Item #: SCP-XXXX
Object Class: Safe Euclid
Special Containment Procedures:
The object is to be stored in Ultra High Vacuum (UHV)-proof chamber for storage, dimensions of the chamber are 0.5x0.5x1m. Internal pressure is to be monitored by a commercially available ionization-based pressure gauge for UHV. Chamber evacuation is to be performed by turbo, turbomolecular and ion pumps.
Description:
SCP-XXXX is an early design combustion-based rocket engine. The object was recovered in the collapsed storage facility near Leningrad in 196█, following the report of a sudden storage bunker collapse which was breached during the expansion of the subway system. Our agents have discovered SCP-XXXX, classified documentation for it, as well as 6 freeze-dried corpses dressed in NKVD uniforms. SCP-XXXX was put in the van and delivered back to Site 35 for temporary containment and future study. The object is deemed safe.
Dimensions:
The external circumference of the combustion chamber is exactly one meter, with a measurement error of + 300 pm. Attempts to calculate the diameter have led to a transcendental number very close to 1/π. The reasoning behind this choice of dimension is currently unknown. De Laval nozzle neck diameter is also a function of π, being very close to 1/4π, the measurement error is the same.
The combined chamber and nozzle external length correspond closely to a value of 2/e, also a transcendental number; the measurement error remains the same.
The combustion chamber has a designation of "ОРМ-66-А", written in Cyrillic, cast directly into the side of the chamber. It is believed to originate from the Jet Propulsion Research Institute of the USSR, given the virtually identical superficial appearance to ORM-65 experimental rocket engine. Additionally, directly on the neck of the de Laval nozzle there is a knob labeled "Шкала", with markings 0,10-10,10-1,1,101,1010, and ∞. The current setting is ∞.
The internal measurement of the chamber and nozzle length have shown that the "inside" length of the SCP-XXXX is significantly longer than the measured outside length. Using a laser to measure the distance, we have not been able to receive the beam reflection. Using an assembly of rods connected end to end, we managed to measure 10 km of length, mostly due to the fact that we ran out of rods.
Anomalous properties:
SCP-XXXX's first anomalous effect manifests itself in any pressurized environment. There is a constant flow of air into the nozzle and combustion chamber, regardless of how much time has passed.
SCP-XXXX's anomalous properties were tested in the following series of tests.
Introduction
Test of the functionality of the engine.
Experiment setup:
KB-Yuzhnyj vacuum test chamber, standard engine test setup.
Test #1:
During the first test fire, no exhaust gas was registered leaving the engine. The thrust produced was an order of magnitude greater than designed for. The heat radiated by the engine corresponded to its' normal functioning when compared to non-anomalous ORM-65 firing. After exactly 3 minutes of test-firing, the fuel and oxidizer was cut off, the thrust persisted, decaying exponentially over time, but never reaching zero. After 4 days, the thrust was considered negligible, and the heat radiated by the engine also was negligible.
From this experiment, it is evident that the engine possesses a reality-warped nozzle and reality-corresponding combustion chamber. It is highly likely that the nozzle is internally infinitely long.
Further experiments are deemed safe to perform. Proceed with a change of dial settings.
Introduction
An attempt to change the nozzle settings. If the markers are to be believed, we suspect this will change either the chamber length or chamber volume. According to the date stamped, this engine likely was accumulating air for decades, and suddenly decreasing the volume could lead to explosive results.
Experiment setup:
Novaya Zemlya nuclear testing polygon. Engine directed sideways, encased in a protective shroud, and anchored to a concrete base. The official cover is a test of a low-yield nuclear device.
Test #2:
Using an electric actuator, the switch was turned to a 1010 setting. As soon as the switch reached the marked position, a brilliant flash was seen from the test site. An expanding fireball followed. According to sensors, the explosion was registered at roughly 10 kT. After an extensive search, the engine was found on the far end of the island (roughly 8 kilometers away from the epicenter), buried 10 m below ground. Starting from 500m away from the engine, the air temperature begins to exponentially drop, reaching roughly -250 degrees celsius in the epicenter above ground.
Due to extreme temperature, a globe of solid nitrogen and oxygen began to accumulate around the suspected engine position. This temperature remained stable for 6 days, 13 hours and 58 minutes, the globe reaching 1000m in diameter at this point in time. In the following month, the globe evaporated. Afterwards, we dug up the engine and assessed it. It had suffered no heat-induced damage, and only mild mechanical deformations thanks to a protective shroud. the shroud itself had completely fractured in many shards, likely due to thermal expansion stress. By the time the engine temperature stabilized close to room temperature, no flow of air was perceived.
It took approximately 66 seconds for laser beam to bounce back from the rear end of the chamber, confirming that the dial displays distance in meters.
Conclusions
It appears that the engine abides by the first two thermodynamic laws, however, is capable of reversing the entropy, thus violating the third law. We theorize that after rapid compression and the resulting explosion, the engine began the process of "energy recovery" to compensate for the energy spent during compression. An investigation into possible links to SCP-2966 is requested.
The test proceeded mostly as expected. Link to entropy-reversal as in the case of SCP-2966 is curious. Proceed with engine fire-tests using other settings.
Introduction
Test in a high vacuum chamber of KB-Yuzhnyj, standard test fire at all the finite settings.
Experiment setup:
a) Test fire at a 1010 setting.
After a 3-minute test fire, it took approximately 40 days for the exhaust to begin exiting the nozzle. The temperature of the exhaust was below 10K, the pressure was approximately the same as the pressure in the chamber (10 Pa).
b) Test fire at a 101 setting.
During a 3-minute test fire, it took roughly 4 ms for the exhaust to reach the nozzle exit. Exhaust velocity was recorded to be 2458 m/s, exhaust pressure was close to 1 MPa, exhaust temperature 500K.
c) Test fire at a 1 setting.
During a 3-minute test fire, exhaust reached nozzle exit at the design-specified time,and the engine performed nominally. The exhaust went in a narrow cone
d) Test fire at a 10-1 setting.
During a 3-minute test fire, exhaust reached nozzle exit over-pressurized, close to 3 MPa in pressure, and at near-combustion chamber temperatures. The exhaust went in a wide cone.
e) Test fire at a 10-10 and 0 settings.
The effect was almost identical in both cases, the engine worked as if it had no nozzle, the exhaust from the combustion chamber went everywhere in a semi-spherical direction from the point of origin.
After the tests, the engine was found to be close to 1K in temperature. After being flooded with superheated Argon plasma for 2 days, it returned to normal temperature. This is likely linked to changes in volume requiring energy.
Conclusions:
The engine performed nominally, with few side-effects.
Deconstructive tests are authorized. Perform nozzle separation and inspection. Use the setting of 1 during the process. Make sure the dial stays intact.
Addendum: [Optional additional paragraphs]
Per 
