/sci/ - Science & Math

It's difficult and expensive to build something nobody has ever built, to operate in a place where few people have been, and to provide a service which nobody currently provides

>>7501063
This plus private space industry is still a fledgling business. Its cheaper to use conventional airplanes rather than put passengers into low earth orbit.

>>7501130
I'm talking specifically about orbital spaceplanes for launching payloads and providing a means of transportation to the ISS. Commercial suborbital spaceplanes will come after IMO.

>>7501214
>orbital spaceplanes for launching payloads and providing a means of transportation to the ISS

been there done that

>>7501234
SSTO spaceplanes.

because this world and humanity is messed up. we all revolve around money. we do this so much that we would even let our planet die because of global warming, prevent possible scientific breakthroughs and revolutionary things from not happening because we're afraid of money or stock market crash or whatever. just because something that isn't tangible can leave us in a period of sadness and low stock of bananas. well fuck this humanity and its economy. we're so pathetic we care more about some paper of currency other than a whole universe out there. imo
>inb4 you're a part of humanity too faggot

>>7501453
youre part of humanity too faggot

ayy lmao

>>7501453
It's easy to be idealistic when you are ignorant as fuck. Going to space is fine but you can't justify the cost of advancing space frontiers when people are starving and getting killed in wars.

>>7501051
BAD PAYLOAD FRACTION

>>7501234
enjoy your 10% useful mass

>>7501511
nuking africa and asia when?

>>7501512
/thread

>>7501511
It's not about people starving it's about there being no military benefit. Since weapons in space are banned there is no incentive to research SSTO spacecraft. NASA did a half assed attempt with the Space Shuttle but it got shut down before it could go further. Conventional rockets are only funded because they can launch military satellites and double up as ballistic missiles.

>>7501574
> there being no military benefit
it's all about the military

>>7501574
>Conventional rockets can double up as ballistic missiles.
Ballistic missiles and launch vehicles diverged a long time ago.

>>7501051
Because stacking air intakes doesn't work IRL

Best hope is Skylon.

>>7501574
>Since weapons in space are banned
but you can always do it in secret, right?

>>7501982
Not really.

>>7501511
> It's difficult to justify wars when feeding everyone and building spaceplanes would cost less.
FTFY

>>7501051
Even the Indian shuttle one looks like it's about to shit.

>>7501051
>1969+46
>we still don't live in space
The fuck is up with this shit?

>>7501051
Lol did the indians design their spaceship on spore?

>>7502080
jews control funding

>>7501453

Misanthropic, possibly an animal lover too.

>>7501051
Because they only really work well for Earth ops. Capsules work well with all kinds of celestial objects and are easier to use with modular space stations. I used to hate capsules but it is what it is.

>>7501623
>Both use rocket engines
>Both have the same range
>Diverged
>>7501982
Anon, space is the least secret place, anyone with a telescope can track your shit which has to follow super predictable orbital paths.

>>7502202
Conventional liquid-fuelled orbital launchers come from ballistic missile development for early, primitive nuclear weapons, which were few in number and heavy. So large payload capacity was a big deal.

For instance, the Soviet R-7 (which launched Sputnik, and which Soyuz is based on) as a ballistic missile carried a ~5-ton H-bomb payload with a ~3 megaton TNT yield. The American Atlas ICBM was about half the size and performance, for the more efficient American H-bomb of similar yield.

However, as plutonium production and bomb design became more competent, the fashion shifted to smaller, more numerous thermonuclear devices. Current strategic nuclear warheads are around 100 kg, and about 0.2-0.8 megatons.

Smaller, less efficient missiles are adequate for these lighter warheads, and after the initial mad rush to copy Nazi V2 technology, solid propellant technology matured and became obviously more suitable. Modern solid-fuel ballistic missiles, though they have poorer specific impulse and cost more per unit payload, can be stored for years without maintenance and fired off at a moment's notice.

Space Elevator

>>7502301
Forgot to mention that the Atlas, like the R-7, was adapted to be a manned vehicle (although the modern Atlas V has basically no relation to the original Atlas, aside from the Centaur upper stage, which uses a similar balloon tank design). The Mercury program, which put the first Americans in space, used an Atlas with various upgrades for precision and safety.

>The Skylon

That's LAPCAT, not SKYLON.

>>7501511
>end military funding
>divide equaly on social, evironmental and space projects
>wait 10 years
>literally ???
>profit!

it is a fucking shame what we have accomplished in all these years since humans first put engines into things to get humans and material off the ground.

