A helicopter catches a rocket mid-flight!

The New Zealand and American company Rocket Lab has been carving out a good reputation in the space industry for several years now. The firm that chains commercial launches with its light launcher Electron has taken another step towards reusability, which it has made its goal.

The named mission There and Back Again (Round trip) took place as a “routine” mission on the night of May 2 to 3 (French time) and successfully deployed 34 small satellites designed by several countries in the world, including a French one.

One goal: to reuse

It’s the 6^and success in a row for the little one rocket which has so far experienced three failures out of its 26 orbital launches since the peninsula from Māhia, in the north of New Zealand. So far Electron remains a single-use rocket like almost all rockets used today. But the company’s goal is to make it reusable, not by hovering like the space shuttle or by powered landing like rockets. SpaceXbut by helicopter !

However, several things diverge from the draftElon Musk, if the latter maintains that reuse allows the lowering of launch costs, Rocket Lab’s desire is to allow a high rate of fire. Moreover, as the landing is not propelled, Electron keeps almost all its carrying capacity contrary to a Falcon 9 which must keep reserves of fuel, unused fuel therefore to place loads in orbit.

The enormous constraints posed by spatial reuse nevertheless remain. Electron has seen its materials adapted for atmospheric re-entry at high speedand in particular those which constitute the nine thrusters Rutherford. The rocket must ensure a reversal in theair in the manner of Starship and proper deployment of parachutes. These steps have already been completed, but the biggest piece remained to be done.

And back again…

The first stage of Electron has already been recovered during a previous mission simply using parachutes, and capture by helicopters has also been attempted but with a rocket stage dropped in the air, which did not return so not high-speed space travel.

The real general rehearsal in real conditions is now done, after takeoff at 00:50 (Paris time) and 18 minutes of flight, Electron performs his maneuvers correctly, deploys his parachute and gets caught by the helicopter as expected. However the behavior of theaircraft turned out to be abnormal and, for safety, the pilot preferred to unhook the precious package which was then deposited by parachute on the surface of the ocean.

A success therefore for Rocket Lab which has reached a great milestone. We will find the company and the little Electron very soon for the exciting mission capstone of the Nasaa nanosatellite which will be sent around the Moon to test the trajectory of the future lunar space station Gateway !

Rocket Lab is preparing to recover the main stage of its launcher in full flight

Article of Remy Decourtpublished on November 30, 2021

Since its first test flight, carried out in May 2017, the small Electron launcher from Rocket Lab carried out 21 missions for a total of 107 satellites in orbit. A fine performance for this small launcher which is destined to become partially reusable, like the Falcon 9 of SpaceX. For now, this launcher is not. It could become so in 2023 with the reuse of a main stage recovered during a flight scheduled for the first half of 2022.

During Electron’s last mission, on November 18, 2021, Rocket Lab took advantage of the parachute return of the small launch vehicle’s main stage to demonstrate the recovery helicopter’s capabilities to track and approach close enough to upstairs to capture it in midair. The maneuver did not go to the end. That was not the goal. As planned, the stage ended its flight by landing on the ocean. It was only a demonstration.

After its separation with Electron’s upper stage, the main stage was turned back towards the ocean under parachute. He again performed a controlled “dive” into the ocean, from where he was recovered. While parked 370 kilometers offshore from the point of impact, Rocket Lab’s recovery helicopter successfully tracked the stage’s return. During its descent, the stage reached a maximum speed of about 10,000 km/h, while maintaining communications with the Rocket Lab control and recovery building stationed at sea.

Rocket Lab crews joined the stage floating on the ocean to secure it and prevent it from sinking approximately 80 minutes after liftoff, halving the time taken on previous recoveries to reach the stage. Stages that are currently not reused are brought back to the Rocket Lab production complex in Auckland, New Zealand, where they are reviewed in preparation for future refurbishment operations to be re-employed.

An unprecedented aerial capture

After the success of this demonstration, Rocket Lab is done with the water landings. Time for much more serious things with the recovery of the stage in full flight using a helicopter which will carry additional fuel tanks to guarantee it sufficient flight time to fly behind the stage, catch it in full flight and bring it back to dry land. This first attempt is planned for the first half of 2022.

For this capture in full flight, the stage will have to be modified. It will be equipped with a thermal protection system applied to the entire floor and to its nine Rutherford engines to help it withstand the high temperatures which may rise to 2,400 degrees Celsius during the re-entry. The parachute will be reinforced and modified with the addition of a line of engagement so that the helicopter can capture it.

Recovery harder than it looks

As surprising as it may seem, it is more complicated to recover a small storey than a large one, in particular because its constructive index is high. This index measures the ratio mass of the floor and mass of the propellants embarked. The higher this index, the greater the heat flow. As a result, the floor will enter like a ball, which most certainly explains the choice to recover it in flight rather than landing it on solid ground or on a offshore platformas SpaceX does so well! Converselya larger stage will have a lower constructive index and therefore will brake much better than a small stage.

Rocket Lab will recover the main stage of the Electron launcher by helicopter

Article by Rémy Decourt published on 08/08/2019

A pioneer and now leader in the reuse of launcher stages, SpaceX has paved the way and shown that it is technologically possible. Although theequation economics of this reuse has not yet been resolved, Rocket Lab is committed to this path and wants to make its Electron launcher partially reusable… with the help of a helicopter!

the Rocket Lab’s Electron light launchercapable of launching payloads of 150 kilograms in orbit sun-synchronousideal to meet the needs of the markets of theearth observation, could become partially reusable. Rocket Lab has just announced its intention to recover and reuse the main stage of its launcher, the cost of which is around 5 million dollars. This stage uses nine Rutherford engines which run on a mixture of oxygen liquid and of kerosene.

This choice is dictated by economic considerations. It is also made possible by SpaceX which has technologically demonstrated that the reuse of a floor was possible. In addition, satellite operators are now much more inclined than yesterday to use second-hand launchers to launch their satellite.

SpaceX, pioneer of reuse

That said, the difficulty of completing this program should not be underestimated. As surprising as it may seem, it is more complicated to recover a small storey than a large one, in particular because its constructive index is high. This index measures the ratio of the dry mass of the stage to the mass of the onboard propellants. The higher this index, the greater the heat flow. As a result, the floor will enter like a ball, which most certainly explains the choice to recover it in flight rather than landing it on solid ground or a offshore platformas SpaceX does so well! Converselya larger stage will have a lower constructive index and therefore will brake much better than a small stage.

To limit the costs of this adaptation (the stage was developed as a classic consumable stage), the latter will therefore not use a landing system like the SpaceX’s Falcon 9 for example, whose motors are used to bring the stage back to the ground, which lands by deploying the legs. Rocket Lab’s idea is to use a helicopter instead of such a system. After separating from the upper floor, the main floor will descend back into theatmosphere and will deploy a parachute, in order to reduce its speed. When the time is right, the helicopter will catch it by the cable that connects it to the parachute.

In June, during a commercial flight, an Electron launcher carried a few instruments allowing it to collect data specific to its recovery efforts. So will an upcoming launch later this month, with a view to making a first attempt at recovery later this year.