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Earth-Mars Artificial-G NEP Architecture Sun-Earth L2 Architecture 3-Week Parametric Trade Study Presented to JSC/Exploration Office March 3, 2003 Low Thrust Trajectory Team – GRC, JPL, JSC, MSFC Presentation prepared by: Jerry Condon / JSC / EG5 / 281.483.8173 / [email protected]

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Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

Earth-Mars Artificial-G NEP Architecture

Sun-Earth L2 Architecture

3-Week Parametric Trade Study

Presented to JSC/Exploration Office

March 3, 2003

Low Thrust Trajectory Team – GRC, JPL, JSC, MSFC

Presentation prepared by: Jerry Condon / JSC / EG5 / 281.483.8173 / [email protected]

Preliminary


Inter center study team

Inter-center Study Team

  • GRC

    • Melissa McGuire, Rob Falk

  • JPL

    • Jon Sims, Greg Whiffen

  • JSC

    • Jerry Condon, Ellen Braden, Dave Lee, Kyle Brewer, Carlos Westhelle

    • Jim Geffre

  • MSFC

    • Reginald Alexander, Larry Kos, Kirk Sorensen


3 week study

3- Week Study

  • 2 Studies – NEP parametric mission design trades

    Study 1 - Round trip Earth/Mars mission

    • Augment results from NEP (EM-L1 departure) study done last year at JSC

      • Determine cost (mass, time) to depart from Earth orbit and spiral to/from selected Mars parking orbits for Earth return

        Study 2 - Sun-Earth libration point (L2) mission

    • Deploy/maintenance of satellite constellation

    • Dress rehearsal for Mars mission

  • Due date – March 3, 2003

  • Customers

    • JSC/ExPO – Kent Joosten, Bret Drake, Brenda Ward, etc.

    • HQ/Gary Martin


  • Contents

    Contents

    • Study 1 - Round Trip Earth/Mars Mission

    • Study 2 - Sun-Earth L2 Libration Point Mission

    • Appendix

      • Mars Arrival Parking Orbit Analysis

      • Mars Parking Orbit Lifetime

      • Integrated Reference Mission

      • Effects of Parking Orbit Geometry on Mars Lander Mass

      • Trapped Proton Belt Data


    Study 1 round trip earth mars mission

    Study 1Round Trip Earth/Mars Mission


    Assumptions

    Round Trip Earth/Mars Mission

    Assumptions

    • Two vehicles

      • NEP Mars Transfer Vehicle (MTV)

        • Object of parametric study

      • Lander/Ascent Vehicle (LAV)

        • Previously deployed at Mars

    • Use same vehicle specifications as last year (2002) study for Artificial Gravity Mars transfer vehicle*:

      • Power = 6 MW, Engine efficiency = 60%, Isp = 4000 sec, Tankage fraction = 5%

      • Final mass target (back at Earth) = 89mt

        • No thrust vector turning constraints

          • Determine vehicle thrust vector steering requirements unconstrained by Artificial Gravity (AG) vehicle configurations

          • Results may influence AG vehicle configurations

    • 2026 opportunity, <90 day stay in Mars vicinity >30 days surface stay

    • Initial Earth orbit 700 km circular LEO

    • Crew taxi transfers crew from ground to crew transfer altitude (30,000 – 90,000 km)

    • No constraint on heliocentric closest approach to Sun

    Fire Baton

    Artificial-G NEP

    Mars Transfer Vehicle

    * Preliminary Assessment of Artificial Gravity Impacts to Deep-Space Vehicle Design, JSC/EX Document No. EX-02-50, 2002


    Goals and objectives

    Goals and Objectives

    • Perform parametric study to enhance understanding of propellant and trip time requirements for both a round trip Earth-Mars mission and a Sun-Earth L2 Libration Point mission

      • Compare results generated using different tools (e.g., VariTOP, RAPTOR, Copernicus, Mystic)

    • Minimize initial mass in low Earth orbit (IMLEO)

    • Crewed trip time <700 days

    • Perform parametric assessment of Mars parking orbit altitude

      • Determine preferred (minimum propellant mass) orbit apoapse and periapse altitudes for selected semi-major axis altitude targets

