The Great Ongoing Space Exploration Thread

A survey of scientific researchers have released a report detailing the space science they would like to see prioritised over the next decade. This report is released every decade and is extremely influential.

They have identified Uranus and Enceladus as priorities. The last tome we sent a probe to Uranus was Voyager 2 which flew past at a very fast rate, so there is certainly a gap in our knowledge here.

They should make two identical probes and send one to Uranus and one to Neptune. I’m assuming that would be cheaper than making two individual probes, but perhaps it wouldn’t save that much.

PS Need to change the name of Uranus. Too many juvenile ass jokes.

PPS Not to Urectum. Although that joke was funnier than just about any other Uranus joke.

This is good news:

Rocketlab successfully captured their first stage via helicopter



Caught it, but had to drop it due to the pilot not liking the flight dynamics. Still, a heck of an achievement.

Finally, some high-res pictures from the JWST:

That’s a very impressive improvement over Spitzer.

What’s that thing that flies off @44.47 in that rocket/helicopter video ? …
(This bit)

That’s one of the battery packs that powers the propellant pumps. The Electron rocket uses electric pumps instead of being pressure-fed or using a fuel-powered turbine. It’s not as efficient as the latter, but it works well on a small rocket like that and was easier to develop. The pack is ejected when it’s depleted to cut down on mass. IIRC, there are two sequential packs on the upper stage.

Thanks !
(I guess i’d probably know that if i’d bothered to turn the sound up !!)

Dr Becky reacts to latest Sagittarius A* (black hole at center of Milky way) picture with infectious enthusiasm:


I have often remembered a “truism” about launch vehicle development that I picked up someplace (gotta be lying around here somewhere): You shouldn’t develop a launch vehicle unless it’s in support of a solid, funded, agreed-upon space mission plan.

The SLS on the other hand, has seemed to me to be a launch vehicle project without a definite mission. Oh, sure, there’s a lot you can do with it, and many of these potential missions are OK. But it’s different from, say, the Saturn series, which were built in support of a very clear goal and sequence of steps that got humans to the moon.

So…I’ve seen a number of graduating students (I’m at Purdue Aerospace Eng. department) headed toward SLS related projects, and I try to let them know that perhaps the SLS will fly, maybe even more than once, but it might not be a great long term project. (Ref. Constellation…anyone remember that? The parallels seem pretty strong to me.)

I am very much in favor of space exploration, including large spacecraft for ferrying astronauts here and there within the solar system. I just don’t believe NASA / US Gov’t is the most reliable source of funding, being based on US public sentiment, which is fickle, and not a strategic military urgency (which was the case for Apollo, right?). Thus, I hope that SpaceX / Starship actually makes it, and is profitable, because it will push human space exploration forward, perhaps more reliably, than waiting for NASA to retake the lead in human spaceflight.

It’s not a bad policy, but I don’t think this is completely universal. “If you build it, payloads will come” works if you prioritize low cost and reliability. Typical rocket development prioritizes political interests like spreading out manufacturing and development centers across those areas that have political influence, and in that case it’s a good idea for your rocket to have a particular mission. But if you’re just trying to make money flying cargo, then you can just build a rocket with a decent payload and low costs. The Falcon 9 was designed to be capable of lifting capsules to the ISS, but mainly it’s just an inexpensive medium/heavy lift rocket that works well for all but very high energy payloads.

Yeah, there are two ways to look at rocket development: One is to assess the size of the market and then develop a rocket that fits within a niche in that market. The other is to try for a revolutionary step change in launch costs, confident in the belief that if launch costs drop dramatically the market will expand to the point where fleets of reusable rockets will find customers.

There are still a lot of technical, regulatory and financial hurdles in front of Starship. It is by no means a done deal. And iterative development that works great in the early goings when prototyping can be done quickly and cheaply may not work so well when each rocket you blow up has 32 engines on it, heat shields, and all the other stuff you need for an orbital rocket. That gets spendy.

Even if Starship works, the timeline could be long. They were supposed to have a lunar version of that rocket ready for 2024, but here we are halfway through 2022 and there hasn’t been an orbital launch attempt yet. If that goes wrong, it could easily be 2023 before we see another attempt. And after they get the orbital inaertion and return working they have to prove out the ability to land the rocket back on the pad with the ‘chopsticks’.

Once they achieve all that, they have to figure out orbital refueling because without it Starship is nearly useless. That requires multiple ships and a fast launch cadence. They will also have to prove out Starship’s ability to stay in space for days and then still be able to relight the engines for landing.

To get all this done will likely require dozens of launches. If even one or two of them fail, it will be another long setback. And we haven’t even started on building out the payload fairings, human living spaces, heating, cooling, and all the other systems the rocket will need.

If it all succeeds, the next issue will be finding customers for all those Starships coming off the assembly line. At the rate Musk wants to build them, he would soon have the capacity to fly 100 ton payloads almost every day. No one knows if the launch market will expand to accomodate that, even at an order of magnitude reduction in current launch costs. Starship could still bankrupt SpaceX even if it works perfectly.

My money is on Elon, but this isn’t a done deal. However, reusability is here to stay, and other providers are getting into the game. New rockets that aren’t at least partially reusable will have a hard time competing. Even Electron, which tried to replace reusability with low cost rockets is getting into the reusability game.

Well, the third is to not consider commercial viability at all, only political viability. And the latter is what I’d consider the common case, up until very recently. Perhaps the most common political reason is to promote and retain local talent, both to keep the money local and to decrease dependence on other nations. Such a rocket still needs a customer base–that will likely be mostly military, with a little extra from other government-run operations like weather and climate tracking. And maybe a few commercial payloads mixed in in exchange for tax breaks or some other quid pro quo.

Then there are the political prestige missions, like Apollo or the ISS. The Shuttle was built in part to deliver payloads to a space station. The Saturn V and Shuttle were not commercially viable at all, but served a political purpose.

I would posit that every expendable rocket under development, aside from very small ones, exists only for political reasons. The Ariane 6, for instance, would not be viable at all if it weren’t for the guarantee of European customers and for various subsidies.

I guess I should have said the only commercial reasons. You either try to take market share, or you try to build the market. Established companies tend to stick to the former, while entrepreneurs are often trying to build the market. For example, Tesla built the market for EVs, now the big auto makers are fighting to grab share.

Musk is trying to build a large market for space transport by lowering costs and creating new goals like Mars colonization. The others are playing catch-up and trying to find niches they can survive in.

One thing SpaceX has going for it is that it has built part of that market itself with Starlink.

Exactly…the reasons to develop a (really expensive) launch vehicle are not just commercial, but also very often political. Makes me interested in seeing how the “commercial” SpaceX company is affected by political considerations.

Like it or not, the political considerations are there…look at the Roscosmos guy grousing and threatening Elon over his replacing Soyuz, and the money stream that supported it, by Dragon.

Starliner is undergoing docking now. It’s within 100m(?) and they have already successfully come in and went back out.