Many planetary scientists believe that Europa may be the best choice for us to find evidence of alien life in our backyard. Although this is a large backyard, the planned Europa Clippers mission requires a powerful rocket to reach Jupiter’s moon. Congress had previously required that the mission must be launched on the massively delayed Space Launch System (SLS), but NASA’s latest budget has restricted the agency’s work.
The Europa Clippers is an ambitious long-term robotic mission that aims to study Europa up close through multiple orbital overflights. NASA hopes to launch the spacecraft in 2024 and send it to Jupiter for six years. Once there, the spacecraft will spend at least four years flying around Europa to scan its entire surface. The probe will also provide tools to characterize the suspicious underground ocean beneath the cracked ice sheet.
Continued problems in the completion of the SLS rocket have added to the uncertainty of the Europa Clippers schedule, and the National Aeronautics and Space Administration (NASA) has been prohibited from exploring alternatives. This restriction is attributed to a vote deal in Congress-the former U.S. representative from Texas raised funds for the Clippers mission and gained the support of the Republican Richard Shelby in the Senate by joining the SLS mission. Shelby’s home country, Alabama, has a large number of aerospace contractors who will benefit from SLS.
NASA has urged Congress to reconsider this task, and it seems that this news has finally been realized. In the recently approved budget, NASA partly includes modifications to the SLS mission-not yet complete, but NASA has more freedom to explore alternative ways to put the Europa Clippers into space. If NASA is ready in 2024, it will still have to use SLS, but if SLS is still behind, the agency can switch to something like SpaceX Falcon Heavy.
Congress promoted the space launch system to replace the constellation plan cancelled by the Obama administration in 2009. In return, the US government won the Commercial Crew Program, which recently successfully sent astronauts into space. The SLS will become the most powerful rocket in the world after its completion, but it is an expensive one-off vehicle with an estimated launch cost of more than US$2 billion. The launch of Falcon Heavy will save NASA approximately $1.5 billion. Although SLS does have enough power to fly directly to Jupiter, the launch of Falcon Heavy will involve some planetary slingshot exercises.
It’s not clear what NASA’s development direction is-SLS is currently expected to conduct its first test flight in 2021 and a manned mission in 2023. If so, NASA can still use SLS for Europa Clipper. Fortunately, if there are more delays, the agency will not be affected.