Assuming the SpaceX Starship eventually works, when in the past could an equivalent rocket have been built if someone decided to pay for it?For this question, assume "equivalent" means: --big (50 t or more to LEO) --inexpensive (stainless steel, lots of inexpensive engines) --fully and rapidly reusable --methaloxCould this have been done in 1980?
https://www.google.com/search?client=firefox-b-d&q=%22boeing+space+freighter+Boeing. Space. Freighter. It even had methane first engines, because post 1973 oil shock Pdt Carter wanted to replace oil with methane manufactured out of coal (which would have been en envronmental disaster).
The space shuttle was designed and built in the 1970s. I don't see any fundamental technology in starship that was not available then.
It's a little funny in the video the way that the siren goes off 7 seconds before main engine ignition. What's the purpose? To wake up any unfortunate pad workers who slept through the evacuation boat so they won't die in their sleep?<snip>
Thanks, all.I especially like the use of human pilots to remove the need for modern avionics: the date does not depend critically on modern electronics.Now that I think on it, this thread is too soon. We will not know if Starship is cheap and fully and rapidly reusable until it has flown a few times. My biggest concern is the TPS. If the TPS turns out to be the big gating factor, then those older designs may not have been feasible until the tiles are very robust and the turnaround (inspection, waterproofing, replacement) is cheap and fast. But this never happened during the 30-year life of the Space Shuttle, and we don't yet know if SpaceX has solved the problem even today. I love Starship and I'm hopeful that SpaceX will create a robust and inexpensive TPS eventually, but we don't know yet if the current one is it.
Quote from: DanClemmensen on 05/31/2022 02:18 pmThanks, all.I especially like the use of human pilots to remove the need for modern avionics: the date does not depend critically on modern electronics.Now that I think on it, this thread is too soon. We will not know if Starship is cheap and fully and rapidly reusable until it has flown a few times. My biggest concern is the TPS. If the TPS turns out to be the big gating factor, then those older designs may not have been feasible until the tiles are very robust and the turnaround (inspection, waterproofing, replacement) is cheap and fast. But this never happened during the 30-year life of the Space Shuttle, and we don't yet know if SpaceX has solved the problem even today. I love Starship and I'm hopeful that SpaceX will create a robust and inexpensive TPS eventually, but we don't know yet if the current one is it.Radio-controlled would have worked. We had good enough computers in the 1950s, and analog versions since the 30s?
Quote from: Robotbeat on 05/31/2022 02:47 pmQuote from: DanClemmensen on 05/31/2022 02:18 pmThanks, all.I especially like the use of human pilots to remove the need for modern avionics: the date does not depend critically on modern electronics.Now that I think on it, this thread is too soon. We will not know if Starship is cheap and fully and rapidly reusable until it has flown a few times. My biggest concern is the TPS. If the TPS turns out to be the big gating factor, then those older designs may not have been feasible until the tiles are very robust and the turnaround (inspection, waterproofing, replacement) is cheap and fast. But this never happened during the 30-year life of the Space Shuttle, and we don't yet know if SpaceX has solved the problem even today. I love Starship and I'm hopeful that SpaceX will create a robust and inexpensive TPS eventually, but we don't know yet if the current one is it.Radio-controlled would have worked. We had good enough computers in the 1950s, and analog versions since the 30s?RC won't work well during re-entry, and that is one of the critical times.
Quote from: Robotbeat on 05/31/2022 02:47 pmQuote from: DanClemmensen on 05/31/2022 02:18 pmThanks, all.I especially like the use of human pilots to remove the need for modern avionics: the date does not depend critically on modern electronics.Now that I think on it, this thread is too soon. We will not know if Starship is cheap and fully and rapidly reusable until it has flown a few times. My biggest concern is the TPS. If the TPS turns out to be the big gating factor, then those older designs may not have been feasible until the tiles are very robust and the turnaround (inspection, waterproofing, replacement) is cheap and fast. But this never happened during the 30-year life of the Space Shuttle, and we don't yet know if SpaceX has solved the problem even today. I love Starship and I'm hopeful that SpaceX will create a robust and inexpensive TPS eventually, but we don't know yet if the current one is it.Radio-controlled would have worked. We had good enough computers in the 1950s, and analog versions since the 30s?RC won't work well during re-entry, and that is one of the critical times. My point is that RC was not needed because those large vehicles could be piloted. This whole thing is purely hypothetical, so the issue is moot. Basically, A very rich obsessed individual could have done it. Howard Hughes was fifteen years too old, Delos D. Harriman was fictional, and Elon had not been born. Sigh. https://en.wikipedia.org/wiki/The_Man_Who_Sold_the_Moon
And Buran was fully automated.
I'm thinking that one of the key developments for Starship may have been somebody recognizing that lox/hydrogen is not necessarily the way to go.
Could a pilot plus a very crude guicande system allow for a vertical landing? Probably.
But as far as I know, reentry was always controlled by the flight computer for Apollo, which had very tight parameters for reentry angle when returning from the Moon. The Shuttle was also on computer control during reentry.
Quote from: JayWee on 05/31/2022 06:16 pmAnd Buran was fully automated.But Buran was mid-1980's, while some of the proposals mentioned here go back to 1970. If we are looking for the earliest time that we could have had cheap access to space, I think we can say that is was not limited by the avionics.There may have been a limit imposed by lack of CAD, but maybe not: Saturn did not use a lot of CAD. I suppose this might rule out a spaceplane in 1970. Could a pilot plus a very crude guicande system allow for a vertical landing? Probably.