>>7502917
>end military funding

>>7501051
There actually are. Countries have them, they're just not spoken about because they don't want other countries to have them which they don't trust. For similar situations, see the ST-71 "Blackbird"

>>7503002
>ST-71
SR-71... I hit "T" by mistake

>>7501271
Shuttle is 1.5 stages. It only shed boosters and an external fuel tank. It was damn close to a SSTO.

>>7503002
The SR-71 couldn't go to space.

>>7503031
Dude, that's two stages it had beyond the main shuttle. The main shuttle only had enough fuel for 300 m/s delta v.

>>7503131
>Dude, that's two stages it had beyond the main shuttle.
Neither of which were particularly valuable. All of the important equipment was returned to the ground onboard the shuttle.

>>7503031
The boosters (i.e. the first stage) were more of the liftoff mass than the rest of it.

Ditching the fuel tank isn't an SSTO move, either.

>>7503188
The fuel tank is a pretty big expense on a rocket, especially a hydrogen-fueled one. In terms of indispensable parts of a launch system, the only stuff the shuttle took to orbit and brought home were the engines and the payload fairing. And those engines came back in pretty rough shape.

>>7503240
>In terms of indispensable parts of a launch system, the only stuff the shuttle took to orbit and brought home were the engines and the payload fairing.
...oh, and the avionics. Those aren't free, although they're pretty cheap today.

>>7503128
I never said it could. I was using as an example of an air craft which a government had, but was kept secret, for they didn't want others they did not trust to have the information about its existence. Barely anyone knew anything about them outside of those who worked on them until the mid 1980s, and they have been around since the early 1960s. I can almost assure you that there must currently be an aircraft in a similar classified position, just from this previous situation. And that aircraft could very very likely be an SSTO.

>>7503552
>that aircraft could very very likely be an SSTO.
No, that's exceedingly unlikely.

There are limited military purposes served by going to orbit, and far more limited purposes served by coming back. Orbital launches are pretty much impossible to hide. Nothing natural flies up to space, and the hot rocket exhaust is easy to see. There are satellites from several countries constantly watching for any new spaceflight from anywhere in the world.

An inventory of solid-fueled expendable orbital rockets is a much better military asset, and we know they have those in the form of ICBMs.

>>7501051
There's no reason for SSTOs. The fact you can't shed mass means they will always be less efficient. Additionally, since they are subject to such extreme temps and pressures, you would have to tear them down and rebuild them every flight or two (just like the shuttle) nullifying the "reusability" argument.

Skylon is bumbling and clumsy and looks like something Wallace and Grommit would fly to the moon looking for cheese

Hyper plane looks like a turd floating down the Ganges

NASP looks like a movie prop

Based Germany will outlive us all

>>7501051
Sänger was pretty cool, but it was cancelled 1995

A lot of people look at a rocket, and say, "Why can't this be more like an airplane?"

One of the things they most often miss is the sheer scale of rockets. The largest aircraft in history (An-225) has a maximum takeoff weight of 640 tons. It's 285 tons empty, and can carry a payload exceeding 250 tons. The largest rocket, the Saturn V, had a takeoff weight of 3,000 tons. It was 185 tons empty, and could carry a payload of 140 tons. The space shuttle had a 2,000 ton liftoff mass and carried a payload of 24 tons.

As you add reusability, the payload mass fraction gets much worse. So if you want to make an SSTO that takes off like an airplane, you're going to be developing a really huge supersonic aircraft that will cost an absolute fortune to build and test fly, and the fuel consumption is still going to be so high relative to the payload, that you're not going to have customers to fly it a lot.

You look at something like the 747, there have been 1,500 built, and most of those flew thousands of flights. Millions of flights, billions of passengers and freight customers.

We pay to develop such excellent aircraft because we can use the fuck out of them. We make shitty rockets because even if they were good, we couldn't afford to fly them enough to make developing better ones worthwhile.

That's why what SpaceX is doing is neat. By taking advantage of modern computers, they're figuring out how to make a good, reusable rocket without a lot of development money or test flights. You have to find ways to cheat at this game.

>>7501511
>All funding for space travel is cut
>africa still starving
>wars still raging
>people still dying from drought and plague
>eventually everyone dies because no one established civilization off planet
Good job!

>>7504074
This

>>7501051
Because all NASA engineers are still busy building the smallest possible Duna landers.

