JOURNA SPACECRAFF LO ROCKETD TAN S Vol. 30, No. 5, September-October 1993 Evaluation of the National Launch System as a Booster fortheHL-20 James B. Duffy* Rockwell International, Huntsville, Alabama 35806 and Jack W. Lehnert and Bill Pannell$ NASA Marshall Space Flight Center, Alabama 35812 e capabilitTh proposea f yo d national launch system (NLS booso )t e personneth t l launch system (PLS) manned vehicl bees eha n examined referencA . configurationS eNL NLS-e th , stag5 21. e vehicle referenca d ,an e HL-20 PLS configuration were used for the study. Performance has been analyzed for several PLS insertion orbits to support the Space Station Freedom resupply mission. The reliability of the NLS launch vehicle and its contribution to crew safety requirements have been determined. The launch-processing and launch facility requirement thesf so e combined systems were also analyzed. Previous studie thesf ssystemo o etw s have focused o mannenS eithePL e drth elemenlauncS NL hr t o vehicle . This paper combine resulte sth priof so r studien a n si analysi integratee th f so d NLS/PLS configuration. This analysi founs sha proposee stag 5 dth 1. eS launcdNL h vehicle to be an excellent booster for the PLS. Predicted performance margins for this launch-vehicle configura- tion are more than adequate, and acceptable reliability and safety levels are anticipated. Integration of this NLS/ PLS configuration into NASA mixed-fleet launch architectures is feasible. Introduction This paper documents some of the work that is applicable to the TUDIES of next-generation manned launch systems that question of NLS as a manned launch vehicle booster. The work S augment or even replace the NASA Space Shuttle have identi- represents analyses publishe e baseth n do d resultS botf PL so e hth fied several promising options. Amon candidate gth e launch sys- and NLS studies. Since both the PLS and NLS are on-going stud- NASe th tem e Aar s personnel launch system (PLS NASAd an ) / ies, the reference systems' configurations may not reflect current USAF national launch system (NLS). Both of these systems have designs t attemptbu , s were mad accuratelo et y reflec mose th t t been studied in some detail by government and industry teams. recent design prograd san m definitions. The focus of these studies, however, has been on one system or the integraten a n o t dotheno d PLS/NLran S system. Launch Vehicle Configurations The NLS family of launch vehicles is a joint NAS A-US AF pro- The NLS family of launch vehicles consists of three classes of gram that has evolved from the ALS launch vehicle family and a payload delivery capability to LEO: 10,000- to 20,000-lb class cargo-only version of the Space Shuttle system known as the Shut- (NLS-3), 50,000-lb class (NLS-2) 150,000-ld an , b class (NLS-1). tle-C. To date, the NLS program has focused on launch vehicle A representative vehicle configuratio eacr n fo thesf ho e families si development to perform a range of cargo delivery missions with shown in Fig. 1. The NLS-3 is intended to be a versatile launcher the objective of being a man-rated booster in the future. The NLS for a variety of small, unmanned pay loads. This payload capability progra identifies mha d desig e somth f eo n constraint systed san m NLS- e smal o considereth ie sto r b 3o lfo t boosteda envie th r - rfo requirements that will be required to carry manned pay loads. The sione conceptsS dPL NLS-e mose Th .th s t2i appropriate th f eo initial flight configurations of NLS vehicles may or may not con- NLS family of vehicles for launching the PLS concepts. Although tain the necessary systems for launching pay loads such as PLS. the design studies for this vehicle are driven by unmanned payload requiree Th d systems coul addee db d late vehicls a r e modifica- delivery requirements resultane th , t configurations remain quite tions. Sinc eproposee mosth missionf S o t NL d s wil cargoe b l - sufficient for the PLS mission. The NLS-1 is a heavy-lift version related, the vehicle development efforts must first achieve efficien designes i t d an deliveo S dt oNL f r upward f 150,00so 0 payf Ibo - Downloaded by UNIVERSITY OF STRATHCLYDE on February 17, 2015 | http://arc.aiaa.org DOI: 10.2514/3.25574 design thesr sfo currenee missions casth e studS r th efo s tPL i - s A . load to low Earth orbit. This payload capability is much greater ies, this is a sufficiently challenging task to focus the NLS study than necessarmaked an S s familS launco thit yPL NL se