Quote from: DanClemmensen on 05/31/2022 07:11 pmQuote from: JayWee on 05/31/2022 06:16 pmAnd Buran was fully automated.But Buran was mid-1980's, while some of the proposals mentioned here go back to 1970. If we are looking for the earliest time that we could have had cheap access to space, I think we can say that is was not limited by the avionics.There may have been a limit imposed by lack of CAD, but maybe not: Saturn did not use a lot of CAD. I suppose this might rule out a spaceplane in 1970. Could a pilot plus a very crude guicande system allow for a vertical landing? Probably.Initially, the designers of the Mercury capsule toyed with the idea of not having manual controls at all, something the astronauts - all test pilots - thoroughly vetoed. On the Russian side of things, the Vostok capsules had only very limited crew control capability. Yuri Gagarin's orbital flight was done entirely on automatic controls.
Reentry could be done by slowing the spacecraft down and just dropping from orbit. No heat shield needed. Problem is it would currently take a lot of fuel to slow down. I've often wondered what the trade off would be to use a titanium layer underneath the tiles. It has a higher melting point than stainless steel, but is still light, around 3,000 degrees F vs around 2,000 degrees stainless steel. Reentry is about 3,000 degrees. So, can titanium be made in thin layers to go under the tiles? If so, it might be able to loose some tiles and still make it back to earth. However, the price of titanium may be too expensive to make a reusable spacecraft.
2022.SpaceX Starship is the culmination of all knowledge in aerospace. It could not have been done before today. Just because some engineer drew something 50 years ago does not mean it would ever see physical reality regardless of resources available. Engineering Systems is about trade-offs and constraints. Even today what Musk wants and needs for his Rocket is not what anyone else wants or needs. If Musk of 20 years ago had his present day knowledge and funding, he might still not get present day Starship sooner than today.
Quote from: spacenut on 06/01/2022 12:47 pmReentry could be done by slowing the spacecraft down and just dropping from orbit. No heat shield needed. Problem is it would currently take a lot of fuel to slow down. I've often wondered what the trade off would be to use a titanium layer underneath the tiles. It has a higher melting point than stainless steel, but is still light, around 3,000 degrees F vs around 2,000 degrees stainless steel. Reentry is about 3,000 degrees. So, can titanium be made in thin layers to go under the tiles? If so, it might be able to loose some tiles and still make it back to earth. However, the price of titanium may be too expensive to make a reusable spacecraft. You do realize that titanium was mostly from the Soviet Union during the Cold War era. Recall the special means the CIA and the USAF did to procured enough titanium for the A-12 and the SR-71 aircraft programs. Never mind the high machining cost of working with titanium at that time. So thin titanium strips seems not very practical for that era.
I remember STS figures of 62 flights/year, 50 years on, we'll see how predictions for SH/SS turn out.
Quote from: Hog on 06/01/2022 10:51 pmI remember STS figures of 62 flights/year, 50 years on, we'll see how predictions for SH/SS turn out. Indeed, there is a risk that SS/SH will not pan out. But I think the risk is much less than for the Shuttle, because it is less of a technological leap, it can fly without a crew, and the scale of production permits continual improvement.
The lack of support (money) from Congress for some sort of a Shuttle 2.0 was probably the the worst aspect of the STS program as a whole. Shuttle was an incredible machine, but it was really the first attempt at a reusable orbital space plane (X-15 was suborbital) anywhere, and it is no surprise that there were some lessons learned along the way. Unfortunately, NASA didn't have support to implement those lessons, and in terms of the vehicle overall, Atlantis flying STS 135 in 2011 wasn't substantially different from the glide tests Enterprise did in 1977.
Quote from: Proponent on 06/02/2022 10:45 amQuote from: Hog on 06/01/2022 10:51 pmI remember STS figures of 62 flights/year, 50 years on, we'll see how predictions for SH/SS turn out. Indeed, there is a risk that SS/SH will not pan out. But I think the risk is much less than for the Shuttle, because it is less of a technological leap, it can fly without a crew, and the scale of production permits continual improvement.The lack of support (money) from Congress for some sort of a Shuttle 2.0 was probably the the worst aspect of the STS program as a whole. Shuttle was an incredible machine, but it was really the first attempt at a reusable orbital space plane (X-15 was suborbital) anywhere, and it is no surprise that there were some lessons learned along the way. Unfortunately, NASA didn't have support to implement those lessons, and in terms of the vehicle overall, Atlantis flying STS 135 in 2011 wasn't substantially different from the glide tests Enterprise did in 1977.SpaceX has show a remarkable ability to implement changes and not get stuck in the sunk cost fallacy. Assuming SS/SH is flying 10 years from now, the SS component (at least) will probably be a substantially different vehicle than what eventually flies the first orbital mission.
Re-entry was designed to be done by computer controls on Mercury, Gemini, and Apollo. However, for both Mercury and Gemini, there were a few instances where control had to be taken manually.But as far as I know, reentry was always controlled by the flight computer for Apollo, which had very tight parameters for reentry angle when returning from the Moon. The Shuttle was also on computer control during reentry.
1) I’m a huge fan of SpaceX & of SS/SH, but I agree with others that we’re being premature here. I know there’s no such thing, but I don’t want to jinx the thing.
2) Even so, if SS/SH can even meet HALF it’s design goals—either on orbit refueling or a notably faster/cheaper reuse rate than STS—along with its massive payload lift capacity & fairing volume, it’s a huge game changer.
A Shuttle 2.0 likely would have been a better vehicle. But like Shuttle 1.0, it would have suffered from being supposedly designed for economy by an outfit that has never displayed had a knack for cost control. And I'll bet it still would have had technological overreach, maybe not as bad as Shuttle 1.0's, but still to much for a supposedly operational vehicle.