Suborbital flight / The spacecraft

The Rocketplane is a refined aircraft with an impressive length of 43 feet and a diameter of 5 feet. Just like any spacecraft which can take off on its own thrust, the Rocketplane has two types of power – jet power and rocket power.

The Rocketplane needs kerosene for fuel and liquid oxygen for combustion. When in acceleration phase, it is propelled by a rocket engine and uses liquid oxygen for fuel. Its landing area should normally be same as the one for take-off. Both turbo-jet engines will be activated in the last portion of the flight. Top speed hovers around Mach 3.5. 

With only four seats, it can not accommodate many tourists, not at this stage of development anyway. The design is for suborbital flights which can reach an altitude of 330,000 feet or 62.5 miles (100 kilometres). What is so great about this spacecraft is that it requires no assistance for launch – it uses the turbo-jet engines for take-off. The rocket engine is turned on at an altitude of about 25,000 feet and is shut off at about 150,000 feet. In its propulsion phase, the astronaut-pilot and passengers will feel about 3 to 4 G’s. At the end of propulsion phase, a few minutes will go by in weightlessness.

The Rocketplane XP utilizes the conventional aircraft technology with the basic conception of a Learjet 25 modified to meet the requirements for a suborbital mission. A RS-88 rocket engine, built by Rocketdyne, uses liquid oxygen for fuel and the thrust pushes the spacecraft on a trajectory similar to a ballistic missile.

When the rocket engine ends its thrust at about 150,000 feet, it keeps its momentum toward its peak or final altitude of 330,000 feet. Re-entry is then started, decelaration at 20,000 feet. Jet engines are turned on to bring back the XP spacecraft to the landing field.  The complete flight time from takeoff to landing is about an hour.

The craft’s total operating weight is around 18,500 lbs. This includes the fuselage, the propulsion section (jet and rocket engines), payload and all fuel needed for the flight. Craft’s weight without fuel and payload is approximately 8,500 lbs. The interior of the cabin (for the crew and passengers) is designed to maintain 10 P.S.I. (pounds per square inch) which is lower than the 14.7 P.S.I. at sea level. This lower atmospheric pressure reduces stress on the fuselage; oxygen is slightly reduced to limit the possibility of fire hazard.

Aluminium is mostly used for the fuselage, support structure, new wing design and vertical tail wings which are being built now. The leading edge slats and engine penetration cones are made of titanium. The internal components of the jet engines and rocket are made of high temperature resistant steel alloys.

Beside the titanium and other high temperature resistant steel alloys, a special high emissivity thermal protection is added. This thermal protection was developed by NASA Ames Research Center and commercialized with the help of the NASA Technology Transfer program. It is a perfect solution to fulfill the needs of the spacecraft’s Thermal Protection System (TPS). The main ingredient is made of liquid quartz, applied on the surface like paint and oven dried. Through every thermal cycle on re-entry, the heat bakes the paint a little more which transforms it into a long lasting coating.

The craft itself is used for commercial and military means. It can carry up to 900 pounds of payload. Interval between missions is estimated to be every 3 to 5 days.

Combined with the help of a conventional aircraft design, we believe the Rocketplane is in perfect position to become ‘’the’’ first company to bring the very first commercial tourists in space.