Starship, how many decades did we loose?

[magnemoe]

Following the progress of Starship prototype being build in an field in Texas, one thing nags me.
This is pretty low tech, yes the engines are good but 100 ton to LEO with full reuse is kind of overkill, let settle for 20 ton with full reuse, you can go expendable on flagship missions or just scale up. 
Computer has getting better but they was probably good enough 30 years ago.You could do lot from ground control outside of reenter and touchdown and could even man first and second stage. 
Any other restrictions rater than no need? 

Musk style is kind of the early space age, however a bit more refined. as in trying lots of stuff fast but watch the budget closely. 
Here is the problem,current politicians and current NASA could probably not done the falcon 9 landing development as once they stated they wanted to reuse first stages each fail would be an failure even if stage would be lost anyway.  

[ZooNamedGames]

NASA wouldn't have attempted a reusable booster like SpaceX designed, yes. As it's extremely costly and NASA is in the business of innovation and discovery and reusable boosters is more of a cost saver than anything new. We were reusing plenty of hardware thanks to the Space Shuttle program, so it didn't discover much and wouldn't innovate enough to keep NASA's interest. It's why NASA has always been focused on efforts above and beyond that of LEO since the end of the space shuttle- NASA doesn't tread where others can do it more cheaply and despite what others claim- so far only NASA has the ability to send crew BEO. SpaceX isn't there yet.

That said- I appreciate Musk trying to innovate with BFR and it's great for lifting heavy hardware but it's not as practical as he claims. For full reuse- a plane style SSTO (cough Skylon cough) would be vastly better. Being able to launch from any properly set up airport and launching to any inclination and avoid bad weather by flying around it or above it. Rockets can only launch from very special facilities and require extensive care during assembly and payload loading. A spaceplane can have the payload inserted like any normal cargo aircraft, and then rolled onto the runway after an inspection. With a rocket, it has to be picked up, and in the case of the F9, tipped over onto it's side, and then carried to a processing center elsewhere. A spaceplane can fly and carry itself to the processing center. Saving a lot of time and money.

But that's just my opinion and I've been called crazy before.

[tater]

NASA did attempt a reusable SSTO, in fact:

 

21 minutes ago, ZooNamedGames said:

That said- I appreciate Musk trying to innovate with BFR and it's great for lifting heavy hardware but it's not as practical as he claims. For full reuse- a plane style SSTO (cough Skylon cough) would be vastly better. Being able to launch from any properly set up airport and launching to any inclination and avoid bad weather by flying around it or above it. Rockets can only launch from very special facilities and require extensive care during assembly and payload loading. A spaceplane can have the payload inserted like any normal cargo aircraft, and then rolled onto the runway after an inspection. With a rocket, it has to be picked up, and in the case of the F9, tipped over onto it's side, and then carried to a processing center elsewhere. A spaceplane can fly and carry itself to the processing center. Saving a lot of time and money.

All that matters is cost/kg.

[ZooNamedGames]

1 minute ago, tater said:

NASA did attempt a reusable SSTO, in fact:

 

All that matters is cost/kg.

Got me with the Yankee Clipper. I knew of it and it did slip my mind.

cost/kg is a big factor but not for making space more accessible as we're locked behind launch scrubs and delays in getting things launched when spaceplane SSTOs can do it quicker and more routinely. Besides once that door is open, SSTO companies will become rampant.

[tater]

7 minutes ago, ZooNamedGames said:

cost/kg is a big factor but not for making space more accessible as we're locked behind launch scrubs and delays in getting things launched when spaceplane SSTOs can do it quicker and more routinely. Besides once that door is open, SSTO companies will become rampant.

There's only one being worked on, and they are investing only chump-change on it. I'll be dead before Skylon flies, probably.

HTHL spacecraft have been proposed for a while, but they will have to demonstrate real operational reuse (like aircraft) before we can say they are any better than the similarly unknow costs of craft like Starship.

SSTO I don't really care about, TSTO is just as good (regardless of how it lands).

[ZooNamedGames]

2 minutes ago, tater said:

There's only one being worked on, and they are investing only chump-change on it. I'll be dead before Skylon flies, probably.

HTHL spacecraft have been proposed for a while, but they will have to demonstrate real operational reuse (like aircraft) before we can say they are any better than the similarly unknow costs of craft like Starship.

SSTO I don't really care about, TSTO is just as good (regardless of how it lands).

We just need to overcome the hurdle of making SSTOs and I'm comfortable in saying that more will pop up since they promise easy use and require no additional downtime than a normal aircraft.

[tater]

1 hour ago, ZooNamedGames said:

We just need to overcome the hurdle of making SSTOs and I'm comfortable in saying that more will pop up since they promise easy use and require no additional downtime than a normal aircraft.

