By Brad Eckhardt, Lockheed Martin Space Operations, Houston, Texas|
Laith Zori, Fluent Incorporated, Lebanon, New Hampshire
The use of computer simulation to help build it right the first time is one major reason why the estimated costs of building the X-38, also known as the “lifeboat” for the International Space Station, are less than one-tenth the cost of previous space vehicles. In one typical example, Lockheed Martin engineers are using CFD software to ensure the effectiveness of the climate control system of the space vehicle. The engineers built a computer model of the X-38 and its contents, and used CFD to simulate the airflow and heat transfer throughout the vehicle’s cabin, eliminating the costs of building and testing a physical prototype. Preliminary simulations showed some areas with potential ventilation problems due to equipment blocking airflows.
NOTE: The X-38 project is currently suspended and is under review as a result of funding issues associated with the International Space Station (ISS).
The X-38 is designed for use on the International Space Station (ISS) as an emergency crew return vehicle (see Figure 1.). It is for this purpose that the term "lifeboat" is used. One of the goals of the X-38 program is to build a human spacecraft for an order of magnitude less cost than ever before. In the late 1980’s, prior to the X-38, one crew return vehicle project was estimated to cost as much as 2 billion dollars. The X-38 project is expected to build and test fly two prototypes in space for 90 million dollars. Several factors will contribute to the reduced cost. For example, the X-38 uses a lifting body design derived from the U.S. Air Force's X-24A experimental project in the mid-1960’s. Additionally, parts of the X-38 will be bought over the counter, using existing, rather than newly designed technology - a marked difference from past NASA spacecraft.