Astra Space Is Making Progress On Rocket 4
Since the unfortunate cancelation of Astra’s Rocket 3 line, the company has been working on a new and improved launch vehicle and system. Inconsistent launches among a few other reasons caused the company to move on to the next generation of rocket. While Rocket 4 shares a lot of similarities with the past versions, it also has some differences that Astra is confident will help them succeed going forward.
In the past couple of months, we have received various updates on the progress being made. Just days ago the company revealed details about a new tank pressure test. With this complete they are now moving on to qualification tank builds along with work on the upper stage. As of right now, Astra is still hoping to launch this rocket later this year.
In addition to Rocket 4, they are also working on a completely revamped launch system. This system includes the rocket itself, the various ground systems, and mission control. They highlight that a reliable launch system is about much more than just a rocket, it’s about creating an integrated system that works seamlessly together. Here I will go more in-depth into recent progress the company has made, what exactly Astra is working on, what to expect in the future, and more.
Rocket 4 Tests
Not long ago Astra announced that they would begin work on Rocket 4. Only four days ago on the 25th the company tweeted saying, “As we progress in the building of Launch System 2, we continue to focus on reliability + scale through rigorous testing + design processes. Test Tank 1 met all testing objectives and allows our team to move into qualification tank builds of both the first + upper stage.” This included a short video highlighting some of the work and tests being done.
Specifically, the company recently completed a tank development test for rocket 4. Designed to prove out manufacturing at scale and reliability of the design. The point of these tests was to verify the performance of the design and their new manufacturing process.
Back on December 9th, Astra Space tweeted mentioning, “Building a scalable system includes having simplicity and consistency in our production process. Enter our new Friction Stir Welder: responsible for all of the vertical weld seams on Rocket 4’s tank sections.” This included another short video going over the new system and process that Astra is using. They also commented in another tweet mentioning, “With the transition to a common diameter upper stage, this new tooling will help Astra automate and scale both first stage and upper stage Rocket 4 tank production.”
Rocket 4 is the product of extensive learning that took place during the design, manufacturing, and launch of the prior Rocket 3 series. With much of its architectural heritage coming from the Rocket 3 series, Rocket 4 capitalizes on Astra’s existing flight heritage, while working to fine-tune the rocket for improved reliability and manufacturability. Astra has focused on building its rockets using proven and cost-efficient metallic structures, leveraging multidisciplinary production techniques and eschewing labor- intensive processes such as carbon composite layups. These techniques allow for rapid manufacturing and reduced production costs, which are realized in lower launch costs to customers.
Focusing back on the pressure test completed only days ago, the test was trying to ensure reliability. Here test tank 1 was subjected to significantly more pressure and cycle testing than a typical flight tank would undergo. The final step was a water burst test where an intentional over pressurization of the tank occurs to provide data on its strength. Astra reported that this process went very well and they are now moving on in the rocket’s development.
Astra’s Future Plan
Now that we know more about some of the recent tests being completed by Astra, we can take a closer look at the rocket itself and some of the changes the company is making. Astra’s goal with Launch System 1 was to achieve orbital capability as quickly as possible and demonstrate that they could mass-produce rockets. Following the flight anomaly on their last launch, the company points out that they listened to their customers, their team, and their stockholders and made the strategic decision to accelerate the introduction of a higher performance rocket and add additional testing that we believe will increase the reliability of future launches.
Throughout the vehicle, they have incorporated mass-saving features such as common dome tank designs and submersed helium tanks. The first stage consists of two cylindrical tanks, enlarged relative to the Rocket 3 series, but using the same proven design and fabrication approach. The LOX and fuel tank are an aluminum common dome tank set, designed and qualified in-house. The longitudinal seams are friction stir welded and the circumferential seams are TIG welded. The domes are now formed directly from thin sheets of aluminum, and the cylinders are rolled sheets. Helium COPVs are submerged in the fuel tank for packaging efficiency. The tank includes slosh baffles and anti-vortex devices. The upper stage is now essentially a shorter version of the first stage, utilizing the same welding techniques on a similar architecture, though a number of elements are further weight optimized given the increased weight sensitivity of the stage. Like the first stage, it is a common dome assembly with Helium COPVs submerged in the fuel tank.
In addition, one of the biggest updates that Astra released in the past couple of months was progress on its new Rocket 4 main engine. The Rocket 4 first stage is powered by two turbopump-fed LOX engines, each with an expected maximum sea level liftoff thrust of 40,000 lbf. The engine features a regeneratively-cooled combustion chamber operating at over 1,000 psia chamber pressure which is fed by a turbopump. Each engine can gimbal to provide vehicle steering and control. Actuation of the Thrust Vector Control actuators is “fueldraulic”, powered by high-pressure fuel tapped off from the main fuel circuit. Fueldraulic actuation simplifies the vehicle as it does not require an external high-pressure or high-voltage source for actuation systems that require significant power. The pyrophoric ignition of the engine is ground-based, eliminating another plumbing system from the vehicle and further reducing cost, weight, and complexity. Astra is developing and qualifying an upgraded derivative of a previously qualified engine for this application. The company’s past engine was responsible for a few issues on Rocket 3 launches and Astra is trying to change that going forward.
Launch System 2 is their answer to existing launch customers, and an increasing number of satellite operators around the world, that need affordable and frequent dedicated orbital launch services to enable new space services. These launch services have the potential to unlock next generation communications services, critical national security and defense applications, and a wide range of Earth observation capabilities that will create a healthier planet. They believe Launch System 2 will provide Astra’s customers the launch services they need, whether that be constellation deployment, constellation management, or responsive missions. Dedicated small launches give satellite operators the ability to deploy their spacecraft directly to their operational orbits and allow them to start providing services and adding value sooner.
While the new launch system builds on the heritage of Launch System 1, Launch System 2 is more than just upgraded hardware – it represents a cultural shift from the primary focus on schedule to a focus on reliability. This launch system is the result of a significant change in how Astra designs, builds, qualifies, and operates their launch system. While Launch System 1 began its initial development with just a handful of people in a garage six years ago, Launch System 2 is being designed by teams of world-class engineers in a 225,000 sq. ft. manufacturing and testing facility. They are a completely different company than when they designed Launch System 1 and that shows in the level of investment they’re making into the reliability of this system. The entire system has been scrutinized, and re-engineered where necessary, to support their plans to reliably and repeatably deliver their customers’ payloads to orbit. This shift encompasses every stage of the development process, with multiple teams in the organization focused primarily on reliability, quality, and system safety. Astra makes it clear that they are better-resourced across the board than we were during the development of Launch System 1, including the creation of a new System Verification and Assurance team, quality control lab, and failure analysis lab with state-of-the-art testing capabilities.
As partially mentioned prior, the Astra launch system is comprised of three key subsystems: The Rocket – the launch vehicle itself, which ultimately delivers payloads into their final orbit The Ground System – the infrastructure on the pad when Astra launches. And Mission Control – the interface between their operators and the rocket. Something we can expect to see more of not long from now in the future.
Conclusion
Astra Space is continuing to work on Rocket 4. In the last couple of weeks, they have been hard at work trying to test this new system and its various components. This includes a water pressure test completed only days ago with good results. We will have to wait and see how it progresses and the impact it has on the space industry.
