totm nov 2023 SpaceX Discussion Thread

[kerbiloid]

Spoiler

24 minutes ago, Nibb31 said:

• Develop BFS.
• Realize that is much harder than we thought.
• Delay or backscale the original plan.

1.Declare an ambitious project.
2.Get hype.
3.Get lulz.
4.Postpone the ambitious project.
5.Declare a new, even more ambitious project.
6.Goto p.2.

Spoiler

29 minutes ago, PB666 said:

I can only imagine the look on this guys chief extraterrestrial engineer when he tells him "I want a city of mars by 2028"

The extraterrestrial engineer would panic, set it all 17 tentacles off, run away and tell his/her/whatever boss that terrestrial guys are also going to build their city on Mars.

 

Edited January 18, 2018 by kerbiloid

[Starman4308]

Even if Musk's greatest hopes for engineering the BFR work out, his 2024 Mars dreams run into one significant problem.

"It was NASA's planetary protection officer, in the mission control room, with a baseball bat."

Musk is proposing we send a vehicle that has not been heat-sterilized, one that will be exposed to ambient conditions during rollout and launch, to Mars. Unless Musk can prove the BFR is a reliable vehicle to carry out crewed Mars exploration, I don't think he's going to get the green light on this.

This is, of course, assuming it's even ready for operations by then, which I'm not very sure of. Musk is very optimistic with his timelines, and BFR relies on a suite of new technologies not just to work, but to work economically.

[sh1pman]

Is there any info on how many orbital refuelings will need to be done to completely fill a BFS in LEO? 

Ok, I'm dumb. 1,100t/150t=7.3 refuelings. 

Edited January 18, 2018 by sh1pman

[NSEP]

7 minutes ago, sh1pman said:

Is there any info on how many orbital refuelings will need to be done to completely fill a BFS in LEO? 

The total amount of fuel the BFS can carry is 1250 tons. So if we used the reusable variant of the BFR that can carry 150 tons to LEO, that would be 1250 : 150 = 8.33333 refuels. So bassicly 9 refuels.

Edited January 18, 2018 by NSEP

[sh1pman]

Just now, NSEP said:

The total amount of fuel the BFS can carry is 1250 tons. So if we used the reusable variant of the BFR that can carry 150 tons to LEO, that would be 1250 : 150 = 8.33333 refuels. So bassicly 9 refuels.

I thought it was 1,100t total fuel capacity. 

Anyway, 7-9 refuelings should be enough.

I wonder if a "Heavy" tanker variant can be made with 2 additional S1 side boosters. Technology can be mastered with FH. That way the tanker will have much more fuel once in orbit, substantially decreasing the number of launches required.

[HebaruSan]

27 minutes ago, Starman4308 said:

Even if Musk's greatest hopes for engineering the BFR work out, his 2024 Mars dreams run into one significant problem.

"It was NASA's planetary protection officer, in the mission control room, with a baseball bat."

I'm not sure they've got the authority, and neither is she (article from 2014, emphasis mine):

https://www.scientificamerican.com/article/meet-nasa-s-one-and-only-planetary-protection-officer/

Quote

There are a growing number of commercial space activities. Is nasa able to regulate their level of cleanliness?
We've been spending considerable taxpayer money over the years to protect other planets from contamination. Now we're in the process of figuring out how the U.S. can have an appropriate level of visibility into what our nongovernmental groups are doing. In a situation in which nasa isn't providing support, who's responsible for oversight is currently open.

Will we need a new law to regulate these groups?
We have to consider that. The Federal Aviation Administration already has authority over launches and landings, so we can regulate activities within the atmosphere, and nasa has a framework for providing input into the faa process. But we're not a regulatory agency.

There are plans for nongovernmental manned missions to Mars in the next few decades. That must create a new set of problems in terms of protecting the Red Planet.
Absolutely. Will the humans be alive by the time they get to Mars? If they die on Mars, are they then contaminating the surface? [Such events could] interfere with future science.

I'm sure someone will chime in if such a law was passed between 2014 and today.

[_Augustus_]

43 minutes ago, Starman4308 said:

Even if Musk's greatest hopes for engineering the BFR work out, his 2024 Mars dreams run into one significant problem.

"It was NASA's planetary protection officer, in the mission control room, with a baseball bat."

Musk is proposing we send a vehicle that has not been heat-sterilized, one that will be exposed to ambient conditions during rollout and launch, to Mars. Unless Musk can prove the BFR is a reliable vehicle to carry out crewed Mars exploration, I don't think he's going to get the green light on this.

Trust me, if/when he gets a Mars-capable manned vehicle on the pad, no one is going to care. How does NASA plan on sterilizing their Mars vehicle proposals?

