SpaceX News

[DeltaV]

What's the point?

The point, Mr. Science, is that unclassified SSL power levels in 2015 are order-of-magnitude sufficient to damage a rocket over several seconds of dwell time (as I stated before you did). Your other posts also indicate ignorance of progress in optics/lasers and a poor understanding of classified vs. unclassified technology levels.

[DeltaV]

The failure point from a different angle.

There is a non-zero angle of attack, so it's not clear if the vapor trail originates at the arrow or is wrapping around the cylinder.

[hanelyp]

Since they were already having trouble with their helium tanks, I wonder if one of these were to spring a leak, is there a valve that would prevent the helium from escaping back into the helium tank and and out once all the helium was lost?

Given that the helium tank is at much higher pressure than the systems it's directly connected to, I very much doubt reverse flow is a problem. If helium tank pressure does drop low enough to be a problem there's probably already a critical failure elsewhere.

[GPecchia]

My wild guess of a failure sequence.
1. MVAC chilldown starts some 18 seconds before O2 venting.
2. As O2 tank pressure drops because of chilldown O2 flow, pressure regulator opens He tank valve to keep O2 tank pressure constant (The He tanks are located in the O2 tank).
3. Pressure regulator closes He valve after O2 tank is back up to normal pressure, He tank experiences a hammer shock effect and ruptures because of an inherent weakness of the He tank.
4. He tank failure causes massive O2 tank over pressure which ruptures the top of the O2 tank and taking out the avionics just above it.
5. Telemetry stops because of loss of avionics.
6. F9 1st stage continues operation until 2nd stage completely disintegrates then does an internally generated self destruct.

[DeltaV]

The NASA video shows a bright spot fading for 2 frames.

Conventional interpretation A: Stage 1 plume briefly interrupts sunlight reflecting off of <what?>.
Conventional interpretation B: Venting vapor jet briefly interrupted.
Conventional interpretation C: Electrical arcing briefly interrupted.
Fringe interpretation: Laser beam adaptive optics transient.

[Giorgio]

What's the point?

The point, Mr. Science, is that unclassified SSL power levels in 2015 are order-of-magnitude sufficient to damage a rocket over several seconds of dwell time (as I stated before you did). Your other posts also indicate ignorance of progress in optics/lasers and a poor understanding of classified vs. unclassified technology levels.

Even a 10Kw laser is sufficient to damage a rocket, provided that you can compensate for Scattering and beam divergence.

The point is that no one can still compensate for these two issues (with actual technology) to allow a 100KW laser to damage a rocket flying at the altitude at the moment of the explosion.
And you cannot object this statement claiming that the technology exists but is "classified", because it does not add anything to your theory or your point and clearly seems just an excuse to escape the most logic conclusion that SpaceX rocket exploded for a (yet unknown) technical issues.

Should one blindly accept your "Classified" statement as a valid theory than anything could be believed simply on the basis of a "it's true but I can't prove it because is classified!" statement.

[DeltaV]

Even a 10Kw laser is sufficient to damage a rocket, provided that you can compensate for Scattering and beam divergence.

Even a linear extrapolation of the above SSL power chart to 2015 gives a current unclassified power level over 200 KW.

In Feb 2010, ABL (1MW COIL laser) destroyed a liquid-fuel booster off of Pt. Mugu.

http://www.reuters.com/article/2010/02/ ... arketsNews
http://www.mda.mil/global/documents/pdf/laser.pdf
http://www.mda.mil/news/10news0002.html

At 8:44 p.m. (PST), Feb. 11, 2010, a short-range threat-representative ballistic missile was launched from an at-sea mobile launch platform. Within seconds, the ALTB used onboard sensors to detect the boosting missile and used a low-energy laser to track the target. The ALTB then fired a second low-energy laser to measure and compensate for atmospheric disturbance. Finally, the ALTB fired its megawatt-class High Energy Laser, heating the boosting ballistic missile to critical structural failure. The entire engagement occurred within two minutes of the target missile launch, while its rocket motors were still thrusting.

Adaptive optics performance confirmed.

The point is that no one can still compensate for these two issues (with actual technology) to allow a 100KW laser to damage a rocket flying at the altitude at the moment of the explosion.

