The ever-receding Space Launch System
Today a story at Space News reveals that NASA has decided to forgo construction of a second mobile launcher for its Space Launch System (SLS). Instead, they will modify the one they have.
The mobile launch platform, originally built for the Constellation Program and currently being modified to support the SLS, will be used for one launch of the initial Block 1 version of the SLS, designated Exploration Mission (EM) 1. That platform will then have to be modified to accommodate the taller Block 1B version that will be used on second and subsequent SLS missions.
Agency officials said late last year they were considering starting work on a second mobile launch platform designed from the beginning to accommodate the Block 1B version of the SLS. They argued that doing so could shorten the gap of at least 33 months between the first and second SLS missions caused in part by the modification work to the existing platform.
The first mobile launcher was built and modified for an estimated $300 to $500 million. NASA obviously has decided that the politics of building a second won’t fly. The cost is too great, as would be the political embarrassment of admitting they spent about a half a billion for a launcher they will only use once. (That this mobile launcher is leaning we will leave aside for the moment.)
What this does however is push back the first manned SLS/Orion launch. At present, the first unmanned mission is likely to go in June 2020 (though don’t be surprised if that date sees further delays). If it takes 33 months after that launch to reconfigure the launcher for the first manned mission, that manned mission cannot occur any sooner than April 2023. That second launch however is planned to be the first to use SLS’s new upper stage. To put humans on it untested seems foolish, doesn’t it? NASA is going to have to fly an extra mission to test that upper stage, which is going to add further delays to the schedule.
In November I predicted that the first manned SLS/Orion mission would not happen before 2025. At the time it was assumed that the second flight of SLS would have to launch the unmanned Europa Clipper mission, in order to test that upper stage. Now however it appears that the Trump administration wants to shift Europa Clipper to a commercial launch vehicle, probably Falcon Heavy.
This means that either astronauts will be flying on an untested SLS upper stage, or NASA will have to add a test launch in April 2023, followed some time thereafter by that manned mission. Since NASA does not at present have a budget for a third mission, I am not sure what is going to happen here.
What I do know is that SLS is certain to get delayed again. By 2025 we will have paid close to $50 billion for SLS and Orion, and the best we can hope for is a single manned mission. And that one mission will have taken 21 years to go from concept to launch.
This is not how you explore the solar system. With a schedule like this, all SLS and Orion are doing is distributing pork to congressional districts and to the big space companies (Boeing and Lockheed Martin) that are building both. Establishing the United States as a viable space-faring nation is the last thing these players have in mind.