This article tells you how difficult it is to successfully launch a spacecraft

In a space launch, any small fault may cause the launch to fail completely. As one of the most complex industrial products, the millions of parts of a launch vehicle are crucial, and they do not work independently.

Saturn V carries Apollo 6 off launch pad 39A

The launch vehicle is divided into multiple systems, including the power system that overcomes gravity and rises with difficulty, the control system responsible for controlling the attitude and direction, the electrical system that supplies power and information to each system, etc. This article selects several cases to explain which faults caused the failure of rocket flight.

Power system failure

1. The rocket leaked oil

On June 15, 2007, the Atlas 5-401 rocket was launched again as the third launch after the establishment of the United Launch Alliance. The payload was two Baiyun-3 ocean surveillance satellites numbered NROL-30 (National Reconnaissance Office of the United States). Both of the Baiyun-3 satellites carry signal intelligence (SIGINT) payloads. The NROL-30 mission plan is to be launched into a low earth orbit at an altitude of 1,100 kilometers and an inclination of 63.4 degrees. This mission is the first launch of the Baiyun-3 satellite by the Atlas 5 rocket.

"Cosmic God" launches Baiyun-3 ocean satellite

The rocket took off, the Russian-made RD-180 engine was shut down, the single-engine Centaur upper stage separated, and the RL-10A-4-2 engine ignited...

However, the two Baiyun-3 satellites only entered an orbit with a perigee of about 900 kilometers and an apogee of 1,100 kilometers. Even after the main engine was shut down and the auxiliary thrusters were fully used to raise the orbit, the semi-major axis deviation still exceeded 100 kilometers. Strictly speaking, this launch was not a success. The Baiyun-3 satellite is equipped with a huge monitoring antenna and is unlikely to have great maneuverability.

The problem was with the Centaur upper stage's RL-10A-4-2 engine, which shut down four seconds early because of a leak in the liquid oxygen valve that caused the engine's oxidizer/fuel mixture to deviate too much.

2. An explosion caused by a rag

On February 22, 1990, an Ariane 4 rocket carrying two communications satellites was launched from the Kourou Spaceport in Guiana, France. The 470-ton Ariane 44L configuration uses four liquid boosters, each using a Viking 6 liquid rocket engine installed at a 9° inclination. The first stage uses four Viking 5C liquid rocket engines. The second stage uses a Viking 4B cryogenic propellant rocket engine, all of which use a bipropellant of nitrogen tetroxide and UH-25. The H10 stage using cryogenic propellant is continuously burned for 759 seconds by an HM-7B rocket engine to send a maximum payload of 4.73 tons into geosynchronous transfer orbit.

Ariane 44L rocket

The rocket ignited and took off, but before it even left the launch pad, one of the core stage Viking-5C engines shut down. For the 44L configuration, the eight engines contribute a total of 535 tons of thrust in the vertical direction to push the 470-ton launch vehicle. After losing one engine, the thrust was reduced to just slightly greater than the mass of the rocket, and the rocket slowly rose, and the gas washed the top of the launch pad. The staff at the Kourou Space Center did not expect the rocket to barely rise to reach orbit, but they certainly did not want to detonate the launch vehicle over the launch pad. If so, the explosion of 400 tons of highly toxic propellant would completely destroy the launch pad and fill the entire base with toxic smoke. The rocket slowly accelerated for more than a minute before being torn apart by air resistance, and the fragments fell into the swamps of French Guiana. The two communications satellites, Superbird2 and BS2X, worth $500 million, were completely destroyed.

The problem was soon found. The culprit was a rag lying in the wreckage of a Viking-5C engine. If the bipropellant is mixed and burned according to the equivalent mixing ratio, the temperature will exceed 3000 degrees. Obviously, such high-temperature gas is completely unable to drive any turbopump, and any alloy material will melt. The Europeans chose to use a pump to add cold water to the gas generator on the Viking engine to cool the gas. The problem is that this water pipe is blocked, so that the turbopump is immediately destroyed by the high-temperature gas, causing the engine to lose thrust.

The investigation revealed that a water pipe in the engine needed to be re-polished, and the technician in charge put a handkerchief in the pipe, which resulted in him being sick over the weekend. The new person in charge was unaware of the handkerchief, which remained enclosed in the Viking-5C engine as a foreign object until the rocket was launched.

