AlAA, 99-4803 From Leo. to th.e Planets Using Waveriders ‘. A. D. McRonald,J1 E. Randolph., Jet PropulsionLaboratory CaliforniaInstitute of Technology. M.‘J. Lewis Universityof Maryland E. p. Bbnfiglio,J:Longuski .- PurdueUn iversity I’ P.Kolodziej NASA-AmesResearch Center th International’ Space Planes and Hypersonic Systems arid Technologies Conference. and _ 3rd Weakly Ionized-Gases Workshop l-5. November 1’999 Norfolk, VA For permiss/on to copy or republish, contact the American Institute of Aeronautics and Astronautics 1801 Alexander Bell Drive, Suite 500, Reston, VA 20191 (c)l999 American Institute of Aeronautics & Astronautic‘s or publisher! with permission of author(s) and/or authdr(s)’ sponsoring organization. t i AIAA-99-4803 . FROM LEO TO THE PLANETS USING WAVERIDERS A. D. McRonald, J. E. Randolph Jet PropulsionLaboratory California Institute of Technology. M. J. Lewis University of Maryland E. P. Bonfiglio, J. Longuski PurdueUniversity P.Kolodziej Ames ResearchCenter ABSTRACT control surfaces, along with engines and propellant to escapefrom Earth, Other advantagesof this A revolution& interplanetary transportation techniqueover normalinterplanetary delivery methods techniqueknown as Aero-Gravity Assist (AGA) has will be discussed. beenstudied by JPL and others to enablerelatively, short trip times betweenEarth andthe other planets. INTRODUCTION AND BACKGROUND It takes advantageof an advancedhypersonic vehicle known as a waverider that uses its high lift to fly The idea to employ the terrestrialplanets as an energy through the atmospheresof Venus and Mars to sourceusing aero-gravity-assist(AGA) maneuversto provide exceptionally large velocity changesusing significantly increasethe velocity of interplanetary gravity-assist maneuvers. The concept has been spacecraft was first discussed for the Stat-probe understudy in a joint programbetween JPL and the mission to the sun] in 1982. Some preliminary University of Maryland for almost a decade. More -analyses were then completed by Longuski2 that recentlyPurdue University andNASA Ames Research suggestedthe necessity of a very high performance Centerhave also become partners. The waverider aerodynamicvehicle having a lift/drag (L/D) ratio of concepthas been proposed as an upper stagevehicle almost 10. This high performanceat the extreme compatible with the ‘LockheedMartin Venture Star Mach numbersnecessary for AGA maneuversseemed SST0 vehicle. This integratedvehicle conceptcould unattainableat that time and the concept was not be used to launch spacecraft on interplanetary pursued. In the mid 198Qswe becameaware of an missions. The paper will discuss the mission aerodynamicvehicle concept introduced by Nonweiler possibilities enabledby a waveridervehicle as well as in the 1950~~which had beenunder study for some the necessarydevelopment program. time at the University of Maryland.4 The first public presentationofsfhe AGA conceptwas made in 1989 Flight durationsto various destinationsin the solar by McRonald and soon thereafterthe connection systemcan be reducedby largefactors (e.g.,2-5 times between the AGA conce t and waveriders was shorterduration). The paper will presentresults of publishedby Lewis, et al7H) ’ from the University of recent studies of interplanetary and atmospheric Maryland. This began a lengthy collaboration trajectories to many bodies, with navigation errors betweenJPL andthe University of Maryland, which andmake-up, of velocity loss at eachAGA maneuver. is ongoing today, and representsthe nucleus of the Vehicle design includes possible ablation of heat teamthat continuesto pursuethe AGA idea for future shield material, andpossible location andnature of interplanetarymissions. A.D. McRonald is a SeniorMember of the Technical Staff, J.E. Randolphis the Study Managerfor the Solar Probe,both at JPL, California Institute of Technology. M.J. Lewis is a Professorin the Department of AerospaceEngineering, University of Maryland,E. P. Bonfiglio is now a Member of the Technical Staff at JPL, and was. previously a graduatestudent of ProfessorJ.Longuski, who is at the School d Aeronauticsand Astronautics, Purdue University, and P. Kolodziej is a Member of the Technical Staff at NASA Ames ResearchCenter. The researchdescribed in;this paperwas carried out by the .Jet Propulsion Laboratory,California Institute of Technology, under a contractwith the National Aeronauticsand Space Administration. The paperis to be presentedat the AIAA 9th InternationalSpace Planes and Hypersonic Systemsand Technologies Conference at Norfolk, VA on November 1-5, 1999. Copyright 1990by the American Institute of Aeronauticsand Astronautics,Inc. The U.S. Governmenthas ’ a royalty-freelicense to exerciseall rights underthe copyright claimed herein for Governmentalpurposes.. All otherrights arereserved by the copyright owner. 