Ti ritengo intelligente per non cadere nel giochino dove si attribuisce alla NASA un atteggiamento che sarebbe così facilmente sgamabile, almeno in questo caso.
Le spiegazioni fornite a queste foto sono chiare, non si tratta di convincersene in base alla propria "inclinazione ufologica", ma bisogna osservare quel che è. In questo documento ufficiale in pdf:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060024715_2006175325.pdfin merito alla missione STS-88 da cui sono tratte quelle immagini, possiamo leggere:
During spacewalks debris, both small and large, are often thrown off the station for convenience, although sometimes tools unintentionally slip away. Such was the case in December 1998 when a slidewire carrier and a worksite interface were lost by the STS-88 crew while conducting an extravehicular activity (EVA) for ISS. These objects were large enough to be tracked by the U.S. SSN and were cataloged (U.S. satellite numbers 25564 and 25565). Three other objects were also released by STS-88 spacewalkers, one inadvertently (an insulation blanket) and two by design (antenna spools), although only the former was officially cataloged (Debris, 1999).