Because of increased funding to SLS from Congress, NASA is now pushing Boeing to do upgrades to the interim SLS upper stage as well as its final full power upper stage, dubbed the Exploration Upper Stage (EUS) and originally planned for most SLS missions.
Those changes were prompted by the decision NASA made earlier this year to delay the introduction of the EUS. That stage was originally planned to enter use with the second SLS mission, Exploration Mission (EM) 2. Instead, the first flight of what’s known as the Block 1B configuration of SLS has been delayed to the fourth SLS launch, likely no earlier than 2024.
“That has put a slow down on the Exploration Upper Stage work,” said (John Shannon, vice president and program manager for the Space Launch System at Boeing). “We were rapidly approaching the critical design review.”
NASA has asked Boeing to spend some time to try and “optimize” the EUS with the goal of increasing the amount of additional payload it can carry. Such co-manifested payloads, such as modules for NASA’s proposed lunar Gateway, would be carried on the SLS underneath the Orion spacecraft. (emphasis mine)
Shannon also made what might be the biggest understatement I have ever heard when asked about SLS’s endless delays, noting that “We underestimated that somewhat,” referring to the time it has taken to build the rocket.
NASA got Congress to give them extra money to allow more flights of the interim stage, since putting humans on EUS on its first flight was absurdly risky. This way they could also avoid further delays on that first SLS/Orion manned mission, now set for 2023, almost twenty years since it was first proposed. By pushing for more upgrades, they can also justify again stretching the program out longer, thus stretching out the pork without actually flying anything.
The contrast with SpaceX’s development of Falcon Heavy with NASA’s development of SLS continues to be striking. The former was conceived, built, and launched in less than ten years, for a cost of half a billion. The latter remains unflown and unready to fly after fourteen years of development, and likely will not fly for another six years plus. And its development cost will likely top $50 billion by that time.
If I was a customer looking to buy a product, I would laugh NASA out of the room if it tried to sell me its SLS rocket. Unfortunately, the critters in Congress aren’t that smart, and continue to pour money into this dead end project, money that could be much more effectively spent buying rockets from the private sector.