Above 30 km the atmosphere is practically a vacuum. CRS-7 broke up near 45 km.



As one would expect, USAF did not release the ABL intercept range. It was reported elsewhere that the expected range against liquid fuel boosters was 600 km.

http://webcache.googleusercontent.com/s ... clnk&gl=us

As of early 2009 the beam had been fired in the air and was performing well to ranges beyond 100km. According to an American Physical Society report in 2004, the Airborne Laser could shoot down a typical liquid-fuel intercontinental ballistic missile (ICBM) from up to 600km away. However, against solid-fuel ICBMs, which are more resistant to heating, the useful range would be about 300km. The weapon system's ability to compensate for atmospheric conditions between it and its target was a make-or-break matter, and at that time it was doing fine.

For CRS-7, required range would be under 100 km. The size of ABL's beam director is dictated mostly by the areal power density (W/cm^2) that can be tolerated without damaging the optics. Assuming the same areal power density, the required beam director's aperture area for 200KW (1/5 the power of ABL) would be 1/5 of ABLs, giving a required aperture diameter of 1/sqrt(5) or 45% of ABLs. This would fit in a ConEx box.

And you cannot object this statement claiming that the technology exists but is "classified", because it does not add anything to your theory or your point and clearly seems just an excuse to escape the most logic conclusion that SpaceX rocket exploded for a (yet unknown) technical issues.

Should one blindly accept your "Classified" statement as a valid theory than anything could be believed simply on the basis of a "it's true but I can't prove it because is classified!" statement.

Should one blindly accept your statement that anything should not be believed simply on the basis of "it's false and I can prove it because it's not unclassified!"

But let's not get bogged down in philosophical arguments. Remember, I said earlier that I'm exploring the "fringe" interpretation because nobody else will, just in case there is something there. I'm exploring "solution space", not trying to start a cult (or WW3).

[D Tibbets]

A very (?) important consideration is that the air born laser platform would be flying at perhaps 40,000 feet, as mentioned this is above most of the atmosphere. Shooting from there to a missile at an even higher altitude- if it was not too far over the horizon, would avoid most of the turbulence and defocusing and absorption effects in the lower atmosphere. A surface/ ship laser would have to punch accurately through this dense lower atmosphere before it reached a level playing field comparable to the air born laser. I don't know if it is improbable, but it is more difficult than the technology demonstrated with the air born laser platform, which was a dedicated 747 airliner massively and very expensively modified. Shooting straight up instead of low near the horizon would help considerably.

Dan Tibbets

[Giorgio]

In Feb 2010, ABL (1MW COIL laser) destroyed a liquid-fuel booster off of Pt. Mugu.
...SNIP....
As one would expect, USAF did not release the ABL intercept range. It was reported elsewhere that the expected range against liquid fuel boosters was 600 km.
....SNIP....
Adaptive optics performance confirmed

The main idea about ABL was that by flying at 40K feet (above Tropopause level in most of the world) and "shooting horizontally toward the target" would have eliminated some of the main issues of laser disturbances in the atmosphere.
The tests showed that during design phase they didn't consider the issue of "thermal blooming". This caused the ABL to reach an effective range of only few km in horizontal direction (even if shooting from 12Km altitude!!) and lead to the project dismissal. The video of the test shows clearly how near the plane and the target was:
http://www.mda.mil/news/gallery_altb.html#!

The "thermal blooming" is caused by several factors at same time, but the most troublesome one is the presence of "turbulence cells" in the atmosphere. Thermal blooming effects are able to dissipate several MW of laser power in the first vertical 10Km and even to break the laser Beam integrity in some cases.

The reason behind this is that small differences in temperature at different positions in a mass of air generate small volumes of contracting and expanding "air cells". The "average diameter" of these cells is few Cm at ground level and few tens of Cm above Tropopause altitude.
All these "air cells" will have a small different refractive indexes from each other. These differences will cause the laser rays passing through them to be bent in random directions, and (because the cells diameter are smaller than the Laser diameter) the beam is dispersed.
It is even possible to reach the point where the dispersion will break the Laser beam into multiple separate and smaller beams. If this happens than the adaptive optics cannot correct the beam.
These are potential showstopper for any ground based defense Laser aimed to high altitude rockets!

