Author Topic: Why was Delta IV less successful than Atlas V?  (Read 26761 times)

Offline TheKutKu

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Re: Why was Delta IV less successful than Atlas V?
« Reply #20 on: 08/15/2024 11:29 pm »
"EELV Program Background
Cost Perspective
Curt Khol"

A short PDF to remember the economic assumptions behind the EELV program.


Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #21 on: 08/15/2024 11:54 pm »
Atlas V was more popular with the USAF, which constituted the majority of the demand for ULA. Customer demand is a great indicator of how well your product is doing...

No.  Delta IV was primarily a DOD vehicle. Only 7 of the first 20 Atlas V were DOD. 15 of the first 20 Delta IV were DOD.  Only 7 of the total 45 Delta IVs were non DOD.  56 of the 101 Atlas V were DOD.

Offline Jer

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Re: Why was Delta IV less successful than Atlas V?
« Reply #22 on: 09/01/2024 11:33 am »
Atlas V cores were identical and could do any configuration including the heavy
I thought the triple-core configuration never made its way past the proposal stage, was there actual hardware (or vestiges) of that in some Atlas V cores?
I don't know - it does seem odd that Atlas V Heavy never got to fly, especially as Jim points out they could do this with little or no modification - something I didn't know.
Perhaps GSE updates, or ensuring two dissimilar systems... Again. :)

It never flew because it would've been a deadly threat to Ares I.

Offline Proponent

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Re: Why was Delta IV less successful than Atlas V?
« Reply #23 on: 09/01/2024 02:53 pm »
Delta IV Heavy was chosen over Atlas V Heavy in the 1990s, years before the Constellation program began.
« Last Edit: 09/01/2024 02:53 pm by Proponent »

Offline sdsds

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Re: Why was Delta IV less successful than Atlas V?
« Reply #24 on: 09/01/2024 08:37 pm »
DIV-H was selected by the USAF for NSSL missions. DIV-H was selected by Lockheed-Martin for the first flight of an Orion capsule. AV-H was never selected by NASA because its capabilities were so similar to Ares I, and Ares I provided commonality with (pre-paid some development costs of) Ares V.
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Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #25 on: 09/01/2024 08:39 pm »
Atlas V cores were identical and could do any configuration including the heavy
I thought the triple-core configuration never made its way past the proposal stage, was there actual hardware (or vestiges) of that in some Atlas V cores?
I don't know - it does seem odd that Atlas V Heavy never got to fly, especially as Jim points out they could do this with little or no modification - something I didn't know.
Perhaps GSE updates, or ensuring two dissimilar systems... Again. :)

It never flew because it would've been a deadly threat to Ares I.

It was way before Ares I existed

Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #26 on: 09/01/2024 08:41 pm »
DIV-H was selected by the USAF for NSSL missions. DIV-H was selected by Lockheed-Martin for the first flight of an Orion capsule. AV-H was never selected by NASA because its capabilities were so similar to Ares I, and Ares I provided commonality with (pre-paid some development costs of) Ares V.

AV-H wasn't wasn't there for NASA to select. 

Offline Jer

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Re: Why was Delta IV less successful than Atlas V?
« Reply #27 on: 09/02/2024 12:34 am »
DIV-H was selected by the USAF for NSSL missions. DIV-H was selected by Lockheed-Martin for the first flight of an Orion capsule. AV-H was never selected by NASA because its capabilities were so similar to Ares I, and Ares I provided commonality with (pre-paid some development costs of) Ares V.

AV-H wasn't wasn't there for NASA to select.

That's my point, that if AV-H was already flying in the mid 00s it would've put a target on the back of Ares I. There would've been no rhyme or reason for Ares I to exist.

A 5-meter core (using Delta IV tankage) version of the AV-H was presented to the Augustine Commission. ULA was even suggesting a possible 8.4m super heavy lift version. If Congress was gonna throw money at Boeing and Lockheed, they should've at least thrown on something good. Imagine SLS powered by a cluster of RD-180s..
« Last Edit: 09/02/2024 12:40 am by Jer »

Offline edzieba

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Re: Why was Delta IV less successful than Atlas V?
« Reply #28 on: 09/02/2024 05:09 pm »
DIV-H was selected by the USAF for NSSL missions. DIV-H was selected by Lockheed-Martin for the first flight of an Orion capsule. AV-H was never selected by NASA because its capabilities were so similar to Ares I, and Ares I provided commonality with (pre-paid some development costs of) Ares V.

AV-H wasn't wasn't there for NASA to select.

That's my point, that if AV-H was already flying in the mid 00s it would've put a target on the back of Ares I. There would've been no rhyme or reason for Ares I to exist.
Atlas V 'heavy' had ceased to be a thing before Ares-I was conceived. Time travel would need to be involved for the two to have had any influence on each other.

Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #29 on: 09/02/2024 06:26 pm »


A 5-meter core (using Delta IV tankage) version of the AV-H was presented to the Augustine Commission. ULA was even suggesting a possible 8.4m super heavy lift version.

