Human Lunar Exploration Mission Architectures

Transcription

1 Human Lunar Exploration Mission Architectures LPI Lunar Knowledge Requirements Workshop March 1-2, March 2004

2 Guiding Principles for Exploration (excerpt NASA New Space Exploration Vision, January 14, 2004) Employ Human and Robotic Capabilities NASA will send human and robotic explorers as partners, leveraging the capabilities of each where most useful. Robotic explorers will visit new worlds first, to obtain scientific data, demonstrate breakthrough technologies, identify space resources, and send tantalizing imagery back to. Human explorers will follow to conduct in-depth research, direct and upgrade advanced robotic explorers, prepare space resources, and demonstrate new exploration capabilities 2 1 March 2004

3 Program Interrelationships Potential Destinations and Science Objectives Technology Development Requirements Reference Lunar Operations Concept #4 Fully Reusable MOON Architecture s Technology x2 SEP Freighter x1 LEO Prop Depot Trade: Lunar Orbit or Lunar L1 Reference Lunar Operations Concept #3 Lunar SEP Tug Technology Propellant Propellant Freighter x SEP 1 Lunar Lander/CEV Technology Pre-deploy Pre-deploy x 1 per CEV + Power & Propulsion Architecture s x1 MOON Crew Crew Space-Based Space-Based Lander, Lander, Propellant Propellant Propellant Propellant SEPs SEPs Emergency Emergency Architecture s x 1 per x1 Normal Normal Mission Mission MOON Technology EARTH x 2 per Injection Stage Crew Crew Abort Capacity Pre-deploy Pre-deploy Lander Lander Crew Launch Launch LaunchVehicle Vehicle Trade Trade Study Study Lunar Lander LEO Prop Depot LEO Depot x 1 per CEV + Power & Propulsion Power & CEVPropulsion Reused? Trade: Lunar Orbit or Lunar L1 SEP SEP Evolution to Orbit For NASA Internal Use Only - Pre-Decisional 49 Reference Lunar Operations Concept #1 Abort Capacity JSC/EX/Code T Visit x 1 per CEV + Power & Propulsion x 2 per Injection Stage EARTH x 1 per CEV + Power & Propulsion Robotic Precursor Missions Power & Propulsion Option Option for for Reusability Reusability 16-Feb-04 Abort Capacity Pre-deploy Pre-deploy Launch Vehicle Launch Vehicle Lander Lander Trade Trade Study Study x 1 per Lunar Lander CEV Reused? MOON Prop Prop Trade: For NASA Internal Use Only - Pre-Decisional Lunar Orbit 48 or Lunar L1 JSC/EX/Code T Visit Orbit Crew Launch Launch LaunchVehicle Vehicle Trade Trade Study Study x 1 per Lunar Lander Architecture s 16-Feb-04 Lunar Basic Crew Crew Crew Launch CEV Reused? EARTH Power & Propulsion For NASA Internal Use Only - Pre-Decisional 47 JSC/EX/Code T Visit Orbit 16-Feb-04 Abort Capacity Launch Launch Vehicle Vehicle Trade Trade Study Study Crew Launch CEV Reused? EARTH JSC/EX/Code T Visit Efficient Efficient InInAeroassist Space Prop.. Aeroassist Space Prop.. Low-cost Low-cost Cryo Engines Cryo Fluid Fluid Engines Robust/Efficie Management Robust/Efficie Management nt Power Lightweight ntlightweight Power structures structures systems, systems, sensors, sensors, micro/nano micro/nano electronics electronics Normal Normal Mission Mission Option Option for for Reusability Reusability Trade: Lunar Orbit or Lunar L1 Reference Lunar Operations Concept #2 x 1 per Injection Stage Orbit Mission Analyses Technology Building Blocks Mission Architectures For NASA Internal Use Only - Pre-Decisional Feb-04 3 Robotic Precursor Mission Requirements Acquire data sets Human safety Engineering Demonstrate key technologies Deliver Infrastructure 1 March 2004

4 Recent Exploration Architecture Studies Office of Exploration 1988 Case Studies o Human Expedition to Phobos o Human Expedition to o Lunar Observatory o Lunar Outpost to Early Evolution 1989 Case Studies o Lunar Evolution o Evolution o Expedition Lunar & Program Office NASA 90-Day Study 1989 o Approach A Balance and speed o Approach B Earliest possible landing o Approach C Reduced logistics o Approach D - Relaxed dates o Approach E Reduced scale The Synthesis Group 1991 o Exploration o Science Emphasis for the Moon and o The Moon to Stay and Exploration o Space Resource Utilization Advanced Development Office Exploration Missions o Design Reference Mission Version o Design Reference Mission Version o Design Reference Mission Version o Combo Lander (JSC) o Dual Landers 1999 Decadal Planning Team / NEXT o o o o s Neighborhood Architecture Asteroid Missions Short and Long Stay NEP Artificial-gravity Exploration Study o s Neighborhood Architecture o Lunar Oasis (RASC) Special Studies 2003 o Exploration Programs Office First Lunar Outpost 1993 Early Lunar Resource Utilization 1993 Human Lunar Lunar Architectures Supporting o Comptroller/Space Architect o Comptroller/Code M 4 1 March 2004

