Rocket Lab aims to do for small rockets what SpaceX has done for big ones
By Cat Hofacker|November 5, 2020
16th flight to loft 30 satellites, recover Electron booster
Rocket Lab has added another item to the to-do list for its next launch.
In addition to launching 30 satellites aboard an Electron rocket later this month, the California-based small-launch company announced today that it will attempt to recover the first stage of the rocket.
The recovery test during the upcoming mission, which the company has dubbed “Return to Sender,” would cap a year of low-altitude drop tests and data gathering from previous launches Rocket Lab has conducted over the last year to prove the company can reuse the first-stage of its Electron rockets. CEO Peter Beck hopes this will lead to cheaper and more frequent launches.
“About 80% of the mass and cost of launch vehicles resides in the first stage,” Beck told reporters during a briefing yesterday. “If you can successfully bring back a first stage and do none-to-minimal refurbishment, you can realize a good savings.”
At 17 meters tall and 1.2 meters in diameter, an Electron is too small to carry heavy retrorocket engines for a vertical landing the way Blue Origin and SpaceX do for their larger launch vehicles. Instead, Rocket Lab plans to snag the boosters out of midair via helicopter as they tumble back to Earth, a scenario practiced during an April flight test with a booster test article.
But for the November test, the Electron booster will splash down in the Pacific Ocean under parachutes “to understand the structural condition of the stage” before attempting a midair capture, Beck said.
The “Return to Sender” mission has a 14-day launch window that opens Nov. 16 local time. Rocket Lab plans to stream the launch from its New Zealand complex on YouTube and release footage of the booster recovery after.
Here’s the sequence of events: An Electron rocket will blast off from Rocket Lab’s Launch Complex 1 in New Zealand. Two and a half minutes into flight, the first and second stages of the rocket will separate, and the second stage will fire its engines to loft the 30 satellites to a 500-kilometer sun synchronous orbit. Meanwhile, the kerosene Rutherford engines on the first stage will shut down. As the booster begins to fall from an altitude of approximately 80 kilometers, a series of thrusters will pulse to rotate the booster 180 degrees. This reorients the booster so its heat shield will bear the brunt of the searing heat of reentry.
Once the booster reaches an altitude of roughly 14 kilometers, a drogue parachute will deploy to slow the descent, followed by the main parachute unfurling at about 3 kilometers. If all goes as planned, this booster will gently splash down in the Pacific Ocean about 400 kilometers off the coast of New Zealand, after which Rocket Lab will send two ships to hoist the booster onto a recovery vessel and back to Rocket Lab’s production facility.
From there, Beck said engineers will spend the coming weeks disassembling the booster and examining “how well each of the components and the subassemblies” performed during reentry.
“At this stage, it’s way too early to understand what condition we’re going to get it back in,” Beck said, and that will determine what future tests Rocket Lab will conduct.
“We’ll probably splash down a few more” boosters to determine how much refurbishment is needed between launches, Beck said, and once the stages are consistently returning in good condition, “we’ll start bringing the helicopter in” to test a midair capture.
“The ultimate goal here is to get it back in such a condition we can put it back on the pad,” refuel and launch again, he said.