Military Forum for Russian and Global Defence Issues
Big_Gazza likes this post
Well Russia has of course played with glider type designs for reusable stages, but I am not aware of any flyable prototypes. But a self powered landing using the stage's own engine and retractable landing gear is a SpaceX thing whether we like it or not (That is what the Amur is supposed to be too). It might not be as efficient as the glider concept but it is all we have right now. And I credit Musk for making it happen. Credit where it is due. I honestly don't get the treatment that guy gets around this forum. He may be an opportunistic oligarch but he invests in projects and gets things done. And as far as I am aware, he is not a russophobe or anything, is he?Scorpius wrote:
Yes, yes, of course. After all, before Elon, no one came up with the idea of creating reusable launch vehicles.
Re: Russian Space Program: News & Discussion #3 The-thing-next-door Tue Jan 12, 2021 7:12 pm
Daniel_Admassu wrote:
Well Russia has of course played with glider type designs for reusable stages, but I am not aware of any flyable prototypes. But a self powered landing using the stage's own engine and retractable landing gear is a SpaceX thing whether we like it or not
(That is what the Amur is supposed to be too)
It might not be as efficient as the glider concept but it is all we have right now. And I credit Musk for making it happen. Credit where it is due. I honestly don't get the treatment that guy gets around this forum. He may be an opportunistic oligarch but he invests in projects and gets things done. And as far as I am aware, he is not a russophobe or anything, is he?
Big_Gazza likes this post
Especially for you, I will bring this picture here (taken from an open source):kvs wrote:By the way, almost none of these morons who write thoughtful articles about how to properly manage the space industry, for some reason did not notice a small fact: NEM (scientific and energy module) is the first module of the next generation architecture, not created on the basis of the FGB (functional cargo blocks from the Transport Supply Ship come from the seventies).
That is, Roscosmos has actually created a new design of orbital station modules, but with the creation of a transport ship, it should have unsolvable problems? Seriously?
There was not enough Musk type snake oil salesman hype around this development. So it is not considered news by various
species of "analyst" imbecile. If Roscosmos PR-spazzed about some hyperloop or car in small tunnel technological marvel
maybe the autistics would be excited. Maybe. I think this is just crypto-hate. All these articles pissing on Russia and
predicting its doom are evidence of malice and not genuine concern.
Big_Gazza and kvs like this post
Daniel_Admassu wrote:Well Russia has of course played with glider type designs for reusable stages, but I am not aware of any flyable prototypes. But a self powered landing using the stage's own engine and retractable landing gear is a SpaceX thing whether we like it or not (That is what the Amur is supposed to be too). It might not be as efficient as the glider concept but it is all we have right now. And I credit Musk for making it happen. Credit where it is due. I honestly don't get the treatment that guy gets around this forum. He may be an opportunistic oligarch but he invests in projects and gets things done. And as far as I am aware, he is not a russophobe or anything, is he?Scorpius wrote:
Yes, yes, of course. After all, before Elon, no one came up with the idea of creating reusable launch vehicles.
Big_Gazza and kvs like this post
Scorpius wrote:
So they have already worked out all possible schemes for launching payloads into space, and conducted research in the field of reusable launch vehicles with completely different parameters. Including the landing of the first stages with the help of engines. In particular, methane engines designed for 25-fold use were developed. And all this was long before anyone heard about the existence of Elon Musk. Therefore, to say that Russian developments are "inspired" by SpaceX developments is nonsense. In reality, the process was rather the opposite.
But a self powered landing using the stage's own engine and retractable landing gear is a SpaceX thing whether we like it or not
kvs likes this post
GarryB wrote:
Powered craft with undercarriage that lands on its own... that was the US Space Shuttle and the Soviet Buran wasn't it?
Using wings and aerodynamic shape for air braking to land on a conventional runway is vastly more efficient and safer than a vertically landing rocket....
Re: Russian Space Program: News & Discussion #3 The-thing-next-door Wed Jan 13, 2021 8:29 am
The-thing-next-door wrote:I was just wondering. Would a booster with a few smaller engines at the top angled outwards like the ones on the Soyuz launch escape tower allow for the rocket to avoid flying back down trough its own hot fumes?