This simply isn't true.

We literally have no idea, not a clue, what the refurb time of spaceplane might be. There are what, 2 examples (Shuttle and X-37), and they are nothing remotely like SSTO spaceplane concepts. You know where the most useful data is likely to come from---long before anything like Skylon even flies in the atmosphere, much less space? Starship.

Not knowing is a legitimate answer, and indeed in most cases it's the right answer.

Do we know Starship will work? Nope, not at all.

Do we know any part of Starship will work? Yes, rocket engines are a known entity. Yes, the booster will likely work (it's just a big F9). Stage 2 reuse (TPS, etc)? Nope, we don't know.

Do we know any parts of Skylon that will work so far? Engine? Nope. TPS? Nope.

Those "nopes" don't mean that they won't work, just means we don't know.

Edited May 17, 2019 by tater

[ZooNamedGames]

19 minutes ago, tater said:

This simply isn't true.

We literally have no idea, not a clue, what the refurb time of spaceplane might be. There are what, 2 examples (Shuttle and X-37), and they are nothing remotely like SSTO spaceplane concepts. You know where the most useful data is likely to come from---long before anything like Skylon even flies in the atmosphere, much less space? Starship.

Which is like comparing a car to a boat. They will operate completely differently. Starship has to be mated to a launchpad, can only launch from set launchsites, required uniquely trained personnel and so on. Skylon would not.

[RocketSquid]

7 minutes ago, ZooNamedGames said:

Which is like comparing a car to a boat. They will operate completely differently. Starship has to be mated to a launchpad, can only launch from set launchsites, required uniquely trained personnel and so on. Skylon would not.

Skylon uses liquid hydrogen fuel, which means it cannot just launch from ordinary runways. It will still need to be mated to a similar umbilical system, will still need to be launched from set launchsites, and will still need uniquely trained personnel. The advantage of skylon is lower total fuel mass and thus, theoretically, lower launch cost.

[ZooNamedGames]

1 minute ago, RocketSquid said:

Skylon uses liquid hydrogen fuel, which means it cannot just launch from ordinary runways. It will still need to be mated to a similar umbilical system, will still need to be launched from set launchsites, and will still need uniquely trained personnel. The advantage of skylon is lower total fuel mass and thus, theoretically, lower launch cost.

But can operate bimodally- meaning it can launch using typical jet power. Allowing it to launch from typical runways. Augmenting existing airports would be vastly easier than having to find a suitable launchsite based on launch inclination, build the launchsite and then purchase additional hardware for moving any rockets as we do currently.

[Exploro]

As envisioned, Skylon does not utilize conventional jet engines of any kind.

[RocketSquid]

1 minute ago, ZooNamedGames said:

But can operate bimodally- meaning it can launch using typical jet power. Allowing it to launch from typical runways. Augmenting existing airports would be vastly easier than having to find a suitable launchsite based on launch inclination, build the launchsite and then purchase additional hardware for moving any rockets as we do currently.

No, it can't. Even with the SABRE in air-breathing mode it uses liquid hydrogen propellant. And "augmenting existing airports" for the skylon would be extraordinarily difficult. There are not currently any paved runways long enough to handle it, and it needs an exceptionally durable runway as well. It needs a total of 7.4 kilometers of runway, all of which must be able to accommodate 275 metric tons concentrated on three fairly small landing gear units. The longest paved runway is only 5.5 kilometers long. There are plenty of unpaved runways that are long enough, but they're unlikely to accommodate the forces involved. So no, it would not be easier. The advantage of the skylon is that it could theoretically be carried by a fairly reasonable airplane.

[ZooNamedGames]

1 minute ago, Exploro said:

As envisioned, Skylon does not utilize conventional jet engines of any kind.

It's bimodal, meaning it runs in both rocket mode and an airbreathing mode. From the wiki- https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

"The design comprises a single combined cycle rocket engine with two modes of operation.^[3] The air-breathing mode combines a turbo-compressor with a lightweight air precooler positioned just behind the inlet cone. At high speeds this precooler cools the hot, ram-compressed air, which would otherwise reach a temperature that the engine could not withstand,^[8] leading to a very high pressure ratio within the engine. The compressed air is subsequently fed into the rocket combustion chamber where it is ignited along with stored liquid hydrogen. The high pressure ratio allows the engine to provide high thrust at very high speeds and altitudes. The low temperature of the air permits light alloy construction to be employed and allow a very lightweight engine—essential for reaching orbit. In addition, unlike the LACE concept, SABRE's precooler does not liquefy the air, letting it run more efficiently.^[2]

After shutting the inlet cone off at Mach 5.14, and at an altitude of 28.5 km,^[3] the system continues as a closed-cycle high-performance rocket engine burning liquid oxygen and liquid hydrogen from on-board fuel tanks, potentially allowing a hybrid spaceplane concept like Skylon to reach orbital velocity after leaving the atmosphere on a steep climb."

