Tory Bruno answers questions about Vulcan and ULA

United Launch Alliance's Tory Bruno recently hosted an 'ask me anything' on the subreddit r/ula! This article has picked out the more interesting questions that were answered by Bruno. A table has also been attached below to explain any acronyms or terms used.

Q: Vulcan was initially supposed to fly in 2020, then 2021 then 2022, and here we are now. We know that pretty much every rocket is late and it’s complicated. However, can you point to specific things you would have done differently with the benefit of hindsight to make Vulcan fly on the original schedule or closer to it?

Vulcan was originally intended to fly with Atlas' Centaur III. As the market evolved, we made a decision to develop a more advanced Centaur V. And, the BE-4 took a little bit longer to get through development. Great engine now.

Q: If you could do anything over again, what would it be and why?

Started with Centaur V to begin with (versus beginning Vulcan with a Centaur III on top).

Q: Why was the development of ACES abandoned?

Not abandoned. Absorbed into Centaur V and its future planned upgrades.

Q: How many Vulcan boosters and Centaur V's are currently in the process of being built?

22

Q: Starship competitor, when?

Now.

Q: What is your best estimate for the dry mass of the new Centaur V? How much mass did you save by dropping from 1.35mm steel to 1.07mm steel?

My best estimate is the actual exact mass. Quite a bit.

Q: How are the new GEM63XL solid boosters different than past solid boosters ULA has used and how do those updates help Vulcan’s capabilities?

GEM63XL is much larger than the GEM63 now flying on Atlas. And, some differences in the design of the nozzle and throat.

Q: Where do you see the future of Vulcan going? Such as Vulcan II? Will you be flying overlapping versions like with Delta II and IV, or will it be more sequential to streamline production/flight?

We will be continually upgrading Vulcan over time.

Q: What is the current performance penalty for SMART recovery? Do you anticipate that going down?

Approximately 1 lb of payload per 7 lbs of inert weight. Yes.

Q: Fairing recovery seems at first glance, a simple addition to lower launch costs and increase flight rate. Have ULA investigated the concept for Vulcan, and could it be incorporated at a future date?

Yes. Fortunately or unfortunately our fairing cost is so much lower that it is no longer at the top of the reuse list. Maybe later.

Q: When will ULA go for full reusability?

When we introduce a LEO-optimized architecture. Booster fly-back is inappropriate for a high energy design, which is why we are doing engine recovery on Vulcan.

Q: Are you happy with selecting BE-4? Having the knowledge that you have now, which engine would you select? What if SpaceX would offer you Raptor?

Yes. BE-4. Raptor would not work well with Vulcan's architecture.

Q: What can you disclose about the current state of BE-4 production/delivery as presumably the production rate is far higher now compared to earlier in the year? Are there any current plans to further improve the versatility of Vulcan such as a configuration similar to Delta 4 and Falcon Heavy? Or an optional wider faring to increase the range of payloads that are capable of being launched?

The large and modern BE-4 rocket engine factory in Huntsville is up and running and full of WIP. Ramping up production rate as we speak. Yes.

Q: How would the engine bay recovery and refurbishment operations work for BE-4 and Vulcan? Do you think there will be problems with contamination from seawater?

Recovery will return to Florida. Initial engines will likely return to factory for full check out. Later on intend to inspect and reinstall at the Cape. The key is to not get them wet. Fortunately, the exit plane of the bells sits over 20 feet above the water. Also developing options for spray shields.

Q: Is ULA working on any nuclear thermal propulsion projects? Are you bringing on any folks with a nuclear background to fill that expertise gap?

Yes. I'm already here...

Q: Vulcan has been contracted to launch DRACO, a Nuclear Thermal Propulsion demonstration. With that in mind, what does the certification path look like for Vulcan to be able to fly Nuclear payloads?

There is a specific set of requirements for flying nuclear payloads. To date, ULA is the only US provider to have flown nuclear payloads. So we are well familiar with the process.

If you'd like to read the rest of the questions and Tory Bruno's answers they are available here.