sure why.)

It's been the silence from Russian officials that's suspicious

The location of this mystery experiment is familiar at least. In 2014, on the Progress M-24M, a similar spacecraft to the one being sent skyward on Thursday, Russian engineers used the spot to strap on the Otrazhenie-5 (reflection) experiment. This was an optical sensor designed to monitor atmospheric phenomena and its reflective properties. The observations with the Otrazhenie were short-lived, gathering data after the undocking from the station and before burning up in the Earth's atmosphere.

The Otrazhenie-5 experiment is visible on the left top edge of Progress M-24M, which was launched to ISS in 2014.

Such a study could have military benefits by perfecting reconnaissance and early warning sensors used to track missiles and other military targets. NASA engineers speculatethat the unidentified instrument on the Progress MS-07 might be the latest incarnation of the Otrazhenie experiment, even though the hardware looks somewhat different. Really it's been the silence from Russian officials that's suspicious, a NASA source told Popular Mechanics.

According to the latest flight schedule, Progress MS-07 will dock at the ISS just three hours after launch at 5:32 a.m. EDT, cutting in half the fastest flight timeline. The spacecraft is expected to remain docked at the outpost until March 2018.

Anatoly Zak is the publisher of RussianSpaceWeb.com and the author of Russia in Space, the Past Explained, the Future Explored

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more