Structural failure

1. Launch "stuck" by rocket fairing

The first batch of Mars probes were developed using a structure called Mariner C. The 261 kg probe would be launched using an Atlas-Agena D rocket. It was planned to depart for Mars in the Earth-Mars transfer window in November 1964. On November 5, the Atlas-Agena D rocket launched the Mariner 3 probe. The Atlas rocket stage separated normally, and the Bell 8096 engine of the Agena D stage ignited. After separation as planned, the probe telemetry showed that the solar panels did not open. Engineers soon realized that the fairing was not opened. After the ground failed to send a command to open the fairing, NASA engineers suggested igniting the attitude control thrusters to blow the fairing open, but in fact the launch had already failed - the added dead weight of the fairing made the Agena D upper stage not accelerate the probe enough to go to Mars - in fact, it only entered an orbit with a perihelion of 0.983 AU and an aphelion of 1.311 AU. The launch failed. Not long after, the Mariner 3 probe "died" due to exhaustion of power.

Atlas Agena D launches Mariner 3

The accident investigation initiated by NASA showed that the cause of the failure was the lack of testing of the new fiberglass honeycomb fairing. When it passed through the atmosphere, the pressure difference between the undeflatable honeycomb monomer and the external vacuum caused the fairing's inner shell to rupture, causing the separation mechanism to jam. The agency prepared a new magnesium alloy fairing within two weeks for the launch of the Mariner 4 probe. On November 28, Mariner 4 embarked on its journey to Mars.

2. Booster Assassin

The mysterious STS-27 mission will deploy the first Lacrosse synthetic aperture radar imaging satellite. Its internal code name is Onyx and it was launched on December 2, 1988, aboard the Atlantis space shuttle, the second space shuttle mission after the failure of STS-51-L. The satellite was deployed in an orbit with a perigee of 437 km, an apogee of 447 km, and an inclination of 57°, and was numbered USA34.

STS-27 was a dangerous mission. Due to weather conditions, the shuttle was placed in the humid Kennedy Space Center for several days. Since the Onyx-1 satellite was a top-secret mission, the takeoff time was not finalized until 24 hours before launch. To prevent the leakage of images from the top-secret radar satellite, the STS-27 mission only used the lowest bit rate mission image transmission. After the deployment of the Onyx-1 satellite, the mission control center told the shuttle crew that debris may have hit the thermal protection system, so the crew performed a mechanical arm visual inspection of the thermal protection system. They were horrified to find that the thermal tiles on the belly of the cargo compartment were severely damaged, and the mechanical arm could not reach the leading edge of the wing where the heat flow was most severe. They reported the damage to the mission control center, but the prehistoric quality of the pictures made the engineers at the mission control center unable to see anything, so they believed that the damage was not serious. The angry commander knew that the space shuttle would not survive the reentry. But he was helpless. No space shuttle was in time to rescue the "Atlantis" in orbit. He told the crew to enjoy the flight over the next few days.

A completely destroyed piece of belly insulation tile

On December 6, the space shuttle orbiter executed a deorbit ignition. Fortunately, underneath the completely destroyed thermal tile was a set of S-band antenna components that were more heat-resistant, and Atlantis miraculously escaped the disaster.

When NASA finally realized the severity of the damage to the shuttle, they launched an investigation. The problem was locked in the nose cone of the shuttle's reusable solid rocket booster, which was a chlorosulfonated polyethylene rubber. According to the plan, the material only needed to be stored for 15 days before launch, but during the STS-27 mission, it was stored in a humid test range for 45 days. The pressure limit of the nose cone dropped rapidly, and it would drop by 30% to 40% within a week. In addition, the agency inferred that the speed exceeded Mach 2.5 when the impact occurred, and ordinary small fragments could not pass through the shock wave around the orbiter at all. The fragments may be 1.5 to 3 meters in size.

New manufacturing procedures have improved the nose cone process of the Space Shuttle's reusable solid rocket boosters, greatly reducing the threat of nose cone fragments and other damage to the Space Shuttle's thermal protection system. These investigations and improvements took place 14 years before STS-107.

Electrical system failure

1. Reverse control circuit

The AS-502 mission was the second flight test of the Saturn V launch vehicle. The payload was the LTA-2R lunar module test piece and the CSM-020 spacecraft, which were used to test reentry at near second cosmic speed.