5 Example Near- Mission Trade Space Launch Vehicle Capability Small (<35 mt) Proton, EELVs Shuttle Medium ( mt) Large (100+ mt) Shuttle-C, Shuttle-Z, Magnum Heavy Lift Launch Vehicle LEO Assembly? No Yes Space Station 1988 Lunar Observatory 1988 Lunar Outpost 1989 Lunar Evolution Day Study 1993 First Lunar Outpost 1993 Lunar Resource Utilization 1996 Human Lunar 2000 s Neighborhood 2002 Exploration Study #1 Duration of Surface Stay <14 Days Live in in Lander Days Habitat Lander 45+ Days Outpost High Degree of Transportation Reuse? No Yes 5 1 March 2004

6 Lunar Mission Design High level program groundrules & constraints can have significant implications for system operational characteristics For Project Constellation these G & Cs include: Launch capacity Lunar surface access requirements (lunar latitude) Surface duration The operational impacts include: Crew return opportunity frequency Abort practicality Overall minimum duration System mass & performance 6 1 March 2004

7 Lunar Injection Constraints Lunar Orbital Motion ~13 o /day Posigrade Moon at Lunar Arrival Assumptions Lunar will involve multiple launches with aggregation in LEO Crew launched to LEO Operational Implications Combination of LEO nodal regression and lunar motion provides lunar injection opportunities ~ every 9 days Lighting conditions at a given landing site will vary greatly from one opportunity to the next Vehicle performance, wait times in earth and lunar orbit will need to be traded against operational flexibility Parking Orbit ~5 deg/day Nodal Regression Lunar Orbital Motion Lunar Morning at Site Injection Window #1 SUN Moon s Antipode at Lunar Arrival (Point of TLI) Injection Window #2 Injection Window #3 Lunar Night at Site Lunar Afternoon at Site 7 1 March 2004

8 Landing Site Restrictions for Lunar Orbit Rendezvous (LOR) Assumptions Access to non-equatorial landing site will be desired Lunar stay time of more than a few days will be desired Operational Implications High-latitude lunar landing sites will imply high inclination lunar parking orbits (assuming LOR) Free- transits probably not practical Lunar decent/ascent to high-latitude site available once every ~ 14 days from lunar polar orbit Region of unattainable landing sites Descent/ascent to polar site available every 2 hours from polar orbit Region of unattainable landing sites All landing sites available Orbiting Spacecraft Equatorial Parking Orbit In-plane lunar descent/ascent available every 2 hours for equatorial landing sites; all nonequatorial sites unavailable Mid-Inclination Parking Orbit In-plane lunar descent/ascent available every days for landing site latitudes less than orbit inclination; all higher latitude sites unavailable Polar Parking Orbit In-plane lunar descent/ascent available every 2 hours for polar landing sites or every 14 days for non-polar sites 8 1 March 2004

9 Restrictions from Lunar Polar Orbit Assumptions Access to non-equatorial landing site will be desired Lunar stay time of more than a few days will be desired Operational Implications Trans- Injection from Lunar Polar Orbit only available every ~ 14 days TEI V Day 7: Non-Regressing Polar Orbit is is 90 o from the desired TEI orientation 3-Impulse V = 2015 m/s Moon s Mean Motion: ~13.2 o /day Moon to TEI V Day 0: Minimum-Energy TEI is is Available on Pass Under Moon TEI V = 848 m/s Day 14: Minimum-Energy TEI is is Available on Pass Over Moon TEI V = 848 m/s Moon to TEI V TEI V Day 21: Non-Regressing Polar Orbit is is 90 o from the desired TEI orientation 3-Impulse V = 2015 m/s 9 1 March 2004

10 -Moon L1 Characteristics Crew departs from LEO Crew Exploration Vehicle L 1 Lunar Lander Moon s Orbit L 4 Alternative to Lunar Orbit Rendezvous Gravitational Balance Points in -Moon System L1 Point ~55,000 km from lunar surface Weakly unstable small stationkeeping required Synchronization of, Moon, L1, and Lunar Surface Continuously open windows from L1 to anywhere on lunar surface and back Four days from, two days from Moon (high thrust) L 3 Distance from s Center (km) L 1 L March 2004 L 5 Distance from Moon s Center (km) L L L L L

