The launch of the Proton rocket in 2010 did not succeed not because it did not have enough fuel, but because there was too much
of it. Atlas, the head of the space launch department at the Air Force Supply Directorate of the Pentagon Secretariat.
One of the most common problems leading to plane crashes was the pilot sitting quietly in the cockpit until the car ran out of fuel. With space launches, such failures occur less often, but in some particularly indicative cases during the first launches, shutdowns of propulsion systems were recorded due to lack of fuel.
Most of the liquid-fueled launch vehicles lacked a fuel-level tracking system - not even as simple as a confused pilot staring at the falling fuel gauge readings. The engines were tested, their consumption was recorded, and the amount of fuel and oxidant required was calculated using simple formulas. Apparatus with liquid oxygen as an oxidizer was simply filled with a full tank - this was necessary, since oxygen evaporated until the last seconds before the start, when the valve was closed. The estimated amount of fuel was loaded, plus a little more, just in case. This is how the Thor, Titan and Delta missiles worked, as did most missiles outside the United States.
Atlas worked differently - it used a fuel recovery system that measured the amount of fuel and oxidizer in the tanks and adjusted the engine thrust to maximize efficiency. However, it was only launched while the propulsion engines were running - right after the large booster engines reached their design thrust levels in the first couple of minutes of flight. The system was turned on when the device was driven by the central propulsion engine. It was this system that allowed the Atlas 19F rocket to recover from a severe loss of speed during the NOAA-B mission on May 29, 1980.
The difficulty of calculating the correct amount of fuel was well illustrated by the failure of the Thor LV-2F F34 mission to launch military meteorological satellites, which was launched at Vandenberg Air Force Base on February 19, 1976. At that time, too simplified process of calculating the amount of fuel. The launch team used data from operational tests of the first stage of the accelerator to calculate the required fuel load, and a counter was used to measure the amount of fuel loaded into the rocket. And that's all. The required amount of fuel was loaded into the tank of the accelerating engine, the countdown began, takeoff took place. However, the payload did not reach a stable orbit and returned to the atmosphere after the first orbit.
Subsequent investigation found that the engine performance test data was incorrect. The engine required more fuel to achieve the desired performance than the data indicated. The situation was similar to how if you went to a car dealership and chose a new car that consumes 6 liters of gasoline per 100 km, although all other cars of the exact same make, model and with the same options would have this figure equal to 7 liters a hundred; and you would not even think about why this car is so much more economical than others. For the remaining launches, Project Thor undertook extensive research and more detailed analysis.
Another accident occurred at Vandenberg Air Force Base on August 3, 1981 with a Delta 3914 missile from the Dynamics Explorer mission. The normal launch order assumed that the second stage of the rocket was fueled during the countdown. In that mission, a novelty was added to the refueling equipment: a "mill" spinning in the refueling hose as an indicator of the fuel supply, similar to the wheel that turns at some gas stations. Unfortunately, the new wheel jammed and a fuel leak occurred, causing the refueling team to assume the second stage was fully fueled. She ran out of fuel 16 seconds ahead of schedule, which is why the payload did not reach the desired orbit 160 km. Then it turned out that there were disputes about the required orbit altitude, so the adherents of a lower orbit were satisfied,unlike everyone else.
April 18, 2001 was a big day for the Indian space program - then the first rocket was launched to launch the GSAT 1 satellite on a carrier rocket for launching geosynchronous GSLV satellites. The celebration of achievements did not last long. The third stage used a Russian-made engine that had not flown before, and it lacked thrust. The satellite entered space with a speed deficit of 0.5%, which is why it could not reach the desired place in orbit. The satellite worked fine, but quickly descended, crossing the orbits of other satellites and interfering with their work. This was unacceptable and it was turned off after just a few days.
On December 6, 2010, a new version of the glorious Proton booster engine lifted a rocket from the Baikonur cosmodrome carrying GLONASS satellites. A new upper stage was used on the upper stageDM-03 . The payload never entered orbit and fell into the Pacific Ocean. The situation was the opposite of the Dynamics Explorer case. The volume of the tanks of the new upper stage was significantly larger than that of the previous models, and this moment was not taken into account when refueling. Although the mission did not require additional fuel, it was still poured - 2000 kg more than was needed. And instead of a lack of fuel, like the missions "Thor F34" and "Delta" Dynamics Explorer, "Proton" had too much of it.
Why has excess fuel become a problem? In the case of the Tor F34 crash, the problem was not simply that there was not enough fuel on board. During the launches of military meteorological satellites, the tanks of the Thor rocket and the upper stages were too small, and the mass of the entire ship increased with each mission. One of the solutions to this problem was the replacement of RP-1 fuel with RJ-1. The RJ-1 fuel, designed for ramjet engines, was denser than the RP-1, allowing more fuel per unit volume to be crammed into the limited space of the Thor fuel tank — and therefore more energy.
The allegedly high thrust of the engine used on the Thor F34 mission had been noted several years earlier, so it was chosen specifically for the heaviest mission in this series of missiles. However, in fact, not only this engine did not have such a thrust - in principle, no engine of such a device could give such a thrust. It was impossible to stuff enough fuel into the Thor tank for this mission to take off successfully - since the increase in fuel weight only reduced the engine thrust.
The DM-03 had the same problem. There was plenty of fuel at the upper stage, but in the end it turned out to be too heavy for the rocket to reach its intended trajectory. In the design of the Delta-4 and Atlas-5 missiles, the main parameters were the cost of development and production, and the engines cost clearly more than the fuel stored in the tanks. Previous rockets, which used RL-10 engines in the upper stages, had at least two such engines, but it was possible to calculate the trajectory so that only one engine was used. The trajectory should go almost vertically upwards during the operation of the first stage, thereby avoiding both aerodynamic drag and gravitational losses that are associated with lower and more efficient trajectories. Having risen high enough, the upper stage of the RL-10 could work for quite a long time,picking up speed much slower, but saving a lot of money on expensive equipment. This approach raised some range concerns, but since missiles from American test sites fly over the ocean, this obstacle was not insurmountable.
Perhaps the Proton with the DM-03 upper stage, launched on December 6, 2010, could have gone into space along a similar trajectory and brought the upper stage to such a height at which it could use additional fuel, but no one thought about such opportunities, since this stage was not supposed to pump so much fuel.
So the challenge is not just making sure you fill the tank full before the trip, but rather making sure you have just the right amount of fuel for the mission. And before choosing a car, first read the characteristics of several copies.