Friday, September 23, 2016

New seals have to be used until all known flaws are redundant. AKA "Air pressue matters"

Reusable space vehicles have problems with their reuse. We witnessed the trouble with the Shuttle program. It was suppose to be an ECONOMICALLY efficient vehicle that was actually going to turn a profit for the country. That was under Reagan. We all know what happened there with the Challenger disaster and it's frozen O rings.

September 23, 2016
By Loren Grush

...Though SpaceX (click here) is narrowing down the possible sources of the explosion, it still has yet to determine what caused the breach in the helium system. "All plausible causes are being tracked in an extensive fault tree and carefully investigated," SpaceX said in a statement. The company's Accident Investigation Team is still conducting its investigation, which involves analyzing 3,000 channels of data, according to SpaceX. The team is also looking at video and audio recordings of the event. But despite all this information, the team is reviewing an accident timeline that boils down to just 93 milliseconds.

While this most recent explosion is not connected to what brought down SpaceX's Falcon 9 in 2015, the problems for both failures originated in the vehicles' upper liquid oxygen tanks. And both involved the vehicle's helium system in some way. However, the Falcon 9 failure last year was caused by a faulty strut in the liquid oxygen tank, used to hold down one of the helium pressure vessels. These vessels help to pressurize the rocket....

Reusable space vehicles have a challenge, they have to work going up and then coming down only to go back up again. There is considerable stress during every rocket launch on the vehicle and the pattern of stress is not consistent. The weather and climate are different. There are some stresses such as frozen O rings that are as plain as the nose on anyone's face, but, for the most part the launch within Earth's oxygen environment is unpredictable on the vehicle.

I have said this over and over through the years, there is no such thing as an economic space program.

Space X has an incredible investigation tool, but, we don't everything about everything. It is called exploration for a reason. It seems to me the most predictable break down in any space vehicle are all the seals that contain the liquids and fluids that keep the vehicle powered. These vital parts of a space vehicle have to be taken apart and replaced with every launch.

The removed seals can be gone over with intense investigation to realize the stress each one has received. Maybe then the vehicles will be more predictable, but, until a few dozen sets of seals are examined there really can't be a predictable outcome with these stressed components.