PLD Space set to launch Spain’s first private rocket into space

PLD Space aimed to launch Spain's first privately developed rocket into space, the Miura 1, this Wednesday. Liftoff was initially targeted to occur on May 31 at 6:30 AM CEST (04:30 UTC) but was later scrubbed due to upper-level winds. PLD Space will attempt to launch again in the coming days, but no specifics have been given yet.

The launch will occur from the company's launch pad in Médano del Loro, located within Spain's National Institute for Aerospace Technology (INTA in Spanish) base in El Arenosillo, Huelva.

The launch weather forecast was near-ideal conditions during the window with only easterly upper-level winds being a watch item for the flight.

https://www.youtube.com/watch?v=htb4TVnKLg4

PLD Space Background

PLD Space was founded in 2012 in Elche, Spain, with the goal of increasing access to space, especially in the European sector. The company plans to accomplish that by building Spain's first privately developed rocket and Europe's first micro-launcher service to orbit.

To this end, PLD Space envisioned a two-step development approach. The first step consisted in developing a reusable suborbital rocket that would demonstrate the capabilities needed for an orbital rocket. This not only involves the knowledge and expertise gained from developing the technology for it but also practicing important activities such as launch range coordination, safety hazard zone clearance, and bureaucracy to a lesser extent.

The company aims to finalize this first step this year with the flight test of their Miura 1, their reusable suborbital rocket. The second step, already underway, involves the design, development, and flight of their partially reusable orbital rocket, the Miura 5.

Miura 1 SN1 Test Flight Overview

The Miura 1 is a single-stage reusable suborbital rocket that uses airplane-grade kerosene as its fuel and liquid oxygen as oxidizer.

Its only engine, the TEPREL-B, is a pressure-fed engine with a liftoff thrust of 30 kilonewtons, regenerative cooling, and a two-axis thrust vector control system that allows for pitch and yaw control during flight.

Miura 1 SN1's single TEPREL-B engine. (Credit: Alejandro Alcantarilla Romera for NSF)

Roll control during flight is provided via a series of cold gas thrusters that will also help to control the rocket's attitude for entry into the atmosphere. After its mission is complete, Miura 1 is designed to parachute down to the ocean for recovery and inspection.

Although originally conceived as a rocket with a regular launch cadence, PLD Space now only plans to launch Miura 1 twice before moving onto the larger Miura 5 rocket. This means the recovery portion of its flight will only serve to inspect the rocket after flight, allowing engineers to gather as much data as they can.

More importantly, though, this will also serve as practice for the future recovery of the company's Miura 5 first stage, which is also reusable.

The rocket consists of a monocoque Aluminum-copper alloy structure, and it is divided into six major sections.

The uppermost section, a 70-centimeter diameter nosecone, hosts the payloads for the mission. It is nondetachable, and it is built to sustain the thermal loads during ascent and entry back through the atmosphere.

For the first flight, Miura 1 will carry a microgravity research experiment from the Center of Applied Space Technology and Microgravity (ZARM in German) of the University of Bremen. This first flight will also carry additional secret payloads that won't be revealed until closer to launch or afterward.

"We have a couple of surprises. One of them is somehow traditional in the space industry, and another one is an internal and also technical experiment from PLD Space that we think will be very interesting," said Ezequiel Sánchez, president of the company, in an interview with NSF.

Annotated view of Miura 1's different sections. (Credit: Alejandro Alcantarilla Romera for NSF)

Underneath the nosecone section resides the avionics bay with the rocket's onboard computers and payload monitoring systems.

The section right below the avionics bay contains the Composite Overwrapped Pressure Vessels (COPVs) storing the helium for pressurization and nitrogen for the attitude control system (ACS) thrusters. This is also where these thrusters are located on the vehicle.

The rocket's two propellant tanks are located right underneath and are separated by an intertank structure. The liquid oxygen, which sits above the kerosene tank, is routed from the intertank and into the engine section through two transfer tubes running down the sides of the kerosene tank.

At the aft end, the engine and recovery section hosts the propulsion systems for the main engine as well as the parachutes for recovery.

The countdown sequence of Miura 1 takes about a day with most of its early phases dedicated to the checkout of the rocket's onboard systems, pad systems, and clearance of the launch range.

The start of propellant load begins at T-6 hours with the start of kerosene load onto the rocket. This takes about half an hour, and it is followed by engine inspections and filling of the onboard nitrogen ACS thruster COPVs.

A planned hold is scheduled to take place at T-4 hours during which the launch platform will be reconfigured for the start of helium and liquid oxygen load.

The load of these commodities should start 30 minutes after the hold is lifted at the T-3 hour and 30-minute mark.