1 (c)1999 Ayerican Institute of Aeronautics & Astronautics or published with permission of author(s) and/or author(s)’ sponsoring organization. .. More recent publications 9*10”’ document detailed Figurei 1 illustrates a planetary waverider:launched to . investigations of actual AGA trajectories.to various HE0 on a Delta II 7925 or carriedto ’ LEO on the planets. Also, new analyses of specific waverider Venture Star. In both cases the waverider would designsappropriate to CO2 atmospheres(e.g., Venus. havea LH-LOX linear aerospikeengine to producea and Mars) have led to more optimized waverider C3,of ,over50 km2ls2, entailing a delta-V of over 5.2 shapes.A model waveriderbased on thesewas tested km/s from LEO and over 2.0 km/s beyondthe Delta in 1993and the results ‘s were very well predictedby from HEO. the analytical codes. WAVERIDER DESIGN Beginning in 1997, NASA first directly fundedthis research.This led to the formation of an AGA team Waveridersare supersonicshapes in which the bow consisting of Mark Lewis at the University of shockwaveis directly attachedto the leading edge. Maryland, JamesLonguski andEugene Bonfiglio of This meansthat all of the flow that passesthrough Purdue University; and Angus McRonald, James the shockwave on the lower lifting part of the Randolph,and Robert Miyake at JPL. One of the waverideris containedbelow the .waverider.This has more significant productsof this team effort was the the benefit of producing a generally high value ‘of developmentof a more’ detailedparametric. “ mission availablelift/drag ratio (L/D) at high Mach numbers space”for AGA trajectorieswithin the solar system with lhigh lift, and reducing cross flow and non- using a new computer code. A program called uniformities on the compressionsurface. STOUR14had been developed to parametricallystudy interplanetary . trajectories with gravity assist Wavetiderswere first definedby Nonweiler.’ They maneuversat intermediateplanets. This program was are generatedby starting with a known flow with a modified by the team membersat Purdue University given shockwave; a stream surface parallel to the to incorporateAGA maneuversat each intermediate direction of flow under the wedge is selected to planet. The resulting new code (STOUR-AGA) representthe- lower surface of the waverider. The’ formed the basis for a. Master’s thesis at Purdue by intersection of that lower surface and the original Bonfiglio.‘*. This new program has been used to shockwavedefines the leading edgewith an attached explore in detail the parametrictrajectory spacethat shockwave.This whole process works becausethe exists for the AGA conceptas a function of launch flowfield is mathematically hyperbolic, so that the energy, waveriderL/D ratio, and which’ intermediate carved-outsection which forms the waveridersurface, planets will be chosen for a near optimum AGA representingperhaps a small portion of the original trajectory to a destination. flowfield, still retains the propertiesof that flowfield even:though the generatingbody has been ignored Another teaming relationship has recently developed oncethe waverideris defined. .asa result of a new NASA initiative that has formed an Aeroassist Team composedof members from the Other generatingbodies can also be used as the NASA centers who are developing a future starting point of the waverider flowfield design technologyplan for aeroassisttechnologies, including process.Conically-derived waveriders have been used the AGA technology. As a result of this initiative, a extensively because they tend towards higher new group from NASA Ames Research Center volumetric efficiency than the wedge-derivedforms. (ARC) has beenadded to our AGA team. Members Combinations of cones and wedgeshave also been of this group bring to the team expertisein high exploredfor creatingthe generatingflowfield. ’ For a temperaturethermal protection systems (TPS) and given flight Mach number, both the wedgeand cone- I materials,as well as an experiencein flight testing of shapedforms have only one degreeof fresdom: the aerodynamicentry systems. The new materials that oblique surface-angle. Burnett and Lewis showed are underdevelopment as part of the SHARP program that conically-derivedshapes can also be optimized at ARC promise to perform well in the extremeTPS with volumetric considerations,to produce vehicle environmentof AGA maneuvers. forms that strike an acceptablecompromise between aerodynamicsand packaging, and with realistic, This paper will include the latest results from the roundedleading edges. In fact, nearly any shapethat waveriderconfiguration designs from Maryland, the has associatedwith it a shockwave and supersonic parametric trajectory studies,from Purdue, the TPS downstreamflow