      • Compare against circular orbit altitudes for same semi-major axis target

    • Understand effect of parking orbit geometry on lander vehicle mass


    Mission overview

    Round Trip Earth/Mars Mission

    Mission Overview

    >30 Day Surface Stay

    Landing

    Launch

    Pre-deployed

    Mars Lander

    500 -> 90,000 km

    (Elliptical or Circular Orbits)

    Heliocentric Flight

    Earth - Mars

    Heliocentric Flight

    Mars - Earth

    Rendezvous/Dock

    Of Descent/Ascent Vehicle

    And Mars Transfer Vehicle

    Mars Crew Transfer Vehicle

    Constant Thrust

    Power = 6 MW

    Efficiency = 60%

    Isp = 4000 sec

    Mass Return to Earth = 89 mt

    Crew Delivery Taxi

    (Possible Emergency Return Vehicle)

    HEO

    30,000 –> 90,000 km

    (Circular Orbits)

    Crew

    Return

    Rendezvous/Dock Of Crew Taxi and

    Mars Transfer Vehicle

    LEO (700 km)

    On-orbit Construction

    of Transfer Vehicle

    Launch of NEP

    Transfer Vehicle

    Launch Of

    Crew Taxi

    Launch for

    Crew Pickup

    Courtesy: Jerry Condon/JSC


    Mission overview1

    Round Trip Earth/Mars Mission

    Mission Overview

    • Spiral NEP Mars transfer vehicle from LEO (700 km) to selected crew transfer orbit (flight crew not onboard)

    • Crew taxi launches from ground to Mars transfer vehicle (30,000 – 90,000 km)

      • Crewed mission begins with crew transferred to Mars transfer vehicle above the trapped proton radiation belt

        • Avoids crew spiral through proton radiation belt

        • Crew will, however, spiral through the larger trapped electron belt

    • Mars transfer vehicle spirals from crew transfer orbit to heliocentric orbit targeted to Mars

    • Mars transfer vehicle transitions from heliocentric space to selected Mars parking orbit (semi-major axis) altitude target (500-90,000 km)

    • Mars surface stay (>30 days)

    • After surface mission complete, Mars transfer vehicle spirals from Mars parking orbit (500-90,000 km) to heliocentric space targeted to Earth return

    • Mars transfer vehicle transitions from heliocentric space to original crew transfer orbit at Earth (30,000 – 90,000 km) for crew pick-up with crew taxi


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Earth-Mars Trajectory Analysis Sensitivity StudyExploration Study 1 Follow-on(Three week Quick Study preliminary results)

    Melissa L. McGuire

    Robert D. Falck

    NASA Glenn Research Center

    7820 / Systems Analysis Branch

    February 28, 2003 (Updated March 3, 2002)


    Report out of quick turnout study

    Earth-Mars Trajectory Analysis Sensitivity Study

    Report out of Quick Turnout Study

    • Trajectory Analysis Methods

    • Trajectory Sensitivity Study Analysis Methods

    • Point design case Data and Trajectory Plots

    • Sensitivity Study results

      • IMLEO and Total trip time as a function of Mars/Earth orbital altitudes

      • Table of raw data for sensitivity study


    Mission and system assumptions

    System Assumptions

    Power: 6 MW

    Specific Impulse (Isp): 4000 sec

    Thruster efficiency: 60%

    Tankage Fraction: 5%

    Mission Assumptions

    Mass returned to Earth: 89 mt

    Launch Date: 2026

    Stay time in Mars space: approx 90 days

    Resulted in stay times at Mars in orbit from 37 to 77 days

    Mission Total Trip time goal: 700 days

    Limiting Orbit Assumptions (for sensitivity trade)

    Earth departure orbit altitude : LEO of 700 km

    Earth return orbit altitude: vary between 30,000 - 90,000 km

    Mars parking orbit altitude: vary between LMO of 500 km and aerosynch

    Earth-Mars Trajectory Analysis Sensitivity Study

    Mission and System Assumptions


    Trajectory analysis methods

    Varitop, JPL low thrust trajectory analysis code

    Trajectories contain spiral escape at Earth, spiral capture/escape at Mars, spiral capture into Earth orbit upon return

    Set the final mass at Earth return to 89 mt

    Set launch date guess to generate a 2026 launch opportunity

    Earth orbits modeled as circular

    No constraints on heliocentric orbit proximity to Sun

    No propellant allotted for Mars orbit operations (eccentricity, inclination, etc. corrections)

    Four bookend point design cases used Mars stay times of 40 and 70 days for low and high Mars parking Orbit altitude cases respectively

    These stay times allow for approximately 90 days in Mars vicinity.

