SpaceX rockets are not optimized for probes, for the higher speeds needed to toss stuff at interplanetary speeds. Sure, they can haul more to orbit and a customer could stack an additional stage, but that is very expensive compared to rockets with established cryogenic/efficient/faster upper stages. SpaceX is optimized for what it is doing (LEO/GEO) and, despite the presentations, shows little engineering interest in exploration beyond the moon.
The tech to keep your eye on is orbital refueling. If someone can finally crack that, all bets of this sort are off. While I'd love to see a nuclear rocket or something, even just the energy advantage of being able to refuel in orbit rewrites all our intuitions about time and expense of exploring the Solar System. We are so bound by having to launch things as single bundles of stuff from the ground... the rocket equation does not like that.
>> even just the energy advantage of being able to refuel in orbit rewrites all our intuitions about time and expense of exploring the Solar System.
Except that it doesn't. Refueling in LEO only helps if your gas station is in the same orbital inclination you need for your target. As each interplanetary launch will be via a different orbital plane/inclination, there is little use for generic infrastructure. Just using a bigger one-time rocket will be more efficient than trying to refuel and then boost interplanetary from an inappropriate orbital plane.
Now in higher orbits refueling can start to make sense as inclination becomes less of a handicap, but boosting from a higher orbit is less efficient than from a lower (oberth). A single larger rocket will still be the way to go.
If you're launching the fuel for the purpose of extending the range of a probe, well, of course you'll put it in the right place.
There's no point of conceiving of a world where we can afford to launch fuel but still have to treat every single launch as exceedingly precious and expensive such that we can only afford to set up One Fuel Depot in space, the way we have One Space Station. Either this gets cheap enough that SpaceX basically has a "launch + more fuel launch(es)" as a standard package or it never happens at all, there isn't much in between.
To get to the moon SpaceX needs to go beyond LEO. You cannot say in one breath that non-leo isn't their wheelhouse, then in another say it is.
Further, my post mentions new propulsion designs.
You're also 1980s thinking launches are expensive. They're cheap, and mass to orbit is cheap, and going to get much cheaper.
We all need to understand the change that is coming. Getting to space is being removed as a barrier. Think about projects where mass to orbit cost is unimportant, or think of projects where many launches is not a concern.
Think of 1000 super light, highly disposable attempts to make tiny sensor platforms which can endure distance, environment, and time.
Keep in mind losing 1/2 of them, even all is just fine, if you gleam valuable data to iterate and move down a path of low cost, tiny workable design.
It's not 1980. Cost to space is cheap. We now need to work on cost to planets, and even other solar systems.
We need to test engine designs, new methods of hardening platforms, all with low cost, simple designs.
And to others, yes, space is hostile. So? That's why we're iterating on a fix.
>> Keep in mind losing 1/2 of them, even all is just fine,
The cost difference between a spacecraft with a 50% failure rate and one with a 1% failure rate is basically not a thing. If you are at 50% success then you are already doing 99% of the job correctly. It is comparable to professional sports. If your NFL team wins a game or two during a season, you must be doing 99% of things right.
>> It's not 1980. Cost to space is cheap.
The cost for an interplanetary shot hasn't changed all that much recently. The SpaceX stuff is efficient to LEO/GEO and the moon... at a stretch. (Even the moon would require a variety of new refueling techs.)
What high flight rate would enable is testing in situ rather than expensively preventing possible failures at the design stage. That is, expend effort on the things that actually fail, rather than things that might fail. It also enables production of the probes on an assembly line.
An assembly line of probes would be amazing. Many have said we should built a dozen copies of Kepler space telescope to then detect millions of planets. Sadly, that just isn't what the scientific community wants. Each probe is bespoke. Some parts are standardized but the actual instruments tend to be designed for one specific mission. As for testing in leo, that isn't as useful as one would think. Space in LEO is very different in terms of temperature/light/radiation. LEO orbit is much warmer and dynamic (rapid orbits) than say deep space on the way to Jupiter. So it is better to test sensors on the ground in conditions that better match those where the probe is actually going. LEO is a good vacuum, but most probes wouldn't feel any difference between real space and a vacuum chamber on earth.
I wonder if we can come up with an experiment that requires a ton of identical probes as a middle ground. Like, can we make an astronomical interferometer telescope out of thousands of probes? Maybe? As someone who doesn’t understand space or astronomical interferometers, that sounds cool as heck.
