NASA is conducting an internal review of the Space Launch System rocket's affordability, two sources have told Ars Technica.
Concerned by the program's outsized costs, the NASA transition team appointed by President Joe Biden initiated the study. The analysis is being led by Paul McConnaughey, a former deputy center director of NASA's Marshall Space Flight Center in Huntsville, as well as its chief engineer.
The SLS rocket program has been managed by Marshall for more than a decade. Critics have derided it as a "jobs program" intended to retain employees at key centers, such as Alabama-based Marshall, as well as those at primary contractors such as Boeing, Northrop Grumman, and Aerojet Rocketdyne. Such criticism has been bolstered by frequent schedule delays—the SLS was originally due to launch in 2016, and the rocket will now launch no sooner than 2022—as well as cost overruns.
For now, costs seem to be the driving factor behind the White House's concerns. With a maximum cadence of one launch per year, the SLS rocket is expected to cost more than $2 billion per flight, and that is on top of the $20 billion NASA has already spent developing the vehicle and its ground systems. Some of the incoming officials do not believe the Artemis Moon Program is sustainable with such launch costs.
McConnaughey is leading the study for Kathy Lueders, NASA's chief of human spaceflight. Even before the study's initiation, McConnaughey had been pushing for the SLS program to become more cost-effective. One goal of this analysis is to find ways for the large NASA rocket to compete effectively with privately developed rockets as part of the agency's Artemis Moon program.
For example, although SpaceX's Falcon Heavy rocket does not have as much lift capacity as the SLS rocket, it has the advantage of being already in use and costing about one-tenth as much per flight. Blue Origin and United Launch Alliance are also developing heavy-lift rockets that are intended to deliver components of a Human Landing System to lunar orbit.
Perhaps most significantly, SpaceX is continuing a flight test campaign of its Starship Launch System, which may make its first orbital flight in the next 12 months. This is a launch vehicle that could potentially out-lift the SLS rocket, be reusable, and cost a fraction of the price. If SpaceX succeeds in getting Starship into orbit, there would be little technical justification for continuing government subsidization of the less capable SLS booster, which is expendable and costs much, much more.
Proponents of the SLS rocket are not blind to this. Some believe SpaceX will not succeed with its Starship program, and indeed myriad technical challenges remain. Others think NASA could find ways of making the SLS rocket more competitive, and that is one point of this study.
Another reason for the new analysis, however, is to assess whether NASA really needs the SLS rocket at all as part of the Artemis Program. Already, companies are planning to deliver the lunar lander to the Moon with private rockets. The main job left for the SLS rocket is launching Orion, with crew, to the Moon. Launching Orion may also be doable with private rockets, or the crew could simply launch on SpaceX's Starship, obviating the need for Orion itself.
Although the Biden administration has committed to continuing the Artemis Program started under President Donald Trump, it has other priorities for the space agency, particularly ramping up Earth science activities to better understand climate change. If the Office of Management and Budget no longer needs to spend $3 billion annually to "develop" the SLS rocket and its ground systems, the White House will at least look at the possibility.
One initial step may involve slowing or ending work on an upgrade for the SLS rocket, sources indicated. After NASA completes the first iteration of the Space Launch System rocket, the plan is to upgrade it to "Block 1B," the main part of which is an upgraded second stage. This piece of hardware is known as the Exploration Upper Stage. In the FY 2021 budget bill, Congress provided $400 million for development of this stage.
However, some senior NASA officials would like to at least pause work on this upper stage. To them, it is premature to work on an upgraded rocket while the first version of the SLS rocket is yet unproven, especially if Biden space officials determine the SLS rocket will only play a limited role in future exploration plans. One source said Biden White House may seek to fly SLS only a handful of times, halt work on the Exploration Upper Stage, and plan the future of Artemis around commercial launch vehicles.
All of this remains in flux, however, and the US Congress will have a big say in whatever the future of NASA's deep-space exploration programs hold.