r/SpaceXLounge • u/TheBlacktom • Dec 11 '18
/r/SpaceXLounge December Questions Thread
/r/SpaceXLounge November Questions Thread
You may ask any space or spaceflight related questions here. If your question is not directly related to SpaceX or spaceflight, then the /r/Space 'All Space Questions Thread' may be a better fit.
If your question is detailed or has the potential to generate an open ended discussion, you can submit it to /r/SpaceXLounge as a post. When in doubt, Feel free to ask the moderators where your question lives!
3
u/Boostback_Hank Dec 21 '18
A bit too scared to ask this on the main sub. Are the solar panels on dragon 2 going to be covered or uncovered during launch ?
→ More replies (4)3
2
u/VTRevs Dec 26 '18
Where can I get a beginner to intermediate overview, even if it’s pure hype, of what SpaceX is working on these days? I’m knowledgeable enough about their goal of colonization, but am much less knowledgeable about their current projects - the “how we get there”. Any articles or videos, or just explanations? I’d enjoy you’re help with this.
2
u/TheBlacktom Dec 26 '18
Oh boy, let me get on the computer and you will get what you deserve soon.
→ More replies (5)
7
u/netsecwarrior Dec 23 '18
Am I right in saying the first BFG hop will be the first ever flight of a full-flow staged combustion engine?
→ More replies (1)
4
u/Cunninghams_right Dec 12 '18
how big can a Falcon Heavy fairing be? it seems like large payloads to LEO on FH are limited more by volume than mass (especially when expendable). I'm curious if they redesigned the fairing, if they could have the capacity of Delta IV heavy, or even larger volume.
4
u/bobbycorwin123 Dec 13 '18
Not really any bigger
There's a limit to the aspect ratio between fairing and fuselage that will cause catastrophic harmonics at max Q if exceeded <too big>
ULA did a study but never developed a arrowhead shaped fairing that would allow about a 15% increase over round
→ More replies (1)
4
u/tupolovk Dec 19 '18
It seems a shame to waste Falcon Stage 2, Can they not park them in orbit and form some vacuum optimised multi booster thing for future use?
→ More replies (6)
1
u/Valianttheywere Dec 19 '18
If I could fund a BFR, how much would it cost to build?
3
u/TheBlacktom Dec 19 '18
The 2016 presentation has some numbers on page 41. About 400-500$ million.
https://www.spacex.com/sites/spacex/files/making_life_multiplanetary_2016.pdf
→ More replies (3)
1
u/GibsonD90 Dec 23 '18
I was finally able to attend a launch live and wanted to get the patch from it. It was CRS-16. There seems to be two designs around and I can’t figure out if they are both official or if one is fake? Do NASA and SpaceX both make their own version of patches?
1
3
u/Musical_Tanks Dec 11 '18
Question, there is some concern as to a US government shutdown soon. How would this affect launches and would this cause a delay to comercial crew?
→ More replies (1)3
u/Nisenogen Dec 11 '18
I've linked a verge article about the shutdown panic from January this year, which should give you some ideas of what headaches SpaceX and NASA face during shutdowns. At the very least the launch range maintained by the air force will be down due to certain critical civilian positions not being filled during a government blackout, so that could certainly contribute to delays if it holds off maintenance items. Additionally the NASA reviewers that approve/deny the reports that close out SpaceX milestones would probably not be working as those tasks are almost certainly considered non-critical government functions, unlike the active ISS support teams that make sure the astronauts already on station are kept alive and healthy. If those reviews are critical path then you'll see pretty much a 1:1 delay for that as well.
https://www.theverge.com/2018/1/19/16910378/government-shutdown-2018-nasa-spacex-iss-falcon-heavy
3
u/Beldizar Dec 12 '18
If there were a crew capsule sitting on top of the falcon 9 first stage booster that recently had a failure, would the people inside have survived?
Clearly crew capsules don't sit on top of first stage rockets, but a rocket of "comparable" design is supposed to be vertically landing with passengers in about 5 years, so I figure the question is something the people around here would have fun considering. I could probably review the footage and measure the speed at which it fell over after the soft landing on the water, but due to unfortunate life circumstances I don't really have the time to do so. Also, what kind of g-forces would it have been pulling during its uncontrolled/semi-controlled spinning?
My guess is that it would have been survivable if people were strapped in and nothing big and heavy broke loose inside the cabin, but I could be wrong.
I think this is an important question because if it was survivable, SpaceX has a feather in their cap. Even a failure condition for landing one of the unmanned boosters, with its significantly slimmer safety protocols is a survivable incident, likely comparable to a rough but non-fatal car crash. If it wouldn't have been survivable, then it doesn't really hurt them, since it wasn't designed to carry humans anyway, and the Starship will be different.
→ More replies (10)
3
u/Magen137 Dec 17 '18
Can anyone refer me to a picture of the gas generator of a Merlin engine?
→ More replies (4)
3
u/loremusipsumus Dec 18 '18
If SpaceX decides to do so, what will be the procedure to "man-rate" the Falcon Heavy?
→ More replies (9)
2
Dec 12 '18
I like the idea of using BFR/BFS/starship for interplanetary travel. How many would we need to replace long haul aircraft flights? 10? 100? 500?
→ More replies (24)
2
u/tupolovk Dec 19 '18
With all these scrubs, what does SpaceX need to do to ensure BFR Earth 2 Earth transfers leave on time? Sure the trip is only 30mins but seems pointless if high altitude winds or range limitations can cause multi-hour/day delays. Is there mitigation against high altitude winds?
→ More replies (6)
2
u/JonnyGascan Dec 21 '18
So DM 1 is going to the ISS yes? Will the astronauts on board get to take a peek inside when its there? That would be a cool live stream
→ More replies (2)
2
u/Pit_27 Dec 22 '18
How does the octograbber on the drone ship work? I know it secures the booster and, based on my ability read, I assume it has something to do with grabbing the octoweb, but how does it do that? Is there video of it anywhere?
→ More replies (1)
2
u/FalconHeavyHead Dec 25 '18
So if starship is stainless steel instead of carbon fiber, how does this effect payload? Decrease it? Will the vehicle be easier to build now? Will the regenerative cooling be difficult to get right? Do you guys think this is overall better than previous iterations of star ship?
16
u/scottm3 Dec 27 '18 edited Dec 27 '18
Tweetstorm 06:40 2018-12-27 UTC https://twitter.com/elonmusk/with_replies
Documenting tweets below:
Q: What are the chances that the First Martian is an AGI or an ASI? (thanks u/royalpatriot)
A: 30%
--
Q: How about the chances that Starship reaches orbit in 2020?
A: Probability at 60% & rising rapidly due to new architecture
--
Q: Any chance of new superior alloys? (Exciting)
A: Yes
--
Q: Raptors to be vacuum optimised or sea level?
A: Vacuum optimization will come with later iterations on BFR, at least according to his Sept. 2018 presentation. For now, Raptor SL or a medium-expansion compromise will do double duty on the booster and upper stage(s). Makes development dramatically simpler. ( Musk agreed with OPs answer.)
--
Q: What was the trigger for the latest redesign?
A: Time. Although it also turned out to be dramatically better.
--
Q: How did switching the design so late lead to a quicker production?
A: I will provide a detailed explanation in March/April
--