Lunar Lander Vehicle Design Overview Wayne Lee Lunar Lander Industry Day 13 December 2007

Vehicle Architecture Airlock Three Primary Elements Ascent Module Descent module Provides propulsion for LOI and powered descent Provides power during lunar transit, descent, and surface operations Serves as platform for lunar landing and liftoff of ascent module Ascent module Provides propulsion for ascent from lunar surface after surface mission Provides habitable volume for four during descent, surface, and ascent operations Contains cockpit and majority of avionics Airlock Accommodates two astronauts per ingress/egress cycle Connected to ascent module via short tunnel Remains with descent module on lunar surface after ascent module liftoff Ascent Module Descent Module

Key Preliminary Specifications Number of Crew up to 4 Sortie Mission Duration 14 days LEO (unoccupied) 4 days trans-lunar coast 1 day LLO 7 days surface 7 hours ascent (including disposal) Total Mass at Lift-off 45,000 to 53,600 kg Total Propellant Mass 26,652 kg (sortie) Height of Vehicle Stack 10.52 m, legs uncrushed Height of DM Deck Above Surface 6.97 m, legs uncrushed Maximum Diameter of Vehicle 7.5 m, legs stowed Diameter of Landed Footprint 14.53 m, legs deployed Descent Propulsion LOX/LH2 Main, MMH/NTO RCS Ascent Propulsion MMH/NTO Main and RCS Total V Capability ~2960 m/s

Configuration Variants Vehicle will be configurable as three different variants Sortie variant Utilized for surface missions up to seven days where crew will use ascent module as living quarters and a base of operations for EVAs Employs all major elements -- descent module, ascent module, airlock Outpost variant Utilized for surface missions up to 210 days where crew will work out of a lunar base Configured similar to sortie variant, but without airlock; crew will depressurize ascent module upon landing and head directly for outpost Keep-alive power assumed to be provided by outpost Cargo variant Utilized to deliver large, presumably outpost modules to the surface No ascent module or crew; cargo will sit on upper deck of descent module Vehicle components normally resident in ascent module will be attached to upper deck of descent module

Configuration Variants Sortie Variant 45,000 kg Descent Module Ascent Module Airlock Outpost Variant 45,000 kg Descent Module Ascent Module Cargo Variant 53,600 kg Descent Module Cargo on Upper Deck

Configuration Commonality Design paradigm is to maximize commonality across variants Descent module structure optimized to deliver maximum amount of payload mounted to the deck in cargo mode, but use same structure for all three Descent propulsion is identical for all three with exception of propellant load Launch mass allocation of 45,000 kg for sortie and outpost variants increased to 53,600 kg for cargo mission due to benefit of Ares V not needing to accelerate Orion vehicle through TLI burn Tanks sized for propellant volume needed for 53,600 kg cargo mission, but only filled to level needed to support sortie and outpost variant mass Ascent module structure and propulsion is identical for sortie and outpost variants Other subsystems are identical in concept for all three variants Choice of components and sizing are the same for all three variants Minor variations in schematics and physical layout to account for mission-specific details

Mass Distribution Comparison of Variants Sortie Mission Lander Outpost Mission Lander Uncrewed Cargo Mission Lander Dry Mass 9,522.1 kg Non-Propellants and Other 2,568.7 kg Propellant 26,651.7 kg Manager's Reserve 2,856.6 kg Mass Available for Payload 3,400.9 kg Total Vehicle 45,000 kg Dry Mass 8,971.9 kg Non-Propellants and Other 2,287.5 kg Propellant 26,780.0 kg Manager's Reserve 2,691.6 kg Mass Available for Payload 4,269.0 kg Total Vehicle 45,000 kg Dry Mass 6,901.2 kg Non-Propellants and Other 1,351.0 kg Propellant 26,319.3 kg Manager's Reserve 2,070.4 kg Mass Available for Payload 16,958.1 kg Total Vehicle 53,600 kg

