SpaceX/NASA BTFO

I stand corrected, I didn't know that actually.

Spoken like a gentleman, sir.

They refurbished big metal tubes that got dunked in the sea at a cost that was likely greater than just making new ones because then they make more money off of it.

gotta recover the tube anyways

Tiangong-1 finished it's operational life. They intended to deorbit it. Tiangong-2 is fine.

The reusable boosters were the best part of the space shuttle (yes, despite the Challenger disaster -- they were used out of spec, that's not a design flaw). The only trouble was the low launch rate. You need to keep those pick-up boats and refurbishing plants working.

It didn't have the potential for airliner-like reuse that flyback boosters with propulsive landing does, but it did have the potential to be considerably cheaper than building new booster stages every time. It's disappointing that the focus was on the reusable orbiter.

A similar, probably better approach would have been pressure-fed liquid-fuel boosters. Not quite as rugged as solid boosters, but considerably moreso than pump-fed boosters.

STS boosters were among the most sucesfull elements of the project even if they just reduced the price by a few % vs new casings for each flight.The entire sts was a huge disaster from tps to hpftp

Imagine what could have been if NASA hadn't been such a shitshow
like 500+ billion dollars with nothing to show for it

I feel good about the prospect that the 2020s will FINALLY be the decade that truly surpasses the 1960s

There's so many different actors on such a wonderful mad scramble

>A similar, probably better approach would have been pressure-fed liquid-fuel boosters. Not quite as rugged as solid boosters, but considerably moreso than pump-fed boosters.
Tell that to the Soviets.

>Seafloor not littered with Saturns, Atlases, Redstones, etc.

It is insane to use solid rocket motors for manned flight. The fact that the STS system killed its crews via other means twice indicates how sloppy the rest of the system was, not that the concept of solid rockets for human flight is sound.

Note the original concept for the shuttles used a liquid-fueled "carrier/booster" that also landed like a plane after use -- but that shit got Proxmired, so they had to use crappy design or not fly at all.

I'm not sure a wonderful mad scramble with scattered, poorly-defined goals, is going to work out as well as you anticipate. I will be very happy if I am wrong and you are right

Newer, cheaper, safer, bigger rockets means more people can chase their pipe dreams even if its only lowering costs from tens of billions to ones of billions or from billions to millions.

Half a dozen agencies are pursuing unique near-Saturn V level rockets and amazingly enough almost none of it looks like vaporware

Yeah, and all that may work out. Since it hasn't yet, I'm in a decent position to continue to have doubts.

At the moment, only the Russians really have a functioning launch program(the Chinese have a working vehicle and booster, but seem to be doing little with it.)

Everybody else has plans.

And there is a lack of mission, even if those plans came to fruition.
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Sure, maybe everybody will scatter-gun off in all directions and accomplish everything all at once. To me, that seems unlikely, but I guess we might as well hope, hope is free.

I feel "70 ton rocket is the new 20 ton rocket" is a simple enough and entirely feasible dream, in the same sense "computer the size of a piano instead of computer the size of a warehouse" was. If a big rocket doesn't cost significantly more than a medium one there's really no reason to keep using the medium ones.

>It is insane to use solid rocket motors for manned flight.
That's nonsense. They can be very reliable. The huge dual SRBs on the shuttle have a flawless record except for that one time when they were used outside of the specified temperature range.

Note as well that SpaceX has had two rockets blow up from the middle of the liquid-fueled upper stage. It's not only solid-fuel rockets that can just blow up all of a sudden. Any rocket can do that.

The problem with SRBs on crewed flights is an issue of safety not reliability; they cannot be stopped once started. So in the event of an emergency while they are burning, you can't shut them down as part of abort procedures unlike liquid fuelled engines.

Russia just grounded proton for another 6 months and second angara 5 went for scrap because it failed qc.flying soyuz is hardly a working space program

>The problem with SRBs on crewed flights is an issue of safety not reliability;
Safety is primarily an issue of reliability. Consider airliners: no ejection seats, no parachutes, very safe.

>they cannot be stopped once started.
This might be true in individual cases, but it isn't true in principle. You can have it designed with blowout panels and extinguisher injection so it loses combustion chamber pressure and cools until the reaction is no longer sustained.