Once the liquid oxygen is fully loaded onto the vehicle, the ground systems will continuously keep the tank topped off until much closer to T0 under what is usually called stable replenishment.

Miura 1 fully loaded on the pad ahead of its static fire test performed in early May 2023. (Credit: PLD Space)

At T-1 hour and 15 minutes, ground controllers will perform ground segment checks with INTA, the launch authority, and coordinate the final extensive range monitoring.

After a final test of the avionics system and configuration of the guidance, navigation, and control system for flight, the count will be held at the T-2 minute mark for a final go/no-go poll ahead of launch.

Once controllers poll "go" for flight, the count will resume, and the rocket will enter launch autosequence. This initiates an automated sequence of events that will involve transitioning the rocket into internal power, handing over command of the countdown to the onboard computers, and pressurizing the rocket tanks for flight.

Unlike most rockets in the western hemisphere, Miura 1 will ignite its engine at the T0 mark and will lift off a few seconds later. However, this is very similar to another European rocket, the Ariane 5.

Ariane 5 ignites its main engine at T0, and the rocket lifts off several seconds later after igniting its two side-mounted solid rocket boosters.

After this point, the company's goal for the mission is "to collect as much flight data as possible." Under nominal conditions, the rocket will begin its flight heading straight up for about 30 seconds, after which it’ll initiate its pitch sequence to the south from the launch pad.

Miura 1 should reach the speed of sound approximately one minute into flight. Main Engine Cutoff (MECO) of the TEPREL-B engine should come up about two and a half minutes into flight.

From that point onward, the rocket will start the microgravity phase of flight and coast to apogee, which is planned to be at around 80 kilometers. This will end the primary phase of flight and start the secondary phase of flight, which consists of the entry and recovery of the rocket.

The vehicle will use its ACS thrusters to point itself headfirst and maneuver through entry. After entry is complete, a set of drogue parachutes will initially slow down the descent of the rocket, followed by a main parachute that should bring the rocket to a soft splashdown on the ocean.

PLD Space aims to launch another Miura 1 vehicle, Miura 1 SN2, later this year after reviewing data from the first flight. The vehicle is currently in final steps of manufacturing at the company's headquarters in Elche.

A third vehicle, Miura 1 SN3, is also under construction but will only fly if the company deems it necessary to obtain additional flight data before moving onto Miura 5.

Miura 5 Overview

PLD Space plans to launch its Miura 5 rocket in the fourth quarter of 2024 with another test flight planned for 2025. Launches of the Miura 5 rocket would take place from the Guiana Space Center in Kourou, French Guiana.

The company will start this summer the development of the TEPREL-C engine, a gas generator cycle version of the TEPREL-B engine, which will be flying on Miura 5.

Miura 5 overview slide on a presentation given to media by Raul Verdú, co-founder of PLD Space. (Credit: Alejandro Alcantarilla Romera for NSF)

Five TEPREL-C engines will power the first stage of the Miura 5 rocket for a total liftoff thrust of 950 kilonewtons. A single vacuum-optimized version of the TEPREL-C engine will be flying on Miura 5's second stage.

An optional kick stage will also be a part of PLD Space's offer for customers. This kick stage will initially be outsourced to other companies, but work is underway to develop an in-house orbital transfer vehicle to deliver the payloads into different orbits.

Miura 5 should be capable of carrying up to 1,080 kilograms to a 300-kilometer circular 9.1-degree inclination orbit and up to 540 kilograms to 500-kilometer circular Sun-synchronous orbit (SSO).

These performance capabilities would be slightly less than other similar smallsat launchers such as Firefly's Alpha rocket or Rocket Factory Augsburg's RFA One rocket.

Miura 5 would add yet another rocket to the crowded smallsat launcher environment, but the company thinks they have a place as a European launcher. "Today in Europe, we have a problem with the launcher services. Ariane 6 is not available, Ariane 5 is canceled, Vega had a recent failure, Soyuz is not available anymore due to the situation in Ukraine. Europe's situation is not good. So we aim to add more capacity using our small launch vehicle Miura 5," said Raul Verdú, company co-founder, in an interview with NSF.

PLD Space aims to start commercial launches in late 2025 with a regular 14-flight-a-year cadence targeted to start in 2028.

For the moment, there are no plans for a larger rocket, but the company is not closing that door. Ezequiel Sánchez, in an interview with NSF, stated, "Our main target has always been small payload and satellites for Earth observation and telecommunications, but — of course — there are many opportunities, and we’ll be ready. We want to be a significant operator."

(Lead image: Photo of Miura 1 on the pad during a media visit at the company's launch pad in El Arenosillo, Huelva. Credit: Alejandro Alcantarilla Romera for NSF)