One major piece of rocket news this week is the announcement that NASA’s Europa Clipper spacecraft will launch on a commercial launch vehicle, SpaceX’s Falcon Heavy, in 2024. This is a big deal for several reasons. Europa Clipper is the first spacecraft to specifically investigate Jupiter’s moon Europa. It will explore the potential habitability of the moon, including confirming the existence of a subsurface water ocean and its composition (if geysers allow), while looking for key compounds related to life. It will also look for signs of recent geologic activity that could provide the energy needed for life. Finally, it will look for a spot for a future lander to set down. All of this science makes Europa Clipper a very large spacecraft, over six metric tons at launch.

Europa Clipper requires a large launch vehicle for its high-energy trajectory. NASA’s Space Launch System was originally intended to send the spacecraft on a three-year, direct flight to Jupiter. However, in early 2021, delays in the development of SLS in addition to concerns about flight conditions led NASA to recompete this launch. Specifically, there were concerns that SLS would shake the spacecraft too much on ascent from a combination of the solid boosters and aerodynamic loads. Two companies, United Launch Alliance and SpaceX were invited to bid after an early draft process.

SpaceX bid their Falcon Heavy rocket and ULA bid their Vulcan Centaur in its largest configuration with six solid boosters. The bids were evaluated on several criteria: past performance, suitability, and cost. Suitability was deemed the most important, followed by past performance and cost. SpaceX’s proposal was deemed suitable, and they were highly rated for having performed numerous past missions with similar requirements using similar rockets.

ULA’s proposal was deemed unsuitable from the start; the proposed rocket was simply not capable of performing the mission. It fell short by about a metric ton. Other factors working against ULA included the fact that they proposed a vehicle that had not flown, yet, so their extensive past performance with Atlas and Delta rockets was not relevant to evaluating the proposal. In addition, the rocket would not be certified to fly the important mission because it would not have enough flight history in the required period before launch. Basically, they proposed something that didn’t fit the required criteria, with being able to lift the payload being one of those criteria.

Based on these factors, SpaceX was awarded a $178.3 million dollar contract to launch the mission in 2024. ULA’s bid was significantly higher, but the specific amount was not stated.

The downside to using the Falcon Heavy instead of SLS is it will take 5.5 years to reach Jupiter, not three, and involve two gravity assists: one from Earth and the other from Mars. This isn’t all bad, as it gives the science team an opportunity to test their instruments on a real target and have time to solve any problems before it arrives at Jupiter in 2030.

More Information

PDF: Clipper Summary OPAG (LPI)

Europa Clipper Mission Concept: Exploring Jupiter’s Ocean Moon (Eos)