Re: Russian Space Program: News & Discussion #3 The-thing-next-door Wed Jan 13, 2021 11:47 am
Daniel_Admassu wrote:Theoretically you can have a powerful engine at the top to land a stage with the potential advantage of solving the 'balancing' problem of bottom engines. But the downside would be extra weight as the rocket will also need a bottom engine for liftoff in the first place. With computers doing the balancing work for most rockets however, it is a moot advantage.
Scorpius likes this post
Re: Russian Space Program: News & Discussion #3 The-thing-next-door Wed Jan 13, 2021 5:43 pm
kvs wrote:we will have hordes of Musk lemmings
bitch that vertical landings are superior and reflect higher levels of technology.
GarryB, dino00, thegopnik and LMFS like this post
kvs wrote:
Vertical descent is really an idiotic concept. Instead of using aerodynamics afforded by the thick layers of the atmosphere, we
have the pointless fighting of gravity which requires extra fuel to be carried up and then down. It also means burning out any
reusable engine twice as fast.
Big_Gazza likes this post
The Shuttle and Buran didn't use powered descent, they were gliders.
The Buran however was also supposed to have turbojets for the atmospheric phase of its descent which would have given it much more control of the landing.
What I really don't buy is this notion that reusability is less efficient than the alternative. How come?
That does not mean that ultimately reusable craft (even powered ones) won't be more efficient than discarded ones in the hands of someone else. Even hot parts of engines might one day become reusable with minimal overhaul.
But the downside would be extra weight as the rocket will also need a bottom engine for liftoff in the first place. With computers doing the balancing work for most rockets however, it is a moot advantage.
Vertical descent is really an idiotic concept.
With a descent flight the problem essentially reverses and the rocket becomes more and more unstable as it slows down. With the engine located at the bottom, thrust gimballing would be less straightforward. So this is an inherent downside of vertical landing.
2. The amount of fuel and engine thrust required for descent is far less than for liftoff not just because you would be carrying less load but also because you are not working against gravity as hard - as you want to descend, not ascend
3. Aerodynamic reentry will inevitably require additional hardware such as wings, folding mechanism, stabilizers and landing gear, while a vertical powered one will only require the latter. This additional gear also needs to be carried along with the associated compounded fuel problem discussed above.
4. Unpowered gliding is inherently a less controllable flight as it is constrained for trajectory and timing. It also depends a great deal on the weather condition. Unlike the Shuttle and Buran which can reenter at a suitable moment, separated rocket stages do not have such luxury.
Overall sophisticated control systems are rendering much of the previous avionics problems obsolete. In my opinion revisiting the reusable vehicle idea is worth the effort, whichever one a design team is comfortable with.
kvs wrote:
This advance in rocket manufacturing economics suggests that detachable URM engine sections that can parachute back to the
surface may be the optimal solution. One would assume that the cost of the fuel tanks is less than the cost of either the RD-191
or RD-171 based on complexity. It is doubtful that the cost of the metal used for the tanks and shell are high.
The parachute option over land would involve the use of small retro-thrusters like the manned capsules.
Re: Russian Space Program: News & Discussion #3 The-thing-next-door Thu Jan 14, 2021 2:23 pm
kvs wrote:
The parachute option over land would involve the use of small retro-thrusters like the manned capsules.
GarryB likes this post
Big_Gazza wrote:
The Zenit-based strap-ons for Energia and Buran were originally intended to be recoverable by parachute, and was to include landing gear for a horizontal touchdown. They never got around to trialling the recovery option (mass simulators were fitted instead), but the intent was clearly there.
......
Regarding the propellant tanks, it is not just about the metal cylinders but also the associated lines, pumps, valves, sensors, wiring and all the man hours spent on their production and inspection. They might not be as expensive as the engines (Which I am not sure) but they constitute a large part of the cost. So recovering them intact would be great.
Adding retro thrusters for touchdown would over complicate the solution and defeat the purpose.
The Zenit-based strap-ons for Energia and Buran were originally intended to be recoverable by parachute, and was to include landing gear for a horizontal touchdown. They never got around to trialling the recovery option (mass simulators were fitted instead), but the intent was clearly there.
Interesting. I have always (subconsciously) wondered what those bulges were on the side of the Energia strapons. Pity they didn't get to try them out.
This ofcourse was at the late years of the Soviet Union and probably cost overruns and budget issues have compelled the engineers to include some efficiency measures. Russia should also continue on that effort.
Big_Gazza and Scorpius like this post
|
|
|
Home
Register
Log in