Mystery Module for X-37B
Such pre-launch photos have been conspicuously absent from recent launches of the mysterious vehicle, prompting this analyst to suggest that something carried on or with the spacecraft was being kept secret. This time, we can see the spaceplane clearly, looking good but showing some signs of weathering from its previous trips into space. Most importantly, the photos don't show any design changes from any previous missions.
The mission could thus seem refreshing for its relative openness. Not so fast! One critical difference between this flight and previous missions is a new Service Module being carried at the rear of the spacecraft. We have been told that the Service Module will be used to house experiments on this flight, but that's about all we have been told. Curiously, the photographs of the X-37B seem framed and cropped to make sure we can't see the Service Module, which lies just beneath the rear of the spacecraft.
Looking closely at the released images, we can see what appears to be a very small portion of the upper part of the module. It's white, and seems to be like a tapered cone. This suggests that the module reduces in diameter at its top to match the rear of the X-37B, and then expands downwards to produce a larger volume for its contents. This tapered cone probably gives way to a short and stubby cylinder.
This module covers the main engine for the X-37B. Thus, it seems probable that some form of propulsion must be featured on the module. The X-37B would use its own main engine to execute a de-orbit burn at the end of its mission, after the Service Module has been discarded.
Adding extra experiments to the Service Module could require larger power demands than the spaceplane would normally generate from its own solar panel. Thus, some form of solar panel must be included on the Service module. It's possible that the panel isn't a deployable wing, like most satellites use. The panel could simply be bolted to the side of the module, as Japan has done with its HTV cargo spacecraft.
A Service Module with its own power and propulsion has the potential to serve as an independent spacecraft in its own right. Thus, we could expect that the Service Module could remain in orbit for long after the X-37B itself returns to Earth.
The Pentagon mentioned that a small satellite is being carried on this flight. That satellite is most probably carried aboard the Service Module. But other experiments will also be included in the module. Clearly, they will need to be payloads that do not need to be returned to Earth. The materials tests and seed experiments slated for the mission will thus fly aboard the main spaceplane. But the experiment designed to convert solar-generated electricity into microwave-beamed power would be ideal for the module.
The Service Module does not need to be aerodynamic. Thus, there are probably no coverings or fairings over the payloads it contains. This is probably a major reason for keeping the module away from prying eyes. As with previous missions, classified payloads inside the spaceplane's payload bay are protected from view when the bay doors are closed. So there's nothing to be lost by showing photos of the closed-up X-37B itself.
We still don't know all (or most) of what is being carried on the mission, regardless of which part of this tandem spacecraft we consider. Those mysteries are likely to remain with us for a while.
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.
