| 31. | After these first two prototypes were flown, an improved engine was introduced to reduce problems with LOX turbopump cavitation.
|
| 32. | Preliminary failure analysis by Orbital pointed to a possible turbopump failure in one NK-33 / AJ-26.
|
| 33. | Beginning the turbopump operation, hot gas entered the nozzles and, in turn, the first stage turbine wheel.
|
| 34. | The turbopump is controlled by an electronic controller which measures outlet pressure and RPM, adjusting HO flow as necessary.
|
| 35. | This offers a lower-cost approach than a regulated LFRJ requiring a turbopump and associated hardware to supply the fuel.
|
| 36. | This was fed under pressure into the various bearings in the turbopump system, both lubricating it and carrying away heat.
|
| 37. | The oxidizer turbopump uses a single-stage centrifugal pump with a helical inducer driven by a two-stage turbine.
|
| 38. | Subsequent investigation found that the LOX turbopump had exploded, although a specific reason for the failure could not be determined.
|
| 39. | Before the test got under way, engineers discovered a propellant leak in the test rocket's high pressure oxidizer turbopump.
|
| 40. | But nitromethane and hydrogen peroxide are significantly less efficient than liquid oxygen, which cannot be used alone to run a turbopump.
|
