RCgothic
-
Posts
2,872 -
Joined
-
Last visited
Content Type
Profiles
Forums
Developer Articles
KSP2 Release Notes
Bug Reports
Posts posted by RCgothic
-
-
I'm about an episode and a half into the Netflix documentary so far and I'm struggling to hold it together. Inspiration 4 is really awesome!
-
The thought occurs that for excavating a hole for a sub-surface sample Starship's main engines may be extremely effective.
-
Nobody's saying it won't be cool to see a superheavy rocket fly.
-
Liquid nitrogen also costs about 50p per liter, so it's a lot more expensive than water.
-
In microgravity volume can be used far more efficiently than in gravity.
Obviously this has implications for spinning a pair of Starships up with a tether to produce artificial gravity.
-
The pressurised volume of Starship is on the order of 900m3 (32,000cuft).
Sure, it'll be cramped by earthly standards, but mariners have endured worse.
-
Probably panoramic sunroofs rather than actually being black.
-
Engineering is already a field that is heavily male dominated. Anything that makes it preferable for women to work in a different state is not fine, and I'm sure SpaceX agrees. There will be women at SpaceX Starbase considering their positions, and there are enough women working there that there a decent chance some will go who wouldn't have had to otherwise.
And indeed, male employees may wish to live in a state more sympathetic to their partners as well, so it may not be just women considering their positions/applications.
I can't see any company that wants to employ world-class talent being happy about this tbh
-
Starship may be capable of some downmass though
-
1 hour ago, michal.don said:
I should have made it clearer, I specifically meant the "largest thing we've tried to reenter" bit. Of course Starship would be much heavier when reaching LEO, but it seemed to me the reentering mass would be quite similar. But then again, in some cases the Starship might reenter and land with significant payloads (crew?) and become the heaviest thing ever reentered with significant margins.
Ah. The heaviest spacecraft at landing was STS-83 at 106.8t. The space shuttle remained roughly the same weight through re-entry to landing.
-
1 hour ago, michal.don said:
I'm not sure about that - do we know how heavy the S20 is? I believe the "final" starhip will be around 150 t, but what about this one? Will it still beat the 80-ish tons the space shuttle had?
We need to be clear what we mean.
From Tim Dodd's interview with Elon, SN 20 with heat shield shouldn't be much more than 100t dry. Note that the goal is very much to reduce this.
In terms of mass to LEO, final Starship version might be 80t dry, 30t landing propellant, 100+t payload. 210+t to LEO.
The space shuttle weighed about 78t dry, 110t wet and carried payloads of up 24t. The wiki entry for heaviest spacecraft puts it at 122.7t max on orbit (onboard fuel is expended to establish orbit). Being generous, the external tank is nearly at orbital velocity, and weighs 35t empty. Bringing it to orbit is estimated to cost 5t payload, so that's an extra +30t. 150t ish to LEO for the space shuttle assuming you count all the bits that aren't especially useful (maybe you want to turn an external tank into a fuel depot or wet workshop, who knows).
So starship will weigh around the same as the site orbiter dry, but place vastly more mass in LEO.
As a point of interest I've seen an analysis that suggests Saturn V INT-21 would probably have been capable of around 177t to LEO inclusive of the S-II stage (185kmx200km @ 28.5deg).
-
I think the Apollo transposition docking and extraction manoeuvre is pretty cool.
-
-
It sounds like SpaceX aren't the only ones who are capable of getting into trouble with the FAA:
-
No, I'm having second thoughts. You'd expect the long side to be the catch side of the treads, and the logo would be inverted in that orientation.
-
I wonder...
-
It isn't hard to imagine a fully self driving vehicle being safer than a human. The self-driving vehicle can see in every direction at once, never disregards traffic laws, never gets bored, distracted, or drivers whilst impaired by fatigue or substances. Humans are the weak link, and the data shows self-driving vehicles are *already* a lot safer than human drivers.
I don't have a Tesla. I have a high-end 2018 Ford with adaptive cruise control and lane keeping.
Ford's 2018 adaptive cruise control is great on long journeys, though it does have flaws. It tends to brake too aggressively when the traffic in front slows down, and leaves a gap to the car ahead that invites other vehicles to cut in front unless you use a short distance setting that aggravates the aggressive braking. It also sometimes gets confused by corners, braking for traffic in other lanes. So in practice I tend to takeover when I notice traffic about to merge into my lane or slowing down ahead, which limits the usefulness a little.
The lane-keeping is definitely best described as a driver-assist. It won't keep the vehicle centred, but applies a correction (and/or steering wheel vibration) if it approaches a line. On a corner it'll correct the first time, but then the car will drift over thereafter. And on straight lanes it will tend to pinball until the angle gets too large to correct. It's not good enough to release the steering wheel, and you'll get a shouty driver-alert to keep hands on steering wheel if it doesn't notice you applying some steering wheel torque for too long (even if your hands are on the wheel). Though I have the lane-keeping on at all times, generally it only gets to kick in if I'm impaired by fatigue (which the car also recognises and warns about), so that's a good time to stop or switch drivers.
I can definitely agree that if my attention weren't required for lane-keeping my attention would not be on the road. I can't spend long periods of time babysitting an automatic function, is just not how my brain works. I have friends who can perform low-activity monotonous tasks for ages, but I'm definitely not one of that sort of people.
-
6 hours ago, Beccab said:
That really was a hell of a launch, now I know how the people who watched that Proton live mush have felt. Most exciting rocket launch i've ever watched
The theory I have heard that seems the most likely is that one of the 5 engines failed to ignite, giving a TWR near 1. The first stage then wasted a large amount of propellant trying to still liftoff (which it did) preventing it from reaching the right MECO altitude and setting it on a spin
I've heard the engine failed one second into flight. If it had just failed to ignite there would have been a hot fire abort and the launch clamps wouldn't have released.
May have been a further issue around maxQ, looked to be beginning to shimmy before the terminate command was sent (which I've heard was due to flight trajectory departure).
Not sure at this point if MECO was near maxQ because of the wasted propellant early in flight or due to the terminate command being sent.
-
10 hours ago, cubinator said:
RGV guys really upgraded, huh?
-
Nov 1st not extended:
-
Nov 1st not extended:
-
22 hours ago, tater said:
I'm sure that's not for each, obviously, it's gotta be the required lead time. It's still absurd.
Bruno said a while ago that engines were the long lead time item (and he wasn't even talking about delayed engines) at ~36 months. This was around the same time Musk was saying that they were down to a little over 48 hours per Raptor, working their way down to 1/day.
Literally 48 hours right now, vs >48 months for RS-25 right now.
To be fair, a raptor didn't spend just 48h in the factory. I'd guess it's more like 3-4 months and they have multiple on the go at once.
Still, 3-4 years is "nuclear power plant" or "hydroelectric dam" timescales. No way a single engine should take that long to make.
-
An environmental impact statement for using Boca Chica as a launch site for vehicles up to Falcon Heavy exists.
https://www.faa.gov/space/environmental/nepa_docs/spacex_texas_eis/
Suborbital launches of Starship from BC are covered under this assessment.
Orbital launches of Superheavy probably require a new statement. The determination of the new statement is widely known to be in process.
-
SpaceX Discussion Thread
in Science & Spaceflight
Posted
I was actually surprised that Inspiration 4 was even in the same inclination as the ISS, but I guess it makes sense for pre-programmed ascent abort corridors and such.