Rocket Lab Is About To Attempt Its New Recovery Method
After multiple attempts to catch Electron’s first stage out of mid-air with a helicopter, the company is rethinking what’s best for partial reusability. In the lead up to Rocket Lab’s first mission catch attempt, they tested the process of recovering the booster from the water with a controlled descent. Now in early 2023, this initial testing method looks like it might be the official future strategy.
In just two days from now, Rocket Lab will launch from LC-1 and plans to recover the booster after a safe water splashdown. In the few times this process has been completed, it’s not only been much safer but the results have also been very promising despite the vehicle being partially submerged in the water.
Even the Rutherford engine has proven to be reusable after a water splashdown with recent testing showing exactly that. While more testing is necessary, the upcoming mission is a great example and shows where Rocket Lab is headed in terms of reusability. Here I will go more in-depth into the upcoming mission, how Electron water recovery works, what to expect in the near future, and more.
Upcoming Mission
On March 22nd, “The Beat Goes On” mission will launch two of BlackSky’s Gen-2 Earth-imaging satellites from Pad B at Rocket Lab Launch Complex 1 in Mahia, New Zealand and will bring the total number of satellites delivered by Electron to orbit to 159. Electron will deliver the satellites to a circular 450KM orbit, which will bring the total number of satellites in BlackSky’s constellation to 16. Yesterday Rocket Lab tweeted saying, “So how do we launch a rocket to space, bring it back to Earth under a parachute, splash it down in the ocean, and then pick it up with a boat to return it to our rocket factory? Pretty much like this. Our next marine recovery mission launches March 22nd, weather dependent.” This included an image highlighting the mission profile and recovery stages.
The pair of high-resolution, multi-spectral, Gen-2 satellites to be launched on Electron will expand BlackSky’s network in space and its offering of real-time geospatial intelligence and monitoring services. BlackSky combines high-resolution images captured by its constellation of microsatellites with its proprietary artificial intelligence software to deliver analytics and insights to industries including transportation, infrastructure, land use, defense, supply chain management, and humanitarian aid. As a secondary mission, Rocket Lab plans to recover Electron’s first stage after it parachutes back to Earth and splashes down in the ocean. Rocket Lab’s recovery team will retrieve Electron using a customized vessel and transport the stage back to Rocket Lab’s production complex for analysis. Data from this recovered stage will inform Rocket Lab’s ongoing recovery and reuse program.
Looking at a more detailed flight profile better explains the plan to recover Electron’s booster. At two and a half minutes after launch, at an altitude of ~80 km, Electron’s first and second stages will separate, and the second stage will continue on to orbit for payload deployment. With the engines shut down, Electron’s first stage will coast to apogee. During the coast, a reaction control system will re-orient the first stage 180-degrees; this will put the stage on the ideal angle for reentry, enabling it to survive incredible heat and pressure during its descent back to Earth. After decelerating to Mach 2, a drogue parachute will be deployed to increase drag and stabilize the stage as it descends. During the last couple of kilometres, a large main parachute will then be deployed to further slow the stage and enable a soft water landing. Rocket Lab’s vessel will rendezvous with the stage after splashdown and retrieve it for transport back to Rocket Lab’s production complex for inspection and reuse.
This shift in Rocket Lab’s plans was revealed last month when CEO Peter Beck made comments relating to possible changes for Electron recovery. He first said that the company was weighing recovering stages from the ocean and refurbishing them for launch rather than catching a stage with a helicopter. The overall sentiment was that mid-air recoveries are very cool but there are a lot of external factors not to mention the difficulty of consistently catching a falling booster with a helicopter. Ideally, Rocket Lab could just parachute the booster down into the water safely each mission and then grab it with their special ship before refurbishing it for the next mission.
