Rocketdyne's LR-101 was a small, secondary (or "vernier") engine. Two LR-101s were mounted on the Atlas and Thor missiles (and, later, the Delta launch vehicle, by virtue of its first stage being a modified Thor missile). It was produced in several versions and operated under different conditions, but the LR-101 generally produced about 1,000 pounds of thrust. Later, in its Atlas Space Launch Vehicle configuration, its thrust was downrated as adequate role
Pegasus engine
and attitude control could be accomplished at a lower thrust rate and the corresponding lower propellant flowrate meant that more propellant was available to the sustainer engine, in turn producing improved overall launch
F402
vehicle performance.
On the Atlas, the two outer booster engines were gimballed; two gimballed engines allowed for yaw, pitch, and roll control. After about two minutes of flight, the boosters were jettisoned, leaving the single center sustainer engine. While this engine was also gimballed, roll control is not possible with only one engine. The primary purpose of the LR-101 vernier engines was to provide roll control after the booster engines had been jettisoned. They also contributed to thrust and, after the sustainer was shut down, powered the Atlas to its final velocity and position.
AMPS stage
CR 863 converted
The LR-101 was a single-start, fixed-thrust engine with an expansion ration of 6:1. In at least some configurations, ignition occurred by means of pyrophoric (hypergolic) fluid which ignites spontaneously in the presence of oxygen. (A former Rocketdyne employee contacted me after I initially put up this page saying that in the July 1956 to July 1957 timeframe, they were ignited "by a sparkler stuck in the throat". The LR-101 was a long-lived engine, so it appears that different versions were ignited via different methods.) Its thrust chamber weighed only about 15 pounds; in its -NA-15 configuration, the mount and bearing assembly added another 27 pounds.
Here is a cut-away diagram of the LR-101 thrust chamber assembly: LR101-NA-1
turbo jet
Vernier
Rockwell_1980_1K_LH2_Expander
Rockwell_1980_3K_LH2_Expander
rockwell-vtol-2
SM_RCS_thruster600
surveyor-vernier-cutaway
Turbofan Operation
1000 lb. Thrust
Vectored engine
{| class="specs"
|THRUST. . . . . . . . . . . . .
|(NA-13) 669 ± 5% @ sea level, pump fed (NA-15) 1000 ± 3% @ sea level, pump fed
|-
|PROPELLANTS . . . . . . . . . .
|Liquid oxygen (MIL-P-25508C) and RP-1* (MIL-R-25576B)
|-
|O/F WEIGHT RATIO. . . . . . . .
|1.8 ± 0.1
|-
|RATED DURATION. . . . . . . . .
|322.5 sec** (ATLAS), 184 sec (THOR)
|-
|PROPELLANT FEED . . . . . . . .
|Sustainer engine turbopump until cutoff; thereafter they are tank fed
|-
|THRUST VECTOR CONTROL . . . . .
|Gimbaled thrust chambers ± 75° yaw, -35° and -25° in pitch (ATLAS), ± 47° pitch, +6 and 34° yaw (THOR)
|-
|CURRENT USE . . . . . . . . . .
|Verniers for ATLAS and THOR missiles
|-
|STATUS. . . . . . . . . . . . .
|In production. Preliminary design was completed in June 1958 for the LR101-NA-3
|-
|SPONSORING AGENCY . . . . . . .
|U. S. Air Force through ATLAS and THOR contracts
|}
RJ-1 (MIL-F-25558B) has been utilized in the LR101-NA-11
At altitudes above 100,000 ft, the thrust is approximately 1154 lb and specific impulse is 238 lbf-sec/lbm for the NA-13
Vernier Jet
VSTOL diagram
Abstract : Presented is a summary of test results from a program to develop the YLR101-NA-15 vernier engine. The program was completed in three phases: (1) Downrating the tank-fed thrust of the YLR101-NA-13 vernier from 830 pounds to 525 pounds, (2) modifying and repackaging the 525pound-thrust vernier into the YLR101-NA-15 configuration, and (3) developing a modified vernier injector to minimize a thrust chamber erosion problem which
n the fictional Star Trek universe, the impulse drive is the method of propulsion that starships and other spacecraft use when they are travelling below the speed of light.[1] Typically powered by deuteriumfusion reactors, impulse engines let ships travel interplanetary distances readily. For example, Starfleet Academy cadets use impulse
vernier engines
vernier engine diagram
VSTOL diagram
Saber Notes
Saber Airflow
Saber engines
web engine
engines when flying from Earth to Saturn and back.[citation needed]
There are three practical challenges surrounding impulse drive design: acceleration, time dilation and energy conservation. In the show, inertial dampers compensate for acceleration. These hypothetical devices would have to be set so that the propellant retained its inertia after leaving the craft otherwise the drive would be ineffective.[2] Time dilation would become noticeable at appreciable fractions of the speed of light. Regarding energy conservation, the television series and books offer two
Star Trek Warp Engine
Warp Engine Star Trek
Star Trek Warp Engine
Warp Engine
explanations:
Wave Motion Engine, the ship's main power generator unit is a refined, improved and slightly larger variant used on the Yamato as well featuring and extra smaller one. Auxiliary energy is provided by the four Fusion Reactors each one mounted in the 4 secondary engine gondolas. The ship have 4 engines systems: Main Wave Motion engine providing the primary source for sub light and warp speeds 4x Secondary engines in gondolas to provide extra boost or low speed travel 4 Auxiliary engines in the lower forward hull section just below and behind the wings.
Star Trek: The Next Generation Technical Manual indicates that the impulse engines are nuclear fusion engines where the plasma from the fusion reactor powers a massive magnetic coil to propel the ship. It is a form of magnetohydrodynamic or magnetoplasmadynamic thruster. This is used in conjunction with the ship's warp drive's alteration of the ship's relativistic mass, to achieve mid-to-high sub-light speeds. Thrusters, on the other hand, are closer to the designs of a high-efficiency reactant propellant (i.e. a sophisticated rocket engine) and are usually used for high-precision maneuvers. Ion propulsion drives are explicitly detailed to be used in Star Trek by Dominion and Iconian Starships and facilities.
Since a ship traveling at impulse velocities (slower than, but approaching, the speed of light) is still traveling in the normal space-time continuum, concerns
vernier
RCS Jet
of time dilation apply, and it is written in the ST:TNG Technical Manual that high relativistic speeds are avoided unless absolutely necessary; impulse power is therefore customarily limited to a maximum of 1⁄4 lightspeed. (Warp travel, on the other hand, is stated in the Manual to cause no kinds of time dilation effects.)
