NASA's Europa Clipper Launch

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.

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.

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.

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.

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?

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!

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)

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.

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 $.

https://blogs.nasa.gov/europaclipper/wp-content/uploads/site...

Any private business's primary mission is to serve its customers - in order to even exist.

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.

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.

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?