The Venture Star
A picture of a Venture Star
The series of X-planes made the most important advancements in aviation and space technology. For instance, the first supersonic flight was made by X-1, flown by Chuck Yeager. Now, 3 more X-planes are set to continue the pioneering tradition.
These 3 X-planes are the X-33, X-34 and the X-37. The X-33 is the main prototype for the replacement of the space shuttle, and it is ¾ done.
The X-34 was built to test technologies to reduce personnel, cost and time for space trips.
The X-37 was built to test some space plane technologies, such as re-entry
capability. The main focus of the X-33 project is to create the commercial successor to the space shuttle, called the Venture Star.
The proposed Venture Star will be twice the size of the present X-33.
There are 3 main differences between the proposed Venture Star and the space shuttle. Firstly, the space shuttle requires booster rockets and a large external fuel tank (both jettisoned before orbit) to achieve orbit. The Venture Star will eliminate these, encompassing the required within its own large frame. This will partly reduce cost, as these "extras" are costly (especially the unsalvageable fuel tank).
Secondly, the cost of putting the Venture Star into orbit is expected to be 1/10 the cost of putting the space shuttle into orbit. This is important, because each pound of payload in the space shuttle's cargo bay costs US$10,000 to be put up there. The lowered cost will thus enable it to be commercial viable. In fact, it may even be used as a space tourism vehicle.
Thirdly, the Venture Star uses a vastly different rocket engine from the space shuttle. The new Linear Aerospike engine is more suited for the aircraft's wedge-shaped frame than the conventional Bell rocket engine. The nozzle of the Aerospike is V-shaped, like a ramp, unlike the circular Bell nozzle.
The success or failure of this X-33 project will be the crux of the matter of putting the Venture Star into space.
Since the Venture Star is a fully reusable space vehicle, it will be able to deliver payloads to orbit much more reliably and less expensively. This will enable it to be financially viable for privately financed operations.
The Venture Star will be 15,2m long, 4,6m wide, 4,6m deep (50 x 15 x 15 feet). The target is to carry 25 000 kg (56,000 pounds) to low Earth orbit (LEO), and 8 000 kg (18,000 pounds) to geosynchronous transfer orbit (GTO), roughly equivalent to those of the Space Shuttle than today's launch vehicles. To reach Earth orbit, the Venture Star will have to reach Mach 25, that is roughly 25 times the speed of sound. This is the speed required for any space vehicle to maintain orbit.
The Venture Star will be using the Linear Aerospike engine. This is lighter than the conventional bell engine. This is because it does not use a heavy bell nozzle and steering systems for the nozzle. It also automatically adjusts to the changing atmospheric conditions as the vehicle climbs. Multiple combustion chambers on each engine also make it more failsafe.
The Venture Star was scheduled to make its maiden flight in 2004, however the project is 2 years behind schedule. However, NASA and Lockheed Martin have no intention of stopping the project.
In October 1999, Lockheed-Martin announced that they would redesign the Venture Star, which is to be the planned replacement for the current space shuttle. The new version has already been wind tunnel tested and should provide greater mission flexibility for the proposed re-usable vehicle."
We were still short in terms of internal packaging efficiency," Rising said. Too much fuel space was sacrificed for payload, he said. About 90 percent of the vehicle's mass must be fuel. "As we continued... the packaging efficiency was maximized by taking the payload bay out of the vehicle altogether," Rising said. "It did increase drag," Rising said, "[but] we're more concerned about stability and controllability. Drag is an issue of course, but with this vehicle, we're able to fly a lifting trajectory -- the maximum lift-to-drag ratio."
The payload bay may be made longer and wider, as it being outside the craft allows it to be safely extended and widened. This will also fit nicely with NASA's Crew Return Vehicle.
The redesigning has not and will not further prolong the development.
Pictures of the Venture Star