The fourth flight of the mysterious X-37B robot spaceplane is still hard to decipher. For the first time, the US Air Force did not release any photographs of the spaceplane before launch. This has caused this analyst (and other boffins) to speculate that something strange is being deliberately concealed from us.

In previous articles for SpaceDaily, this analyst suggested that the X-37B that's now in orbit has been radically modified. It could have a different heatshield. It could have additional instruments bolted to its exterior. It could have been modified so greatly that it's no longer appropriate to call it an X-37B!

We have plenty of questions but few answers. It also seems to be difficult to get the answers we seek. The USAF is keeping silent on these matters. There are no statements or leaks through other channels.

Amateur satellite trackers are watching X-37B in orbit, but they have not produced any information that would help us to know what has changed with the vehicle. It's in a lower orbit than previous missions, but that doesn't tell us much.

This could have been done to expose the NASA materials samples on board to a tougher environment, where they will have better contact with the upper atmosphere.

Not to pick on the satellite tracking community. They're excellent people doing what they can with what they have, and we are lucky that these amateur vanguards are watching. But we're running out of leads. What else can we do?

This analyst recently turned his attention to the patches released for the latest mission, known as OTV-4. Most US spacecraft launches have commemorative patches, and X-37B is no exception. Previous patches have featured illustrations of the X-37B, consistent with the detailed photography that has also been released for previous launches. We have no photography for this mission but we can still see pictures on the patches. Again, we see the X-37B, looking essentially no different from it did in the past. But is this misleading?

Let's be fair to the patch designers. The patches are not schematic diagrams, and have never reproduced all the details on the X-37B. It's possible that any changes to the spacecraft are too small to even be documented on a simple graphic design. They would, however, show up on photography.

The vehicle shown on the patches could be fairly accurate, but it's also possible that it's not. If the USAF won't show us secret modifications in photographs, they would certainly not want us to know through other channels. This analyst doubts that anyone connected to the production of the patches knows what has happened to the real vehicle.

Are there any other clues to be deciphered? The hexagonal patch for this mission shows a small globe with the Americas facing outwards. There's a blue star covering the globe with a red star superimposed over it.

This could refer to the USA, the US Air Force, or something else that's indecipherable to outsiders. There's also a boxy building with two parabolic dishes on its roof. This could refer to tracking, communications, or a special experiment on board.

Again, we can speculate, but the graphics say nothing for certain. Other patches for classified programs are filled with "in jokes" that aren't truly understood by anyone outside the program, and that's the whole point of including them. Keeping secrets is more than a duty. It can be fun.

Thus, the patches seem to merely tease us rather than enlighten us. This analyst gives a hat tip to the custodians of this intriguing program. You're not only guarding your secrets. You're doing it with style!

Dr Morris Jones is an Australian space analyst who has written for spacedaily.com since 1999. Email morrisjonesNOSPAMhotmail.com. Replace NOSPAM with @ to send email. Dr Jones will answer media inquiries.