    More refined Mars stay time choices in sensitivity cases

    Earth-Mars Trajectory Analysis Sensitivity Study

    Trajectory Analysis Methods


    Trajectory sensitivity analysis methodology

    First: Ran a series of Mars parking orbit altitudes from 500 to 17,200 km

    Second: For each Mars parking orbit, ran a series of Earth return orbits from 30,000 km to 90,000 km altitude

    For Each trajectory

    Refined guess for stay time in Mars orbit such that the sum of stay time plus spiral capture time and spiral escape time approximately 90 days

    Start from a 700 km LEO departure orbit altitude

    The NEP vehicle flies the whole trajectory from LEO to Earth return capture

    Total trajectory time includes the spiral from LEO to the high earth orbit altitude (I.e., crew delivery altitude) through Earth escape

    Earth-Mars Trajectory Analysis Sensitivity Study

    Trajectory Sensitivity Analysis Methodology


    Earth mars 500 30 000 trajectory point design

    Point Design Assumptions:

    Earth Departure Orbit: 700 km altitude

    Earth Return Orbit: 30,000 km altitude

    Mars Parking Orbit: 500 km altitude

    Stay Time in Mars Orbit: 40 days

    Total Trip time includes LEO to high Earth orbit spiral time

    Point Design Result Highlights (see Table for further details)

    IMLEO: 303.7 mt

    Total trip time (with Earth spirals): 744.8 days

    Earth spiral out/in trip time: 110.7 / 9.6 days

    Earth spiral out/in propellant cost: 44.5 / 3.9 mt

    Mars spiral in/out trip time: 28.4 / 26.3 days

    Mars spiral in/out propellant cost: 11.4 / 10.6 mt

    Time in Mars Vicinity: 94.7 days

    Closest approach of trajectory to Sun: 0.39 AU

    Earth-Mars Trajectory Analysis Sensitivity Study

    Earth-Mars 500/30,000 Trajectory Point Design


    Earth mars 2026 earth return 30000 km mars parking orbit 500 km point design trajectory plot

    Earth-Mars Trajectory Analysis Sensitivity Study

    Earth-Mars 2026 (Earth Return 30000 km, Mars Parking Orbit 500 km) Point Design Trajectory Plot

    • Mission Assumptions:

    • Earth Departure Orbit: 700 km altitude

    • Earth Return Orbit: 30,000 km altitude

    • Mars Parking Orbit: 500 km altitude

    • Stay Time in Mars Orbit: 40 days

    • System Assumptions

    • Power: 6 MW

    • Specific Impulse (Isp): 4000 sec

    • Thruster efficiency: 60%

    • Tankage Fraction: 5%

    Escape Earth

    Spiral for 110.7 days

    November 1, 2026

    Mass after spiral: 259.1 mt

    Close Approach to Sun

    Distance ~ 0.39 AU

    Earth

    Begin Spiral Capture at Mars

    June 27, 2027

    Mass before spiral: 183.5 mt

    Sun

    Start at 700 km Earth orbit altitude

    July 13, 2026

    Initial Mass: 303.7 mt

    Mercury

    Finish capture at Mars

    July 25, 2027

    Spiral for 28.4 days

    Capture into 500 km orbit

    Mass after spiral: 172.1 mt

    Escape Mars

    Spiral for 26.3 days

    September 30, 2027

    Mass after spiral: 161.5 mt

    Capture at Earth

    July 27, 2028

    Orbit altitude 30,000 km

    Spiral for 9.6 days to capture

    Mass after spiral: 89 mt

    Mars

    Stay time 40 days in Mars orbit

    Begin Spiral Escape of Mars

    September 3, 2027

    Begin Spiral at Earth return

    July 17, 2028

    Mass before spiral: 92.9 mt

    Courtesy: Melissa McGuire/GRC, Rob Falck/GRC


    Earth mars 16700 90000 trajectory point design

    Point Design Assumptions:

