Everyday Astronaut: https://www.youtube.com/watch?v=IAixoyE78rE
NASA Spaceflight: https://www.youtube.com/watch?v=9JUn8LmGYEA (This is not an official NASA stream)
Everyday Astronaut: https://www.youtube.com/watch?v=IAixoyE78rE
NASA Spaceflight: https://www.youtube.com/watch?v=9JUn8LmGYEA (This is not an official NASA stream)
> Because Europa Clipper needs a lot of energy to start it on its interplanetary trajectory to Jupiter, the rocket for this launch will be fully expendable, with the exception of a recoverable fairing. This means that there will be no return of first-stage boosters for this launch. Although SpaceX has flown a fully expendable Falcon Heavy before, this is the first time that NASA’s Launch Services Program is launching a mission for the agency with this Falcon Heavy configuration, though the program has extensive experience now with both expendable as well as reusable rockets. In addition to not recovering any boosters, technicians removed components only needed for reuse to increase the performance of the rocket, to launch the largest planetary spacecraft NASA has ever developed and give it the power it needs to travel to Jupiter.
https://blogs.nasa.gov/europaclipper/2024/10/14/nasa-launch-...
* https://www.youtube.com/watch?v=DJO_9auJhJQ
Real Engineering:
* https://www.youtube.com/watch?v=SzKkBOUvsAY
Probe named after the sailing ship design:
> The etymological origin of the word clipper is uncertain, but is believed to be derived from the English language verb "to clip", which at the time meant "to run or fly swiftly".[2]
Since you have to have a burn to slow down and land you have to carry extra fuel to recover. That's always going to be the case, but starship is making strides towards minimizing that as much as possible with belly flops and chopsticks
So, for any rocket, flying it reusably is going to mean not using the full capacity.
Future launches with Starship, analogous to this one, would refuel their upper stage in orbit to their full capacity, so there would be no performance downside to recovering boosters; you would need more launches, but they would all be reusable.
[a] https://elvperf.ksc.nasa.gov/Pages/Query.aspx (I queried for a high-energy orbit with a C3 of 42 km^2/s^2, which I think is correct, or at least very close)
How much science is delayed by the extra 2+ years? Looking at the 'project plan', is the Clipper's arrival (and delivery of data) on the critical path for research? And how much research?
I'm picturing a lot of scientists and research projects waiting an extra 2-3 years, and then all the research, follow-on missions, etc. also delayed. Essentially, the decision might shift everything in this field 2-3 years further away, and then centuries from now human habitation of other planets is 2-3 years later (ok, a bit exaggerated).
But seriously, maybe it's not on the critical path or doesn't impact that much. Is anyone here familiar with the research?
> The SLS was still in development at the time, and would be for a number of years to come. Delays with the powerful rocket, and the need to dedicate at least the first three SLS vehicles to launches for NASA's Artemis moon program, pushed Europa Clipper’s liftoff date into limbo. (SLS debuted in late 2022, successfully sending the uncrewed Artemis 1 mission to the moon.)
> The 2021 U.S. House of Representatives budget proposal instructed NASA to launch Europa Clipper by 2025, and to do so on an SLS "if available." Those two crucial words put the probe on a path toward a commercial launch vehicle, which turned out to be a Falcon Heavy.
So while the flight time may be longer, at least the entire mission is derisked in that it was forced to get off the ground instead of wait for an appropriate gap within the SLS's launch capacity.
[1] https://www.space.com/spacex-falcon-heavy-europa-clipper-lau...
On top of that, there's no guarantee SLS would've actually been able to launch on schedule. The program has had a lot of setbacks, to put it lightly, and has only launched once so far (6 years later than it's original ETA). There's additional rockets in production but if it came down to it the manned SLS missions would probably get priority for political reasons.
Perhaps the term hasn’t quite died out.
The lobbying was from the SLS side. Congress was set on forcing Europa Clipper to fly on SLS regardless of technicalities and only backed off because the Europa Clipper team made it clear they'd want an additional $1B to make the spacecraft able to handle the exceedingly rough ride SLS provides. They were perfectly happy handing $2B of taxpayer money to Boeing, but were unwilling to spend another $1B on science.
On top of that, it's worth considering that SLS wouldn't be ready to fly right now anyway. As it stands, they can't even manage to build one rocket per year, the Artemis-2 rocket has already been delayed to next year, so, Clipper would've launched 2-3 years later anyway.