>>7502917
>end military funding
>get annexed by mexico

>>7504074
Hit the nail on the head, great post

>>7501051
>https://en.wikipedia.org/wiki/Avatar_%28spacecraft%29

The first test flight of the scale model is in October 2015

>>7503979
>>7504020
There's a new German project on a hypersonic transport/spaceliner:
http://arstechnica.com/science/2015/08/german-space-researchers-reboot-effort-to-launch-hypersonic-space-plane/
https://www.flightglobal.com/news/articles/maks-germanys-hypersonic-spaceliner-concept-solidifies-416185/
http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-5898/year-2012/#/gallery/8509

>>7507547
>Lets spend millions of dollars on rocket fuel per launch to make a [passenger] plane that can go really really fast.

We tried this with the Space Shuttle program and it costs a fuckton. The worst part about it is the upkeep and constant maintenance and checks that have to go into a reusable design.

Skylon sounds cool until you realize that they are projecting a 190 million pounds ($290 million) for each aircraft (which is almost certainly a generous price estimate), and it has a small carrying capacity into Low Earth Orbit. Better off spending $15 million for an expendable Indian PSLV, Russian Soyuz 2, or Chinese Long March that gets similar/better capacity and much better value for these kinds of small payloads.

>>7503892
StealthSSTO when?

>>7508053
Skylon is reusable though

>>7508227
Never. SSTOs also have hot rocket exhaust

>>7508264
>Skylon is reusable though

So was the space shuttle.

The problem is that the checks and maintenance of reusable space planes is extremely high. They have to check the engines, replace the thermal tiles, etc.

The program was abandoned for a good reason.

>>7508700
skylon doesn't need thermal tiles

>>7501453
>global warming
I can definitively show you that global warming is both vastly overstated and caused by a myriad of forces outside of human control, with very little being in our power to affect.

>>7503552
yeah but SR-71 was just a faster plane. SSTO is a whole other level.

>>7504074
ah so SSTO and spaceX style reusable rockets are different? Never realized how clever his plan is; reuseable 3 stage rocket instead of reuseable single spaceplane.

>>7508053
Not really comparable with the Space Shuttle. The specs of the Shuttle were meddled with by Congress. It was demanded to throw together the military and civilian plans for a reusable spaceplane. This required the Shuttle to have unusually large wings because it had to be able to divert from course sideways for several thousand miles in order to land without completing a full orbit for added stealth and quickness on military missions. This also added unnecessary weight which compromised the reusability of the engines because they had to be operated at more than 100% nominal performance which seriously deteriorated their lifespan causing a huge cost increase due to increased maintenance insepections.

These points would not be the case with the German spaceliner. Another thing is that all those thousands of individual heat shield tiles caused enormous production and maintenance costs. Germany has another project to inquire whether it is feasible to have such a heat shield composed of very few simple flat surfaces with sharp edges between each other. It's called the Sharp Edge Flight Experiment (SHEFEX) and has seen considerable progress already. SHEFEX III is due to fly next year. The aerodynamics of a sharp edged body are more stable. But the heat is higher at the edges. The goal is to have a such heat shield composed of flat surfaces as this would dramatically decrease manufacturing and maintenane costs. Tiles could simply be cut out of larger pieces and the large pieces easily produced with economies of scale.

>>7509568
Fair point. However I do know for a fact that there are a decent amount of aerospace firms which are at the last researching SSTOs (source: close friend who manages distribution of aerospace materials/parts to companies, like space x, and even NASA at one point)

>>7502111
The Delta Glider in orbiter is a pretty versatile spaceplane capable of lunar and interplanetary travel with its fuel capacity and hover engines. It's airlock is its nosecone which makes it rather easy to dock with modular space stations. These are the types of vehicles we should be designing, although realistically, a spaceplane like this would work best as a landing vehicle for a mission to Mars (even a standalone capsule) won't cut it for sustaining astronauts on a six month journey).

>>7509895
Based Nazis

>>7510590
Look up the delta glider's specific impulse. Also delta glider 2 >> stock dg.

>>7501453
And there you are using an electric computer from the comfort of your own home

>>7510689
>You have to agree with all the bullshit in society unless you're living in a cave with not even fire
>>7501453
Actually everything revolves around the military. The entire history of space exploration is basically the history of military surplus. The Italians only funded Galileo's telescope because it had naval use, when he started doing edgy science with it they shut him down, Liquid rockets were only funded by the Germans because they were desperate as fuck to win the war, the USA and Russia only stole it because they wanted something to wave their dicks with. Basically if WW2 never happened we would not have gone to space full stop.

Will we see Ortillery being used as a first strike measure this century? The idea of taking explosive shits on China from orbit gets me aroused.

>>7512329
No.

>>7501754
What am I looking at here.

(and don't just say KSP)

>>7512512
Mexican programming at its finest

>>7512512
A spacecraft made entirely out of jet engines bolted together.
It's exactly as retarded as it sounds.