Marti Sarigul-Klijn

Air-Launching Earth to Orbit: Effects of Launch Conditions and Vehicle Aerodynamics

Introduction T HE purpose of this study is to determine the benefits of airlaunching expendable or reusable launch vehicles (LV) by using quantitative methods. Air-launch vehicles consist of at least two stages, a carrier aircraft and a rocket-powered LV. The carrier aircraft can be either subsonic or supersonic capable and can even include balloons. Air launch is one of the leading concepts that can meet today’s launch requirements of both responsive and low cost. Previous work in this area has identified nonquantitative benefits and drawbacks of air-launch methods.1 In this Note, many different air-launch scenarios associated with different release, launch conditions, and vehicle aerodynamics are modeled and simulated using trajectory optimizations. The trajectory optimization is conducted using POST, a numerical integration program based on the three-degree-of-freedom equations of motion of a flight vehicle.2 More than 160 simulations were conducted in which launch altitude, speed, and flight-path angle were varied, and the effect of adding a wing was also modeled.

A Study of Air Launch Methods for RLVs

Many organizations have proposed air launch Reusable Launch Vehicles (RLVs) due to a renewed interest generated by NASA’s 2 Generation Space Launch Initiative. Air launched RLVs are categorized as captive on top, captive on bottom, towed, aerial refueled, and internally carried. The critical design aspects of various proposed air launch RLVs concepts are evaluated. It is found that many concepts are not possible with today’s technology. The authors introduce a new air launch concept that is possible with today’s technology called SwiftLaunch RLV.

Flight Mechanics of Manned Sub-Orbital Reusable Launch Vehicles with Recommendations for Launch and Recovery

An overview of every significant method of launch and recovery for manned sub-orbital Reusable Launch Vehicles (RLV) is presented here. We have categorized launch methods as vertical takeoff, horizontal takeoff, and air launch. Recovery methods are categorized as wings, aerodynamic decelerators, rockets, and rotors. We conclude that both vertical takeoff and some air launch methods are viable means of attaining sub-orbital altitudes and wings and aerodynamic decelerators are viable methods for recovery. These conclusions are based on statistical methods using historical data coupled with time-stepped integration of the trajectory equations of motion. Based on the additional factors of safety, customer acceptance, and affordability, we also conclude that the preferred architecture for a commercially successful manned sub-orbital RLV is Vertical Takeoff using hybrid rocket motor propulsion and winged un-powered Horizontal Landing onto a runway (VTHL).

Air Launching Earth-to-Orbit Vehicles: Delta V gains from Launch Conditions and Vehicle Aerodynamics

The advantages and disadvantages of the various methods for air launching expendable or reusable space launch vehicles are described. Many different air launch scenarios are modeled and simulated using trajectory optimizations. The trajectory optimization is conducted using POST, a numerical integration program based on the three-degree-of-freedom equations of motion of a flight vehicle. Results in terms of change in velocity gains are reported as a function of launch conditions and launch vehicle aerodynamics. Air launch benefits are presented for a range of air speeds, altitudes, and flight path angles. The most beneficial launch vehicle parameters are in the following order; launch velocity, launch flight path angle, and launch altitude. Increasing launch vehicle size had the largest effect on payload size. There is an optimum launch flight path angle that maximizes the benefit from air launching. The results show that once above about 15000 meters (49,200 feet), added launch altitude has little additional benefit. Nomenclature Ae = Nozzle exit area = Angle of attack β =

Selection of a Carrier Aircraft and a Launch Method for Air Launching Space Vehicles

Marti Sarigul-Klijn 1 Ph.D. and Nesrin Sarigul-Klijn Ph.D. Mechanical and Aeronautical Engineering Department, University of California, Davis, CA 95616-5294 Gary C. Hudson and Bevin McKinney AirLaunch LLC, Kirkland, Washington, 98033 Jim Voss and Phil Chapman Transformational Space Corp, Reston, Virginia, 20190 Bob Morgan, Jim Tighe, and Jason Kramb 7 Scaled Composites LLC, Mojave, California, 93501 Ken Doyle and Mike Quayle Protoflight LLC, Mojave, California, 93501 and Charlie Brown Space Vector Corp., Chatsworth, California, 91311

Flight testing of a new earth-to-orbit air-launch method

This paper describes the development and flight testing of a new air-launch method for safely launching personnel and cargo into low Earth orbit (LEO). A new rocket is also being designed that will be carried by and launched using the new air-launch method from a modified 747 airliner. This new air-launch method, called trapeze-lanyard air drop (t/LAD) launch, will greatly improve simplicity, safety, cost, and reliability of launching personnel into LEO. A t/LAD launch eliminates the need for wings or fins on the launch vehicle; greatly reduces ascent dynamic pressure, sideways accelerations and bending forces, and rocket engine thrust vectoring control; and allows the use of a simple and very safe vapor pressurization (Vapak) engine cycle for the launch vehicle. This paper reports on the flight-test results of dropping three 23%-scale drop test articles using the t/LAD launch method.

