mikegarrison

With hindsight, everything that anyone has already accomplished was obviously quite possible to accomplish.

Wow. Apollo in less than a decade was "not a lofty goal"? When the US had not yet even put a person into orbit at that point? And no one else has landed a person on the moon in more than 60 years since? I mean, it gave rise to the use of the word "moonshot" as meaning an ultimate all-hands-on-deck stretch goal. But whatever. I guess you have your opinion.

Aren't you forgetting Kennedy's 1961 speech saying the US "should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth"?

Both. But again, *many* companies handle this just fine. The fact that SpaceX has not only not handled it correctly but also has refused to fix the problem for at least three years after the DOJ first warned them about it suggests that the problem lies in SpaceX management, not the laws.

No, it did not say that. It said only if they are equally qualified.

The rules can be be quite complicated and tedious to follow, but SpaceX is not a "startup" and certainly has the legal resources to be expected to understand and comply with the rules. And as I said, the DOJ told them they were out of compliance three years ago. It's not like they just didn't know they were breaking the law.

If you just have a blanket ban on hiring people with refugee status, how can you claim the people you do hire are "equally qualified"? Other companies handle this just fine. There is no reason SpaceX can't. The DOJ brought this to their attention more than three years ago and told them to fix their practices. They refused. So now it is moving to legal action.

They can be careful, yes, but not at the expense of discriminatory hiring practices. They are expected to be able to follow both sets of laws.

Yes. EAR and ITAR laws carry heavy penalties for violations. Both fines and prison time are possible.

Hiring permanent residents (including refugees) does not conflict with ITAR. You can be a "US Person" for ITAR and EAR legal purposes without being a US citizen. You just need to have permanent resident status.

Pretty certain the answer must be yes, or otherwise why all the designs with flame trenches and water deluge? I would guess those designs came about due to experience.

Testing it first at half thrust is the prudent choice. If it fails at half thrust, then they know it will fail at full thrust, without the danger and expense of a full thrust test. If it does not fail at half thrust, then they can move on to a full thrust test later, which we all know they are going to do in the flight test if not before.

Of course. That's why they are testing. But it's pretty annoying to see people in this forum apparently smugly saying "SpaceX knows what they are doing" when the observed reality suggests that they do *not* actually know what they are doing. Yes, that's why you test. I have no problem with test failures (other than easily predicted, dangerous but unmitigated test failures). I have a problem with the sarcasm levels. Sometimes when you try something new that goes against all the conventional wisdom, you find out that the conventional wisdom no longer applies (or maybe even never did). But sometimes you find out that the conventional wisdom (like water deluge) was was hard-won and there for a reason.

That level of sarcasm is pretty strongly undercut by the very public failure of their reinforced pad the first time. I'm sure they will get it right eventually, but this rush to defend their untested (at full power) new pad design, after the failure of the previous untested (at full power) new pad design, and after the failure of the initial pad design, seems pretty defensive.

That's what they thought the first time....

This is obviously untrue. They release PR videos every launch, they have an active social media presence, Musk does publicity talks, etc.

That's an uncontrolled experiment. Maybe your grandfather would have lived to be 105 otherwise.

No form of multi-cellular life on Earth has existed for a billion years.

The problem is that the O2 and CO in the Martian atmosphere is not "free" in the sense of "easily obtainable". You would have to process a massive amount of Martian atmosphere, and then you would have to separate out the O2 and CO. These processes will require energy. I recognize that you discuss this in your blog post, but it all seems kind of hand-wavy. The disadvantage to mining ice is that you then have to break apart the O2 and H2, but the advantage to it is that the ice is concentrated. (That is, assuming you can find some where you want to find it.) You are trading one energy-intensive problem for another one.

All of biology is based on the work of a guy who had no idea that DNA existed. So, what's your point?

I'm not aware of any easy way to balance the tanks for the three-propellant rockets. I tend to not use them. I think maybe they are supposed to work with other engines. Like, if you have nuclear engines that use H2 as reaction mass, you might have a big H2 tank. Then you can use the tri-propellant engines for high thrust when needed by drawing out of the common H2 tank.

I take issue with this characterization. The upper stage would get absolutely 0 kg of payload into orbit by itself. The only reason it can get any useful work done at all is because of all the energy that the first stage has invested into it.

This can't be done. Not accounting for *all* the other bodies. Every asteroid? Every comet? Every bit of human space debris? Every particle of dust? Every bird flying in the sky of Earth? No, you are always going to end up accounting for only those that you think significantly affect the result you are trying to find.

I mean, it's fiction. But there is at least one advantage to not docking, which is that ports don't have to be standardized. We already have, what, three different kinds of docking/berthing ports on the ISS? There are times when we can't send ships up to the station despite there being open ports available because they are not the right kind of open ports. We live in a world where many of our electronic devices have incompatible connections and they are all called "USB". If you travel around the world, you have to deal with electrical outlets that are of wildly different shapes and often connect to power grids that operate at different frequencies and voltages. Why would a station that is intended to receive ships of many different species have a "universal docking port"? Some sort of landing bay would at least eliminate those issues, while creating other issues.

They changed that. It used to be that way, early in KSP history, but they tweaked the numbers a bit so that the Minmus stationary orbit is within the Minmus SOI. Yes, there is a reason. Burning "straight up" incurs what are known as "gravity losses". Burning sideways minimizes those. If you want to do the Minmus refueling tank farm thing, I suggest just sticking the orbital tanks at somewhere around 200-400 km.