The Buran Thread

[libra]

It's interesting to compare the Shuttle and Buran three main propulsion systems
- the main rocket engines
- the two OMS
- the planned jet engines (deleted in '74 for the Shuttle, kept to the very end on Buran but not flown)

In a sense, Buran dropped its SSME-look-alike engines into its Energiya rocket carrier.

And this meant two things
- Buran OMS went to the back end - where the Shuttle had its 3*SSME.
- the AL-31 jet engines went flanking the vertical tail - where the Shuttle had its OMS pods instead
- Note: before 1974 the Shuttle ferry jets (TF30s, then F401s) were to be hanged below the wing and TPS, in a removeable big pod. 

Some more thoughts.

Buran AL-31 were unreheated Su-27 engines, aproximately 1500 kg in weight. One SSME is 3200 kg, and the Shuttle had three of them in the back.

Hence Buran pair of turbojets weighed as much as 1*SSME, and the Shuttle had three of them. Center of gravity issues must have been slighty easier to handle (well, for the computers & FBW system) on Buran, with so much weight removed from the back.

[Hobbes-22]

The aerodynamics testbed had 4 engines. Were they planning to use 2 on the orbital Burans?

[libra]

Yes (according to Bart H. landmark book). My understanding is that OK-GLI needed more engines to takeoff. No such issues for the operational Burans... not with an Energiya giant RATO bottle / ZELL attached to them. 

[Jim]

The aerodynamics testbed had 4 engines. Were they planning to use 2 on the orbital Burans?

No

[B. Hendrickx]

An interesting 1h30m documentary on the Buran program has appeared on the Russian YouTube channel Redaktsia. It has a lot of recent footage of abandoned Energia/Buran hardware and infrastructure at Baikonur. Good to see that the graffiti sprayed on the second flight vehicle inside the MZK building has been overpainted. Security around the building has been stepped up to make sure that no one can enter it anymore.

[libra]

The aerodynamics testbed had 4 engines. Were they planning to use 2 on the orbital Burans?

No

Hmmm... the  author (just above my post - all hail NSF !) had this to say, in his Buran book (with Bert Vis)

So 50-50. 2*AL-31s were part of the original plans, but we will never know wether operational Burans would have carried them.

[Nicolas PILLET]

Two AL-31 were put on the Buran, but they decided to delete them only a few months before the maiden launch. They launched the BOR-5 n°505 in June 1988 without the engine pods to verify the aerodynamics. That's why BOR-5 n°501 to 504 had engine pods, and 505 hasn't.

See comparison between 502 and 505 on my pictures :

502 : https://www.kosmonavtika.com/vaisseaux/bor/visite/monino/monino.html

505 : https://www.kosmonavtika.com/vaisseaux/bor/visite/speyer/speyer.html

So the 1K vehicle which flew in November 1988 flew without the engine pods, but with all associated systems (plumbing, tanks, commands, etc.).

It was the same with vehicle 2K, which never flew.

On second generation Burans (3K, 4K, 5K), engines were deleted since the beginning.

[Alter Sachse]

Interesting photos for the anniversary of the launch

https://www.roscosmos.ru/33339/

[JAFO]

https://twitter.com/katlinegrey/status/1501266013630914564



https://twitter.com/ShuttleAlmanac/status/1501373317176905730

[libra]

An-225 dies, Buran(s) are on the move. Life goes on... 

[Vahe231991]

An-225 dies, Buran(s) are on the move. Life goes on... 

Notwithstanding the fact that the An-225 was originally built to haul the Buran shuttle to Baikonur but subsequently went on to become a heavylift transport years after the end of the Buran program, it is possible that Roscosmos could decide to have the Buran 2.01 completed and either painted in the likeness of the first Buran shuttle and sent to a museum or fitted with functioning hardware to allow it to be launched into orbit to deploy a space trawler to retrieve derelict Soviet-era satellites if it wants the proposed ROSS to avoid being hit by space debris (just as the ISS on occasions has had to grapple with space junk).

[Hobbes-22]

That seems very unlikely to me.

- 2.01 was only 30-50% finished when the program was cancelled
- it has been left outside, exposed to the elements for most of the 30 years since
- it would be absurdly expensive to revive Buran/Energia, there are much cheaper options for satellite disposal

[Blackstar]

https://www.nytimes.com/2023/03/27/world/europe/ukraine-giant-plane-mriya.html

Restoring a Giant Plane: Ukrainian Resilience or Folly?

Ukraine, with far more pressing needs, plans to rebuild the colossal Mriya cargo plane, a symbol of pride that was destroyed last year in a battle for its airfield.
By Andrew E. Kramer
March 27, 2023Updated 2:17 p.m. ET

HOSTOMEL, Ukraine — The gigantic twin tail fins, once stretching as high as a six-story building, are gone.