11 Summary of Lunar Mission Design Constraints Low Latitude Landing Sites (e.g. Sea of Tranquility) Mid-Latitude Landing Sites (e.g. Tycho, Imbrium) Polar Landing Sites (e.g. SP-Aitken Basin) Low Latitude Landing Sites (e.g. Sea of Tranquility) Mid-Latitude Landing Sites (e.g. Tycho, Imbrium) Polar Landing Sites (e.g. SP-Aitken Basin) Outbound to Moon Ascent/Descent to From LEO: Every 9-12 d Declination of the Moon Relative to EPO Declination of the Moon Relative to EPO Tim e (days) Tim e (days) From LEO: Every 9-12 d» Lunar Orbit Rendezvous «W indow Every 3-12 days W indow Every 3-12 days From Low-inc orbit: Every 2 hr From Mid-inc orbit: Every 27 d From Polar orbit: Every 14 d From Low-inc orbit: N/A From Mid-inc orbit: Every 27 d From Polar orbit: Every 14 d From Low-inc orbit: N/A From Mid-inc orbit: N/A From Polar orbit: Every 2 hr» Libration Point Rendezvous «Ascent/Descent Windows Continuously Available From Low-inc orbit: N/A From Mid-inc orbit: N/A From Polar orbit: Every 14 d Outbound to Moon Ascent/Descent to Declination of the Moon Relative to EPO Declination of the Moon Relative to EPO W indow Every 3-12 days W indow Every 3-12 days Tim e (days) Tim e (days) No surface stay time constraints From Low-inc orbit: Every 2 hr From Mid-inc orbit: Every 27 d From Polar orbit: Every 14 d From Low-inc orbit: N/A From Mid-inc orbit: Every 27 d From Polar orbit: Every 14 d Global access reqt results in in surface stay times of of 14 days Windows Continuously Available 11 1 March 2004

12 Comparison of Staging Strategies (assumes mid to high latitude landing) Surface Stay Time, Polar Sites Surface Stay Time, Mid-Latitude Sites Total Mission V Largest Single-Leg V Free Abort (Post-TLI) Available? Anytime Abort from Lunar Surface Available? Frequency # of Major Propulsive Maneuvers Lunar Orbit Rendezvous No Restrictions Limited to 14-day Increments (e.g. 14, 28, 42 days, etc.) 9,400 m/s ~4,400 m/s No No Every 13.6 days 5 Libration Point Rendezvous No Restrictions No Restrictions 10,700 m/s ~5,600 m/s Yes Yes Anytime 9 Representative Scale of Single- Stage Lander Vehicle 12 1 March 2004

13 Lunar Surface Mission Activity Space Radial Distance from Landing Site (kilometers) Apollo Reconnaissance South Pole Aristarcus Taurus-Littrow 8 Seismometers surface access and short term habitation Simulation Short Stay Mission EVA systems Operations augmented power and thermal base power and long term habitation lab and dedicated test/experiment equipment Surface Mission Duration (days) Long Term Research South Pole Aitken Basin Aristarcus Mare Smythii Simulation Long Stay Mission Life support Habitation Power EVA systems Operations Integrated testing ISRU 13 1 March 2004

14 Exploration Life Science Issues Lunar Crew Radiation Protection (Solar Particle Events) Apollo essentially trusted to luck At least one solar particle event occurred between Apollo s which, if it had occurred during a would have represented a severe crew health issue (or fatalities) Analysis capability coming on-line to rapidly assess design concepts for SPE attenuation characteristics Same as above plus Galactic Cosmic Radiation Long-duration microgravity exposure Countermeasures Artificial-g 14 1 March 2004

15 Operations Concept #1 Description Overview Flight elements launched wet, rndz/dock in LEO (depending on launch vehicle capacity) Potential Advantages Minimize transportation technology development and on-orbit operations complexity for early lunar exploration capability Potential Challenges All flight elements must provide autonomous flight functions (e.g. power, thermal, attitude control, orbit maintenance, propellant management) Sensitive to disruption in launch campaign Largest launch capacity requirements Highly sensitive to launch vehicle capacity Little potential for eventual reusable elements Potential Reusable s CEV Applicability to Cryogenic Propellant Storage Autonomous Rendezvous & Capture Lunar Lander System Heritage for Lander Injection Stage for Chemical Injection 15 1 March 2004

16 Reference Lunar Operations Concept #1 Lunar Basic MOON Architecture s x 2 per Injection Stage Trade: Lunar Orbit or Lunar L1 x 1 per CEV + Power & Propulsion Pre-deploy Lander Crew x 1 per Lunar Lander Orbit Power & Propulsion Launch Vehicle Trade Study Abort Capacity Crew Launch CEV Reused? EARTH 16 1 March 2004

