Rocket Lab is ready to launch its first Electron rocket since a failure on Sept. 19. The mission, named “The Moon God Awakens” is scheduled to launch during a two-hour window on Dec. 15 between 5:00 pm and seven:00 pm NZDT (04:00 to 06:00 UTC). If unable to fly on the primary attempt, the window extends into December with two-hour windows every day.
The payload consists of an Earth-observing satellite named for the Japan-based company the Institute for Q-shu Pioneers of Space, Inc. (iQPS).
The Anomaly
The Electron failure occurred in the course of the mission named “We Will Never Desert You,” carrying the third satellite for the Earth-imaging constellation developed by Capella Space.
Rocket Lab CEO Peter Beck spoke with NSF during a recent NSF Live episode on YouTube about what happened in the course of the flight. In response to Beck, the primary stage of the rocket flew exactly as planned, followed by a so-called “ignition transition” of the second stage.
“During that form of ignition transient, there’s an entire bunch of stuff that obviously happens and… if you wish to boil it all the way down to its most basic form possible, there was essentially an electrical arc occurred which pulled down the entire voltage,” Beck said.
The system aboard Electron consists of a high voltage and low voltage system. Beck commented that the arc from the high-voltage rail ended up downing the low-voltage rail as well.
“So we’ve that 500-volt rail there sitting on the potential,” Beck explained. “So when the arc occurred, should you return to the live stream, you possibly can actually visually see, you already know, a giant form of greenish glow for a small period of time. The entire of the entire event was about 1.6 seconds or so.”
Beck noted that the arc was so long as one meter.
This is exclusive to this rocket since the upper-stage Rutherford Vacuum engine uses electric turbopumps to get propellant into the engine. The vehicle is currently the one orbital-class rocket on the planet that uses such an upper-stage system.
Beck described Paschen curves, which in its simplest form is an equation leading to a curve that determines at what voltage and what atmospheric pressure you might be most certainly to see an electrical arc.
“At a really partial vacuum in certain gases especially, it’s aggravated which you can form these big arcs,” Beck noted. “Now with Electron, after all, at stage separation, the rocket Gods wouldn’t be so kind to us. They put us within the worst a part of the Paschen curve possible at that very time limit where the battery voltage is at its highest, after all, because there may be a full battery.”
Beck noted that there was likely a really small leak allowing electrons to flow out and interact with the mixture of trace amounts of nitrogen and helium, plus 500 volts of direct current with alternating current rippling on top of it in that unlucky a part of the curve.
How they were in a position to determine all of this involved individuals who worked on movie sets.
Using the onboard cameras, they were in a position to recreate all the lighting conditions and a few unique shadows on the nozzle. Using those shadows, together with visible sparks, led them to this conclusion of an arc.
“The guy who did all of the lighting work, we kept him segregated from the investigation team,” Beck said. “So he had no idea where the realm that we were looking was. So it was a totally independent and isolated form of project. And, you already know, it was about per week or so in and we’d already identified this area as essentially the most probable when he got here in and presented as a results and it was, bang.”
Corrections to Electron
Beck noted that one of the best option to solve an issue is to delete the issue. After latest instruments were used to check electrical potential fields all the way down to microscopic levels, the team decided to pressurize the whole area near the batteries.
“[In] the upper stage, there’s a battery frame across the upper stage engine and we filled in all the panels across the battery frame and put a versatile boot as much as the nozzle,” Beck said. “So by pressurizing that area, it only must be like a half PSI, principally it’s like being down here on Earth. So there’s no way you possibly can jump arcs at 900 millimeters or a meter. You principally remove any of that form of Paschen law out of the equation.”
Beck noted they’d be ready for the opening of this launch window in November so long as the shopper was ready, which they’re. He credits the team working hard hours to get to this mission. It’s unclear why the launch got pushed from late November to the center of December.
“The team has done a tremendous job, like no one slept for weeks and weeks and just plowed on through it,” Beck said. “It’s one thing to get to know the causes, it’s one other thing to form of implement pretty drastic corrective measures…on this timeframe after which undergo all of the testing and acceptance writing and whatnot.”
The Moon God Awakens Mission
Electron’s return to flight will liftoff from Launch Complex 1B at its custom-built launch site in Mahia, Recent Zealand.
The payload is an artificial aperture radar satellite that may collect high-resolution images of Earth. The satellite will join one other iQPS satellite already in orbit. The goal is a network of 36 satellites that can be able to monitoring the planet at specific fixed points every ten minutes.
While the official satellite designation is QPS-SAR-5, it’s also called , named after the Japanese God of the Moon. That also influenced Rocket Lab’s naming convention for this mission. The satellite will launch right into a 575-kilometer circular orbit inclined 42 degrees.
The satellite was originally set to launch aboard Virgin Orbit in 2022, nevertheless, the corporate went out of business before any iQPS satellites could possibly be launched.
The Flight
Despite the changes to the upper stage following the anomaly, the carbon fiber composite rocket will follow a timeline just like previous missions.
At T-2 seconds, the nine Rutherford sea level engines ignite, running a mix of Rocket Propellant 1 (RP-1), which is a refined type of kerosene, and liquid oxygen (LOX), followed two seconds later by liftoff. The 18-meter-tall vehicle will reach Max-Q, the purpose of maximum aerodynamic stress on the vehicle, at T+1 minute 4 seconds.
At T+2 minutes 40 seconds, the nine engines will shut down during an event generally known as predominant engine cutoff, or MECO. Three seconds later a pneumatic pusher separates the primary and second stages. At T+2 minutes 46 seconds, the Rutherford Vacuum engine ignites. That is the portion of the flight where the previous anomaly occurred.
The fairings will separate about three and a half minutes into the flight. At T+6 minutes 43 seconds, the primary of two engines powering the electrical turbopumps is depleted. During a process generally known as hot swap, the primary battery is jettisoned because the second battery takes over. The second stage will proceed to run until T+9 minutes 32 seconds, at which point the second engine cuts off in a procedure generally known as SECO, followed by separation of a kick stage, positioned underneath the satellite, 4 seconds later.
The kick stage, powered by a 3D-printed Curie engine, ignites at T+54 minutes and 13 seconds into flight. This single burn will last 2 minutes 27 seconds, followed by the deployment of the satellite only one minute later.