Air pollution has long been one of the most important problems of our time. Thus, due to the increased level of toxic compounds in the air of St. Petersburg, it becomes necessary to constantly monitor the change in its chemical composition. Atmospheric probes are also used to assess the state of the environment near settlements.
Unmanned aerial vehicles (UAVs) are often used to launch such probes to the required height. Drones are the most common among them. UAVs of this type, on average, can deliver a payload (PL) with a mass of 1 kg to an altitude of 1.5...2 km during a time in the range of 5...7 minutes.
The RN-E8 launch vehicle (LV), developed by the SteaMf team, has a number of advantages over the previously mentioned UAVs, one of which is speed. In order to deliver a PL with a mass of 1 kg to an altitude of 1.5...2 km using a rocket as a launch system, in this case, only 17...20 s is enough.
RN-E8 has a block-modular design, which makes it easy to replace the elements of the device. A composite — carbon fiber reinforced plastic, which has high strength and can withstand large overloads that occur during flight, was used as a main body material of the rocket. The rest of the parts were 3D printed. The use of a high-strength composite material in combination with the possibility of replacing individual structural units makes it possible to reuse the LV.
A solid-propellant RDK-1000 engine was used as a propulsion system for launching the RN-E8 LV .
The following are the main technical characteristics of the RDK-1000 engine.
RDK-1000 is a solid-propellant rocket engine with a total impulse of 1.0...1.2 kNs, used in scientific and technical work to accelerate training missile models.
The engine has a composite body with a graphite nozzle, without any metal parts. There is an M10 threaded hole in the upper part of the engine for mounting inside the rocket.
The engine is started by an igniter installed through a nozzle into the engine channel.
Technical characteristics of the RDK-1000 engine:
RN-E8 geometrical and technical characteristics:
In the fall of 2021, two successful launches of the RN-E8 LV took place. The starting electronics worked without deviations, thanks to which the start was carried out on the first try.
The SteaMf team has developed an electrical circuit for the operation of the LV electronics according to the selected sensors. The performance of trajectory flight missions (altitude, speed, acceleration) was carried out using the GY-86 module . The launch vehicle location coordinates were successfully determined using the GPS module. With the help of the GSM module, the SteaMf team constantly received SMS. All useful data was recorded via removable media using an SD card module. In addition, NEO-8m and MEGA 2560 Pro were used in this project [3, 4]. When the RN-E8 LV started to move, a check pin was pulled out from the launch pad and the operation algorithm was launched. An audible warning system was also launched to facilitate the search for the LV after landing. The apogee sensor implementation was carried out using a timer, which began its work when the check pin was separated. The expelling charge was ignited using a relay and a separate power source.
Conclusion. The RN-E8 LV project was developed using a solid-propellant engine and has a number of advantages over other UAVs when used for meteorological purposes. RN-E8 has a relatively small mass, and is also capable of accelerating to 300 m/s. This LV is made of durable components making it reusable.