NASA, wisely, always benchmarked the mission on Falcon Heavy, and bailed from SLS as soon as they were allowed to.
Clipper on SLS was more of a "wouldn't it be neat" scenario than the intended mission design.
SLS has been consistently delayed pretty much every year since its conception, most recently the Artemis 2 mission which was supposed to fly this year is now delayed to next. It has only flown one time, now two years ago. It's also an order of magnitude more expensive than the Falcon Heavy with each flight costing upwards of $2 billion.
My guess is if they had been stuck with SLS this mission would not get to Europa until significantly later, if at all.
I was just thinking about how much pressure there must be on everyone involved in Discovery Class missions. People's entire professional careers, billions of dollars, so much at stake!
Is the pressure something significant, or is it spread across so many people that there is little trouble sleeping at night?
If you built even 15 Europa Clippers the cost per-item would come down enormously (because all of those people's work could be re-used), but since the 1970's NASA has not had the budget for multiple probes per missions. So every mission is bespoke, and has to be done again completely from scratch.
1: The engine was normally used for circularizing the orbit of a geosynch comm satellite, so within a few hours of flight. For doing a Mars Insertion burn it needed to sit fueled for months in outer space, which was not appropriately tested, and probably the fuel tank exploded in flight because of that.
Details on the Europa Clipper budget are at https://www.nasa.gov/wp-content/uploads/2023/03/nasa-fy-2024...
(Edit: fixed billion/million typo)
https://blogs.nasa.gov/europaclipper/wp-content/uploads/site...
1: Officially I believe the expectation was "3 minutes" but that was a deliberate under-promise so that a success could be declared as long as they got any message at all from the lander on the surface: I have second-hand accounts that 30 minutes was what the scientists considered the minimum.
2: Even with all that testing, disaster almost struck. It wasn't until after the launch that someone realized even all of this testing had missed something important. The radio communications between Cassini and Huygens would be affected by the Doppler shift of Huygens hitting Titan's atmosphere, which would be unpredictable changes to velocity. After launch they had to rejigger when Huygens would be launched to a time when the signals would be perpendicular to the direction of travel so the shift wouldn't affect the radio waves so much that the Cassini receiver firmware (which could not be modified after launch) could still detect the signals. And also with all of that testing, ESA's instructions to the Cassini probe missed turning on one channel on the receiver and so half of the pictures that Huygens transmitted had nothing listening in and were lost.
Each mission has unique requirements, but since payload mass costs are coming down, ISTM it should be possible to create a standard buss that meets most requirements most of the rime, even if it's heavier than a bespoke effort for any one mission.
However for this type of mission that would still leave the question of "What if we skipped re-usability and paid more to expend the launcher? Could we launch a larger payload and/or get there faster?"
The trajectory for this mission was already a slower transit time than the alternate plan of launching it on the SLS rocket. I think for some missions that are infrequent and targeting far-away destinations there will always be a desire to maximize performance at the cost of reusability on that singular launch.
Here is an HN post from 2014, "How a Swedish engineer saved a once-in-a-lifetime mission to Titan (2004)" [0]
Since the link has rotted away, here is the archive link to the IEEE story. [1]
[0] https://news.ycombinator.com/item?id=7472495
[1] https://archive.is/3oj6P (archive.org is still not working reliably)
In theory falling launch costs will eventually mean maybe we can make space science missions more disposable so a loss from random failure is no big deal, but we're not quite there yet.
I ultimately decided against pursuing a career in aerospace engineering after talking to engineers who worked a similar time frame on a project only to watch it get killed in 30 seconds' debate in Congress.
When you are on contract for something, you deliver to the contract, and are done when you successfully meet the customer's requirements. So in that sense you don't have the same exposure to the program risks.
However, I've been part of one-off science missions before, and there is a different feeling beyond the contract obligations, though it's certainly abstracted through the many layers of sub-, sub-contracts.
really cool to see the trajectory:
- earth mars gravity assists
- complex trajectory around jupiter and its moons
When I took Ae105 at Caltech, the NASA MSL project manager explained it like this (I remember the numbers he used clearly): a mission might cost $500 million with an 80% chance of success, or they can spend twice as much to increase the chance of success to 95% by investing a lot more in upfront testing and R&D. Now, the smart thing to do - given a billion dollar budget - is to take that first option because if it fails you can try again and the probability of both attempts failing is only 4%, compared to 5% for the expensive single mission. Then you’ve got an 80% chance of having $500 million left over for a different mission.