yhth efforts. membe missionS r unsuitePL e th . r Futurdfo e missions that would A more recent study effort initiated by the Marshall Space Flight Center (MSFC) is the advanced transportation systems studies (ATSS). This study consist fouf so rstude base s parti th d yn do san of manned transportation systems to space. Within this study launcS NL efforthe S rolvehiclth e f th PL e,o booste a e s th ea r fo r manned system has been examined. Although other manned launch vehicle boosters are also being examined, a key objective is to understan capabilitie e thin di th sS missioNL f identifd so nan y yan manned booster issues or constraints that should be addressed by programS NL e th . NLS Derived Heavy Lift Vehicles Received Dec. 1, 1992; revision received Feb. 15, 1993; accepted for publication Feb , 1993.18 . This pape declares ri U.Se worda th f .k o Gov - ernment and is not subject to copyright protection in the United States. *Program Manager, Space Systems Division. tContract Technical Representative, Program Development. ^Systems Engineer, Program Development. familS launcNL f Figyo 1 . h vehicles. 622 DUFFY ET AL.: EVALUATION OF THE NATIONAL LAUNCH SYSTEM 623 Table 1 NLS 1.5 stage launch-vehicle in. first-stage flightexampln a s i , f thieo s typ f boostero e e Th . weights summary with PLS payload NLS-2 desig bases ni droppinn do STMEx si ge fouth s f useo r n di Element Weight, Ib s first-stagit e flight e e stageengineb Th .y s individuaa d ma s l engine clustea r so enginef ro s withi propulsiona n module struc- Core stage wit STMEh2 s 127,550 Booster module with 4 STMEs 70,700 ture. MPS propellan liftoft ta f 1,757,703 The reference configuration of the NLS-2 launch vehicle used Tota launcS lPL h weight 33,800 for this paper is derived from the NLS reference design as base- Gross liftoff weight 1,989,753 1992y lineMa . n di Thi s proposed configuration include s10-fa t Boost-module staging weight 78,312 stretch of the external tank, six STMEs (650,000-lb thrust each), Core-module staging weight 145,882 and the staging of four STMEs in a propulsion module. Perfor- Total usable propellant 1,731,759 mance analyses of this configuration are based on design ground Flight-performance reserves 5,571 rules utilized by the NLS program, including an engine-out capa- bility, weight estimate margins d propellanan , t marginse Th . engine-out capability require vehicle sth completo et missioe eth n engine on wit y eh an out . Th esustaineo worstw e tth casrf o ee ison Table 2 PLS (HL-20) weights summary for engines faile liftoft da f fro launce mth h paddeletioe .Th paya f no - NLS-2 booster load shroud normally included in the vehicle design and charged Element Weight, Ib as vehicle weigh uniqus ti NLS- e th o et 2 configuratioS PL e th r nfo mission. This shroud is not required for the PLS payload as the PLS inert weight 19,170 Personne provisiond lan s 1,953 PLS is designed for aerodynamic flight, and the weight of this pay- Fluids and residuals 318 load shroud (approximately 12,000 Ib) is convertible to payload Propellant consumabled san s 4,045 capability for the PLS mission. A weight summary of this NLS ref- Adapter and launch escape system 8,314 erence configuratio provides ni Tabln di e 1. Total launch weight 33,800 configuratioS PL e e HL-2Th th s i n0 design s furthethawa t r developed by Rockwell International and Lockheed for the LaRC studies. The configuration details were documented in the study final report (Ref. 1). The only changes necessary were in the PLS- launch vehicle adapter configuration S studyPL , ,e mth thi s PLS/NLS Baseline Stacked Configuration adapte ALe sizes th Sr wa rdlaunc fo h vehicle whiclargea d hrha diameter than the NLS. A proposed NLS payload adapter was used in this paper that would interfac adapter/launchS e PL wit e hth - escape system (LES). The weight estimates for the PLS and its 27.5' diam. Structural Adapt* adapter are provided in Table 2. These weights are all considered payload-chargeable for the NLS booster. The PLS and NLS-2 con- figuration showe ar s n togethe Fign ri (no2 . scale)o t . These con- figurations wer analyseee useth r dfo s contained within this paper. This combination represents a unique configuration that has not previously been analyzed as an integrated system by either the studiesS NLPL r So . NLS2 (1.5 Stag*) Launch Vvhteto • 10'E/T Stretch- 80x150 s'" '^i — — — 15x220 Altitude • ——— »-.• -^ Launch Eacap* Systam Solid Rock< ^^ ^-— — 50x100 (ft) 300000 • &' f _^S n .