[NSEP]

22 minutes ago, sh1pman said:

I wonder if a "Heavy" tanker variant can be made with 2 additional S1 side boosters. Technology can be mastered with FH. That way the tanker will have much more fuel once in orbit, substantially decreasing the number of launches required.

so bassicly a Monster Falcon Heavy? That would be cool indeed. I first thought this could be used sort of as a short-cut mission for the Mars mission but i think it would turn the people on board into minced meat.

[magnemoe]

6 minutes ago, _Augustus_ said:

Trust me, if/when he gets a Mars-capable manned vehicle on the pad, no one is going to care. How does NASA plan on sterilizing their Mars vehicle proposals?

An manned Mars mission will bring lots of of bacteria to Mars, This is very hard to avoid and impossible to guarantee because you can get accidental leaks. 

[tater]

42 minutes ago, NSEP said:

The total amount of fuel the BFS can carry is 1250 tons. So if we used the reusable variant of the BFR that can carry 150 tons to LEO, that would be 1250 : 150 = 8.33333 refuels. So bassicly 9 refuels.

The refilling would be done in early flights by a cargo version. It will not expend a full tank of propellant to bring 15t of propellant to LEO. Instead, it will carry ZERO cargo, and reach LEO with more than 150 of propellants remaining, hence the 4-5 refillings required to fill the Mars or Moon bound version.

(note I use the SpaceX term "refilling," which I prefer, because it's both fuel and oxidizer)

[kerbiloid]

Spoiler

If "The Martian" were a documentary, the Mars would be already inhabited by a genetic chimaera of human (from Watney's blood on the piece of antenna), potato, and Echerichia Coli (from the crew feces used as compost).

 

[tater]

8 minutes ago, magnemoe said:

An manned Mars mission will bring lots of of bacteria to Mars, This is very hard to avoid and impossible to guarantee because you can get accidental leaks. 

Yeah, planetary protection is a non-starter once people go, honestly. For probes the principal interest is not contaminating the science, not "protecting" Mars. If humans can inoculate life on Mars... so be it.

[CatastrophicFailure]

53 minutes ago, tater said:

Yeah, planetary protection is a non-starter once people go, honestly. For probes the principal interest is not contaminating the science, not "protecting" Mars. If humans can inoculate life on Mars... so be it.

Beat me to it. It is prudent to maintain a certain level of “sanity” (in the biological sense, too) while sending our first feelers out onto these alien worlds, but sooner or later, we’re going to have to dirty the place up a bit to make ourselves at home. 

There will no doubt be new regulations along the way, and what ends up rolling out to the BFR pad may be very different than what we’ve been shown so far, but we only know what we’ve been shown. We don’t have a complete picture of SpaceX’s engineering on the thing, and they can be every bit as secretive as, say, Blue Origin, when they want. I think it’s a bit disingenuous to handwave that away as “handwaving.” Musk is a smart guy, and he’s surrounded himself with other smart people, so I’m fairly sure they’re actively addressing the question of, “ok, how do we turn the dang thing around?”

Their goal is to have the BFR be more economical than the Falcon 9. Whether they can certainly remains to be seen, but if they do, it will be nothing short of revolutionary. I think all the “handwaved” stuff will rapidly fall into line after that. 

[cubinator]

5 minutes ago, CatastrophicFailure said:

Their goal is to have the BFR be more economical than the Falcon 9. Whether they can certainly remains to be seen, but if they do, it will be nothing short of revolutionary. I think all the “handwaved” stuff will rapidly fall into line after that. 

Quite true. 

It would be nice to know my spaceship can land nicely, though.

[Nibb31]

41 minutes ago, CatastrophicFailure said:

Their goal is to have the BFR be more economical than the Falcon 9. Whether they can certainly remains to be seen, but if they do, it will be nothing short of revolutionary. I think all the “handwaved” stuff will rapidly fall into line after that. 

That's not how it works. They need to figure out the tech before BFR gets to fly, let alone fly economically.

The point is, there is a moment between the Powerpoint phase (now) and when BFS flies (somewhere in the future), where someone is going to point out to Musk that "it's turning out much harder than he thought it was".

 

[mikegarrison]

3 hours ago, Starman4308 said:

Even if Musk's greatest hopes for engineering the BFR work out, his 2024 Mars dreams run into one significant problem.

"It was NASA's planetary protection officer, in the mission control room, with a baseball bat."

Musk is proposing we send a vehicle that has not been heat-sterilized, one that will be exposed to ambient conditions during rollout and launch, to Mars. Unless Musk can prove the BFR is a reliable vehicle to carry out crewed Mars exploration, I don't think he's going to get the green light on this.

