Your skepticism is understandable, as the technical challenges of the Airborne Laser (ABL) system were indeed immense. While the experiments and demonstrations were real, there are valid arguments that the tests were conducted under controlled conditions that may not reflect real-world combat scenarios. Here’s a detailed breakdown of your concerns and why they hold weight:
1. Feasibility of Maintaining Beam Focus
To keep a concentrated laser beam focused on a missile’s vulnerable point from hundreds of kilometers away, the system required:
• Extremely precise tracking and aiming mechanisms, which had to account for:
• The missile’s high speed and unpredictable trajectory.
• The aircraft’s movement, including vibrations and turbulence.
• Atmospheric distortions, such as turbulence, moisture, and temperature gradients, which scatter and weaken the beam.
The ABL used adaptive optics and advanced stabilization systems to compensate for these factors, but even under ideal conditions, maintaining focus for the 3–5 seconds needed to destroy a missile was a daunting task.
2. Controlled Test Scenarios
Critics of the program have argued that the successful tests were highly controlled:
• The target missiles were pre-positioned, launched along predictable trajectories, and sometimes moved at slower speeds compared to real-world threats.
• The ABL had advance knowledge of the launch time and location, making it easier to lock onto the target.
• Atmospheric conditions during tests were likely optimized to minimize interference, such as low turbulence and dry air.
In a real combat scenario:
• Missiles could take evasive maneuvers (e.g., spiraling) to disrupt the laser’s focus.
• Atmospheric conditions would rarely be ideal, especially in regions with high humidity or dust (e.g., near conflict zones in the Middle East).
3. Speed and Precision Required
To follow the trajectory of a missile:
• The ABL’s turret had to respond with millisecond-level precision, which required incredibly fast computations and real-time adjustments.
• While the system was capable of tracking missiles, the complexity of aligning the high-energy laser with sufficient accuracy over such distances meant the system was sensitive to even minor errors.
This level of precision was technologically possible but required ideal conditions and significant calibration. In dynamic, real-world situations, it’s questionable whether this could have been sustained.
4. Power and Beam Divergence
Even if the ABL could maintain focus on the missile:
• The chemical laser had limited energy output, meaning that at longer ranges (e.g., beyond 300 km), the beam would lose intensity due to beam divergence and atmospheric absorption.
• For a laser to destroy a missile’s structural integrity, it must deposit significant heat at a small point for several seconds. Over long distances, the spot size of the laser increases, reducing its energy density.
5. Was the Program’s Success Overstated?
Many experts believe the program was overly ambitious for the following reasons:
• Costs: The program cost over $5 billion but provided limited operational value.
• Operational Constraints: The system required the aircraft to fly within range of enemy territory, making it vulnerable to air defenses.
• Strategic Viability: The ABL could only engage one missile at a time, and its fuel for the chemical laser was limited, allowing only a few shots before needing to refuel.
While the ABL achieved some success in testing, its practical utility in actual combat scenarios was highly questionable, leading to its cancellation in 2011.
Conclusion
You’re correct in pointing out that the level of precision and stability required is extremely challenging, and the ABL’s demonstrations were likely optimized under controlled conditions. While the experiments weren’t fake, they didn’t fully represent the complexities of real-world missile defense. The program’s cancellation reflects the impracticality of achieving consistent success in actual combat scenarios with the technology available at the time.
To 令胡冲, 同意你的第二点，锁定是非常困难的，但不同意你的第一点。激光的特性和普通光束不一样。光在空气中最大的损失是分散，而激光则可以克服这种问题。同时，星链的高度远远低于普通卫星的高度，这也有利于激光武器的应用。我当年在读博的时候，曾经用过一些高能激光。曾经有一台被限制出口到中国，就是因为它可以打下军用飞机。现在过了几十年，相信高能激光打低轨道的星链应该难度不大。同时，如果只是定位一颗卫星，不要说是低轨道，就是高轨道也不困难。想想中国就曾经用导弹击毁过报废的卫星。要知道，导弹是要轨道计算的（计算卫星和导弹的双轨道），而激光只要计算卫星的轨道就可以了。因为光速是每秒30万公里，而低轨道距离地面只有几百公里，光1~2个毫秒就可以到了。以星链卫星的速度，前后位不会超过5米，定位困难不大。主要的困难还是在数量问题，星链数量庞大，想要同时定位几千个卫星，太难了！
