In the recent months, Virgin Galactic is talking about some Delta spaceship that is about to launch space tourists every week. They want to retire the SpaceShipTwo this year and shall begin flight testing of Delta in 2025. I don't recall Virgin Galactic having ever officially presented that spacecraft, only the SpaceShip III which was announced two or three years ago I believe.

Now that VG is talking about that Delta spaceship, is it the very same spacecraft as the originally announced SpaceShip III, just renamed or having gotten a name (like Unity for the SpaceShipTwo) or did VG change their mind and now build a different spacecraft instead of the SpaceShip III? Or do they build both?

  • $\begingroup$ Judging by a 2022 article, spaceship 3 and delta are two entirely different craft. 3 is an improvement over 2, and is seen as a medium term class, in-between spaceship 2 and delta. By 2022 effort was directed towards delta, and spaceship 3 is on a slower schedule with the second spaceship 3 in limbo. Priority in 2022 was to return unity and eve to flight, and get delta on a faster development schedule. Delta is a different development path to spaceship 2/3 $\endgroup$ Commented Jan 29 at 19:30
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    $\begingroup$ @blobbymcblobby - all indications point to Spaceship III being cancelled. I was going to post an answer with quotes from VG, nothing conclusive it's more about what is not being said. Unless you are already working on an answer then I will hold off since your comment effectively answers the first part of the question. $\endgroup$ Commented Jan 30 at 17:31
  • $\begingroup$ @StevePemberton please go ahead, id run out of time to spend looking further, so my info is pretty out of date. Yes, i was waiting off something conclusive but as you say not much is being said, so please go ahead :) $\endgroup$ Commented Jan 30 at 17:55

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To answer the first part of your question, SpaceShip III is not the same as Delta class. As for the second part of your question, it appears that SpaceShip III has been effectively cancelled, based on Virgin Galactic statements over the past couple of years about program priorities, and essentially confirmed in November 2023 by CEO Michael Colglazier in the Q3 2023 earnings call (timestamp 50:52, after clicking the link select Continue without a Q4 account/I am an individual attendee)

Our Delta class ships are powerful economic engines. Because of their breakthrough capacity in revenue generation, we are choosing to leapfrog past our third generation ship VSS Imagine and move directly to our fourth generation the Delta class as the model type basis for our production fleet. VSS Imagine will be used to support ground based elements of the Delta program and we will not bring that ship into service.

VSS Imagine was the first of two planned SpaceShip III vehicles, including VSS Inspire.

As for your question about similarities between the two vehicles, the goals for both SpaceShip III and Delta were similar; to increase the number of paying passengers per flight from four to six, and to also fly at a higher frequency than SpaceShipTwo VSS Unity. Along with other operational and production cost reductions compared to SpaceShipTwo, all of this is planned to result in higher revenue and profitability.

The original plan for SpaceShipTwo was to carry six paying passengers in addition to the two pilots, as shown in computer renderings of the SpaceShipTwo cabin that Virgin Galactic made available in July 2020.

SpaceShipTwo cabin

However so far Unity has only carried a maximum of four passengers, which is presumably due to performance limitations of SpaceShipTwo, since it seems that the SpaceShip III and Delta modifications are needed to increase to six passengers. Although as indicated in a SpaceNews article about the VSS Imagine unveiling which included quotes from Virgin Galactic’s chief of spaceflight operations Mike Moses, some of the limitation was also apparently due to VSS Unity still carrying some instrumentation weight from its prior use in the test program.

As you indicated, VSS Imagine was announced in early 2021. The press release for VSS Imagine stated:

the SpaceShip III class of vehicles are built to enable improved performance in terms of maintenance access and flight rate.

The press release did not mention the number of passengers that Imagine would carry, although Mike Moses was quoted in the SpaceNews article as saying that SpaceShip III would carry six passengers.

Delta however is being designed to take these improvements much further. Whereas SpaceShip III was planned to be able to fly twice a month, double the flight rate of SpaceShipTwo, Delta has a goal that each ship will eventually fly eight times per month, as well as ambitious goals for vehicle lifecycle (500 flights) and low production costs, with an estimated vehicle payback after only six months of operation, as seen in this slide from the Q1 2023 earnings call which was based on the previous one flight per week goal for Delta:

Q1 2023 earnings call slide

As stated by Michael Colglazier during the Q1 2023 Q&A about changes that would occur with Delta (timestamp 21:25):

The main things that we’re changing you may have heard from us in the past, we’re keeping the look, the shape technically the outer mould line of the vehicle the same. We are changing the composite system and moving with a high temp composite with that. That gives us the ability to reduce weight in a variety of places, change the way we manage the thermal forces upon the ship. We will make updates into our avionics packages, things like that.

It's not clear if any of the Delta changes actually began during SpaceShip III development, other than a general comment made as Colglazier continued:

And generally take advantage of all the learning that we’ve had across the flight test program and across the development of Imagine.

This likely included some of the production changes that were being developed for SpaceShip III, as mentioned in the SpaceNews article about the VSS Imagine unveiling:

Moses said the most significant change is in the structure of the vehicle. Engineers took the design of SpaceShipTwo and adjusted the structure to make it “more efficient and more elegant,” which reduces the weight of the vehicle and also makes it easier to inspect and maintain.

Virgin Galactic also switched to a more modular approach for building Spaceship III. With SpaceShipTwo, the company built up the vehicle in a single cradle, starting with the wings and then adding the cabin and other components. “It made it serial and very much limited the number of people who could work on the ship at any one time,” he said.

With Spaceship III, different components of the vehicle can be built in parallel and then assembled into the final vehicle. “From that standpoint, you get a much faster build and a much more efficient build,” he said. That approach also improves maintenance, he added.


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