So are the tailplane, flaps, hydraulic systems, fuel pumps and three of six engines of the plane, which was destroyed in fighting in the first days of the war.

Piece by piece, workers are now dismantling the wreckage of the gigantic Mriya cargo plane, the heaviest airplane ever flown, with plans to build a new one with salvaged parts. The restoration of the plane, whose name in Ukrainian means The Dream, has begun.

With the war still raging, the immense job of rebuilding Ukraine, where hundreds of thousands of homes, hospitals, schools and bridges are blown up, still seems a distant prospect. Measured against those daunting challenges, the work on the new plane is hardly a top priority from a humanitarian point of view. But it is meant in part as an inspiration, according to executives at the aircraft company that owns it, Antonov.

If something as gargantuan and complex as this airplane can be restored, they say, so can the rest of the country.

“People should have hope,” said Vladyslav Valsyk, deputy director and chief engineer of Antonov, a state-owned company. “They have to know this plane is not abandoned. Yes, there is a lot of work to do, but we are working.”

But critics say that devoting money and energy to rebuilding the plane would be a misplaced priority.

Valery Romanenko, an aviation analyst, has said to Ukrainian media that Antonov should focus only on “doing something urgent for the armed forces” during the war, such as making drones. “There are just no words,” he said of the plan to build a new Mriya.

President Volodymyr Zelensky announced last May that Ukraine would rebuild the Mriya, the only one of its kind ever completed. Over the summer, the British entrepreneur and aviation enthusiast Richard Branson visited the wreckage and expressed excitement about helping in its restoration, when the time came.

[hoku]

https://www.nytimes.com/2023/03/27/world/europe/ukraine-giant-plane-mriya.html

Restoring a Giant Plane: Ukrainian Resilience or Folly?

Ukraine, with far more pressing needs, plans to rebuild the colossal Mriya cargo plane, a symbol of pride that was destroyed last year in a battle for its airfield.
By Andrew E. Kramer
March 27, 2023Updated 2:17 p.m. ET
<snip>

A couple of pictures of the 2nd - unfinished - An-225, which is mentioned in the article. Looks like a good basis to get one flying again (assuming that the 2nd one did fare better during the Russian attacks). And while they are at it, maybe swap in some western, more fuel efficient and less noisy engines?

[Vahe231991]

https://www.nytimes.com/2023/03/27/world/europe/ukraine-giant-plane-mriya.html

Restoring a Giant Plane: Ukrainian Resilience or Folly?

Ukraine, with far more pressing needs, plans to rebuild the colossal Mriya cargo plane, a symbol of pride that was destroyed last year in a battle for its airfield.
By Andrew E. Kramer
March 27, 2023Updated 2:17 p.m. ET
<snip>

A couple of pictures of the 2nd - unfinished - An-225, which is mentioned in the article. Looks like a good basis to get one flying again (assuming that the 2nd one did fare better during the Russian attacks). And while they are at it, maybe swap in some western, more fuel efficient and less noisy engines?

Notwithstanding the fact that the second An-225 was built as a static test airframe, if the second An-225 is completed with components from the salvaged wreckage of the first An-225, it could be powered by four Rolls-Royce Trent 900s, given that the new in-development Aviadvigatel PD-35 intended to power the proposed Antonov An-124-102 won't be delivered for a few more years. After all, the D-18T powering the An-124 and An-225 was designed in the 1970s and so a variant of the Rolls-Royce Trent 900 would be appropriate for the second An-225 given that the the Trent 900 was conceived in the late 1990s.

[JAFO]

 if the second An-225 is completed with components from the salvaged wreckage of the first An-225, it could be powered by four Rolls-Royce Trent 900s,

All it would take is a complete redesign of the wing to use 2 engines/side instead of 3, plus complete redesign of the fuel, electrical, hydraulic, pneumatic systems, integrating them all together, then flight testing....


Nothing to it. Couple of 'Riddle interns could probably knock it out as a summer project. You should call Antonov.

   

[Blackstar]

All it would take is a complete redesign of the wing to use 2 engines/side instead of 3, plus complete redesign of the fuel, electrical, hydraulic, pneumatic systems, integrating them all together, then flight testing....

One of my favorite planes is the B-52. There have been proposals dating back to the 1990s to re-engine the B-52 with high-bypass turbofans. In the 1990s, this was proposed to replace the 8 engines on the wings (in four pods) with 4 high-bypass turbofans. That was rejected at the time due to money. Dumb decision, because USAF could have saved a lot of fuel over the past 30 years. (In the 1980s, USAF had replaced the 4 engines on many of its KC-135 tankers with 4 high-bypass turbofans, so there was experience both in USAF and Boeing with re-engining older aircraft.)