Launch Vehicle Adaptor (EDS) Structures Summary Descent Module Structure Cruciform truss configuration, four landing legs (stowed at launch) Aluminum construction Current mass w/o growth 2110 kg Ascent Module Structure Cylindrical-shaped pressure vessel Composite construction Current mass w/o growth 625 kg Airlock Structure Current mass w/o growth 312 kg Ascent Module Airlock Landing Leg Launch Vehicle Adaptor (EDS)

Descent Module Configuration Cruciform Primary Structure LH2 Tanks (4) LOX Tanks (4) Upper LH2 Support Struts (32) (tension rods) Lower LH2 Support Struts (16) (stabilizers) Lower LOX Tank Support Cones (4)

Ascent Module Configuration Docking Window Frame (2) LIDS Docking Adaptor (previous version shown) Front Window Frame (2) Top Flange (4) MMH Tank (2) Tank Structure (24 struts) NTO Tank (2) Lower Interface Beam Separation System (Marmon Band) AM/DM Adapter Engine

Airlock Configuration Pressure Shell Skin EVA Hatch Frame AM / Airlock Tunnel Frame EVA Hatch Window EVA Hatch AM / Airlock Tunnel Bottom Flange (4) Truss Structure Strut (8)

Propulsion Summary Ascent Module Propulsion Descent Module Propulsion Single MMH/NTO main engine, 24,465 N (5,500 lbf) thrust 16 MMH/NTO RCS thrusters 2 MMH, 2 NTO tanks shared between main and thrusters Current dry mass w/o growth 666 kg Descent Module Propulsion Single LOX/LH2 main, 82787 N (18,627 lbf) thrust, restart capability, 3.3:1 throttle ratio 4 LOX, 4 LH2 tanks 16 MMH/NTO RCS thrusters Current dry mass w/o growth 2510 kg Thrusters (position TBD) MMH Tank NTO Tank Helium Tank Ascent Main Engine LH2 Tank LOX Tank Descent Main Engine

DM Main Propulsion Schematic GHe GHe Pneumatics/Purge s P Pneumatic Valve Pneumatic Vent/Relief Valve GHe GHe VR Press/Pre-press Power System Interface Relief Valve s Solenoid Valve GHe Fill/Vent Check Valve s s s s Pressure Regulator Filter Thermodynamic Vent System LOX Vent TVS LH2 Vent Diffuser s s s s P LOX Fill/Drain VR VR VR VR LH2-1 LH2-2 LH2-3 LH2-4 P s TVS VR TIVF1 TIVF2 TIVF3 TIVF4 TIVF1-P TIVF2-P TIVF3-P TIVF4-P P LH2 Fill/Drain LOX-1 LOX-2 LOX-3 LOX-4 Engine #1 P P P P TVS TVS TVS TVS TIVOx1-P TIVOx2-P TIVOx3-P TIVOx4-P TIVOx1 TIVOx2 TVCA-1a TIVOx3 TIVOx4 TVCA-1b

Ascent Propulsion Schematic GHe GHe Function: Service Hand Valve, HV High Pressure Latching Valve, HP Regulator, Rg Check Valve, CV Filter, F Low Pressure Latching Valve, LV Solenoid Valve S Burst Disk/ Relief Valve RV Heater Ht Pressure Sensor P Temperature Sensor T Fluids: Helium He Nitrogen Tetroxide (NTO) Ox Monomeythhydrazine (MMH) Fu tHe1 tHe2 GHe GHe tHe1 tHe2 HVHe01 pHe1 HPHe1 FHe1 RgHe1 FHe5 FHe6 HVFu01 HVOx1 Thruster 1,2,3,4 Thruster 5,6,7,8 CVHe2 LVFu1 CVHe1 LVOx1 RVFu1 RVOx2 S S S S S S S S pp1 pp2 t9 t10 t11 t12 t13 t14 t15 t16 t5 p3 tp1 HVFu4 tp3 tp5 tp7 HVOx4 MMH MMH NTO NTO t6 p4 tp2 tp4 tp6 tp8 t3 t4 HVFu2 HVOx2 RCS Thruster Quads LVFu2 LVOx2 FFu1 FOx1 p5 HVOx3 HVOx5 t7 t1 p1 HVFu5 t2 p2 t8 p6 HVFu3 t17 t18 t19 t20 t21 t24 S S S S S S S S S S t22 S t23 S S S S S Ascent Engine Thruster 9,10,11,12 Thruster 13, 14, 15, 16

