Russian Space Program: News & Discussion #5

Great story. Buran was better than its US counterpart. Better thermal protection, the launch system itself was also better. The Energia rocket could carry large-sized payloads. The remote landing of Buran in the late 80s was a great success. The US did it only on the much smaller X-37. Unfortunately, the collapse of the USSR killed the entire project. Although the shuttles themselves turned out to be very uneconomical.

Theoretically if you could fly in a scramjet powered aircraft to 11km/s or faster you could nose up and leave earths orbit...

To expand on that if you were flying in a scramjet powered jet aircraft at say 40km altitude... the air is thin and cold but there is air there so your scramjet will operate and the speed you are travelling at the volume of airflow into your engines is enough to keep you flying at speed.

Now so far the only operational scramjet powered weapons we know of are Zircon missiles which move at only 3km/s.

11km/s is significant because that is the speed to escape the gravity of the earth to go to the moon or mars or anywhere else.

If your scramjet engine could accelerate you to about 7km/s that would probably be enough to get into a stable low earth orbit but you are not flying directly upwards, you are flying horizontally around the earth.

As you increase speed you will find you automatically gain altitude because as you move forward at very high speeds the ground you are covering increases to the point where the land below you falls away with the curvature of the planet and you climb while flying horizontally.

In a rocket you are not afraid of flying in a vacuum so when you watch those rocket launches you see it starts off vertical and climbing but then it rolls over and starts to go around the earth with its nose up slightly and accelerating and climbing all the way... this is because when the rocket reaches space there is no drag so it can accelerate faster, but a scramjet powered aircraft would drop its nose so it can continue to accelerate but remain inside the atmosphere.

Eventually it will reach a speed where it could raise it nose and climb to the orbital altitude it should be flying at at that flight speed but is not because the nose is down and essentially it is descending using airflow to remain inside the atmosphere.

Once in space it can't use airflow or lift to manouver and can only move with rocket propulsion and climb and descend by accelerating or decellerating on its orbital path.

If it pointed it nose directly up and fired its rocket and climbed 20km its orbital speed will not have changed because it flew sideways and didn't speed up or slow down. That means when the engine stops it will fall back to its previous orbital path because that is its path at that speed. If it pointed forward in the direction it was travelling and fired the rocket and accelerated to a higher orbital speed it would climb to a higher orbital path.

If it reached and orbital speed of 11km/s then it would leave orbit and head out into the solar system.

Buran was better than its US counterpart.

So many people think it was a carbon copy of the US shuttle and that it must have been inferior because they didn't really use it, despite having space stations.

Of course they were fundamentally different... the American space shuttle was like a C-130 that had an enormous fuel tank attached to its belly which required two enormous solid rocket booster engines to get it off the ground. I remember reading a comment that if the US space shuttle took off with an empty cargo bay and in orbit took on board its max payload capacity of 10 tons of gold and then landed normally and you could sell the gold to offset the cost of the launch the flight would still cost 300 million dollars. The flight would cost 600 million but you get 300 million back with the 10 tons of gold to sell.

Of course it never comes back with gold, but if you can repair a multi billion dollar satellite without having to scrap it and launch another super expensive satellite then it is a good cost effective thing.

Delivering crew to a space station and bring other home is a horribly inefficient use for the shuttle.

In comparison the Soviet shuttle was a glider... without 10 tons of engines that burn all that fuel in that huge fuel tank the US shuttle launches with the Soviet shuttle can carry 20 tons of payload and is the same overall weight.

More importantly the Energyia rocket is a rocket so you can take the Buran off and put a 120 ton payload on its back and launch it into orbit in one piece... if you are building a space station that could be several core pieces already attached together. Construction in space is difficult... the extreme temperatures and vacuum mean some metal materials fuse on contact with each other. Let go of a spanner and it will float away forever... and become a serious danger to other things in different orbits.

Buran only has manouvering rockets and deorbit rockets, making it rather lighter on most missions.

The heat shielding was also rather more efficient and effective. The US shuttle used tiles which often fell off leaving holes in the thermal protection while AFAIK the Soviet Buran had a coating that was reapplied between uses... no need to inspect each tile for damage and to see if it was coming loose.

Another feature was a crew escape system that was fitted from the start.