17 LEO Propellant Aggregation Operations Concept #2 Description Overview Decouples hardware and propellant ETO launches through on-orbit propellant aggregation and transfer at LEO Prop Depot Vehicles berthed/assembled at Depot Potential Advantages LEO Depot decouples launch campaign Flexibility in launch vehicle capacity (offloaded flight elements) High launch vehicle packaging efficiency Option of reusability of Injection Stages enabled Potential Disadvantages LEO infrastructure element required Extended times for flight elements in MMOD environment Additional technology development Potential Reusable s CEV Injection Stages LEO Cryo Depot Applicability to Cryogenic Propellant Storage, Gauging, and Autonomous Rendezvous & Capture Lunar Lander System Heritage for Lander Injection Stage for Chemical Injection 17 1 March 2004

18 Reference Lunar Operations Concept #2 LEO Depot Architecture s MOON x 1 x 2 per LEO Prop Depot Injection Stage Technology Trade: Lunar Orbit or Lunar L1 x 1 per CEV + Power & Propulsion x 1 per Lunar Lander Prop Option for Reusability Power & Propulsion Orbit Abort Capacity Launch Vehicle Trade Study Crew Launch CEV Reused? EARTH 18 1 March 2004

19 Operations Concept #3 Description Overview Replaces Injection Stage s Lander delivery function with reusable, high-efficiency solar electric propulsion SEP Stage provides long duration vehicle health maintenance Potential Advantages Reuse of high-value vehicle Reduced launch mass requirements Potential Challenges Infrastructure element required high performance, reusable propulsion system Reusable lander design issues Extended times for flight elements in MMOD environment Additional technology development Potential Reusable s CEV Lander SEP Stage Potential Applicability to Sub-scale Solar Electric Propulsion Stage Thrusters for NEP Vehicle Cryogenic Propellant Storage Autonomous Rendezvous & Capture Lunar Lander System Heritage for Lander Injection Stage for Chemical Injection 19 1 March 2004

20 Reference Lunar Operations Concept #3 Lunar SEP Tug MOON Architecture s x 1 SEP Freighter Technology Trade: Lunar Orbit or Lunar L1 Option for Reusability x 1 per x 1 per Injection Stage CEV + Power & Propulsion Pre-deploy Lander Crew x 1 per Lunar Lander Power & Propulsion Orbit SEP Abort Capacity Launch Vehicle Trade Study Crew Launch CEV Reused? EARTH 20 1 March 2004

21 Operations Concept #4 Description Overview Fully reusable elements Propellant transfer via SEP tugs (applicable for either - or lunar originating propellants) Potential Reusable s All elements are reusable Potential Applicability to Same as previous Operations Concepts, but adds full reusability of all elements, and potential full-scale use of lunar resources 21 1 March 2004

22 Reference Lunar Operations Concept #4 Fully Reusable Architecture s MOON x 2 SEP Freighter Technology Trade: Lunar Orbit or Lunar L1 x 1 x 1 per x 1 LEO Prop Depot CEV + Power & Propulsion Lunar Lander/CEV Technology Pre-deploy Propellant Space-Based Lander, Propellant Crew Propellant Normal Mission SEPs Emergency Orbit Launch Vehicle Trade Study Abort Capacity Crew Launch Normal Mission CEV Reused? EARTH 22 1 March 2004

23 Mission Architecture Implications to Robotic Lunar Precursors From the standpoint of lunar surface activities, the Operations Concept chosen is transparent. Drivers: Surface destination: polar, equatorial, mid-latitude, (far side) Surface duration Surface activities Use of resources Orbital reconnaissance/technology demonstration/infrastructure: Lunar topography at scales relevant to human surface activities, particularly in shadowed regions at high latitudes. Lunar surface and near-subsurface resources, including the abundance and nature of water. Relay communications from the lunar surface to. Rock populations (~>1 meter) in the vicinity of potential landing sites. Surface mineralogy and elemental composition at decameter scales, particularly in the polar regions. Thermophysical and dielectric properties of the surface layer. Surface temperature regime in the permanently shadowed craters. Global lunar gravity field map Global lunar magnetic field map Surface reconnaissance/technology demonstration/infrastructure: Ground-truth verification of landing site characteristics (topography, resources, surface engineering properties, geologic properties including mineralogy and chemical composition) Test engineering flight and surface operations (landing navigation, precision landing, cold environment operations) Test and demonstrate critical technologies (resource utilization, tribology, power, communications, thermal systems) Navigation aid to future s targeted to its landing site. Characterize the environment in permanently shadowed craters 23 1 March 2004