During China’s recent three-person Shenzhou-7 space trek — including a space walk — that mission also ejected a small satellite weighing all of 40 kilograms. Labeled the BX-1, the camera toting toddler of a spacecraft — dubbed a picosat — took images of the Shenzhou-7 as it circled the Earth.

Tracking data shows the BX-1, which was deployed from Shenzhou-7 on September 27 — was ejected just minutes after the International Space Station passed in front of the Shenzhou-7.

According to T.S. Kelso, a senior research astrodynamicist at the Center for Space Standards & Innovation in Colorado Springs, the BX-1 passed within 25 kilometers of the ISS. His analysis shows that the Shenzhou-7 made its own close approach to the station, flying by at one point some 46 kilometers distance.

On the one hand, there was never any concern about a potential collision, and none of the thresholds for ISS collision avoidance considerations were reached, I’ve been told. The passage was like lots of other passes which occur frequently among the resident space object population.

In fact, China’s BX-1 microsat continues in an orbit similar to a left-in-space Shenzhou-7 orbital module.

But all this cosmic closeness has stirred up blog chats - even the specter that the BX-1 is a further honing of China’s anti-satellite skills. Others believe that the “conjunction” of BX-1 and the ISS was coincidental.

Alternatively, one take home message — whether intended by China or not — is the ability for future Shenzhou missions to rendezvous and dock with the ISS - either for logistics supply or crew transfer purposes.

To do that, Shenzhou would have to demonstrate a slightly higher inclination (51.6 degrees versus 42.4 degrees for the last three piloted Chinese flights). They already have the altitude needed.

According to one source, if the Long March launcher used to boost Shenzhou craft into orbit does not already have the excess capacity for the higher ISS inclination, such would certainly appear to be within reach, given a modest modification to their booster.

So what’s all this about?

“I’d venture that this goes back to the issue of Chinese opacity in their space program,” said Dean Cheng, Senior Asia Analyst with CNA in Alexandria, Virginia.

“Either the Chinese knew that their Shenzhou would close to a fair distance of the ISS, and their picosat would get even closer, or they did not,” Cheng advised me.

Cheng added: “Neither should be reassuring. If they did not, why not, especially since the ISS’ orbit is known and they could easily have obtained this information simply by asking. If they did, then the question becomes why they did such a close approach…what political and perhaps even military messages does this portend?”

The lack of transparency means that Western analysts have little basis for determining which of the two may be true, Cheng said. “In a crisis situation, such a close approach to military satellites — as opposed to the ISS — might well be seen as escalatory, or at least provocative.”