In the question What is a propellant burner trailer? I mention that

CNN and NPR have pointed out that the US president recently tweeted a surveillance photo of an explosion of a rocket on a launch pad.

The NPR article linked above speculates on the source of the tweeted surveillance photo, mentioning that it might not be a satellite product. At one point it says:

It was not entirely clear where the president's photo came from. Panda believes it was most likely taken by a classified U.S. satellite. But Melissa Hanham, deputy director of the Open Nuclear Network at the One Earth Foundation, believes that the resolution is so high, it may be beyond the physical limits at which satellites can operate. "The atmosphere is thick enough that after somewhere around 11 to 9 centimeters, things get wonky," she says.

That could mean it was taken by a drone or spy plane, though such a vehicle would be violating Iranian airspace. Hanham also says that the European company Airbus has been experimenting with drones that fly so high, they are technically outside the atmosphere and thus operating outside national boundaries. But she says she doesn't know whether the U.S. has such a system.

This comment suggests that answers to Is there a height limit to national airspace? address the height required to operate outside national boundaries, so I have modified my question to ask only the following.

Question: What kind of drone, Airbus or otherwise, might be able to do this?


2 Answers 2


Depending on who you ask, outer Space starts between 80 and 150 km, whereas 100 km is the most common defintion (Kármán line).

Countries do not acknowledge the transition from airspace to outer Space as territorial boundaries. Instead the function of an object is used for distinction:

  • if it flies, it must be an aircraft and subject to national sovereignty
  • if it falls around earth, it must be satellite and subject to Space laws

This distinction works well enough because there is hardly any traffic that could be both. Launchers and missiles are another class. As long as they go up or down, they will clearly be subject to national law at some point. When launchers or missiles are merely crossing over a country, it will be a question of friend or foe.

To answer the question, no object can fly high enough to leave national boundaries, because the act of flying itself makes it part of the sovereign territory.

In order to operate above national boundaries, a drone would have to stop flying and convert to any sort of spacecraft, that is a satellite, a space probe, or a space plane. At the current state of technology, such conversion towards Space is impossible. Only launchers are capable of bringing objects into orbit. Re-entrance of a drone from Space on the other hand side is possible and has happened. See ESA IXV for instance.

IXV in Orbit Artist impression of IXV in Orbit. Image: ESA

This reentry vehicle has some maneuvering capabilities and no engines. A vehicle like this satisfies the definition of a drone during the descent phase, and may be equipped with any sorts of instruments. If it reentered above a country, it would be very hard to agree on the altitude when it entered a national territory. In the end, the fact that it reenters the atmosphere, becomes an aircraft and subject to national territories is undeniable.

IXV flight path IXV flight path. Image: ESA


Normally, controlled airspace ends at 60,000 ft (Flight Level 600). Airplanes flying higher than that would be operating outside of controlled airspace. Currently, there is no internationally agreed definition where national airspace ends. However, aircraft flying higher than 60,000 ft (18,288 m) could claim to fly outside of national boundaries.

There are several airplane designs capable of flying above that height:

  • The venerable Lockheed U-2 should be first on this list, even though it is sometimes loaded with sensors such that it can climb above FL600 only at the end of its mission.
  • Next would be the Lockheed SR-71, but none are still flying.
  • Both the Myasishchev M-17 and the larger M-55 also qualify.
  • But most likely the photo has been taken by a RQ-4 Global Hawk which officially flies up to 60.000 ft high.

Even though those designs fly at a height where 98% of the atmosphere is below them, they are still firmly flying within it, technically or otherwise.

There are several more which can fly much higher, but those are research aircraft which do not take photo trips into Iran. Of course, there can still be a classified design of which we don't know yet.

EDIT: Now it is reported that satellite tracking has identified the source of the photo as USA 224, a spy satellite launched in 2011. Using the shadows in the picture as a sun dial, the exact time could be determined and the corresponding satellite was traced down by amateur satellite hunters.

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    $\begingroup$ @uhoh: You are very welcome! $\endgroup$ Aug 31, 2019 at 19:01
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    $\begingroup$ @uhoh: Yes, that is a possibility, but I am no expert on the resolution of modern satellite cameras. The GH operates in the area, has the required cameras and is known to reach up to 73.00 ft. $\endgroup$ Sep 1, 2019 at 7:32
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    $\begingroup$ @uhoh: Now it looks lie it was a satellite after all. Answer appended. $\endgroup$ Sep 5, 2019 at 5:37
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    $\begingroup$ @PeterKämpf The last sentence in your first paragraph should be revised. As far back as May 1960 both the Russians and Gary Powers knew that 70,000' was well within the national borders of Russia. And on October 27, 1962, U-2 pilot Rudolf Anderson Jr. was shot down during the Cuban Missile Crisis. In both cases,the US knew it was violating the airspace of other countries but thought it could get away with it. $\endgroup$
    – JScarry
    Sep 9, 2019 at 16:21
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    $\begingroup$ @PeterKämpf nobody is trolling here, please avoid throwing accusations around. If you don't want to answer, nobody will force you. But if you decide to engage, please remain respectful of others. $\endgroup$
    – Federico
    Sep 10, 2019 at 8:46

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