The Falcon Launch Vehicle - An Attempt at Making Access to Space More Affordable, Reliable and Pleasant

Falcon is a mostly reusable, two stage, liquid oxygen and kerosene powered launch vehicle being built by Space Exploration Technologies (SpaceX) from the ground up. The vehicle is designed above all for high reliability, followed by low cost and a benign flight environment. Launched from Vandenberg, a standard Falcon can carry over 470 kg to a 700 km sun-synchronous orbit and a heavy Falcon can deliver 1450 kg to the same orbit. To minimize failure modes, the vehicle has the minimum pragmatically possible number of engines (two) and stage separation events (one), as well as dual redundant avionics. Since the first stage is recovered via parachute to a water landing, approximately 80% of the vehicle mass is reusable as compared with 90% for the Space Shuttle. The costs, which nominally assume no advantage for recovery, are $6M for a standard Falcon and$10M for a heavy Falcon. First launch is scheduled for January 22nd, 2004 from Vandenberg, carrying a US government satellite

Changing the Paradigm of Space Testing: The F.A.S.T. Program

The high cost of access to space is driven in part by a cost spiral -- higher costs lead to fewer missions which leads to a demand for higher reliability which leads to higher costs. One way to potentially break this cycle is to introduce the opportunity for rapid, low-cost experiments leading to a larger number of near term experiments which, in turn, should result in higher performance, greater reliability, and lower cost systems which will spur the demand for additional rapid, low-cost experiments. A program has been initiated to help bring this about, initially with suborbital flights and subsequently with orbital flights of small experiments and instruments. The first FAST experiment was flown on board a Scorpius SR-XM suborbital vehicle launched from White Sands Missile Range on March 9, 2001

Low-Cost, Minimum-Size Satellites for Demonstration of Formation Flying Modes at Small, Kilometer-Size Distances

In-flight demonstration of close-range formation flying modes is discussed with emphasis on low cost, based on spacecraft design simplicity and minimum size, and hence minimum launch cost. Piggy-back launch of three identical demonstration spacecraft is the preferred option. This demonstration includes comprehensive collection and analysis, on the ground, of relative motion data derived from GPS signals that are received by the participating satellites. In addition to realistically reflecting the known Keplerian and non-Keplerian characteristics as part of the flight dynamics analysis, an important concern is to demonstrate the less well-known effects of differential drag perturbations. These can be deliberately induced by small aerodynamic cross section variations on the satellites. Results of the demonstration mission will benefit currently projected and other future missions that require close-formation flying, e.g., radar and visual observation missions, by proving feasibility, assisting detailed and comprehensive operations planning, and helping diminish their potential risks

AttSim, Attitude Simulation with Control Software in the Loop

AttSim is a spacecraft attitude simulator that has been specifically developed to design and verify attitude control concepts and flight software architectures and algorithms. Its primary goal is to provide a generic approach to small satellite attitude control development by allowing scalable performance. AttSim specifically allows the user to develop software modules that can be used as flight code, and to verify control logic, controller gains, and other mission-critical elements. The code can be developed in a flight-like environment, allowing quick conversion to actual flight code for a target processor. In addition, AttSim can be used as a systems engineering tool to ensure correct torquer, wheel, and thruster sizing and sensor performance. AttSim allows derivation of subsystem requirements to meet attitude accuracy (pointing and stability) goals. Its use during all phases can help reduce development and verification time as well as cost and risk. Several missions have been developed to verify the AttSim system architecture and the cost savings associated with its implementation. The simulator\u27s performance has also been verified using actual mission data, showing the simulations deliver realistic data. Using this accelerated, integrated development approach for the attitude control system, small satellites can be developed at lower cost and risk