LOST... Old concepts to project never going off paper

[DDE]

1 hour ago, darthgently said:

because ... tradition? Maybe?

Supply chains. The thing distinguishing SpaceX the most is that it went past a whole lot of aerospace suppliers that normally expect a piece of the action. Often, this has cost them, but ultimately that's where their cost savings come from.

Dunno if they'll manage to keep this up given the reliability levels needed for their ambitions.

For ESA, where spreading the pork internationally was the mandate from the start, this would have been even worse.

[tater]

4 hours ago, SunlitZelkova said:

Say what you want about old space but they were totally justified in knocking down this proposal. Shuttle showed that reusability with 1970s technology was not what it was cracked up to be. X-33 went on to show 80s and 90s tech wasn’t up to the task either.

I disagree. I think many of the concepts from that era were possible, but they would have still required dangerous, iterative testing. Dangerous because many ideas—like flyback boosters—required pilots (as Shuttle did).

[SunlitZelkova]

54 minutes ago, tater said:

I disagree. I think many of the concepts from that era were possible, but they would have still required dangerous, iterative testing. Dangerous because many ideas—like flyback boosters—required pilots (as Shuttle did).

I think the designs were certainly feasible, they just would have been super expensive and at a total disadvantage compared to expendable rockets of the era. Zero point in reusability.

When I was researching my “The Quest For Rapid Reusability” thread I found that the fly back booster for the DC-3 was planned to use the same TPS as the Shuttle. The booster was huge, if the IRL Shuttle took months to service to be ready to fly again, the booster would take even longer.

So even with dangerous testing set aside, such proposals would not be economical.

As I said in another thread; the discussion about how the Soviets could never have landed on the Moon ahead of the US, I believe that both in the USSR and US spaceflight proposals were completely out of touch with the economics of the time. Despite being the world’s two superpowers, they were still not developed enough to be able to support extensive, sustained space exploration.

Maybe reusable spacecraft that actually are competitive with or better than expendable rockets could have been achieved by the 1980s, for example using my proposal in the Quest thread: just build so many vehicles you can have one ready to fly every week even if that means 20 are in processing at all times.

But to support and sustain that architecture you’d need to somehow take the national economy from the 1970s into 21st century levels in the span of a decade. Otherwise there would not be enough to build and maintain so many spacecraft.

[tater]

2 minutes ago, SunlitZelkova said:

So even with dangerous testing set aside, such proposals would not be economical.

Probably not. Some of the superheavy VTVL (splashdown) models might have been reusable, course refurb might have been really extensive—though for 450t to LEO, that's not as much of an issue.

[farmerben]

Manned fly back boosters would be super cool.  

At suborbital velocity you could use the rogallo wing.

https://en.wikipedia.org/wiki/Rogallo_wing

[magnemoe]

17 hours ago, darthgently said:

To some extent, but the budget to do hopper testing is relatively small and with control circuitry cost, mass, and power consumption dropping exponentially at the time I think it fair to say many missed an obvious opportunity to at least test the waters with a few jumping grain silos.  RC enthusiasts were doing amazing things making all kinds of programmable, autolanding, acrobatic helos, quadcopters, etc.  I think what happened at SpaceX was simply grabbing low hanging computational fruit that many others simply were in denial was relevant, because ... tradition? Maybe?

SpaceX was very lucky with their falcon 9 design with 9 smaller engines so they could reuse it as an vacuum engine for upper stage, this let them use center engine to land on, and the engines was reusable so they could do lots of test firings. 
This let them modify the rocket for reuse something who else would be almost impossible, only only existing rocket who aim for reuse is electron who splash down with parachutes, this work as its small. 

Standard rocket before falcon 9 was an 2.5 stage rocket usually with SRB, this does not work well for reuse.  And developing reuse only make sense if you launch often, if you launch twice a year its not worth it. 
Also then lots of engineers thought about reuse they fell into the trap who is SSTO because its cool. NO, just no it does not work, and if you somehow managed to get it to work it would but couple of ton into orbit and be more of an hangar queen than the shuttle. 