The public and decision makers react irrationally to any failure, putting funding for other missions and the entire program in jeopardy. NASA and ESA have to make some extremely suboptimal decisions to make sure that funding doesn’t get catastrophically cut.
The above is the example the instructor used to easily illustrate his point but he said the real numbers are even more stark. Often times the cost savings of just building a second copy of the payload along with the first means it costs $600 million for the first attempt, and only $200 million for the second (the cost of the launch vehicle and keeping people on staff), saving hundreds of millions overall.
https://en.wikipedia.org/wiki/Comparison_of_satellite_buses
For example, the SSL 1300 apparently has hosted 118 satellites so far:
https://en.wikipedia.org/wiki/SSL_1300
Though maybe the distinction between "satellite" and "spacecraft" bears importance here.
Is there room here for making things more reusable? For example, instead of creating one big satellite with tens of instruments, how about they create 10 satellites with one instrument each? or would that still be too bespoke to lower the cost per item?
The time between boosters first being reused in Falcons and this mission is the same as the time between JFK's 'we choose to go to the moon' speech and the actual moon landings.
Since SLS launches are now upwards of $2B per launch by some estimates, how does this math work? Wikipedia also suggests $2 billion saved.
https://en.wikipedia.org/wiki/Space_Launch_System#Europa_Cli...
Which, incidentally, is one of the key reasons SpaceX has had the success they have: they're set up to handle failure and avoid this politics. How many Starships have blown up? If Starship were a NASA program, how many explosions ago would it have been cancelled? And yet this approach to risk is pretty effective!
The whole strategies of exploration haven’t shifted yet to this new paradigm. Hopefully NASA starts making smaller probes and launching them far more often.
For exploration missions and anything in deep space (basically, beyond Lunar Orbit) people have kicked around ideas for common buses, there have been plenty of proposals, but no one seems to have enough value in them to be the third or fourth user of one- everyone has found it better to start from scratch than use someone else's bus design. It is possible if there was a sustained, focused effort at one kind of project, say, something where Mars orbiter launches were guaranteed every 26 months for more than a decade, that the investment in a common bus might pay off. But as long as we are bouncing between Mars, Jupiter, Pluto/KBO's, E-S L2, and inside Mercury's orbit, it just isn't actually reusable.
Just as one point, until the past few years everything in the outer planets had to be RTG powered, which requires a totally different design than something solar. It was only with Juno (and now the Europa Clipper) that solar has been demonstrated for outer planets at all, and it is still not exactly a design you'd have off the shelf, nor would the power design you'd want for outer planets solar be at all similar to the design you'd want for inner planets solar. The same is true for comms, for thermal management, for rad-hardening, etc.
https://news.ycombinator.com/item?id=41757578
It's really hard to discuss any topic that brushes SpaceX tangentially on HN. I asked about the research, not about the rockets, but if one even mentions SpaceX in anything less than glowing terms they get six (so far) responses re rockets, all defending SpaceX, and not a mention of the research.
NASA and SLS are actually the property of the people posting; their mission is to serve all Americans. SpaceX is a private business, whose mission is to serve only itself and, in the practice of its owner's businesses, has zero regard for everyone else.
In that context it's bizarre that people are fans of the latter. In context of social media, where mass influence is bought, it's perhaps what we'd expect - that's not NASA's business.
It is possible for a swarm of small satellites to fill niches in space exploration. Closely studying Europa isn't really one of them with today's technology.
Compare the responses to a failure by Boeing or SLS and to a failure by SpaceX.
Also, SpaceX hasn't had a serious non-experimental failure yet (?). I'm sure their PR is preparing for that eventuality, but when non-fans are upset over a bad outcome and then learn about the risk tolerated, they will swing from admiring risk to condemning it. Imagine the Congressional committees.
Even if SpaceX is super-conservative when flying humans (which we shouldn't assume - cultures tend to be consistent), if someone dies then all that risk-seeking behavior will be attacked.
(To be clear, as long as SpaceX can manage risk in production - i.e., with high-value payloads such as people and NASA flagships - I think they and everyone else should use risk efficiently.)