The first stage of the rocket separated 149 seconds after takeoff, and then the five J-2 engines ignited and worked until 319 seconds, at which time the thrust of the No. 2 engine dropped by more than one-third. 412.92 seconds after takeoff, the temperature in the No. 2 J-2 engine compartment suddenly rose, and the engine was subsequently shut down. More than 1 second later, the No. 3 engine was also shut down. However, the controller inside the rocket's instrument compartment only considers the ballistic changes when a single engine fails, and it has no built-in plan when two engines fail. So it still tried to restore the designed 4-engine working mode. The rocket continued to accelerate in the wrong "head-up" mode until 576 seconds, and the S-II stage separated, burning 57.81 seconds longer than expected, sending the rocket into a seriously wrong trajectory.

Two issues with the S-II stage - a leak in the bellows of the No. 2 engine igniter caused the No. 2 engine to shut down because of fuel cuts, and the No. 3 engine shut down because the control wires to the two engines were mistakenly connected reversely, sending the command to close the oxidizer valve to the No. 3 engine, causing it to shut down prematurely.

2. Wrong parameter settings

The SES-14 communications satellite is a 4,423-kilogram all-electric satellite built on the All-Electric-Star-3000EOR platform and carries NASA's GOLD payload. GOLD is a far-ultraviolet hyperspectral detector that operates in the 132nm~162nm band and has two identical and independent detectors. It is mainly used to observe the Earth's ionosphere and can be used to study the effects of geomagnetic storms and solar storms on the ionosphere and some properties of the ionosphere itself.

SES-14 communications satellite

The Al Yah-3 communications satellite weighs 3,795 kg and is built on the GEOStar-3 platform. It belongs to the UAE's Al Yah Satellite Communications Company. The satellite uses BT-4 thrusters manufactured by Ishikawajima-Harima Heavy Industries to raise its orbit and XR-5 Hall thrusters to maintain its position.

On January 26, 2018, Beijing time, the Ariane 5 rocket lifted off two communication satellites, with the target orbit being a special supersynchronous transfer orbit with a perigee of 250 km, an apogee of 45,234 km, and an inclination of 3 degrees. This orbit was designed because SES-14 is a fully electric satellite, in which the satellite is illuminated by the sun 24 hours a day, and it is also convenient to ascend to an elliptical orbit with a period of 24 hours, so that the electric propulsion is always turned on to raise the orbit. The secondary satellite Al Yah3 is also equipped with electric propulsion, so the impact on it is not too great.

But seconds after the first stage was shut down and separated and the second stage ignited, the rocket's telemetry signal was lost.

In fact, the rocket was in the wrong direction when it took off. Ariane said it was due to a problem with the second stage of the rocket. Later that day, the signals of the two satellites were captured by the ground station.

The satellite entered an orbit with a perigee of 232 km, an apogee of 42,163 km, and an inclination of 20.64°. SES announced that the life of the SES-14 satellite would not be greatly affected, but it would take an additional 4 weeks to raise the orbit. Al Yah 3 was unlucky. Due to the incorrect argument of perigee, if the chemical thrusters were used directly to raise the orbit, the life of the satellite would be reduced by at least 16 years, which is equivalent to a total loss.

The Al Yah3 satellite entered an elliptical orbit through four chemical thruster firings. On May 9, 2018, the Al Yah3 satellite was finally successfully positioned. In October 2019, SES-14 also successfully completed positioning relying on electric propulsion.

The problem was with the Ariane 5 rocket's navigation system. This mission was a special one, a supersynchronous transfer orbit. Therefore, a parameter in the Ariane 5 rocket's inertial guidance unit was set to 70 degrees according to the special flight azimuth requirement, but it was actually set to 90 degrees, which eventually caused the rocket to roll 20 degrees more to the south - and finally the rocket flew out of the telemetry range at T+566, and lost the signal.

Control system failure

Ignored mathematical symbols

On July 22, 1962, the Atlas Agena B was successfully launched from Cape Canaveral Air Force Station, but the mission soon failed. In the last few seconds before the Atlas rocket was shut down, the rocket attitude diverged and was detonated by the mission control center, and the fragments fell into the Atlantic Ocean. After several months of investigation, the problem surfaced. The guidance algorithm of the Atlas rocket was based on the average speed calculation. When this variable was entered into the navigation computer, a small bar representing the average was ignored, so the instantaneous speed measured by the radar replaced the average speed. This problem has occurred before, but it did not affect the flight. Because the rocket usually receives the speed data measured by the ground station through the antenna four times, but this time the receiving antenna did not lock the ground, the navigation computer automatically switched to the guidance algorithm on the arrow and introduced an overcorrection that caused the rocket to deviate from the course.