XCOR Aerospace: Lynx Suborbital Vehicle

The Lynx is XCOR’s entry into the commercial reusable launch vehicle (RLV) market. This two-seat, piloted space transport vehicle will take humans and payloads on a half-hour suborbital flight to 100 km (330,000 feet) and then return safely to a landing at the takeoff runway.

Like an aircraft, Lynx is a horizontal takeoff and horizontal landing vehicle, but instead of a jet or piston engine, Lynx uses its own fully reusable rocket propulsion system to depart a runway and return safely. This approach is unique compared to most other RLVs in development, such as conventional vertical rocket launches and air-launched winged rocket vehicles “dropped” at altitude from a jet powered mothership.

The Lynx aircraft-like capabilities allow high tempo operations, up to four (4) flights per day, rapid call-up, fast turnaround between flights, low cost operations and maintenance (O&M), and a focus on safety and reliability.

Lynx has an all-composite airframe that makes it lightweight and strong. With an added thermal protection system (TPS) on the nose and leading edges it is able to handle the heat of re-entry from the edge of space. The wing area is sized for landing at moderate touchdown speeds near 90 knots. Lynx is about 9 meters (~30 feet) in length with a double-delta wing that spans about 7.5 meters (~24 feet).

Using the same concept of operations (CONOPS) as XCOR’s earlier rocket-powered vehicles, we have learned much about how to operate the Lynx, even though it has higher performance than our EZ-Rocket and X-Racer. From the EZ-Rocket we learned how to 1) develop a safe, reliable, and reusable propulsion system and integrate it into an airframe, 2) implement low cost, efficient, and safe operational procedures, and 3) work with the regulatory process. Building the X-Racer enabled us to 1) fly a previously designed and matured piston pump in a high performance rocket plane application, 2) improve low cost operations and safety regime processes, and 3) increase knowledge and skill sets for systems integration (airframe, avionics, and propulsion).

As with any production aircraft development program, XCOR has planned a Lynx prototype named the “Mark I” and a production model called the “Mark II.” The Mark I is expected to begin flight test in early 2011. Flight of the first Mark II will follow approximately nine to eighteen months later depending on the prototype’s advancement through the test program.

XCOR’s development, design, and tests focus on a cycle of vehicle safety, reliability, and low cost operations, which is: safety comes from reliability, reliability comes from flying frequently, and flying frequently happens with low cost. The more we fly, the safer we’ll be in the long run, and the cycle repeats itself.

Lynx propulsion will come from four XR-5K18 rocket engines, each producing 12.9 kN (2900 lbf) vacuum thrust with kerosene and liquid oxygen propellants. Engine detail design began in autumn of 2008 and the first hot fire test was conducted on 15 December 2008.

Lynx will be operated as an FAA AST-licensed suborbital reusable launch vehicle. XCOR already has successfully passed the AST licensing process with an earlier vehicle concept, and we have been actively involved in the development of the statutory and regulatory framework within which Lynx will operate. Lynx will have aircraft-like operations up to four times per day from any licensed spaceport with a 2,400 meter (7900 ft) runway, suitable abort options, fast turnaround (two hours), low maintenance intervals (designed for 40 flights before preventive maintenance action), and low cost operations. Lynx operates under visual flight rules (VFR), and initially it will only fly during days of good visibility. Mojave Air and Space Port, the planned first operating location for Lynx, has good visibility 360 days per year and acceptable winds 345 days per year.

The Lynx will offer several multi-mission primary and secondary payload capabilities including: in-cockpit experiments, externally mounted experiments, test pilot/astronaut training, upper atmospheric sampling, microsatellite launch, ballistic trajectory research, and personal spaceflight (space tourism). “Primary” payloads pay for the flight, while “secondary” payloads are on a ride-share basis with a primary payload, typically for a nominal ride-share fee.

Lynx vehicles will carry primary payloads located in the area to the right of the pilot or on the top of the vehicle in an experiment pod. Secondary payloads will be carried in a variety of locations. For Mark I, the primary internal payload will accommodate a maximum mass of 120 kg (265 lbs) to 61 km (200,000 ft). This “right seat” can be a human in a pressure suit, two stacked Space Shuttle middeck lockers (MDLs), or a standard 19 inch electronic equipment rack. The other primary payload location is an external dorsal mounted pod, which holds up to 280 kg (617 lbs). This pod can carry experiments that return with the vehicle or a single upper stage that is launched to a high altitude, long duration suborbital trajectory of 700 km (435 miles) and 11 minutes of microgravity exposure. Secondary payload spaces include a small area inside the cockpit behind the pilot or outside the vehicle in two areas in the aft fuselage fairing (see image below). Detailed specifications of the payload spaces can be found in the Lynx Payload Users Guide.


	Lynx External Payload Locations - Click to Enlarge		Lynx Cabin Payload Locations - Click to Enlarge

The primary internal payload mass of the Mark II is the same as the Mark I at 120 kg (265 lbs), but will achieve higher performance indicating more than 100 km (approximately 330,000 ft) altitude and Mach 3.5 capability. The Mark II external pod can house primary payloads up to 650 kg (1433 lbs) and is large enough to hold a two stage carrier to launch a microsatellite or multiple nanosatellites into low Earth orbit. The Mark II will also have the same secondary payload carrying capabilities as the Mark I.

The Lynx Experience for a Participant

The View at Apogee from Lynx participant seat

A spaceflight participant will sit to the right and just aft of the pilot. Lynx will have a pressurized cabin, and pilot and participant will wear full pressure suits during flight for safety in case of an emergency. The pressure suit is custom designed for XCOR by Orbital Outfitters, who have built in some of the most highly advanced features ever found in an emergency pressure suit.

Prior to a Lynx flight, potential spaceflight participants will go through a screening process, which will take place over five days and four nights and includes familiarizing the participant with all aspects of the suborbital flight experience. To make their flight safer and more enjoyable, spaceflight participants will engage in medical screenings, seminars, altitude chamber training, and a g-force experience.

Watch the Lynx Experience Video:

Mar	APR	May
	30
2009	2010	2011