So as you can see, no Adaptive Optics for a MW class laser that is able to compensate over tens of Km of vertical air has ever been demonstrated yet and will probably never be possible. The 600 km range was a nice sales pitch from Boeing people, but it can't change physics.
But hey, for the sake of a good conspiracy theory we can ignore these petty physics issues!

For the one who wish to learn more here is a good paper on Thermal blooming from 1992!:
https://www.ll.mit.edu/publications/jou ... ooming.pdf
and a more technical paper for the one wishing to run their own simulations:
http://spie.org/samples/PM109.pdf

Should one blindly accept your "Classified" statement as a valid theory than anything could be believed simply on the basis of a "it's true but I can't prove it because is classified!" statement.

Should one blindly accept your statement that anything should not be believed simply on the basis of "it's false and I can prove it because it's not unclassified!"

I can't make a meaning out of this. Do you care to express your point it in a more comprehensible way?

But let's not get bogged down in philosophical arguments. Remember, I said earlier that I'm exploring the "fringe" interpretation because nobody else will, just in case there is something there. I'm exploring "solution space", not trying to start a cult (or WW3).

I am always fine with exploring "fringe" interpretations, but let's do it with technical arguments please, else it become meaningless.


Edited to fix spelling.

[Giorgio]

A very (?) important consideration is that the air born laser platform would be flying at perhaps 40,000 feet, as mentioned this is above most of the atmosphere. Shooting from there to a missile at an even higher altitude- if it was not too far over the horizon, would avoid most of the turbulence and defocusing and absorption effects in the lower atmosphere. A surface/ ship laser would have to punch accurately through this dense lower atmosphere before it reached a level playing field comparable to the air born laser. I don't know if it is improbable, but it is more difficult than the technology demonstrated with the air born laser platform, which was a dedicated 747 airliner massively and very expensively modified. Shooting straight up instead of low near the horizon would help considerably.

Dan Tibbets

Spot on!

[DeltaV]

Propagation of high-power partially coherent fibre laser beams in a real environment

Chinese Physics B Volume 20 Number 9
Tao Ru-Mao et al 2011 Chinese Phys. B 20 094208 doi:10.1088/1674-1056/20/9/094208

http://iopscience.iop.org/1674-1056/20/9/094208

Abstract

The propagation performance of high-power partially coherent fibre laser beams in a real environment is investigated and the theoretical model of a high-power fibre laser propagating in a real environment is established. The influence of a collimating system and thermal blooming is considered together with atmospheric turbulence and mechanical jitter. The laser energy concentration of partially coherent beams in the far field is calculated and analysed based on the theoretical model. It is shown that the propagation performance of partially coherent beams depends on the collimating system, atmospheric turbulence, mechanical jitter and thermal blooming. The propagation performance of partially coherent beams and fully coherent beams is studied and the results show that partially coherent beams are less sensitive to the influence of thermal blooming, which results in that the energy degeneration for partially coherent beams is only 50% of that for fully coherent beams. Both partially coherent beams and fully coherent beams become less sensitive to thermal blooming when the average structural constant of the refraction index fluctuations increases to 1.7 × 10−14m−2/3. The investigation presents a reference for applications of a high-power fibre laser system.

Demonstration of Long-Lived High-Power Optical Waveguides in Air

N. Jhajj, E. W. Rosenthal, R. Birnbaum, J. K. Wahlstrand, and H. M. Milchberg
Phys. Rev. X 4, 011027 – Published 26 February 2014

http://journals.aps.org/prx/abstract/10 ... X.4.011027

Abstract

We demonstrate that femtosecond filaments can set up an extended and robust thermal waveguide structure in air with a lifetime of several milliseconds, making possible the very-long-range guiding and distant projection of high-energy laser pulses and high-average power beams. As a proof of principle, we demonstrate guiding of 110-mJ, 7-ns, 532-nm pulses with 90% throughput over ∼15 Rayleigh lengths in a 70-cm-long air waveguide generated by the long time-scale thermal relaxation of an array of femtosecond filaments. The guided pulse was limited only by our available laser energy. In general, these waveguides should be robust against the effects of thermal blooming of extremely high-average-power laser beams.

