"Every time we saw a leak, it pretty quickly exceeded our flammability limits." //

So why does NASA use liquid hydrogen as a fuel for its rockets if it is so difficult to work with and there are easier-to-handle alternatives such as methane or kerosene? One reason is that hydrogen is a very efficient fuel, meaning that it provides better "gas mileage" when used in rocket engines. However, the real answer is that Congress mandated that NASA continue to use space shuttle main engines as part of the SLS rocket program. //

Among the idea's opponents was Lori Garver, who served as NASA's deputy administrator at the time. She said the decision to use space shuttle components for the agency's next-generation rocket seemed like a terrible idea, given the challenges of working with hydrogen demonstrated over the previous three decades.

"They took finicky, expensive programs that couldn't fly very often, stacked them together differently, and said now, all of a sudden, it's going to be cheap and easy," she told Ars in August. "Yeah, we've flown them before, but they've proven to be problematic and challenging. This is one of the things that boggled my mind. What about it was going to change? I attribute it to this sort of group think, the contractors and the self-licking ice cream cone." //

niwaxArs Tribunus Militumet Subscriptorreply3 days agoReader Favreportignore user
Update: At current funding levels, the delay to mid-october costs $495 million, or the total development cost of Falcon Heavy, or the total development cost of Falcon 9 plus four flights.