[Exploro]

9 minutes ago, ZooNamedGames said:

It's bimodal, meaning it runs in both rocket mode and an airbreathing mode. From the wiki- https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

"The design comprises a single combined cycle rocket engine with two modes of operation.^[3] The air-breathing mode combines a turbo-compressor with a lightweight air precooler positioned just behind the inlet cone. At high speeds this precooler cools the hot, ram-compressed air, which would otherwise reach a temperature that the engine could not withstand,^[8] leading to a very high pressure ratio within the engine. The compressed air is subsequently fed into the rocket combustion chamber where it is ignited along with stored liquid hydrogen. The high pressure ratio allows the engine to provide high thrust at very high speeds and altitudes. The low temperature of the air permits light alloy construction to be employed and allow a very lightweight engine—essential for reaching orbit. In addition, unlike the LACE concept, SABRE's precooler does not liquefy the air, letting it run more efficiently.^[2]

After shutting the inlet cone off at Mach 5.14, and at an altitude of 28.5 km,^[3] the system continues as a closed-cycle high-performance rocket engine burning liquid oxygen and liquid hydrogen from on-board fuel tanks, potentially allowing a hybrid spaceplane concept like Skylon to reach orbital velocity after leaving the atmosphere on a steep climb."

To me "typical jet power" implied conventional jet engines providing the means of propulsion. If you meant to say that the Skylon would ferry from one airport to another via the SABREs air breathing mode, I stand corrected (Note that an aircraft operating with air breathing rocket engines for such a flight would still be far from "typical").

[tater]

We still have no idea about how such a spacecraft would actually work. Shuttle art from the 70s (and the work done on the project by NASA) always assumes Shuttle launches weekly at minimum, with aircraft level turn around. Skylon is a cool idea, and I hope they get to test it somehow. That said their budget is what NASA spends on coffee every year.

[magnemoe]

1 hour ago, ZooNamedGames said:

Got me with the Yankee Clipper. I knew of it and it did slip my mind.

cost/kg is a big factor but not for making space more accessible as we're locked behind launch scrubs and delays in getting things launched when spaceplane SSTOs can do it quicker and more routinely. Besides once that door is open, SSTO companies will become rampant.

SSTO is an trap, do not even consider SSTO before fully reusable two stage to orbit is common. 
SSTO will always be far harder forcing you to stress everything, like using very light body and engines running at the peak so you can very easy end up with an shuttle style hangar queen. 
Yes it reduce complexity of launches but again everything else is harder. 

[StrandedonEarth]

Unfortunately liquid hydrogen is bulky, requiring huge tanks. And with the mass involved, the idea of a HTHL spaceplane needing to abort shortly before or after takeoff is likely to result in a huge fireball. And with new tech, such an abort is likely. 

[wumpus]

8 hours ago, tater said:

We literally have no idea, not a clue, what the refurb time of spaceplane might be. There are what, 2 examples (Shuttle and X-37), and they are nothing remotely like SSTO spaceplane concepts. You know where the most useful data is likely to come from---long before anything like Skylon even flies in the atmosphere, much less space? Starship.

For suborbital spaceplanes we have the X-15.  199 flights (I'm sure plenty were test flights and with the early engines that couldn't reach space.  And almost all of them didn't go into space but simply went fast horizontally, which is probably harder on the spacecraft than a parabolic spaceflight).  I think this says more in just how much easier it is to go suborbital rather than orbital than the ease of turning around spacecraft.

The number of assumptions made in planning on running while still learning to crawl is amazing.  Elon Musk has mentioned that propellant cost for his rockets simply isn't a concern (although he probably does like how cheap methane is), especially considering that they are busy trying to recover a fairing (and hopefully relaunching one more or less as I type this) that costs roughly 30 times the total propellant cost.

While assembling a multistage rocket does require skilled technicians, there is absolutely no reason to assume that mating a Skylon to some sort of carrier aircraft (which could take off/land on a Concorde or A380 runway).  Also you have all the fun of working with hydrogen (which may or may not be common by the time Skylon might ever fly).