Now how early could you do first stage reuse, falcon 9 style? I would ditch the SSTO idea because its SSTO and make it an first stage with an disposable second stage, this was 1993, pretty sure you could do this earlier. 
Second stage reuse, something like Stoke space second stage, require no exotic stuff. Computers in the 90's would have no issue doing this, its mechjeb yes you had to handle real world sensors and telemetry who could be wrong and select the best but its not something who could not run on a 286. 

Edited March 25 by magnemoe

[Watermel00n]

15 hours ago, farmerben said:

Manned fly back boosters would be super cool.  

At suborbital velocity you could use the rogallo wing.

https://en.wikipedia.org/wiki/Rogallo_wing

The gemini rogallo wing was super cool and perhaps might have worked with testing.

[farmerben]

This one might go off paper.  It will be interesting to see.

 

https://static1.squarespace.com/static/65193472eadeb133523da70f/t/65d603737972197f559e6632/1708524406510/Cargo+Proa+Prototype.pdf

 

[darthgently]

4 hours ago, farmerben said:

This one might go off paper.  It will be interesting to see.

 

https://static1.squarespace.com/static/65193472eadeb133523da70f/t/65d603737972197f559e6632/1708524406510/Cargo+Proa+Prototype.pdf

 

The cargo capacity seems off, not sure.  Also deck based PVs are a loser generally.  That said, proas have huge potential for making the most efficient use of wind for boat propulsion, but generally it is hard to beat displacement hulls for heavy cargo hauling 

[farmerben]

It's almost always more efficient to carry heavier cargo than to make two trips.  Until you stick a rig on it, and realize sails on a massive container ship do not work.  The niche for smaller cargo vessels is limited mostly to island nations.  It's not really fair to compare a vessel that uses fuel and one that doesn't. 

 

What's the problem with deck based PVs?

Other than at 200W/m^2 you're not generating at a sufficient rate for propulsion.  And you need batteries for short range maneuvering, docking, etc. 

Edited March 31 by farmerben

[AckSed]

Think of it this way: it's a glorified grocery delivery van for in-between the islands.

[darthgently]

4 hours ago, farmerben said:

What's the problem with deck based PVs?

They don't wear well if walked on.  If you do walk on them, get used to not going barefoot on your sailboat as they get very hot in the sun.  Because they are mounted in the deck, they make the interior hotter also.  But not going barefoot on a sailboat in sunny weather is unholy in the extreme

A small diesel with PVs overhead on a rigid biminy or sunshade over the cockpit is the common solution for electricity and non sail maneuvers

[tater]

https://www.researchgate.net/publication/245438157_Two-Stage_Launch_Vehicles_for_Heavy_Payloads

 

[tater]

 

[TheSaint]

2 hours ago, tater said:

 

• I love Hazegray, but I hate clip shows.
• So, back around twenty-five years ago, I had a friend who was taking a sound design course at college. His prof gave them an assignment to soundtrack a 30-second clip of a generic animation of a space station in orbit. My friend was going over a bunch of different classical pieces to use, but he didn't want to use "Blue Danube" because he thought it was overdone. I told him to use the intro track to Subdivisions, which is what he went with. Afterwards he told me that, out of a class of thirty people, he and one other guy were the only people who didn't use "Blue Danube". It's so tired.
• Someone needs to show this to the Boeing executive team right before they announce their next 737 variant. To remind them that they used to at least try to innovate.

[magnemoe]

On 3/31/2024 at 12:15 PM, farmerben said:

It's almost always more efficient to carry heavier cargo than to make two trips.  Until you stick a rig on it, and realize sails on a massive container ship do not work.  The niche for smaller cargo vessels is limited mostly to island nations.  It's not really fair to compare a vessel that uses fuel and one that doesn't. 

What's the problem with deck based PVs?

Other than at 200W/m^2 you're not generating at a sufficient rate for propulsion.  And you need batteries for short range maneuvering, docking, etc. 

This, saling ships tended to pan out at around 10.000 ton, yes its larger like SS Great Eastern  and some smaller modern cruise ships. Both sail assisted.
But yes sail ships was used for cargo between islands like Indonesia very late because low operational cost then crew cost was low, and you did not need large speed or high cargo capacity, just servicing the islands.