Air Force reconsiders rocket engine, aims for small rocket launches
Two stories over the past few days indicated some shifts in the Air Force’s commercial space contracting policies.
- Air Force and Aerojet Rocketdyne renegotiating AR1 agreement
- Air Force moves to buy small rocket services
The first story has to do with ULA’s Atlas 5 and future Vulcan rockets. The engine that Aerojet Rocketdyne has been building, AR-1, has received significant subsidizes from the government for its construction, even though its only potential customer, ULA, has said it prefers Blue Origin’s BE-4 engine. ULA has not made a decision yet on which engine to use, but my sense of the politics here is that the main reason ULA is considering the AR-1 is because of heavy political pressure. Nonetheless, it makes sense for them to hold off from a final decision when they have two competitors.
The story suggests however that Aeroject Rocketdyne itself lacks confidence in the engine. It wants to renegotiate its Air Force contract so that it doesn’t have to invest any of its own money on development. This suggests the company no longer expects to get any contracts for it, and thus doesn’t want to spend any of its own money on it. With that kind lack of commitment, the Air Force would be foolish to change the deal.
The second story outlines how the Air Force is now committing real money for buying launch contracts with smallsat rocket companies, something it has hinted it wanted to do for the past year. The idea is for them to depend on numerous small and cheap satellites, capable of quick launch, givingthem a cushion and redundancy should an enemy nation attack their satellites. It will also likely save them money in the long run.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Two stories over the past few days indicated some shifts in the Air Force’s commercial space contracting policies.
- Air Force and Aerojet Rocketdyne renegotiating AR1 agreement
- Air Force moves to buy small rocket services
The first story has to do with ULA’s Atlas 5 and future Vulcan rockets. The engine that Aerojet Rocketdyne has been building, AR-1, has received significant subsidizes from the government for its construction, even though its only potential customer, ULA, has said it prefers Blue Origin’s BE-4 engine. ULA has not made a decision yet on which engine to use, but my sense of the politics here is that the main reason ULA is considering the AR-1 is because of heavy political pressure. Nonetheless, it makes sense for them to hold off from a final decision when they have two competitors.
The story suggests however that Aeroject Rocketdyne itself lacks confidence in the engine. It wants to renegotiate its Air Force contract so that it doesn’t have to invest any of its own money on development. This suggests the company no longer expects to get any contracts for it, and thus doesn’t want to spend any of its own money on it. With that kind lack of commitment, the Air Force would be foolish to change the deal.
The second story outlines how the Air Force is now committing real money for buying launch contracts with smallsat rocket companies, something it has hinted it wanted to do for the past year. The idea is for them to depend on numerous small and cheap satellites, capable of quick launch, givingthem a cushion and redundancy should an enemy nation attack their satellites. It will also likely save them money in the long run.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
ULA seems to have settled on a 5.4 m diameter Vulcan lower stage. I would have thought this indicated their choice of the BE-4, since RP-1’s much greater energy density over methane should mean that if they went with the AR-1 then they would choose something closer to a 4 m diameter lower stage, comparable to the Atlas’s 3.8 m. But in a recent reddit interaction, Tory Bruno said that an AR-1 powered Vulcan would also be 5.4 m in diameter and would be “yes, about” the same height as Atlas V. That seems strange. [1]
Another recent revelation is that when Vulcan first flies (they say mid-2020), it will not be using the current 3.05 m diameter Centaur upper stage, but will instead use a 5.4 m diameter Centaur V, powered by four RL10 engines. That part really surprises me as the RL10 is rumored to be quite expensive, though Mr. Bruno said, “RL10 has had several updates, so it’s not a 1960s engine any more. The elegance of the expander cycle in LOX/LH2 definitely has appeal for its size class. (remembering that the cube-square law limits how big it can go). Aerojet has done really intriguing work in additive manufacturing and how that might be applied to RL10.” [2] so I wonder if some of its updates have target lowering its cost of manufacture.
Anyhow, the Centaur V sounds as if it is half-way between the current Centaur and the eventual ACES (Advanced Cryogenic Evolved Stage), lacking the ACES IVF (Integrated Vehicle Fluids) systems and MLI (Multi-Layer Insulation) which are required for extra-long duration missions and propellant depot operation.
ULA seems to have settled on a 5.4 m diameter Vulcan lower stage. I would have thought this indicated their choice of the BE-4, since RP-1’s much greater energy density over methane should mean that if they went with the AR-1 then they would choose something closer to a 4 m diameter lower stage, comparable to the Atlas’s 3.8 m. But in a recent reddit interaction, Tory Bruno said that an AR-1 powered Vulcan would also be 5.4 m in diameter and would be “yes, about” the same height as Atlas V. That seems strange. [1]
Another recent revelation is that when Vulcan first flies (they say mid-2020), it will not be using the current 3.05 m diameter Centaur upper stage, but will instead use a 5.4 m diameter Centaur V, powered by four RL10 engines. That part really surprises me as the RL10 is rumored to be quite expensive, though Mr. Bruno said, “RL10 has had several updates, so it’s not a 1960s engine any more. The elegance of the expander cycle in LOX/LH2 definitely has appeal for its size class. (remembering that the cube-square law limits how big it can go). Aerojet has done really intriguing work in additive manufacturing and how that might be applied to RL10.” [2] so I wonder if some of its updates have target lowering its cost of manufacture.
Anyhow, the Centaur V sounds as if it is half-way between the current Centaur and the eventual ACES (Advanced Cryogenic Evolved Stage), lacking the ACES IVF (Integrated Vehicle Fluids) systems and MLI (Multi-Layer Insulation) which are required for extra-long duration missions and propellant depot operation. Mr. Bruno did say they have not yet decided if they will stick with the RL10 for ACES.
Kirk: No need to post your comment twice. It did not appear because it included two urls, and such comments require my approval. Either be patience, or include only one url per comment.
“…Mr. Bruno did say they have not yet decided if they will stick with the RL10 for ACES.”
There are supply chain concerns here, of course.
If they go with the BE-3 instead of the RL-10 for ACES, they’ll be reliant entirely on Blue Origin for the engines on both stages of the Vulcan. One senses some discomfort at ULA at such a prospect.
But when you decline to build any of your engines in-house, these are the difficulties you can’t avoid.