| RD-843 (РД-843) | |
| Country Of Origin: | Ukraine |
| First Date: | 2012-02-13 |
| Designer: | Yuzhnoye Design Bureau |
| Manufacturer: | Yuzhmash |
| Purpose: | Upper stage |
| Associated: | Vega |
| Predecessor: | RD-869 |
| Status: | In production |
| Type: | liquid |
| Fuel: | UDMH |
| Mixture Ratio: | 2.0 |
| Cycle: | Pressure fed |
| Combustion Chamber: | 1 |
| Thrust(Vac): | 2452N |
| Chamber Pressure: | 2.04MPa |
| Specific Impulse Vacuum: | 315.5 seconds |
| Burn Time: | Up to 667s |
| Dry Weight: | 15.93kg (35.12lb) |
| Used In: | AVUM |
The RD-843 is a Ukrainian single nozzle liquid propellant rocket engine burning pressure-fed UDMH and nitrogen tetroxide. It is rated for up to 5 restarts, and can gimbal up to 10 degrees in each direction.
It was developed by Yuzhnoye Design Bureau for Avio and is manufactured by Yuzhmash. It uses the RD-869 thrust chamber, the old Soviet ICBM SS-18 Satan final stage engine from which it is evolved, and which was also designed by Yuzhnoye. The RD-843 ground test campaign included 74 tests, 140 ignitions, reaching a total of 8201 s, which is approximately 12 service lives on 4 engines. As of June 2020 it has been successfully used on 14 orbital launches.
It is currently used as the main engine of Vega's AVUM upper stage.