Trade Studies for Air Launching a Small Launch Vehicle from a Cargo Aircraft

This paper describes the concept trade studies that AirLaunch LLC conducted during their Phase I study for air launching an earth-to-orbit launch vehicle for the DARPA/USAF FALCON program. AirLaunch LLC has proposed a rocket carried by and launched from an existing military cargo aircraft for this program. A new method, called Gravity Air Launch (GAL), is proposed that greatly improves simplicity, safety, and reliability of air launching from an unmodified cargo aircraft as compared to existing methods that rely on standard heavy equipment airdrop procedures and equipment. Unlike standard airdrop methods, GAL imparts much of the carrier aircrafts altitude and airspeed onto the rocket, which in turn improves payload mass to orbit.

Flight Testing of a New Air Launch Method for Safely Launching Personnel and Cargo into Low Earth Orbit

This paper describes the development and flight-testing of a new air launch method for safely launching personnel and cargo into Low Earth Orbit (LEO). Transformational Space Corporation LLC (t/Space) has proposed a rocket carried by and launched from either a modified 747 airliner or from a custom aircraft to be designed and built. A new air launch method, called Trapeze-Lanyard Air Drop (t/LAD) launch, is proposed that greatly improves simplicity, safety, cost, and reliability of launching personnel into LEO. A t/LAD launch eliminates the need for wings or fins on the launch vehicle; greatly reduces ascent dynamic pressure, sideways accelerations and bending forces, and rocket engine thrust vectoring control; and allows the use of a simple and very safe vapor pressurization (Vapak) engine cycle for the launch vehicle.

Flight Testing of a Gravity Air Launch Method to Enable Responsive Space Access

AirLaunch LLC is developing a small launch vehicle (SLV) called QuickReachTM that is carried by and launched from an existing military cargo aircraft for the Defense Advanced Research Projects Agency (DARPA) and USAF Falcon SLV program. One purpose of the QuickReachTM development program was to demonstrate AirLaunch’s innovative Gravity Air Launch (GAL) method. Three inert Drop Test Articles (DTA) were successfully dropped from three separate C-17A aircraft onto the Edwards flight test center range to demonstrate GAL. The DTAs were water filled steel tanks with the same outer mold line, stiffness, and mass properties as the actual QuickReachTM launch vehicle. The overall length and weight of the QuickReachTM rocket exceeded those of any single item previously airdropped from a C-17A aircraft. In addition, the airspeed required for the GAL airdrop was significantly higher than the standard airdrop speed. As a result of AirLaunch’s successful GAL program, the envelope of the C-17A aircraft was expanded to handle drops of objects nearly 66 feet in length and 72,000 pounds in weight. This paper describes AirLaunch’s successful GAL flight test program as demonstrated under the Falcon SLV program.

Concept and Design Details of a Universal Gas-Gas Launch Escape System

Human space exploration vehiclesmust be designedwith a reliable and safe launch escape system to be activated in the event of a failure on the pador at altitude.A safe, reliable, highlyflexible, and adaptable launch escape system that can be used with most proposed commercial space capsules was conceived after conducting propulsion and configuration trade studies. The outcome of these studies is a novel gas–gas propulsion system with a tractorconfiguration-based launch escape system. Preliminary design of this joint universal launch escape and assist system is detailed. It is designed to accelerate a crew capsule away froma launch vehicle in case of an emergency on the pador during the early portions of the trajectory at up to approximately 300,000 ft of altitude. It is designed to tractor the spacecraft to a sufficient altitude andwith enough downrange translation so that the parachute landing system of the capsule can safely function. During midand high-altitude aborts, a reentry gravity-reduction mode of this novel escape system can start and stop its high-pressure gaseous oxygen and gaseousmethane engines and can direct thrust in such a way as to shape the reentry trajectory to reduce the abort reentry deceleration. Finally, it has an ascentassistmode that can be used to offset the normal payload penalty in the event that the emergency abort function is not used.