This is, of course, assuming it's even ready for operations by then, which I'm not very sure of. Musk is very optimistic with his timelines, and BFR relies on a suite of new technologies not just to work, but to work economically.

By the time we send humans to Mars, we will have completely given up on the idea of keeping the place isolated from Earth life. We certainly aren't going to sterilize every human astronaut by irradiating them or cooking them in an autoclave.

[CatastrophicFailure]

12 minutes ago, Nibb31 said:

That's not how it works. They need to figure out the tech before BFR gets to fly, let alone fly economically.

The point is, there is a moment between the Powerpoint phase (now) and when BFS flies (somewhere in the future), where someone is going to point out to Musk that "it's turning out much harder than he thought it was".

 

This is what I mean. You're assuming they haven't addressed these concerns already, just because they haven't shared the details with you. 

[tater]

I think that SpaceX has considered the landing operations in some reasonable detail. They are, after all, the leading experts on Earth when it comes to supersonic retropropulsion, and now for propulsive landings, as well. I think at this point SpaceX has now landed more boosters operationally than NASA has propulsively landed spacecraft in the solar system in total (which I think from a count in my head is something just under 20). If NASA still has them beat, that will change in the next few months.

[kerbiloid]

Spoiler

1 hour ago, Nibb31 said:

The point is, there is a moment between the Powerpoint phase (now) and when BFS flies (somewhere in the future), where someone is going to point out to Musk that "it's turning out much harder than he thought it was".

This is .mu phase between .ppt and BFS.
KSP testing. That's now.

Spoiler

1 hour ago, mikegarrison said:

We certainly aren't going to sterilize every human astronaut

Sounds... ominously?

 

Edited January 18, 2018 by kerbiloid

[tater]

 

 

 

1 hour ago, mikegarrison said:

We certainly aren't going to sterilize every human astronaut by irradiating them

Space will do this all itself

[PB666]

1 hour ago, CatastrophicFailure said:

This is what I mean. You're assuming they haven't addressed these concerns already, just because they haven't shared the details with you. 

I think they are still strolling to the hard part of the learning curve, nothing they have done seems to indicate otherwise. To the moment they have just improved on 1960s technology by adding on more computerized step. . . .save some of your fuel, keep a couple of engine starts and reland.

5 hours ago, Starman4308 said:

"It was NASA's planetary protection officer, in the mission control room, with a baseball bat."

Musk is proposing we send a vehicle that has not been heat-sterilized, one that will be exposed to ambient conditions during rollout and launch, to Mars. Unless Musk can prove the BFR is a reliable vehicle to carry out crewed Mars exploration, I don't think he's going to get the green light on this.

This is, of course, assuming it's even ready for operations by then, which I'm not very sure of. Musk is very optimistic with his timelines, and BFR relies on a suite of new technologies not just to work, but to work economically.

The PPO position is open, plays 200 grand per year. I thought about applying.

Say I think the problem with NASA is this, they don't want to contaminated Mars until they have investigated the possibility of life on Mars. Since 2024 is unlikely then he has time, he might have to buy into the biological survey to get it done before he tries (handwaving) to colonize.

[tater]

I think the cargo version is not all that complicated. Strike that, it's really complicated, but it's not something they cannot do in a straightforward way given their expertise.

I think the crew version, particularly with Mars as a goal, is grossly more difficult than they imagine. Life support alone is a daunting issue when it has to work for years without breaking.

[PB666]

Just now, tater said:

I think the cargo version is not all that complicated. Strike that, it's really complicated, but it's not something they cannot do in a straightforward way given their expertise.

I think the crew version, particularly with Mars as a goal, is grossly more difficult than they imagine. Life support alone is a daunting issue when it has to work for years without breaking.

What about off-planet operations, conceptually the cargo version doing stuff in LEO, MEO GTO are local parameters, when you start talking mars you have a different set of parameters . . timing changes....coordinating entry corridors at distances of a couple million miles . . . . . Lets say you choose a point on Mars, you have to choose a burn time and vector in LEO that roughly allows that point (since you are not circularizing) and then correcting velocities to achieve an atmospheric entry that also corresponds to the atmospheric start of the landing phase along an oblique trajectory.

The other problem is that both O2 and CH4 burn off over time, he doesn't have to deal with that problem on the overwhelming majority of launches.

BUT, agree with the plan, get fuel into orbit.

[tater]

By cargo version, I mean the one for Earth orbit operations. Mars will be non-trivial, regardless.

[tater]

Atlas launches later tonight. Dunno if they leave her horizontal, or take her back to the barn during the Atlas launch.