"Rubicon 1" Mission Description
Space Transport Corporation
August 5, 2004

Overview:

Rubicon, Space Transport Corporation's prototype Suborbital Tourism Vehicle is a simple "rocket-ship". It is powered by solid propellant engines and descends by parachute. Fins are the primary means of stabilization. Cold gas thrusters provide stabilization and guidance at low speeds. Patent is pending on this STC design.

In the upcoming supersonic flight, Rubicon 1 will carry 1000 pounds of the total 3500-pound solid propellant fuel capacity (2 of 7 engines loaded). Other than the fuel difference, Rubicon 1's systems will be identical to the systems for the full-altitude (100 kilometer / 62.1 mile) Rubicon with which STC expects to compete for the ANSARI X PRIZE.

Rubicon 1 will rocket to an altitude of 18,000 feet and a peak speed of 1100 mph. It will parachute to a splashdown two miles out in the ocean. The vehicle will be recovered by boat and returned to La Push, Washington.

Rubicon has an engine assembly, a passenger capsule, and a nose cone assembly. On the launch pad, the partially-fueled version will weigh 2500 pounds, including 600 pounds of ballast weight and three mannequins to simulate the ANSARI X PRIZE requirement. The vehicle is 23 feet long and is 38 inches in diameter.

Passenger Capsule:

The airtight/watertight passenger capsule is six feet long and 38 inches in diameter. A high-strength tubular steel structure supports the payload and withstands the powerful compressive force between the engine thrust and the nose cone drag. An onboard video camera will peer past the three mannequins through Rubicon's window, capturing their reaction to the view. Also contained in the capsule is the vehicle's electronics box. The box contains angular rate sensors, accelerometers, a GPS, a radio modem, and two microcontrollers (miniature computers).

Nose Cone Assembly:

The nose cone contains the Attitude Control System (ACS) and parachute systems. A carbon-fiber tank carries compressed air. The compressed air is routed to a regulator and then to six valves that control the air flow to eight thrusters. Four of the thrusters are located near the tip of the vehicle - these control "pitch" and "yaw". The remaining four thrusters are located at the base of the nose cone - these control the "roll" of the vehicle. The roll thrusters are fired in pairs such that an even roll torque is applied (this way, only two valves are needed for the four roll thrusters).

Engine Assembly:

The full-altitude Rubicon's main engine assembly will have seven 12-inch diameter solid propellant rocket engines, each 10 feet long and weighing around 600 pounds. Each engine carries 500 pounds of fuel. Six engines are in a ring configuration around a seventh central engine. Three fins are attached to the engines by aluminum collars.

STC has a patent pending on its solid rocket engine technology. The fuel is based on ammonium perchlorate, aluminum powder, and HTPB rubber. The Rubicon engine design has been verified by ground testing at STC. The engines use a carbon-fiber casing, rubber insulation, an aluminum bulkhead, and a simple graphite converging-diverging nozzle. The thrust of each engine is 2500 pounds at ignition, and builds to a peak of 14,000 pounds before rapidly dropping to zero after 14 seconds. The engines can be refurbished after each flight.

Rubicon 1 Mission Description:

Rubicon will be launched from a mobile launch trailer positioned near the coast of the Pacific Ocean. Launch rails, which support and guide the rocket, will be raised to the correct angle out towards the ocean. The vehicle guidance electronics will go through an automatic initiation procedure to determine orientation and position. Once the attitude control system is set, the engines will be ignited for liftoff.

Rubicon 1 will ignite its two engines for a total of 5,000 pounds of liftoff thrust. The ACS will steer the vehicle during low-speed flight when the vehicle could be turned significantly by a thrust offset between the two engines. Even with no ACS, the vehicle will maintain its course over the water. The fins become effective enough to control any thrust offset after five seconds of acceleration.

Peak speed at 13 seconds (near engine burnout) will be around 1,100 mph or Mach 1.4. The average G load will be around 5 G's. After around 45 seconds, the vehicle will have coasted to an apogee of about 18,000 feet. At this point, a drogue parachute will be deployed. The vehicle, which will be traveling like a dart - nose first - will be turned by the small drogue parachute to a tail first orientation, and slowed significantly. The 28-foot-diameter main parachute will then be deployed and will float the rocket to a 25 mph ocean splashdown about 2 miles off shore. Total flight time will have been around five minutes.

An STC boat team will be observing the launch from about 1 mile off shore. If it is not visibly obvious where it has splashed down, they will find the vehicle by GPS coordinates sent from the rocket. The boom of the 52-foot boat will be used to winch the rocket onboard and haul it back to La Push where the ground team will wait with the launch/transport trailer.

Full-altitude Rubicon Mission Description:

Full-altitude vehicles will ignite four engines for liftoff. Similar to the Rubicon 1 flight, the attitude control is required during low-speed flight. After burnout and a brief coast period, the remaining two outside engines will be burned. The central engine is fired last, when the vehicle is in thin air. This engine staging keeps the total acceleration on the pilot to a reasonable level. Total powered flight time is about 45 seconds. The average acceleration will be about 5 G's, but will peak to about 7 G's.

After the powered flight is over at 100,000 feet up, passengers will soon enter a state of weightlessness. The weightlessness will last a few minutes. During this time, the curvature of the Earth can be seen, a good portion of the United States will be visible, and stars can be seen during the daytime.

During atmospheric re-entry, the vehicle is not going fast enough to "burn up". However, there will be a 5-G deceleration as drogue parachute and full parachute are deployed, and the vehicle will descend to the ocean. Recovery will be the same as for Rubicon 1.

Rubicon's full-altitude flight will last ~25 minutes from takeoff to splashdown. The flight profile is a simple lob trajectory, but should be exciting enough for the average tourist!