The article has a link (citation 17) to a site selling toy models of that vehicle as an image source, I can find one (fourth image in the gallery) there where it sorta looks like the wing is missing because the wing is black against a black background but it's not the same image shown in the paper:

https://fantastic-plastic.com/lockheed-martin-x-33-venturest...

The name "Venturestar" is properly rendered in that image but "NASA" and "Lockheed Martin" are thoroughly mangled the way I'd expect text to be mangled in an AI image. The image from the toy site could have been used as as reference image to create the image in the paper one way or another.

Yes, if you look close, the paper is replete with error-filled generative reproductions of existing illustrations in the citations; including Fig. 6 (MC Escher struts), Fig. 7 (sprouting greeble tubes), and Fig. 8 (actuators replaced by tubes connected to mystery manifolds).

Even Fig. 2 shows the spike geometry magically changing, which is not addressed in the text and seems like an error carried over from the original illustration in the cited source.

Casts serious doubt on the credibility of the rest of the work.