NASA’s Europa Clipper has been liberated from the Space Launch System

Almost unnoticed, tucked into the 2021 fiscal NASA funding section of the recently passed omnibus spending bill, is a provision that would seem to liberate the upcoming Europa Clipper mission from the Space Launch System (SLS). 

According to Space News, the mandate that the Europa Clipper mission be launched on an SLS remains in place only if the behind-schedule and overpriced heavy lift rocket is available and if concerns about hardware compatibility between the probe and the launcher are resolved. Otherwise, NASA is free to search for commercial alternatives to get the Europa Clipper to Jupiter’s ice-shrouded moon.

Europa Clipper is slated to go into orbit around Jupiter and make multiple flyby maneuvers near Europa, an icy world that many scientists believe has a warm ocean under the ice layer. Life may exist in that ocean, the confirmation of which would be one of the greatest scientific discoveries of this or any other century.

The Europa Clipper being mandated to fly on an SLS to begin with was the result of an unseemly side of congressional budget politics. The space probe was championed by former Rep. John CulbersonJohn Abney CulbersonTexas Republicans sound post-2020 alarm bells 2020 Democratic Party platform endorses Trump’s NASA moon program Bottom line MORE (R-Texas), who at the time was the chair of the House appropriations subcommittee that funds NASA. In order to get support for the Europa Clipper, Culberson added the SLS mandate, which garnered support from Sen. Richard ShelbyRichard Craig ShelbyRepublican infighting on election intensifies Bipartisan group of senators: The election is over Bottom line MORE ( R-Ala.), chair of the Senate Appropriations Committee. Shelby’s state contains a number of aerospace contractors involved in developing the SLS.

Ironically, Culberson lost his seat in 2018, in part, because his opponent, Rep. Lizzie Fletcher (D-Texas), accused him of being more concerned with space missions than local issues, such as flooding brought on by Hurricane Harvey. Nevertheless, the Europa Clipper continued without its key champion in Congress.

As Ars Technica points out, launching the Europa Clipper on a SpaceX Falcon Heavy saves the mission $1.5 billion. An advantage of using the SLS has been that it allows for a direct path to Jupiter without the time-consuming planetary flyby maneuvers that previous missions to the outer planets have required. The Falcon Heavy alone would not be able to get the Europa Clipper to Jupiter space directly, though it might be able to if equipped with a powerful Centaur kick stage.

Both the economics and physics of getting to Europa change if SpaceX’s Starship, currently under development in Boca Chica, Texas, becomes available to launch the Europa Clipper in the mid-2020s. The Starship is meant to fulfill SpaceX’s CEO Elon MuskElon Reeve MuskWill Axiom Space provide a commercial space station replacement for NASA’s ISS? World’s richest people added .8T to their combined wealth in 2020 Trump ends Obama’s 12-year run as most admired man: Gallup MORE’s dreams of settling Mars. But the massive reusable rocket would be available for other things, presumably including sending probes to the outer planets.

The massive cost savings by using a commercial launcher for the Europa Clipper creates other possibilities. The Europa Lander could be placed back on. A mission to Saturn’s frozen world Enceladus may also be greenlit.

The SLS is the result of a Faustian bargain struck between NASA and Congress in 2010. Congress was enraged by then-President Obama’s cancellation of the Bush-era Constellation deep space exploration program. According to then-NASA Deputy Administrator Lori Garver, NASA agreed to the SLS in return for Congress supporting the Commercial Crew program that recently came to fruition with the launch of astronauts to the International Space Station (ISS) on a SpaceX Crew Dragon.

The SLS has since been a lead weight on America’s space ambitions. The SLS slated to launch the Artemis 1 uncrewed mission around the moon is currently stuck in a ground-based “green run” series of tests. The SLS is currently using up a great deal of the money allocated to NASA’s Artemis program. The first flight is scheduled for November 2021 at the earliest.

In the meantime, SpaceX has been flying prototypes of the Starship, albeit only in the atmosphere and with occasionally explosive results. NASA is officially disdainful of the idea of replacing the SLS with the Starship. However, a version of the SpaceX massive rocket ship is in the running as a lunar lander for Artemis. It would not be too great a leap to cut out the SLS entirely and go directly with the Starship, if it were not for congressional budget politics.

And that, as Shakespeare would say, is the rub.

Mark Whittington, who writes frequently about space and politics, has published a political study of space exploration entitled Why is It So Hard to Go Back to the Moon? as well as The Moon,…