3 thoughts on “Europa Clipper”

  1. Aw, man, you got me all excited, Rand – or rather, Mark got me all excited. I was thinking this was confirmation that NASA had actually made the decision to use Falcon Heavy.

    (That decision *is* expected in the next several weeks, and is generally assumed to be all but in the bag, but until it actually *happens*…)

    I’m still surprised this allowance actually made it into law. That report on torsional loading on SLS must have been pretty bad.

  2. A couple small quibbles with Mark’s otherwise agreeable essay:

    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 Musk’s dreams of settling Mars. But the massive reusable rocket would be available for other things, presumably including sending probes to the outer planets.

    NASA (specifically, LSP and JPL) *was* looking at using a Star 48 kick stage in order to dispense with the Venus gravity assist, since that would require considerable thermal shielding. But it appears that over the last year that they’ve switched to preferring a Mars-Earth Gravity Assist (MEGA) trajectory, for which a launch window opens in October 2024. It would take about 5.5 years to arrive at Jupiter. It also would not require a kick stage, which is just as well for JPL’s purposes, since apparently that introduces additional loads on the spacecraft that they’d have to design for.

    Also, the idea that NASA could suddenly switch down the road to Starship from FH once it’s operational sounds nice in theory, but can’t happen in practice. JPL is at the point *now* where it has to start making launcher-specific design decisions (which is why they have been so grumpy about Congress dragging its heels on this), so switching to another launcher in a few years is, shall we say, suboptimal. In any case, the Falcons *are* certified for top priority since missions of this category, and Starship will take some time earning those certifications. That will be beautiful for that eventual ice giants oribiter mission, but will come too late for Europa Clipper.

    All that said, I am not (sadly) as sanguine as Mark that the $1.5 billion NASA will save by not using SLS for this mission is going to get used for something else useful for NASA. Not unless the money for a human lander system or Europa Lander is being spent in the very same congressional districts.

  3. Whittington for years was in favor of the whole cost-plus government-managed program variously known as Constellation, Artemis, etc. Why would anyone look to him for insight or bother discussing his article? Just go straight the SpaceNews piece that he references.

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