Electron Waterproofing
Now that we know more about Rocket Lab’s upcoming mission and the plan for recovery, we can take a closer look at how Electron can withstand the water landing and be refurbished. We saw the most recent catch attempt months ago during the Catch Me If You Can mission. Similar to the previous attempt, the goal was to catch Electron’s booster out of mid air using a helicopter. In this case, the company was once again unsuccessful. Specifically, Rocket Lab reported that they had planned to attempt a mid-air capture of Electron’s first stage with a helicopter if conditions allowed. In regard to this most recent failed attempt, Peter Beck commented during the recent call that “This turned out to be quite a happy turn of events. Electron survived an ocean recovery in remarkably good condition, and in a lot of cases its components actually pass requalification for flight.”
He also said, “Pending this outcome of testing and analysis of the stage, the mission may move us towards sticking with marine recovery altogether and introduce significant savings to the whole operation. In 2022 we proved that it was possible to rendezvous with a returning stage mid-air and get it on the helicopter hook, but if we can save ourselves the extra step by just plucking it out of the water we will. What the water landing does enable us to do is recover more vehicles because we don’t have the constraints of the operations of the helicopter,” he said. “So, financially it’s kind of the same, but we get to actually reuse more vehicles.” Even right now with recent missions where the plan is not to land in the water, Rocket Lab is reporting that the first stage is holding up very well. On the upcoming mission, the booster is supposed to have additional water proofing making the refurbishment process even smoother.
As far as actual tests, in September of last year, Rocket Lab successfully test fired a reused Rutherford first stage engine for the first time – a significant technical achievement in the Company’s efforts to make its Electron launch vehicle the world’s first reusable orbital small rocket. Rocket Lab conducted the full-duration, full-thrust test fire of the refurbished Rutherford engine at the Company’s engine test facility. The engine was previously successfully launched to space and returned to Earth during Rocket Lab’s recovery mission, ‘There And Back Again’, launched on May 2, 2022. The mission was the first time Rocket Lab attempted a mid-air capture of Electron’s first stage, using parachutes on the rocket to slow its descent from space before a helicopter plucked the rocket from the sky as it approached Earth’s surface. The Electron stage was ultimately released for a soft ocean splashdown, before it was collected by vessel and returned to Rocket Lab’s production complex.
The refurbished Rutherford engine passed all of the same rigorous acceptance tests Rocket Lab performs for every engine, including 200 seconds of engine fire and multiple restarts. Data from the test fire shows the engine produced full thrust of 21kNs within 1000 milliseconds of ignition and performed to the same standard of a newly-built Rutherford engine. This Rutherford engine will now continue as an engine life leader for future Rutherford development. Peter Beck commented, “We’ve always been at the forefront of innovation with Electron, having pushed the boundaries of many technologies including carbon composites, electric turbo-pumps, and 3D printed rocket engines. Now, we’re leading the pack once again bringing reusability to small launch vehicles.
“Being able to refly Electron with minimal refurbishment is the ultimate goal, and so the fact that the recovered components on this engine performed on the test stand with minimal rework is further validation that we’re on the right path. If we can achieve this high level of performance from engine components recovered from the ocean, then I’m optimistic and incredibly excited about what we can do when we bring back dry engines under a helicopter next time.”
Even on initial water recovery missions, Rocket Lab reported that the stage held up remarkably well after experiencing the trip to space and back in just 13 minutes. They were quoted saying, “The carbon composite structure was completely intact. As expected, the heatshield on the base of the stage suffered some heat damage during re-entry. It was never designed for this load case, but before we strengthen the heat shield we wanted to see just how much heat it could take unchanged. With a wealth of data on this now, our team has already started working on upgrades for future recovery missions.” The upcoming mission is expected to only provide more data and shift Rocket Lab toward only water recovery methods going forward.
Conclusion
Rocket Lab is in the process of testing a slightly different Electron booster recovery method. While the original goal was to catch the booster with a helicopter, failed catch attempts made the company realize that the stages recovered from the water were in great shape. In a few days, we can expect another test of this exact process. We will have to wait and see how it progresses and the impact it has on the space industry.
