Our 20th Century Space Legacy – Part 4: Transporting Humans into Near-Earth Space

March 20, 2012

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After the American landing on the Moon, human space flight returned to low-Earth orbit. The cost to launch a kilogram of payload into near-Earth space under the Apollo Program was prohibitively expensive. Post-Apollo engineers focused on finding a cheaper solution. Both in the United States and Soviet Union, engineers conceived of reusable winged spacecraft. The American program led to the Space Shuttle. The Soviets answered with Buran. Did either lower the cost of putting cargo and humans into near-Earth space? No. When the Space Shuttle program ended in the summer of 2011, payload launch costs amounted to $10,416 per kilogram. Buran costs could not be calculated since it flew unmanned once in 1988 and never was used again.

Buran-Space Shuttle comparison — The American Space Shuttle on the left, and the Soviet Buran shuttle, on the right, closely resembled each other. The latter flew a two-orbit unmanned mission once before being permanently shelved.

If you look at the above picture it is impossible not to note the similarity in design between the two spacecraft. One can argue that both teams worked through the engineering issues and arrived at the same conclusion. That is probably far from the truth.

The Space Shuttle design served both a civilian and military purpose. Preliminary design work began in 1968 with the official program launch in 1972. The first orbital flight took place in 1981. Right from the start the Shuttle was deemed both for civilian and military purposes. This did not go unnoticed in the Soviet Union.

With the Shuttle perceived as a formidable military asset, the Soviets responded, building one of their own. Work began in 1974. The Buran orbiter flew once in November of 1988 in what was deemed an almost flawless performance. It was unmanned and performed launch, orbital manoeuvres and landing perfectly. In 1993 the Russian government cancelled the program justifying it by stating that the Cold War was over and the need for Buran no loner existed. The truth was much simpler. The Russians could no longer afford the cost in the post-Soviet economic collapse.

Comparing the Shuttle and the Buran Orbiter

The Buran and Space Shuttle shared some commonalities. The Soviets freely copied many of the Space Shuttle’s design features, but they made significant improvements as well. They also took advantage of their heavy launch technology in using the Energia, a proven rocket system developed for the Mir program and capable of providing much greater thrust than the combined propulsion systems used for launching the Space Shuttle. A basic comparison of the two spacecraft highlights both the similarities and significant differences:

	Space Shuttle	Buran Orbiter
Dimensions & Weight	37.25 x 23.8 meters, 68 tons	36.37 x 23.92 meters, 62 tons
Cargo capacity	25,000 Kg	30,000 Kg
Launch Configuration	Side mounted to launch vehicle	Side mounted to launch vehicle
Propulsion	3 on-board engines used in lift off with secondary engines for in orbit adjustments. Main engine serves no purpose while in orbit or in descent.	Is a payload of the launch system with no rocket engine onboard; secondary propulsion systems for use in orbit and for descent.
Heat Shields	Ceramic Tile and Advanced Flexible Reusable Surface Insulation in areas where tiles not suited to fit the airframe	Quartz fiber ceramic tile with underlying refractory fabric, oxide and silicon fibre and organic compound coatings on lower heat prone areas
Launch Vehicle	2-solid rocket boosters mated to a central fuel tank connected to Shuttle engine; solid rocket boosters once ignited cannot be shut off – led to the Challenger explosion when an O-ring failed	Energia heavy lift multi-use rocket with 4 strap-on liquid-fuelled boosters; no mated fuel connection to the spacecraft; rocket and boosters capable of being shut down in flight in the event of an emergency
Reusability	Solid rocket boosters outfitted with multiple parachutes and reusable but central fuel tank is not	Entire launch system outfitted with multiple parachutes and retro rockets for soft landing and reuse up to 10 times
Fuel	Combination of solid rocket fuel in boosters and liquid fuel for main Shuttle engines – the failure of the O-ring was in the solid rocket booster causing a burn through on the Challenger	Liquid fuelled avoiding the potential problems associated with solid rocket boosters that led to the destruction of the Challenger
Passenger Safety Design Components	No crew ejection seats – if this feature was on Challenger at the time of the explosion the crew may have escaped; it would not have saved Columbia’s crew	Crew ejection seats from 50 meters to 35 km, capable of use up to Mach 4+; cockpit mounted on shock-absorbers to decrease vibration during flight
Powered flight in the atmosphere	None; Shuttle flew as a glider in the atmosphere	Two Turbojet engines to add stability in landing
Autonomous capability	Requires a flight crew to pilot and land	Remote control capability to land without crew involvement – the only flight of the orbiter was unmanned

The Space Shuttles with all of their design flaws flew for 30 years, from 1981 to 2011. Six were built. The first, Enterprise, never flew in space. Columbia first flew in 1981 and was lost on re-entry on its 28th mission in February 2003. Challenger first flew in 1983 and was lost shortly after launch in January of 1986, its 10th mission. Discovery first flew in 1984 and after 39 missions retired in 2011. Endeavour flew its first mission in 1992 and its 25th and last in 2011. And Atlantis flew for the first time in 1985 and was the last Space Shuttle to fly in 2011 on its 33rd mission. The Space Shuttles ferried 852 crew members into low-Earth orbit during the lifetime of the fleet, travelling more than 864 million kilometers (537 million miles) in 134 flights. The two failures resulted in the deaths of 14 astronauts.

In early missions the Space Shuttles were instruments of Cold War politics and a statement about American space technology. They were used to deploy satellites and do onboard scientific research and observation. Some were used for military missions. Two shuttle missions serviced and repaired the Hubble Space Telescope. Several missions visited Mir, the Soviet space station. And the balance ferried materials and crews to the International Space Station to ensure its successful completion. When the Space Shuttles retired the Cold War had transitioned to joint ventures between Russia, the United States and 16 other nations.

Our 21st century story in space can now begin.