Micrcosm's Scorpius / Sprite

Microcosm, Inc. of El Segundo, California, is developing the Scorpius family of ELVs. Several prototypes are under consideration or in testing, and two suborbital test models, SR-S and SR-XM-1, flew successfully from White Sands Missile Range, New Mexico, in 1999 and 2001, respectively. Eventually Microcosm plans to market up to eight Scorpius variants: two suborbital vehicles, the SR-S and SR-M launchers; three light-lift orbital vehicles, the Sprite Mini-Lift, the Eagle SLV, and the Liberty Light-Lift launchers; one intermediate-lift orbital vehicle, the Antares Intermediate-Lift launcher; one medium-lift vehicle, the Exodus Medium-Lift launcher; and one heavy-lift vehicle, the Space Freighter. Despite the wide range in their sizes and lift capacities, each Scorpius variant is based on a scaleable modular design featuring simple LOX/Jet-A pressure-fed motors without turbopumps and low-cost avionics equipped with GPS/INS (global positioning system/ inertial navigation system). The orbital variants are three stages and feature thick fuel tanks for added durability during flight.

The Scorpius system is designed simply in order to maximize the cost savings and quick launch pad turnaround times sought by government-sponsored responsive space initiatives. As a first step, the test launches of the suborbital SR-S and SR-XM-1 vehicles demonstrated Scorpius' ability to be ready for flight within 8 hours of arrival at the launch pad, using a crew of under 15. When marketed, the SR-S vehicle is advertised as able to loft 200 kilograms Eagle SLV (440 pounds) suborbitally. The SR-M would loft 1,089 kilograms (2,400 pounds) suborbitally.

The Sprite Mini-Lift vehicle is projected to loft up to 318 kilograms (700 pounds) to LEO. Eagle SLV would loft up to 667 kilograms (1,470 pounds) to LEO. The Liberty Light Lift vehicle would loft up to 1,270 kilograms (2,800 pounds) to LEO. Microcosm's intermediate-, medium-, and heavy-lift Scorpius variants will be able deploy payloads to LEO and GTO. The Antares Intermediate-Lift vehicle will be able to deploy up to 2,676 kilograms (5,900 pounds) to LEO and up to 885 kilograms (1,950 pounds) to GTO. The Exodus Medium-Lift vehicle would deploy up to 6,713 kilograms (14,800 pounds) to LEO and up to 2327 kilograms (5,130 pounds) to GTO. Specifications for the heavy-lift Space Freighter are not yet available.

Of the Scorpius variants, the Sprite Mini-Lift and Eagle SLV are furthest along in development. Microcosm currently plans test flights for one or both of those vehicles in the third quarter of 2007.

One possible contender for an Operationally Responsive Spacelift job is Micorcosm's Sprite Mini-Lift Launch vehicle. Research for the ongoing Scorpius-Sprite program is funded by the Air Force and the Missile Defense Agency, and NASA as well as Microcosm's own research and development funds.

Scorpius, the sub-orbital research vehicle, has already flown and will be scaled up to become the fully orbital Sprite. Microcosm estimated the Sprite could be developed in three years at a cost of $90 million. Sprite's per-launch cost could be about $2.5 million, but other estimates peg the price at about $5 million. The estimated $5 million price tag for Sprite launches is less than a third of what it costs to launch a Pegasus.

The Sprite will be 53 feet tall and consist of six 42-inch diameter pods around a central core giving it an an overall diameter of 11.2 feet. It will be a three stage launcher with six 20,000 lb thrust engines followed by a second stage single 20,000 lb engine. Its first two stages would be powered by a common set of engines fueled by liquid oxygen and kerosene. The first stage would have six such engines; the second stage, one. The third stage will produce 2,500 lbs of thrust and place a 700 lb payload in a 100 NM low Earth orbit for $1.8 million. A primary goal is to simplify launch operations so that liftoff occurs only 8 hours after the vehicle is brought to the pad.