Then about 5+ years ago an engine fell off a B-52 and it shocked the USAF, because that engine had recently been inspected. When engines that test out fine suddenly depart a bomber in flight, you have a serious problem. So USAF finally decided to re-engine its fleet of B-52s. But instead of 4 high-bypass turbofans, they are going to replace the 8 engines with 8 new engines (which I think come from a business jet). That's because USAF determined that going from 8 engines to 4 would require a lot of flight test work to requalify the airframe. Think of it this way: if you lose 1 out of 8 engines during flight, it is pretty much the same with the new engines as the old engines, and you don't need to worry about the plane handling any differently. But if you only have 4 engines and you lose one of them, that will put a lot more yaw into the aircraft, requiring more response from the rudder, and dramatically changing the flying qualities. That requires a lot more testing to figure out (you pretty much have to test every possible engine-out failure). So they could replace the 8 engines with 4 engines, but it's a lot more hassle.

Before the Ukraine war, one of the big operators of the An-124 aircraft (the An-225 is based upon the An-124) was considering upgrading the aircraft with Western avionics and engines. I think there was an article in Aviation Week (or Flight International?) about this. The war has scrambled all of that, of course.

[JAFO]

All it would take is a complete redesign of the wing to use 2 engines/side instead of 3, plus complete redesign of the fuel, electrical, hydraulic, pneumatic systems, integrating them all together, then flight testing....

One of my favorite planes is the B-52. There have been proposals dating back to the 1990s to re-engine the B-52 with high-bypass turbofans....

One of the guys in my "silent avian" hangar was very heavily involved in this, among the many other things he did during a very distinguished USAF career, he gave a presentation about it (now called the B-52J) to our chapter one night. Like you said, money and politics killed/delayed this program, replacing the TF33s with single engine pods was nothing but a pipe dream out of a Dale Brown novel due to the amount of redesigning/engineering involved.

Like so many of his type, you could spend an entire evening with him answering his questions about what you flew and had done in your life, and have no idea the guy you were talking to was in the history books.


/thread drift

[Blackstar]

One of the guys in my "silent avian" hangar was very heavily involved in this, among the many other things he did during a very distinguished USAF career, he gave a presentation about it (now called the B-52J) to our chapter one night. Like you said, money and politics killed/delayed this program, replacing the TF33s with single engine pods was nothing but a pipe dream out of a Dale Brown novel due to the amount of redesigning/engineering involved.

There may have been a pre-1990s proposal for re-engining the B-52, but I'm too lazy to look at the pile of books I have on the aircraft. The 1990s proposal was unusual. My memory is that Boeing was offering to pay for the upgrade (probably in concert with an engine provider), but they would then sign a maintenance contract with USAF over a period of time. Essentially, they would be renting the engine upgrade to USAF. It was an unusual contracting idea, but nobody went for it.

There has been discussion of doing the current upgrade in two phases, resulting in a B-52J and a B-52K. I think the J would be the engines and the K would be new radar and avionics. But I expect that they'll all be collapsed into a single upgrade.

Yeah, we've drifted a bit. But Buran and the An-225 are rubble now, so we don't have much to go with.

[Vahe231991]

One of the guys in my "silent avian" hangar was very heavily involved in this, among the many other things he did during a very distinguished USAF career, he gave a presentation about it (now called the B-52J) to our chapter one night. Like you said, money and politics killed/delayed this program, replacing the TF33s with single engine pods was nothing but a pipe dream out of a Dale Brown novel due to the amount of redesigning/engineering involved.

There may have been a pre-1990s proposal for re-engining the B-52, but I'm too lazy to look at the pile of books I have on the aircraft. The 1990s proposal was unusual. My memory is that Boeing was offering to pay for the upgrade (probably in concert with an engine provider), but they would then sign a maintenance contract with USAF over a period of time. Essentially, they would be renting the engine upgrade to USAF. It was an unusual contracting idea, but nobody went for it.

There has been discussion of doing the current upgrade in two phases, resulting in a B-52J and a B-52K. I think the J would be the engines and the K would be new radar and avionics. But I expect that they'll all be collapsed into a single upgrade.

Yeah, we've drifted a bit. But Buran and the An-225 are rubble now, so we don't have much to go with.

This link discusses proposals in the late 1960s to 1980s for re-engining the B-52 with advanced high-bypass turbofans or the Pratt & Whitney PW2000/F117 turbofan engine:
https://theaviationgeekclub.com/usaf-materiel-command-history-office-releases-graphics-of-historical-efforts-to-re-engine-the-b-52-strategic-bomber/

The sole completed Buran shuttle and An-225 were destroyed in different circumstances, and by the time the Buran was destroyed in a hangar collapse, the An-225 found a new lease of life as a freighter years after it was put in storage in 1994 following the end of the Buran space shuttle program. I also wanted to emphasize that if the second An-225 aircraft is it be completed with four Rolls-Royce Trent 900s, the components from the salvaged wreckage of the first An-225 being used for the second An-225 may have to be melted down and remanufactured into new components to enable the integration of new fuel, electrical, hydraulic, and pneumatic systems.