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It is widely agreed that the whole program is a failure. Almost 3 years past due date, and most people believe it will still need more than another year. More

It is widely agreed that the whole program is a failure. Almost 3 years past due date, and most people believe it will still need more than another year. More than double the estimated cost Is providing very little benefit over existing rockets, and providing no benefits over planned rockets in development by others. It is adding no new capabilities, or technologies, and is in fact a step backwards in rocket design, not forward or to the side. Its sole purpose is to employ people, not push the space industry forward of get NASA somewhere. For all those reasons, people think SLS is a huge failure of a program, except at giving Boeing money, which is does great at.

pfdietz 6y ago
Even if SLS delivered the working design instantly at zero cost it would be a failure. The rockets themselves will be too expensive to make and use.
- Beached 6y ago
  Without the existence of Starship, that is difficult to say. I believe the launch cost per rocket (after the first) is roughly $500-600Mil? When you are the most capable rocket BY FAR, and simply the ONLY rocket in existence that can do the missions, it is hard to say if a significantly higher cost then the next best thing is worth it or not. A sls block 1 has about 3x the lift capacity to the moon, and the block 2 about 5x the lift capacity. Short of a moon fly by, the falcon heavy would require multiple launches to perform the same mission of SLS. So the SLS DOES indeed provide lift capability that doesnt already exist. Now if spacex beats Nasa to the moon with starship, all that goes out the window, as startship will be better for sure.
  - pfdietz 6y ago
    The launch cost will likely be much higher than that. I don't think that would even cover the marginal cost of making another rocket. The fixed costs will be substantial (what, you thought all those Shelby-voting engineers in Alabama would be laid off once development was done?) Any real effort to go to the moon will involve propellant stockpiles and transfer in space. These could use LH2, which could be sent up on F9/F9H. There is no reason to do the injection to the moon using the F9/F9H upper stages. I will add that even ignoring F9/F9H, there is no sustainable lunar or Mars program using SLS. The plans to go to Mars would be a flags-and-footprints dead end like Apollo. For space, it should either be go big or don't bother.

pfdietz 6y ago

Even if SLS delivered the working design instantly at zero cost it would be a failure. The rockets themselves will be too expensive to make and use.

Beached 6y ago
Without the existence of Starship, that is difficult to say. I believe the launch cost per rocket (after the first) is roughly $500-600Mil? When you are the most capable rocket BY FAR, and simply the ONLY rocket in existence that can do the missions, it is hard to say if a significantly higher cost then the next best thing is worth it or not. A sls block 1 has about 3x the lift capacity to the moon, and the block 2 about 5x the lift capacity. Short of a moon fly by, the falcon heavy would require multiple launches to perform the same mission of SLS. So the SLS DOES indeed provide lift capability that doesnt already exist. Now if spacex beats Nasa to the moon with starship, all that goes out the window, as startship will be better for sure.
- pfdietz 6y ago
  The launch cost will likely be much higher than that. I don't think that would even cover the marginal cost of making another rocket. The fixed costs will be substantial (what, you thought all those Shelby-voting engineers in Alabama would be laid off once development was done?) Any real effort to go to the moon will involve propellant stockpiles and transfer in space. These could use LH2, which could be sent up on F9/F9H. There is no reason to do the injection to the moon using the F9/F9H upper stages. I will add that even ignoring F9/F9H, there is no sustainable lunar or Mars program using SLS. The plans to go to Mars would be a flags-and-footprints dead end like Apollo. For space, it should either be go big or don't bother.