One way it does that is to serve customers, another is to manipulate, cheat, and squeeze them of every dime the business can get, and then drop them for higher-margin customers. Just look at modern business.
Everyone's just pointing out the obvious fact that SLS wasn't going to be able to do the mission on time or at cost anyway, so the delays were happening regardless, and Falcon Heavy was the only other option. You phrased your question with the assumption that SLS was going to launch on-time, added in the implication that SpaceX lobbied for the launch and caused research to be delayed by a few years, then decided to complain that everyone else was being biased.
>NASA and SLS are actually the property of the people posting; their mission is to serve all Americans. SpaceX is a private business, whose mission is to serve only itself and, in the practice of its owner's businesses, has zero regard for everyone else.
SLS is the property of Boeing, another private business. Its mission is to transfer vast sums of taxpayer money to Boeing under a contract whose terms remove any expectations of good performance and whose use in Artemis is legally mandated by Congress for no technical reason. The NASA Office of Inspector General has constantly been expressing serious concerns over how bad of a deal SLS is for the American people. We've also had genuine technological progress held back because Congressmen wanted to transfer money to SLS. Its ever inflating costs threaten actually useful science programs every year. I don't see how anyone who actually wants American leadership in space can support it.
SpaceX, as you have noted, is also a private business. With NASA being one of its biggest customers, they are obviously beholden to NASA's desires. Unlike Boeing, who has explicitly expressed their intent to refuse contracts which properly hold the company responsible for under-performing, SpaceX consistently insists on such contracts. Currently, they provide most launch services to NASA and have saved NASA billions over the years. They maintain a mutually beneficial relationship, where NASA gains all sorts of valuable data and capabilities from SpaceX's private development efforts, and SpaceX gains business from NASA.
If you're dismissing this as a social media influence thing, despite all the technical points presented to you, then all that shows is that you were just concern trolling in your original post and have no interest in actually having your question answered.
https://www.nasa.gov/jpl/jet-propulsion-laboratory-history/
"JPL led the U.S. into space with Explorer 1, the first U.S. satellite, and joined NASA shortly after the agency formed in 1958. JPL spacecraft have flown to every planet in the solar system, the Sun, and into interstellar space in a quest to better understand the origins of the universe, and of life."
Not many organizations can say that: We've flown to every planet in the solar system. Wow. (And of course, they've done more than that.)
All in all, it would not surprise me if it reaches Europa earlier this way. But, of course, we will never know.
Easier said than done, of course.
On NASA's broadcast someone says, 'we believe ocean worlds are the most common type of planetary body in the universe.' That surprises to me due to the lack of atmosphere on most bodies, the lack of liquid and moisture in space, the prevelance of gas giants, etc. How does that come to be true? Possibly, speaking live, they omitted some qualification and it's not literally true.
Also, looking at the rocket, I wondered about their optimized forms. We're accustomed to their appearance, but why not an even smaller 'forward' (i.e., direction of flight) cross-section? Most of the air resistance has to be on forward-facing surfaces. The rocket might need to be taller for fuel capacity, but so what? ... My question really is, what limits reducing the cross-section? An engine component? Vertical height for some reason? I'm assuming air resistance has a major impact on speed and fuel consumption, but maybe it's just not that important?
(What's the most valuable payload NASA has lost during launch? Apollo 1 wasn't launching, nor were the space shuttles.)
There was some talk about using ISS as a base for on-orbit assembly but the orbit (half-way between best orbit from KSC and Baikonur) isn't great for that and it turns out that constant docking and un-docking ruins scientific experiments requiring microgravity, so ISS really isn't a great base for assembly. Ideally, if you want to start on orbit assembly you'd have another station in the right orbit for KSC which isn't doing any microgravity research, but now we're talking about massive up front investment to save money on research satellites, is NASA ever going to get the scale of research budget for that savings to be worth it?
If something like Space Based Solar Power ever become a thing then such an on orbit assembly station would make sense, but the case for assembly for science missions really only closes if you have the station already for something else.
Here are some factors to consider that generally trend against just "increasing the fineness ratio".
Consider your fuel tanks. Assuming that you have liquid fuel, the static pressure at the bottom of the tank for a given fuel and gravity is purely a function of the height of the fuel column. This means that the taller your fuel tank, the stronger the tank needs to be (at the bottom) to contain it. This will tend to increase your non-payload, non-fuel mass - this is bad.
