The first rocket he worked on solid fuel — it was the powder packetswhose low energy is offset by the ease of manufacture and use. But when it was necessary to solve more complex problems, for example, to deliver an explosive charge at a distance of several hundred kilometers, flying has demanded new technologies — so the fuel was liquid, and the motors changed accordingly.
The way the space was laid on the rockets with LRE. For kerosene-oxygen engines was flown to the Royal “seven”, which put into orbit Sputnik and Gagarin. LRE stand for the American “the Falcon” and “Deltas”, then “Unions” and “Protons”, the Chinese “Changeno”, new Zealand “Electrons”.
The liquid engine is really efficient: its thrust is convenient to manage, it can be off at any time and to include many times. And compact size make it easy to transport engines, and tightly assemble them at the end of the stage. For all its complexity, LRE — and it is a tube and the nozzles, turbopumps, gas generators and nozzle head — has long been technologically available level of perfection to go into space.
But for the pros LRE necessary to pay the complexities of operation. Liquid fuel components are either toxic or cryogenic — and here gets a lot of problems with their liquefaction, protection from heat loss and delamination. Leakage of fuel vapor is toxic and flammable. Starting fueling of the rocket requires a large ground infrastructure: storage facilities for fuel, systems its filing. The whole lump of technological operations complicates the start to his training takes a lot of time. Dressed with rocket, difficult to store at the start it goes white fog is vented evaporating liquid oxygen.
In comparison with the rocket engine solid fuel before the start required nothing more than attaching to the rocket — or filling operations, no strict fire prevention measures, nor any maintenance before the start. And starting is as simple as the ignition igniter.
However, a simple in one respect, the solid-propellant engines is another difficulty. Increase their size turns out to be rocket scientists significant challenges. First, a lot of pressure, locked in a rocket engine combustion chamber, the solid rocket motors extends to the entire body. It needs it to survive — and thus be stronger and therefore heavier.