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Starship Integrated Flight Test 2 at 7 Am Central Time

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Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#291

Post by imetatroll »

Podgajski wrote: post #261
imetatroll wrote: post #241

Earlier quoted context omitted.

The kind of scientific advancements needed to sustain on the moon or mars will tremendously improve our abilities to be sustainable here on Earth. You are willfully ignorant or naive.

Ha! I’m naïve? What are you saying that we’re going to turn the Earth into a Mars or moonlight planet? And we’re all gonna have to live in bubbles? Do you think that’s the answer? Talk about pessimistic and negative…

Not what I am saying. Let me roll my eyes at your willful strawmanning.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#293

Post by ceejayoz »

theyinwhy wrote: post #163
theyinwhy wrote: post #117

[flagged]

Everyone downvoting is hopefully aware that Tesla is doing this exact thing with their autopilot. "10 active lawsuits going to court next year" [0]. But let's all trust Elon to do a better job when roadtrips become spacetrips. [0] https://www.washingtonpost.com/technology/interactive/2023/t...

My biggest objection to autopilot (beyond the misleading branding) is that other drivers and pedestrians haven’t consented to the beta testing that might kill them. I think this is a serious ethical and regulatory failing.

Someone hopping in a rocket presumably knows what they’re signing up for, and I have a lot more confidence in the FAA; they seem to be a lot stricter on safety.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#294

Post by Phenomenit »

ceejayoz wrote: post #268
api wrote: post #265

Earlier quoted context omitted.

Couldn’t Starship detach and fire its engines to get away from the booster? Of course I guess if they are not hypergolic there is startup time.

The real question here is what happens with a crewed second stage that has a problem with its engines/fuel. We’ve yet to see designs for the crewed interior beyond very conceptual stuff. Maybe something like https://en.wikipedia.org/wiki/Escape_crew_capsule for launch abort.

I believe that the crewed version is way in the future when operations are much better understood. There’s no chance in hell they’re catching that 2028 window to march.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#295

Post by Kubuxu »

martythemaniak wrote: post #224
hackeraccount wrote: post #216

Earlier quoted context omitted.

Below orbit is a strange way to put it. Orbit is more speed then height. Google says it was going 1,400 mph when it was lost. Orbital speed is around 17,600 miles per hour. The goal was something just under orbital speed. Not that this wasn't totally amazing. Hopefully the launch pad wasn't damaged and they can crunch the data and have another test that gets further soon.

I think you googled the April launch. Starship was going 24000+kmh, needed 27000, it was like 20-30 seconds away from successfully inserting itself into its target orbit.

They also weren't targeting orbit but just bellow it.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#296

Post by dotancohen »

ceejayoz wrote: post #268
api wrote: post #265

Earlier quoted context omitted.

Couldn’t Starship detach and fire its engines to get away from the booster? Of course I guess if they are not hypergolic there is startup time.

The real question here is what happens with a crewed second stage that has a problem with its engines/fuel. We’ve yet to see designs for the crewed interior beyond very conceptual stuff. Maybe something like https://en.wikipedia.org/wiki/Escape_crew_capsule for launch abort.

This same question was asked in the early years of commercial aviation. In the end, the industry (mostly) settled on aircraft designs that could passively glide reasonably well enough to land (sometimes). But some aircraft, e.g. military jets and Cirrus, came up with different answers (parachutes for the crew and for the whole aircraft, mostly).

We'll see how the commercial spacecraft industry deals with this, but I do think that we are at far too early of a stage to start expecting progress in this area. The first few decades of commercial spaceflight will be dangerous just like the first few decades of commercial aviation, or for that matter the first few centuries of commercial shipping. The answers, varied or uniform, will be interesting and I hope that I'll be around to see them.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#297

Post by FeepingCreature »

HarHarVeryFunny wrote: post #263
icegreentea2 wrote: post #243

Earlier quoted context omitted.

Measuring Apollo's start point in 1961 can be very misleading. Apollo was the culmination of a more or less continuous development process stretching back to the early 50s with the start of the ICBM programs. For example, the F-1 engines that powered Saturn V first stage actually began development in the late 50s, with the first static firing happening in 1959. The (in)famous combustion instability challenges of the…

True, but in same way SpaceX has also been in the rocket business for over 20 years, and building upon know how and organizational expertise gained from the Falcon 9.

Wiki says Raptor development started in 2009-2012 with no predecessor, with first test firing in 2016.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#298

Post by dclowd9901 »

aw1621107 wrote: post #173
mongol wrote: post #90

What is the benfit of hot staging?

To expand on KennyBlanken's answer: Rockets generally want their fuel to be sitting on the bottom of the tank, where the engines are. That's easy enough when the rocket is sitting on the ground and when the engines are firing, but once the rocket starts coasting/decelerating (e.g., when the engines turn off due to reaching the end of their burn) the fuel may drift away from the fuel intakes, resulting in the engines…

Given how successful our Saturn package was, it seems curious to me that we wouldn’t just follow the ullage motor method.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#299

Post by honeybadger1 »

ceejayoz wrote: post #107
KennyBlanken wrote: post #93

Earlier quoted context omitted.

Both the booster and ship have been destroyed. SpaceX can keep claiming these RUDs are 'fine' and 'we're getting data', but the rest of the industry does not consider it normal or a "success." Hotstaging didn't "work" until they can demonstrate the Starship vehicle survives orbital insertion, re-entry, and landing without damage or malfunction caused by the hotstaging.

The industry laughed it up as Falcon 9 failed landing repeatedly. ( https://youtu.be/bvim4rsNHkQ ) Then they shifted to “ok but do it 10x”. They aren’t laughing now. They’ve lost as many Starships as NASA lost Space Shuttles so far, with no deaths. It’s a test program for now. Ask the “rest of the industry” about how Boeing’s Starliner is going. That’s what failure looks like.

Naysayers offer a problem for every solution, can't stand these types. This is an enormous achievement for SpaceX.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#300

Post by aw1621107 »

grecy wrote: post #256
aw1621107 wrote: post #173

Earlier quoted context omitted.

To expand on KennyBlanken's answer: Rockets generally want their fuel to be sitting on the bottom of the tank, where the engines are. That's easy enough when the rocket is sitting on the ground and when the engines are firing, but once the rocket starts coasting/decelerating (e.g., when the engines turn off due to reaching the end of their burn) the fuel may drift away from the fuel intakes, resulting in the engines…

It also makes the rocket more efficient, because any time spent coasting with no engines lit is time that gravity is acting on the rocket and slowing it down. By always accelerating (with engines lit), hot staging improves the payload to orbit about 10%. So it's well worth doing.

Less gravity losses is another advantage, that's true.

I think it'd be interesting to see a breakdown of that 10% improvement number. Hot staging in and of itself resulting in a 10% additional payload capacity seems large enough that I feel it's rather odd that it isn't more commonly used. I'm curious how much of it is due to "direct" improvements from reduced gravity losses and how much is due to "indirect" improvements like (maybe?) not needing to save as much fuel for boostback.

A comparison against what a "Saturn-style" staging that uses ullage motors might achieve could make for a fun addition as well.

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