Those were just rehashes of LM Atlas V Phase 2 studies.

Offline sdsds

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Re: Why was Delta IV less successful than Atlas V?
« Reply #30 on: 09/02/2024 10:31 pm »
Atlas V 'heavy' had ceased to be a thing before Ares-I was conceived.

Is there a definitive date for when AV-H was removed from the list of ULA offerings? (It was offered for awhile even after USAF selected DIV-H for NSSF missions.)
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Offline joek

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Re: Why was Delta IV less successful than Atlas V?
« Reply #31 on: 09/02/2024 11:24 pm »
Is there a definitive date for when AV-H was removed from the list of ULA offerings? (It was offered for awhile even after USAF selected DIV-H for NSSF missions.)

It was "offered" only in the sense that LM would build it if someone payed for it (as other variants). Given that the only likely customer was the USAF EELV program, and that program was not going to pay for it, and that no non-USG/DoD demand existed, it died on the vine.

I would estimate the effective death certificate was probably around or shortly after the launch market crash in the early 2000's, which subsequently resulted in the formation of ULA. After which itt was a moot point.


Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #32 on: 09/02/2024 11:24 pm »
Atlas V 'heavy' had ceased to be a thing before Ares-I was conceived.

Is there a definitive date for when AV-H was removed from the list of ULA offerings? (It was offered for awhile even after USAF selected DIV-H for NSSF missions.)

It never was part of ULA offerings.  When the USAF made the first buy of EELVs missions in 1998, Delta IV got 19 and Atlas got 9 and Atlas V given relief from completing the heavy.  It got relief from building a west coast pad, which was changed a few years later.

Offline sdsds

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Re: Why was Delta IV less successful than Atlas V?
« Reply #33 on: 09/02/2024 11:57 pm »
The period of time in question is leading up to the November 2005 announcement of the NASA Exploration Systems Architecture Study. Prior to that Sean O'Keefe reportedly liked the idea of launching the CEV on DIV-H or AV-H.

Or so says Wikipedia, the encyclopedia that's sometimes even right.
https://en.wikipedia.org/wiki/Exploration_Systems_Architecture_Study#Shuttle_based_launch_system
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Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #34 on: 09/03/2024 02:45 am »
The period of time in question is leading up to the November 2005 announcement of the NASA Exploration Systems Architecture Study. Prior to that Sean O'Keefe reportedly liked the idea of launching the CEV on DIV-H or AV-H.


NASA would have had to pay for pad and GSE completion and to take the design past CDR.

Offline Jer

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Re: Why was Delta IV less successful than Atlas V?
« Reply #35 on: 09/03/2024 09:38 am »
The period of time in question is leading up to the November 2005 announcement of the NASA Exploration Systems Architecture Study. Prior to that Sean O'Keefe reportedly liked the idea of launching the CEV on DIV-H or AV-H.


NASA would have had to pay for pad and GSE completion and to take the design past CDR.

Still would've been cheaper than the cost of the Ares I programme, right?

Offline Spiceman

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Re: Why was Delta IV less successful than Atlas V?
« Reply #36 on: 09/03/2024 10:41 am »
Or at least produce a workable rocket that could launch an Orion with all the goodies: not the castrated weight-trimmed variant we got a decade late.
Goodies like
a) land-landing
b) a service module with 2000 m/s + of delta-v that could, like Apollo, geting IN and OUT of low lunar orbit.

Offline spacenut

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Re: Why was Delta IV less successful than Atlas V?
« Reply #37 on: 09/03/2024 12:54 pm »
Also, Russia gave the green light permission for the US to manufacture the RD-180.  The best of the old Atlas and Delta was IMO, the Atlas V phase II, a 5 or 5.5m Atlas with two RD-180's.  Then an Atlas V phase II heavy version which could have delivered around 700-75 tons to LEO.  The ACES upper stage would have had to be developed with probably 4 RL-10 engines. 

It never was to be because neither NASA nor the Air Force needed the phase II version.  NASA because by that time Constellation came out with Ares V and Ares I, and the Air Force didn't need anything bigger for their satellites.  However history could have taken a different turn and we would already be back to the moon with Atlas V phase II heavy launches.  Don't know how SpaceX would have evolved if that happened. 

In my opinion Delta IV cost more due to using hydrogen than the less expensive Atlas V's for most satellite launches. 

Offline Jim

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Re: Why was Delta IV less successful than Atlas V?
« Reply #38 on: 09/03/2024 02:58 pm »
Or at least produce a workable rocket that could launch an Orion with all the goodies: not the castrated weight-trimmed variant we got a decade late.
Goodies like
a) land-landing
b) a service module with 2000 m/s + of delta-v that could, like Apollo, geting IN and OUT of low lunar orbit.

No, not really.  AV-H could only lift 65klb to LEO.   Orion on orbit mass is 58klb, this excludes the LAS and ESM panels.

Tags: Delta IV Atlas V 
 

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