[RocketSquid]

8 hours ago, ZooNamedGames said:

It's bimodal, meaning it runs in both rocket mode and an airbreathing mode. From the wiki- https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

"The design comprises a single combined cycle rocket engine with two modes of operation.^[3] The air-breathing mode combines a turbo-compressor with a lightweight air precooler positioned just behind the inlet cone. At high speeds this precooler cools the hot, ram-compressed air, which would otherwise reach a temperature that the engine could not withstand,^[8] leading to a very high pressure ratio within the engine. The compressed air is subsequently fed into the rocket combustion chamber where it is ignited along with stored liquid hydrogen. The high pressure ratio allows the engine to provide high thrust at very high speeds and altitudes. The low temperature of the air permits light alloy construction to be employed and allow a very lightweight engine—essential for reaching orbit. In addition, unlike the LACE concept, SABRE's precooler does not liquefy the air, letting it run more efficiently.^[2]

After shutting the inlet cone off at Mach 5.14, and at an altitude of 28.5 km,^[3] the system continues as a closed-cycle high-performance rocket engine burning liquid oxygen and liquid hydrogen from on-board fuel tanks, potentially allowing a hybrid spaceplane concept like Skylon to reach orbital velocity after leaving the atmosphere on a steep climb."

It’s bimodal but not tripropellant. It needs liquid hydrogen, which is hard to store.

In general, SSTO is a trap. It’s more viable to recover the first stage and reuse the upper stage in orbit, either for raw material or as a wetworks.

[Guest]

Except reusing the upper stage in orbit is not viable. Wet workshop require too much effort to convert into anything usable (if you need volume, use inflatables) and we have absolutely no use for raw material in orbit. We'll have Skylon way before we have an orbital foundry capable of recycling an upper stage.

SSTO is the only way you're getting realistic 100% reusability. The only other way is to reuse the first stage and only launch payloads with enough dV to serve as their own upper stage. The real trap is anything that requires building a new pump-fed rocket engine for each flight.

[Guest]

I feel like that we didn't lose any decades. Were going in the best time were we know the best.

14 minutes ago, Dragon01 said:

SSTO is the only way you're getting realistic 100% reusability. The only other way is to reuse the first stage and only launch payloads with enough dV to serve as their own upper stage. The real trap is anything that requires building a new pump-fed rocket engine for each flight.

No SSTOs are not the only thing that can be 100% reusable. Starship is fully reusable except fuel. And second stages can be reused like Vulcan. Fuel is the only thing that isn't reusable 

[Guest]

19 hours ago, magnemoe said:

Following the progress of Starship prototype being build in an field in Texas, one thing nags me.
This is pretty low tech, yes the engines are good but 100 ton to LEO with full reuse is kind of overkill, let settle for 20 ton with full reuse, you can go expendable on flagship missions or just scale up. 
Computer has getting better but they was probably good enough 30 years ago.You could do lot from ground control outside of reenter and touchdown and could even man first and second stage. 
Any other restrictions rater than no need? 

Musk style is kind of the early space age, however a bit more refined. as in trying lots of stuff fast but watch the budget closely. 
Here is the problem,current politicians and current NASA could probably not done the falcon 9 landing development as once they stated they wanted to reuse first stages each fail would be an failure even if stage would be lost anyway.  

Look NASA doesn't build rockets. Were did you get that from? NASA gets contracts EX: First stages of Saturn V developed by Boeing.

NASA is a company that get's contracts from others. The science of SpaceX landing a falcon 9 isn't something that NASA isn't thought impossible. This is what most SpaceX geeks get wrong, NASA never made rockets and it isn't their fault SLS is still around. The landing uses of Falcon 9 were annualized and were concluded to not be that reliable according to ULA; and it's true, I know from science that engines landing down safety by parachute is more likely to be recovered than a falcon 9 propulsive landing. The December incident and Falcon Heavy core tipping over is a risk SpaceX pays for not to include that they have to use some of their fuel in flight.

It's time to stop discriminating rocket scientists that know more than people like us.

[tater]

51 minutes ago, Dragon01 said:

SSTO is the only way you're getting realistic 100% reusability. The only other way is to reuse the first stage and only launch payloads with enough dV to serve as their own upper stage. The real trap is anything that requires building a new pump-fed rocket engine for each flight.

As was said, untrue. TSTO can also be reusable. If SSTO with 100% reuse is possible, so is any other number of stages to orbit. The hard bit is bringing the orbital bit back, booster reuse is now off the shelf.

[Guest]

Starship is the launcher+payload combination I mentioned. So was Space Shuttle. An upper stage capable of deorbiting, orbital entry and landing will have to qualify as a spacecraft on its own. 

[tater]

1 minute ago, Dragon01 said:

Starship is the launcher+payload combination I mentioned. So was Space Shuttle. An upper stage capable of deorbiting, orbital entry and landing will have to qualify as a spacecraft on its own. 

One, Starship is the second stage, the booster is called "Super Heavy."

Two, your statement is still false. You said, "SSTO is the only way you're getting realistic 100% reusability." This is patent nonsense, and in fact it's less likely than 2 stage to orbit (TSTO) with reusability, not the only way to achieve it.

Every single aspect of flight is easier with 2 stages, because the vehicles can be more optimized for their flight regimes, whereas an SSTO has to do all of the flight regimes.