Similarly, as your rocket gets taller and taller, there is more and more structural mass sitting on top that needs to be supported - ie you need stronger structures.
When a rocket second stage is in vacuum, all of the sudden you want the largest possible nozzle you can get to get the most thrust out of your exhaust. Now having a larger diameter to work with is useful since it's now easier and simpler to have a large diameter nozzle.
Rockets exist to launch payload, which often cannot be shrunk below specific sizes and/or have difficulty being mounted in different orientation. The uh... extra phallic shape of the Falcon Heavy in this case is because the payload fairing needs to be large enough to encapsulate the payload. It's not possible (or really useful) to shrink rocket diameters much smaller than their expected payload.
For a size comparison, the Falcon Heavy's payload fairing is 5.2m in diameter. This isn't particularly a small space, but it's not particularly large either - it's basically exactly the length of a F-150 or two sheets of plywood/drywall stacked lengthwise.
(And without real experience, we have real blind spots - we don't even know where they are and guessing is just BS. I knew there had to be some real trade-offs and reasons.)
NASA and the FAA were pretty clear on this actually, they don't see any risk due to that previous failure, falcon 2nd stages haven't had any problems with their primary burn in a long time.
Official word from SoaceX is that the second stage engine failed to shutdown on time, causing it to overshoot its planned landing zone. It ran 500 milliseconds long.
The value captured by the owners is a tiny slice of the value provided to the society. For example, the value I get from my iPhone is much much greater than the money I pay for it - it's just logical, I simply wouldn't buy it otherwise.
And the value received by the owners is the well deserved reward for creating the business - a very hard and low chance of success endeavor - but essential to our society.
Everything in my life is created by private businesses: from the clothes on my back, the food I eat, the car I drive, the house I live in to the computer I earn my living and write this on.
I lived in a society without private businesses, under communism, and everybody was cold and starving.
I had misremembered: it was the Hera launch the FAA cleared because there was no reentry risk. Europa clipper was expected to get the same treatment, but it seems the FAA and SpaceX were happy with their understanding of what happened with the 2nd stage anomaly and returned Falcon 9 to flight. [3]
[1] https://x.com/SpaceX/status/1840245345118498987
[2] https://x.com/jeff_foust/status/1845579767040626798
[3] https://www.reddit.com/r/spacex/comments/1g1kdk3/the_faa_aut...
The simple answer is that people do not believe much of what the government does is in service of the people. SLS is a great example of this.
But in future you would potentially have special boost stage for that. See something like Impulse Space is building.
But for these really powerful throws, its probably just cheaper to just drop an upper stage. Upper stages are a drop in the bucket compared to the cost of a flagship mission. A Falcon 9 upper stage is only a couple million $.
The only question was if the SLS lobby was able to keep forcing SLS. That was the only topic worth debating. You can even track this to the specific people in congress who are known to be in certain districts who tried to force this.
Here is some research you can go do, look at the price and availability of Falcon Heavy, then look at the price and availability of SLS. No more research is needed.
Funny how SLS that feeds literally billions of $ into the pockets of Boeing and Lockheed Marin 'serve all Americans' and SpaceX that makes a profit of a few 10s of million $ is 'private'. You see how that perspective is utterly idiotic right?
Clipper would have to have a schedule fight with Artemis and Clipper very likely would have lost that fight. SLS scaling is very slow so its very likely using SLS would have meant a later arrival.
Either way, one of Clipper or Artemis would have been delayed, this is a 100% fact. So either way one timeline of an important project is delayed.
You ask these scientists if they rather wait a little longer (again questionable) or if they would rather have 2-4 billion $ in extra research grants. That would be a more fair comparison. Now NASA can use that budget actually useful things rather then giving more money to Boeing.
I would also count the Apollo missions. They launched on a single rocket, but the docking between the CSM and Lunar Module was for all intents and purposes equally difficult to assembly on orbit.
There are multiple commercial companies planning to assemble stations over the next few years. This in addition to the on-orbit refueling that SpaceX will be doing should hopefully enable a new generation of larger, assembled interplanetary probes.
But that is closer to what I meant, because they had to worry about separate launches that might fail (GVI, GIX) and find and dock with something you need to use orbital mechanics to approach (basically anything under 30m distance you can just eyeball and fly, but anything over that distance requires the full set of orbital calculations).