-cutaway.pdf. It shows was Wiki shows, but lists this value for the "common booster core". The diagram clearly shows 3 booster cores. Multiplying 710K by 3 gives you the 2.1M figure referenced by Tory Bruno.

I recommend we update the thrust level of the first stage to reflect the 2.1Mlbf value as it is more representative of the actual first stage thrust than showing the thrust of a single one of the three common booster cores. If someone desired, you could even make a page (assuming it doesn't already exist) for the common booster core, and reference that the first stage is made of three of these.

--WhirlpoolBrewer (talk) 13:48, 14 May 2020 (UTC)

Retirement

I added the upcoming retirement to the lede, but my reference says 2023. The body says NROL-70 is the last flight and will be in 2024, but it it unreferenced. If someone has a better reference, please update the lede. -Arch dude (talk) 05:15, 20 March 2022 (UTC)

Fixed-Arch dude (talk) 05:37, 20 March 2022 (UTC)

More history before first launch

Can we have more history before launch in Dec 2004. eg. when did Boeing announce they would build the D4H ? and why ? Was it for a specific USAF or NRO requirement ? Did USAF or anyone else fund the development of D4H ? - Rod57 (talk) 03:06, 5 January 2024 (UTC)

• The U.S. Air Force announces the procurement of Boeing Delta IV launches says

"Delta IV/Evolved Expendable Launch Vehicle Program On Oct. 16, 1998, the U.S. Air Force announced the procurement of 19 Boeing Delta IV launches for the Evolved Expendable Launch Vehicle (EELV) program valued at $1.38 billion.
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This initial launch services contract covers small, medium and heavy payload class launches from 2002 to 2006. It splits 28 missions in a dual-source procurement designed to encourage greater contractor investment and competition in the U.S. space launch industry, and to decrease the Air Force's overall development cost.
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The Air Force also entered into a $500 million agreement with Boeing, supplementing development of the Delta IV family of launch vehicles for meeting all Air Force EELV requirements."

We could add more to the Delta IV History, and in D4H, refer there. - Rod57 (talk) 03:33, 5 January 2024 (UTC)