In any case, with a malfunctioning vehicle, a capability of shutting down the rocket isn't something you can count on. It's just one more safety measure that might work. It's also something that might be accidentally activated, taking you out of routine operation into an emergency situation. There are few failure modes worse than loss of propulsion briefly after liftoff, so the rocket jumps up and falls back down on the pad. Very hard to get crew away from the blast, and it threatens the whole facility.

All of these backup measures also do little to protect the lives of ground crew. For instance, capsule escape rockets have been a wash in terms of human life: they've only been ever been used to save a crew once, and blew up a rocket and killed ground crew another time.

The best safety measure in a vehicle is a focus on keeping routine function correct.

>The problem with SRBs on crewed flights is an issue of safety not reliability; they cannot be stopped once started. So in the event of an emergency while they are burning, you can't shut them down as part of abort procedures unlike liquid fuelled engines.
Where did this meme come from?
"Shutting down engines" to prevent a failure is something that only happens in upper stage flight, where SRBs are rarely used anyways.

SRBs are dangerous because:
>very little time between start of detectable failure and complete destruction of rocket
>between times of t+30-60 seconds, depending on winds, an ejecting capsule may be blown into the srb plume, burning the parachutes
Neither of these failure modes have actually killed anyone.
1 shuttle was killed by srb failure, and one was killed by liquid fuel failure.

In terms of reuse, you can't just refill an SRB
In terms of casual space flight, the SRB is a giant stick of dynamite that needs careful handling

They certainly seem very reliable & safe, if you accept a 150-200 million dollar booster price tag for every launch.

objectively, SRBs are much safer from a ground-handling standpoint

not sure why you'd even bring that up

>"Shutting down engines" to prevent a failure is something that only happens in upper stage flight
...and prior to liftoff. Abort after ignition on detection of an anomaly is one of the more useful options.

>1 shuttle was killed by srb failure
More precisely, 1 shuttle was killed by damage to the liquid fuel tank due to hot gas leakage from a segment joint in an SRB. The SRBs were both still working and had to be remotely destructed because they continued flying.

>In terms of reuse, you can't just refill an SRB
You more or less can. It's the refilling is recasting rather than just tanking, but reusable solid-fuel rockets are very popular with amateur rocket enthusiasts because this isn't hard.

>the SRB is a giant stick of dynamite
No more so than liquid fuel rockets, which are also perfectly capable of just blowing up. A properly-functioning liquid-fuel rocket keeps the oxidizer separate from any fuel, a properly-functioning solid-fuel rocket keeps the fuel out of conditions under which it can detonate, but either can break down due to manufacturing or operational error.

SRB ignition never happens before t-0, where it's too late to abort liftoff anyways

SpaceX's rocket was remote-detonated in 2015 well before the engines were "shut down"

>SRB ignition never happens before t-0, where it's too late to abort liftoff anyways
Know why? It's because they can't just shut down, top off the tanks, and try again if they detect a problem. Once they light off the fireworks, it's do or die. Even if they are extinguishable solid motors, an abort before lift-off would save little more than the payload.

SpaceX has aborted between engine start and lift-off multiple times.

>>"Shutting down engines" to prevent a failure is something that only happens in upper stage flight
>...and prior to liftoff. Abort after ignition on detection of an anomaly is one of the more useful options.

This needs to be stressed a few times.

Well, they are copying the soviet program but with money so it might actually work.

>china
>space program

...

Try reading the NASA report criticizing the use of SRBs on SLS before posting next time.

You sound like a retard making up bullshit.

Elon's Mars rocket is vaporware.
>but muh they built a fuel tank test article!
They didn't even build it themselves.
Elon's tunnel project is more real than the Mars rocket.

>Elon's tunnel project is more real than the Mars rocket.
Of course it is. They're already digging.

At a SpaceX facility, there's a parking lot across a busy road from the workplace. A couple of employees died crossing the road. They're building a pedestrian tunnel.

That's what got him interested in the first place. Tunnels are quite expensive, and he thinks they can be done much more cheaply using modern tech.