32TW atmospheric white-light laser

P. Béjot, et al, Appl. Phys. Lett. 90, 151106 (2007)

http://www.teramobile.org/publications/ ... 151106.pdf

Abstract

Ultrahigh power laser pulses delivered by the Alisé beamline (26 J, 32 TW pulses) have been sent
vertically into the atmosphere. The highly nonlinear propagation of the beam in the air gives rise to
more than 400 self-guided filaments. This extremely powerful bundle of laser filaments generates a
supercontinuum propagating up to the stratosphere, beyond 20 km. This constitutes the highest
power “atmospheric white-light laser” to date.

The literature on nonlinear laser optics is voluminous. These are just some samples. Of course GW or TW is for very short pulses, not average power, so many pulses are required.

A surprising breakthrough in capability would probably involve a synergistic combination of various approaches.

[Giorgio]

1) Propagation of high-power partially coherent fibre laser beams in a real environment
..snip..
2) Demonstration of Long-Lived High-Power Optical Waveguides in Air
..snip..
3) 32TW atmospheric white-light laser

The literature on nonlinear laser optics is voluminous. These are just some samples. Of course GW or TW is for very short pulses, not average power, so many pulses are required.

These examples unfortunately are supporting more my point more than supporting your point.
It's known that Thermal Blooming effect is depending on Laser Beam power and propagation time and wavelength of the laser.
Adapting and reducing any of these factors will of course attenuate the Thermal Blooming effect, which can be extremely useful if you want to use the laser for communication and distance measurement with long distance objects, but absolutely useless for transferring focused thermal energy on an object in a meaningful way as to create a structural damage to it.
Paper 1 reduces coherence (same as reducing thermal power over the same area)
Paper 2 reduces time of pulse laser (natural thermal dissipation of object will be far superior to thermal energy transferred to the the target at the same "time scale" level.)
Paper 3 reduces time and switch to a wavelength that reduces even more the total thermal power of the laser as in paper2.

No one of these 3 papers can lead to an improvement of the desired result of transferring copious amount of thermal energy to an high altitude object.

The 1992 paper I linked before give plenty of experimental and theoretical support to understand why decreasing the thermal power of a laser (coherence, energy, wavelength) decreases the thermal blooming effect.
https://www.ll.mit.edu/publications/jou ... ooming.pdf

A surprising breakthrough in capability would probably involve a synergistic combination of various approaches.

A surprising breakthrough requires technological and theoretical advancements we simply have not reached yet. That's why I stated that the idea of a laser shooting down SpaceX latest launch is not possible at today technological and theoretical knowledge level.

[Carl White]

A surprising breakthrough in capability would probably involve a synergistic combination of various approaches.

A surprising breakthrough requires technological and theoretical advancements we simply have not reached yet. That's why I stated that the idea of a laser shooting down SpaceX latest launch is not possible at today technological and theoretical knowledge level.

I see, you're privy to all the latest military technology and secrets, are you?

[Giorgio]

A surprising breakthrough in capability would probably involve a synergistic combination of various approaches.

A surprising breakthrough requires technological and theoretical advancements we simply have not reached yet. That's why I stated that the idea of a laser shooting down SpaceX latest launch is not possible at today technological and theoretical knowledge level.

I see, you're privy to all the latest military technology and secrets, are you?

Are you? If you are please give us some theoretical hints on these theoretical and/or technological advances.

Or should we all believe that all type of science fiction technology exists already simply because we are NOT privy with all latest military secrets?

Why limit ourselves to think that the military are only hiding an high power and altitude death ray than? Why not consider as real also other technologies? How about:
Secret Cancer cure only for the powerful of the world?
Immortality?
Faster than light travel?
Teletransportation?
Time travel?
Tractor beams to capture planes in mid flight?
ESP power from mutant humans?

Mind you, I am not saying we will not arrive one day to those technologies, I am stating that NOW we don't have those technologies, and for most of them we don't even have a theoretical framework to work on to be able to develop them.

So tell me, where do you set the limit to one's lack of privy with "the latest military technology and secrets"?

Serious question, I would like a serious reply.

[hanelyp]

Back to the topic of the last launch,

Expect to reach preliminary conclusions regarding last flight by end of week. Will brief key customers & FAA, then post on our website.

https://twitter.com/elonmusk/status/617851905969127425