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

Sarigul‐Klijn, Nesrin; Sarigul-Klijn, Marti; Noel, Christopher W.

doi:10.2514/1.8634

Cited by 31 publications

(8 citation statements)

References 2 publications

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“…The launch vehicle is released almost horizontally from the carrier aircraft and its engine is ignited a few seconds later once the carrier aircraft has moved away. The flight begins with a pull-up maneuver [75,76] targeting the optimal flight path angle for the subsequent ascent at zero angle of attack. The kinematics conditions for the Pegasus vehicle are recalled here after [8,36,67,73].…”

Section: Extension To Optimal Pull-up Maneuver Problem (P a )mentioning

confidence: 99%

Geometric optimal control and applications to aerospace

2017

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This article deals with applications of optimal control to aerospace problems with a focus on modern geometric optimal control tools and numerical continuation techniques. Geometric optimal control is a theory combining optimal control with various concepts of differential geometry. The ultimate objective is to derive optimal synthesis results for general classes of control systems. Continuation or homotopy methods consist in solving a series of parameterized problems, starting from a simple one to end up by continuous deformation with the initial problem. They help overcoming the difficult initialization issues of the shooting method. The combination of geometric control and homotopy methods improves the traditional techniques of optimal control theory. A nonacademic example of optimal attitude-trajectory control of (classical and airborne) launch vehicles, treated in details, illustrates how geometric optimal control can be used to analyze finely the structure of the extremals. This theoretical analysis helps building an efficient numerical solution procedure combining shooting methods and numerical continuation. Chattering is also analyzed and it is shown how to deal with this issue in practice.

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Section: Extension To Optimal Pull-up Maneuver Problem (P a )mentioning

confidence: 99%

Geometric optimal control and applications to aerospace

2017

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“…But the railgun is an intrinsically very high-power device (30-1000 TW in proposed configurations). Such power levels impose weight penalties for the structural and energy storage materials, as well as the distribution and dissipation elements, making orbital [41,44] railguns uneconomic. Railgun devices in [3] are capable of launching 0.3 kg payloads with speeds 4-10 km/s (realistic with existing technology), but the launcher itself is likely to weigh more than 300 tons (because at least 200 tons are needed for capacitors alone), with a 5,000-ton weight being a more likely estimate.…”

Section: Overview Of Previously Proposed Lasmentioning

confidence: 99%

“…Reference [40] proposes a solution for an air launch system based on exotic propellant chemistry. Reference [41] finds that the delta-v advantage of launching from 30 km altitude is 700 m/s and optimal angle between launch angle and horizontal is close to 30%, while vertical launch from 30 km altitude gives 500 m/s delta-v reduction to reach the LEO.…”

Section: Overview Of Previously Proposed Lasmentioning

confidence: 99%

“…References [40,41,45] estimate the delta-v saving due to using air launch to be 750 m/s to 1000 m/s for the subsonic carrier aircraft. This delta-v reduction translates to 28% rocket weight reduction for solid-fuel rocket or 19% rocket weight reduction for the LH2/LOX rocket according to rocket equation [46] have also reported 25% rocket dry weight reduction with the subsonic launcher aircraft carrying LOX/LH2 rocket.…”

Section: The Critic Of the Air Launch Conceptmentioning

confidence: 99%

See 1 more Smart Citation

A Low-Cost Launch Assistance System for Orbital Launch Vehicles

Nizhnik¹

2012

International Journal of Aerospace Engineering

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The author reviews the state of art of nonrocket launch assistance systems (LASs) for spaceflight focusing on air launch options. The author proposes an alternative technologically feasible LAS based on a combination of approaches: air launch, high-altitude balloon, and tethered LAS. Proposed LAS can be implemented with the existing off-the-shelf hardware delivering 7 kg to low-earth orbit for the 5200 USD per kg. Proposed design can deliver larger reduction in price and larger orbital payloads with the future advances in the aerostats, ropes, electrical motors, and terrestrial power networks.

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“…However, most air-launch studies consider the use of aircraft [19][20][21][22][23]. Due to the lack of previously published analyses of optimization concerning balloonlaunched low-altitude sounding rockets, this paper has the aim of showing such a close-to-optimal rockoon configuration in terms of commercial use.…”

Section: Introductionmentioning

confidence: 99%