Why do Rockets love to fail?

Reading Time: 8 minutes

Deepak Kumar
Propulsion Engineer, Dept. of Propulsion, STAR

“Rockets, they really don’t wanna work, they like to blow up a lot”


         – Elon Musk

If you take look at all the List of spaceflight-related accidents and incidents – Wikipedia , you’ll realize there have been countless failures. That the answer to “How many”.


Rockets can fail anytime. Moreover, a rocket isn’t a simple machine at all. A massive structure having around 2.5 billion dynamic parts is likely to fail anytime if any of these parts says, “ I can’t do this anymore, I’m done”.


Coming to some of the well known Rocket Failures, this will help you learn how rockets fail!


1. The Space Shuttle Challenger Disaster

Why do Rockets love to fail?

The spaceflight of Space Shuttle carried a crew of 7 members, when it disintegrated over the Atlantic Ocean. The disintegration was caused due to the failure of one of Solid Rocket Boosters(SRB). The SRB failed during the lift-off.


The failure of SRB was caused due to O-Rings. O-ring is mechanical gasket that is used to create a seal at the interface. And here, that interface was between two fuel segments. O-Ring was designed to avoid the escaping of gases produced due to burning of solid fuel. But extreme cold weather on the morning of launch date, the O-Ring became stiff and it failed to seal the interface.

Why do Rockets love to fail?

This malfunctioning caused a breach at the interface. The escaping gases impinged upon the adjacent SRB aft field joint hardware( hardware joining the SRB to the main structure) and the fuel tank. This led to the separation of the Right Hand SRB’s aft field joint attachment and the structural failure of external tank.

Why do Rockets love to fail?

In the video below, the speaker mentions about the weather being chilly on that morning and icicles formed on the launch pad in the morning. One of SRB is clearly visible making its own way after the failure.

2. The Space Shuttle Columbia Disaster

Unlike the above failure, this failure occurred during the re-entry. But again, the story traces back to the launch. During the launch, a piece of foam broke off from the external fuel tank and struck the left wing of the orbiter.

Why do Rockets love to fail?

This is an image of orbiter’s left wing after being struck by the foam. The foam actually broke off from the bi-pod ramp that connects the orbiter and fuel tank.

Why do Rockets love to fail?

The foam hit the wing at nearly a speed of 877 km/h causing damage to the heat shield below the orbiter. The piece of foam that broke off the external fuel tank was nearly the size of a suitcase and could have likely created a hole of 15–25 cms in diameter.

Why do Rockets love to fail?

The black portion below the nose you see is the carbon heat shield of orbiter.

On Feb 1,2003 during the re-entry, at an altitude of nearly 70 km, temperature of wing edge reached 1650 °C and the hot gases penetrated the wing of orbiter. Immense heat energy caused a lot of dange. At an altitude of nearly 60 km, the sensors started to fail, the radio contact was lost, Columbia was gone out of control and the left wing of the orbiter broke. The crew cabin broke and the vehicle disintegrated.



You can clearly see the vehicle disintegrating. **The video is a big one, hang tight. 😉


3. The N1 Rocket Failure

Not many people know about this programme. It was started in 1969 by the Russians. N1 rocket remains the largest rocket ever built till date. The rocket had its last launch in 1972. During this tenure, the were four launches, all of them failed. Yes you heard it right, ALL OF THEM FAILED.

Why do Rockets love to fail?

Before discussing the failures, there is one thing that I never forget to mention about this rocket. Rockets rely on TVC(Thrust Vector Control) to change the direction of the thrust. The nozzle direction is changed to alter the direction of thrust.

Why do Rockets love to fail?

This is TVC. But in case of N1 Rocket, there was something called Static Thrust Vectoring. There were 30 engines in stage 1, 8 engines in stage 2, 4 engines in stage 3 and 1 in stage 4.

Why do Rockets love to fail?

There were 24 on the outer perimeter and the remaining 6 around the centre.

In order to change the direction of rocket, the thrust was changed in the engines accordingly. The engines didn’t move like TVC at all.

Now coming to the failed launches:

Launch 1:

The engines were monitored by KORD(Control of Rocket Engines). During the initial phase of flight, a transient voltage caused KORD to shut down the engine #12. Simultaneously, engine #24 was shut down to maintain stability of the rocket. At T+6 seconds, pogo oscillation( a type of combustion instability that causes damage to the engine) in the #2 engine tore several components off their mounts and started a propellant leak. At T+25 seconds, further vibrations ruptured a fuel line and caused RP-1 to spill into the aft section of the booster. When it came into contact with the leaking gas, a fire started. The fire then burned through wiring in the power supply, causing electrical arcing which was picked up by sensors and interpreted by the KORD as a pressurization problem in the turbopumps.

