Yesterday, President Trump tweeted an annotated image of the Iranian launch site where an explosion apparently destroyed a satellite launch vehicle during launch preparations.
The United States of America was not involved in the catastrophic accident during final launch preparations for the Safir SLV Launch at Semnan Launch Site One in Iran. I wish Iran best wishes and good luck in determining what happened at Site One. pic.twitter.com/z0iDj2L0Y3
— Donald J. Trump (@realDonaldTrump) August 30, 2019
Here is the image at higher resolution (click for maximum resolution).
Earlier, Planet captured an image shortly after the accident from one of their constellation of “Dove” microsatellites which showed smoke rising from the launch site.
What is newsworthy about the image in the Trump tweet is that this appears to be the first time imagery from a KH-11 satellite has been disclosed to the public. KH-11 satellites of five generations have been in service since 1976, but their performance has never been disclosed nor has imagery from them been previously released. The performance of the satellites can be estimated from the diameter of the main mirror, which is known to be around 2.4 metres, the same as in the Hubble Space Telescope, which is reputed to be very similar to the KH-11, and also from the diameter of the payload fairing used on the rockets that launch them and their orbital altitudes which, although not disclosed, is determined by amateur satellite watchers.
It did not take long for satellite watchers to identify the satellite that took the image as USA-224, a KH-11 launched on 2011-01-20, with an estimated time the image was taken of 09:44:21 UTC on 2019-08-29. Resolution in the image is estimated at around 10 cm per pixel, and given the slant angle and range, this gives a maximum resolution from the KH-11 of around 5 to 7 cm per pixel, in agreement with estimates from diffraction-limited performance of an optical system with 2.4 metre aperture.
Here is a Scott Manley video with information about the image, how the satellite that took it was identified, and what it tells us about the performance of the KH-11.