The first of three planned configurations of NASA’s Space Launch System (SLS), known as Block 1, has passed the final Critical Design Review (CDR). This is the final review and paves the way for full-scale fabrication of the first exploration-class rocket since the Saturn V and the most powerful rocket ever built.
According to NASA, the CDR was completed in July, along with a separate review by the Standing Review Board made up of independent NASA and industry experts. Over 11 weeks, 13 teams trawled through more than 1,000 documents and over 150 GB of data before the Standing Review Board confirmed the program’s readiness and ability to meet performance, budget, and timetable requirements.
The individual SLS elements of the core stage, boosters and engines also successfully completed CDRs, with NASA deciding that instead of being painted white, the core stage and Launch Vehicle Stage Adapter of the booster will remain the natural orange color of the insulation covering them, and that the core stage will use cryogenic liquid hydrogen and liquid oxygen fuel for the rocket’s four RS-25 engines.
NASA says that following the completion of manufacturing, integration, and testing, the program will move onto design certification. This will take place in 2017 and compare the finished product against design specifications prior to the flight readiness review, which will be completed just before the SLS’s maiden flight in 2018.
The SLS is designed for deep-space missions using the manned Orion spacecraft. The current CDR is for the SLS Block 1, which is the first of three configurations and will be able to lift at least 70 tonnes (77 tons) using twin solid boosters and four RS-25 engines. The first developmental test series was recently completed on the RS-25 engines, while the integrated spacecraft and payloads are also nearing completion of the their own CDR.
"We’ve nailed down the design of SLS, we’ve successfully completed the first round of testing of the rocket’s engines and boosters, and all the major components for the first flight are now in production," says Bill Hill, deputy associate administrator of NASA’s Exploration Systems Development Division.
"There have been challenges, and there will be more ahead, but this review gives us confidence that we are on the right track for the first flight of SLS and using it to extend permanent human presence into deep space."