Power Summary Descent Module Ascent Module and Airlock Bus PEM fuel cell, 5.5 kW peak production Provides AM and DM power for LLO, surface operations Orion provides 1.5 kW when docked Propulsion residuals provide reactants for surface operations Current inert mass w/o growth 148 kg (sortie) Ascent Module and Airlock Single primary battery, LiSO2 chemistry, 14.2 kW-hr capacity Current mass w/o growth 139 kg Bus 28 V unregulated bus

(another on other side) Thermal Summary Ascent Module and Airlock Inner loop with coldplates and sublimator Heat transferred to outer loop for rejection during cruise, LLO, surface MLI and black Kapton insulation on structure Current inert mass w/o growth 208 kg Descent Module Outer loop utilizes radiators for heat rejection SOFI insulation on propellant tanks, silverized teflon and MLI on structure Current inert mass w/o growth 974 kg (sortie), 990 kg (cargo) Sublimator (attached to AM) Radiator (another on other side)

Life Support Summary Atmosphere Water Waste Between 57 and 83 kPa Cabin loop provides for heat removal Suit loop provides for CO2, moisture, heat removal from suit umbilicals Suit loop also removes CO2 from cabin air via amine swing beds Water Internal tank holds one day of potable water with silver ion biocide External tank accumulates water from fuel cells for internal tank, EVA recharge, and thermal Waste Collection and disposal provided Current mass w/o growth 212 kg (sortie) Ascent Module Components Airlock Components

C&DH Design Status Project strategy regarding C&DH has been not to instantiate a baseline design using available components Over 10+ years to go until first flight Relatively rapid progress in evolution of electronics may render today’s design obsolete Baseline C&DH architecture is currently under study by a multi-NASA-center team with the following objectives Determine functional properties of architectures that have favorable characteristics relative to Lander performance requirements Develop candidate architectural concepts that satisfy the desired characteristics, but are expandable and extensible Identify technology and/or component families suitable for use in populating the architecture Develop a functional/mass equivalent design placeholder using existing parts, if available

GN&C Summary Sensor Suite Control Suite Lidar and Camera (top front of AM) Sensor Suite Star tracker and MIMU data for propagation of attitude and position for all phases of flight Pulsed Doppler radar provides altitude and velocity during landing Lidar provides range and bearing to Orion during rendezvous Rendezvous camera used during terminal approach prior to docking Control Suite 16 thrusters on DM allows for attitude control during cruise, LLO, descent DM main engine gimbals by 6° to keep thrust aligned with c.g. 16 thrusters on AM allows for attitude control and main engine thrust vector pointing during ascent MIMU (inside AM) Star Tracker DM RCS Thruster Pod Radar Electronics (inside DM) Radar Antennas (not shown, mounted on lower edge of DM)

Low-Gain Primary Antennas Telecom Summary Primary Radio S-band transponder for link with Orion and Earth SSPA with 40 W output power 2 ISS-heritage low-gain antennas with 120° field of view Link Performance 80 kbps to 18-m Earth network, 190 kbps to 34-m network 2.3 Mbps to Orion at 100 km range Significant fraction of data volume in minimal functional design occupied by overhead (headers, IP, etc.) EVA Radio 802.16 transceiver currently in development SSPA (top face of AM) Low-Gain Primary Antennas

Summary Vehicle design shown today is from the first design cycle (LDAC-1) Minimum functional design; not intended for flight Design basis was the design reference mission as opposed to a detailed requirements set Implementation choices should not be considered frozen with the exception of a few key architectural features 4 crew, descent propellant, inclusion of an airlock, use of LIDS docking adaptor for Orion Forward work for FY08 Evaluate upgrades for safety and reliability Evaluate upgrades for lunar global access and enhanced functionality Mature preliminary design and develop requirement sets and specifications Evaluate technologies for mass reduction