China prepping a moon mission. Bob Zimmerman

May 24, 12:51 AM


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China prepping a moon mission. Bob Zimmerman

Contamination found in shuttle engines to be used by SLS

May 18, 2018 at 12:03 am Robert Zimmerman

Now we know why the first launch is likely delayed: It appears that contamination has been found in the used and refurbished shuttle engines that the Space Launch System is using.

A “routine quality assurance inspection” of the core stage, he said, discovered contamination in tubing in the engine section of the core stage, which hosts the vehicle’s four RS-25 main engines and associated systems. That contamination turned out to be paraffin wax, which is used to keep the tubes from crimping while being manufactured but is supposed to be cleaned out before shipment.

“The prime contractor determined the vendor was not fully cleaning the tubes and it was leaving residue in the tubes,” McErlean said. “This was retained as a requirement in the prime contractor’s spec, but it was not properly carried out.” Boeing is the prime contractor for the SLS core stage, but he did not disclose the vendor who provided the contaminated tubing.

The contamination was initially found in a single tube, he said, but later checks found similar residue in other tubes. All the tubing in the core stage is now being inspected and cleaned, a process he said is not straightforward because of the “mass of tubing” in the engine section and also because cleaning is a “non-trivial process.”

Some obvious questions immediately arise:

1. These engines were previously flown on the space shuttles, numerous times. How did the paraffin wax, used “to keep the tubes from crimping while being manufactured,” remain in the tubes during all those shuttle flights?

2. Assuming the tubes were a new addition or replacement during the refurbishing process, it still seems astonishing that a subcontractor could be so lax. Did they really believe the wax did not need to be thoroughly cleaned?

3. While they have admitted that they will likely have to delay the launch because of issues with the core stage, why do they deny this contamination problem is the cause? More important, how much is it costing to fix? And how much time are they actually losing to fix it?

4. Finally, this is only one of many similar problems that we have seen with this entire project. Boeing and NASA have gotten so far about $40 billion to build this rocket, and have been working on it since 2006, more than a dozen years ago. Furthermore, they supposedly are building it using shuttle equipment in a Saturn rocket-type design in order to save money and time. Instead, they have wasted billions and taken more than three times longer than it took us to win World War II to get to a point where the program still has not flown.

Does anyone really believe this project is anything but a huge boondoggle? And if so, can they please tell me how it will be possible for the United States to really explore the heavens with a project run this incompetently?