Closer examination makes it pretty clear this is targeted to allow Vinci to compete. The Wiki article also confirms this in the reference section, as their is a history of NASA considering Vinci going back to 2014. The Vinci rocket is 4.2 meters tall, vs an RL-10B is 4.14 meters tall with the extendable nozzle. The RFI says the engine can be 10.5 ft from gimbal to nozzle exit. I can't find the specifications for the RL-10B regarding it's height when the nozzle is not extended, but it seem reasonable that it fits within the 3.2 meters ( 10.5 ft) specified in the RFI. Vinci has a much higher chamber pressure, so it can get to ISP of 460 with a lesser expansion ration than RL-10BThe questions then are can Vinci be made with an extendable nozzle that fits within the allotted form factor, & do the Europeans want to try and do this when they have Ariane 6 to get ready for?
BE-3U variantThe BE-3 will be upgraded with a larger nozzle to operate in the vacuum of orbital space, becoming our BE-3U. One BE-3U will power the third stage of our New Glenn launch vehicle. With extensive testing and use on New Shepard and the BE-3, the BE-3U will be one of the best understood rocket engines before it ever launches into space.
They really don't want the SLS to fly do they with the never ending spec changes. The BO engines may be cheaper but how many billions will it cost to implement? Every day it doesn't go anywhere it still eats through NASA money. Cynical? Me!
Quote from: jak Kennedy on 12/16/2017 05:37 pmThey really don't want the SLS to fly do they with the never ending spec changes. The BO engines may be cheaper but how many billions will it cost to implement? Every day it doesn't go anywhere it still eats through NASA money. Cynical? Me! Meanwhile RS-25 is optimistically about 70 million a piece, and presents a hard limit to flightrate as well, but theres no real effort to fix that problem.
According to information the redesign reduced the number of parts needed to assemble the accumulator from twenty-eight to six, eliminated 123 welds and one bolted joint. The extensive changes would have been impractical or impossible using conventional manufacturing means, and have also reduced the unit cost by a third.
Really?QuoteAccording to information the redesign reduced the number of parts needed to assemble the accumulator from twenty-eight to six, eliminated 123 welds and one bolted joint. The extensive changes would have been impractical or impossible using conventional manufacturing means, and have also reduced the unit cost by a third.https://www.nasaspaceflight.com/2017/12/rs-25-next-phase-testing-stennis-hot-fire/
If a RFI about engines to use on EUS just came out then the pick for which engine would no t occur until contract award sometime after about 9 months from now. Putting the CDR for EUS at about 6 months later or around Apr 2019. Then 3-4 years to build/qualify and that is NET Apr 2022 to as late as Apr 2023 for delivery of first EUS flight hardware. EUS could become the critical path for SLS 1B flights.I thought they had decided on engines for EUS. This RFI says that the design work on EUS is still very preliminary and the detailed design is on hold until a decision on engines.
EUS is not in production yet.