Launch 2:

Launch took place at 11:18 PM Moscow time. For a few moments, the rocket lifted into the night sky. As soon as it cleared the tower, there was a flash of light, and debris could be seen falling from the bottom of the first stage. All the engines instantly shut down except engine #18. This caused the N-1 to lean over at a 45-degree angle and drop back onto launch pad 110 East. Nearly 2300 tons of propellant on board triggered a massive blast and shock wave that shattered windows across the launch complex and sent debris flying as far as 6 miles (10 kilometers) from the center of the explosion. Just before liftoff, the LOX turbopump in the #8 engine exploded (the pump was recovered from the debris and found to have signs of fire and melting), the shock wave severing surrounding propellant lines and starting a fire from leaking fuel. The fire damaged various components in the thrust section leading to the engines gradually being shut down between T+10 and T+12 seconds. The KORD had shut off engines #7, #19, #20, and #21 after detecting abnormal pressure and pump speeds. Telemetry did not provide any explanation as to what shut off the other engines. This was one of the largest artificial non-nuclear explosions in human history.

Launch 3:

Soon after lift-off, due to unexpected eddy and counter-currents at the base of Block A (the first stage), the N-1 experienced an uncontrolled roll beyond the capability of the control system to compensate. The KORD computer sensed an abnormal situation and sent a shutdown command to the first stage, but as noted above, the guidance program had since been modified to prevent this from happening until 50 seconds into launch. The roll, which had initially been 6° per second, began rapidly accelerating. At T+39 seconds, the booster was rolling at nearly 40° per second, causing the inertial guidance system to go into gimbal lock and at T+48 seconds, the vehicle disintegrated from structural loads. The interstage truss between the second and third stages twisted apart and the latter separated from the stack and at T+50 seconds, the cutoff command to the first stage was unblocked and the engines immediately shut down. The upper stages impacted about 4 miles (7 kilometers) from the launch complex. Despite the engine shutoff, the first and second stages still had enough momentum to travel for some distance before falling to earth about 9 miles (15 kilometers) from the launch complex and blasting a 15-meter-deep (50-foot) crater in the steppe.


Launch 4:

The start and lift-off went well. At T+90 seconds, a programmed shutdown of the core propulsion system (the six center engines) was performed to reduce the structural stress on the booster. Because of excessive dynamic loads caused by a hydraulic shock wave when the six engines were shut down abruptly, lines for feeding fuel and oxidizer to the core propulsion system burst and a fire started in the boat-tail of the booster; in addition, the #4 engine exploded. The first stage broke up starting at T+107 seconds and all telemetry data ceased at T+110 seconds.

Besides the mechanical failures, the rockets might fail due to a minute discrepancy in program’s as in case of Ariane 5.

Ariane 5: After 37 seconds later, the rocket flipped 90 degrees in the wrong direction, and less than two seconds later, aerodynamic forces ripped the boosters apart from the main stage at a height of 4km. This caused the self-destruct mechanism to trigger, and the spacecraft was consumed in a gigantic fireball of liquid hydrogen.

The fault was quickly identified as a software bug in the rocket’s Inertial Reference System. The rocket used this system to determine whether it was pointing up or down, which is formally known as the horizontal bias, or informally as a BH value. This value was represented by a 64-bit floating variable, which was perfectly adequate.

However, problems began to occur when the software attempted to stuff this 64-bit variable, which can represent billions of potential values, into a 16-bit integer, which can only represent 65,535 potential values. For the first few seconds of flight, the rocket’s acceleration was low, so the conversion between these two values was successful. However, as the rocket’s velocity increased, the 64-bit variable exceeded 65k, and became too large to fit in a 16-bit variable. It was at this point that the processor encountered an operand error, and populated the BH variable with a diagnostic value.

That’s your answer to “why”. Rockets can fail anytime due even a small malfunction in one of those 2.5 billion dynamic parts or even a small programming error.

Hope you enjoyed the writings up there!

Thank You!

Source: Google and Wikipedia



Looking forward to excel in rocket building?

Check out this link Space Technology and Aeronautical Rocketry- STAR


Reading Time: 6 minutesMost of us since class 11 have hated thermodynamics, isn’t it CBSE guys!

I remorse, we would have not. It’s not our fault, but the way in which we were introduced to it. If we would have first been astonished by the grand history of subject, the efforts of the greatest Lord Kelvin, James Clerk Maxwell,  Ludwig Boltzmann, Sadi Carnot, Rudolf Clausius, W. Gibbs, and more legends, the initial experiments and observations which triggered the human to invent an engine and the story behind the development of axiomatic theory which governs most of the phenomenon of universe, then things could have been different. My dear friends, it boosts adrenaline in me to introduce to you a science of 4 centuries.


The aim of this blog is to break that conventional attitude, to establish the beauty of the subject, and help some of my fellow classmates to get launched into the subject.

It is the science that took 4 centuries, immense labor and enthusiastic effort to take the final current form. The timeline would run on several different tracks, finally will converge to final form.

The science of hot and cold started with trying to understand the day to day life events. The hot summers, the cold winters, the fire, and many fascinating phenomena. These things have strongly influenced life throughout the history of the earth. Human soon realized that he needs to have control over hot and cold in order to increase his comfort as well as to sustain better.

Like most of the sciences, this is also an experimental one, we need to carefully investigate the phenomenon and derive theories to explain the grander picture.


We have pondered for a long time to understand the heat and cold. There were many observations that had been made throughout history that kept thermodynamics in the most worked field among the prominent scientist community.

The quest begins with very simple everyday life observations, one of the most fascinating was the rhythmic motion of a valve mounted on a tightly closed water container being heated. This ignited us to think about the possibility of doing mechanical useful work by the gaseous state of matter.

Since then the ability of the gaseous state of matter to do some mechanical work when we supply heat to it was wondered. A deep analysis of the conversion of the heat of matter ( i.e. the kinetic energy of microscopic molecules) into the useful mechanical work is required, to get maximum possible work from a given amount of heat, hence is this subject of thermodynamics.

So, thermodynamics is a study of the phenomenon of conversion of heat into useful mechanical work.


Unknowingly you just took the words that need much deeper descriptions. Among them are heat and energy.

This timeline is most important as it actually explains the phenomenon on ground level. The whole subject gets launched on a single statement that “the reason for heat energy of any substance of the universe is the continuous motion of the constituent, the atoms and molecules”. At this point you cannot ask any deeper question, hence this can be called the origin of thermodynamics. You cannot ask why the atoms have motion.


Just as the electrical machines rely on one statement that “Moving electrical charge experience force in a magnetic field“, this is the reason for induction of emf in the generator as well as rotation of the shaft in motors. Here you can’t ask why the charge experience force, similar is the above case.

So, heat is the energy that is proportional to the kinetic energy of molecules of the substance.

Let’s look at what is energy:


In our world energy is something we take too easy. The true meaning of energy is ineffable. But we can describe it at least, energy occurs in different interchangeable form.

  1. The energy possessed due to the motion of molecules: The Heat energy
  2. Energy trapped in the bond of molecules: The Chemical energy
  3. Energy trapped in the nucleus- The nuclear energy
  4. Electromagnetic energy

Just for a moment try to trace down any form of energy present on earth back to its original source, you would find that the sun is the highest stakeholder. The most dominant form, electromagnetic energy is the result of a chemical reaction in the sun that emits energy in form of electromagnetic waves of a very wide range of frequencies. The chemical energy or more specifically nuclear energy stored in the sun is the result of the great kinetic energy of protons neutrons which combined to form strong nuclear bonds to form atoms of the different elements, at the time of formation of the sun itself.

The source of the kinetic energy of initial protons cannot be further visualized, hence we can say that this form is the mother of all energy in existence. So all form of energy can be traced down to kinetic energy of constituent of matter.

It is completely theoretical that we assume that atoms have kinetic energy, and so we can explain the phenomenon, hence question on the existence of the kinetic energy of them is not justified, you cannot ask that what is the cause of the kinetic energy of the atom.



Far before humans visualized the microscopic description of thermodynamics they had well analyzed other way to describe and predict the behavior of thermodynamic systems. It was the macroscopic approach. The properties of systems the pressure, the temperature, the volume all the were bounded by mathematical equations, which were determined experimentally.


The ideal gas equation which relates P, V, moles, and temperature of ideal is gas which was determined experimentally and then proved later by statistical mechanics.

At the microscopic level, the atoms molecules or ions have the kinetic energy, which we, at the macroscopic level describe as temperature. So temperature is a term coined to quantify the average kinetic energy possessed by the constituent of any materialistic object.

So can you answer:

What is the temperature of the neutron at 500 Kmph?

This is a void question because temperature is macroscopic quantity and defined for a system.

So, when in summer we say temperature is high. At the microscopic level, the average kinetic energy of molecules have increased and they collide with skin more impulsively and cause discomfort.

It is the force of change of momentum of the speedy molecule which creates pressure on the walls of the container.

So how beautiful is that the event which is actually microscopic can be studied via macroscopic parameters.

Propagation of Energy:

Now you would agree that the kinetic energy of particles is the origin of all the energy around us.

The energy of particles (atomic) i.e. the kinetic energy is converted in a most prominent form, the electromagnetic waves. Which then travels in the vacuum from the sun and reach earth.

Moreover, objects on earth transfer their energy as it is via thermal energy in transfer, heat.

Three ways of heating are the conduction, convection and the radiation.

In conduction, the flow of energy takes place by physical contact and atoms exchanging their kinetic energy by colliding with each other.

The convection is a way of heat transfer in liquids to distribute heat uniformly.

The radiation is the emission of EM waves by an object due to accelerated charged particles.

Well, this is just a blog to ignite the fire in you understand the fire. Many sources can be used to sail through the subject to get core concepts and ideas.

It involves watching documentaries like:


You can also watch an amazing youtube video series by Physics Videos by Eugene Khutoryansky.

Some great books are:

  1. THERMAL PHYSICS: By Blundell and Blundell ( a husband-wife great work), here is the google drive link:  https://drive.google.com/file/d/1jOvE5uzVRP0BUzE-JTqyESwKY-FREGUx/view?usp=sharingTHERMODYNAMICS
  2. Four laws that drive the universe: by Peter Atkins


In the end best of luck for exploring thermodynamics.




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