    Earth Departure Orbit: 700 km altitude

    Earth Return Orbit: 90,000 km altitude

    Mars Parking Orbit: 16,700 km altitude

    Stay Time in Mars Orbit: 70 days

    Total Trip time includes LEO to high Earth orbit spiral time

    Point Design Result Highlights (see Table for further details)

    IMLEO: 271.6 mt

    Total trip time (includes Earth spirals): 692.9 days

    Earth spiral out/in trip time: 98.5 / 2.1 days

    Earth spiral out/in propellant cost: 40 / 0.86 mt

    Mars spiral in/out trip time: 6.23/ 6.06 days

    Mars spiral in/out propellant cost: 2.5 / 2.4 mt

    Time in Mars Vicinity: 82.3 days

    Closest approach of trajectory to Sun: 0.398 AU

    Earth-Mars Trajectory Analysis Sensitivity Study

    Earth-Mars 16700/90000 Trajectory Point Design


    Earth mars 2026 90 000 km earth return 16 700 km mars parking orbit point design trajectory plot

    Earth-Mars Trajectory Analysis Sensitivity Study

    Earth-Mars 2026 (90,000 km Earth return, 16,700 km Mars Parking Orbit)Point Design Trajectory Plot

    • Mission Assumptions:

    • Earth Departure Orbit: 700 km altitude

    • Earth Return Orbit: 90,000 km altitude

    • Mars Parking Orbit: 16,700 km altitude

    • Stay Time in Mars Orbit: 70 days

    • System Assumptions

    • Power: 6 MW

    • Specific Impulse (Isp): 4000 sec

    • Thruster efficiency: 60%

    • Tankage Fraction: 5%

    Escape Earth

    Spiral for 98.5 days

    November 7, 2026

    Mass after spiral: 232.0 mt

    Close Approach to Sun

    Distance ~ 0.39 AU

    Earth

    Begin Spiral Capture at Mars

    June 20, 2027

    Mass before spiral: 160.8 mt

    Start at 700 km Earth orbit altitude

    July 31, 2026

    Initial Mass: 271.6 mt

    Sun

    Mercury

    Finish capture at Mars

    July 27, 2027

    Spiral for 6.3 days

    Capture into 16,700 km orbit

    Mass after spiral: 158.3 mt

    Escape Mars

    Spiral for 6.1 days

    Sept. 11, 2027

    Mass after spiral: 155.9 mt

    Capture at Earth

    June 23, 2028

    Orbit altitude 90,000 km

    Spiral for 2.1 days to capture

    Mass after spiral: 89 mt

    Mars

    Stay time 70 days in Mars orbit

    Begin Spiral Escape of Mars

    Sept. 5, 2027

    Begin Spiral at Earth return

    July 21, 2028

    Mass before spiral: 89.6 mt

    Courtesy: Melissa McGuire/GRC, Rob Falck/GRC


    Earth mars 2026 point design bookend cases data table

    Earth-Mars Trajectory Analysis Sensitivity Study

    Earth Mars 2026 Point Design Bookend Cases Data Table

    Courtesy: Melissa McGuire/GRC, Rob Falck/GRC


    Sensitivity analysis assumptions

    Earth Departure Orbit: 700 km altitude

    Earth Return Orbit: vary from 30,000 to 90,000 km altitude

    Mars Parking Orbit: vary from 500 to 17,200 km altitude

    Stay Time in Mars Orbit: calculated to sum time in Mars vicinity to approximately 90 days

    Resulted in stay times at Mars in orbit from 37 to 77 days

    Total Trip time includes spiral time from LEO to high Earth orbit

    Earth-Mars Trajectory Analysis Sensitivity Study

    Sensitivity Analysis Assumptions


    Imleo vs earth return orbit altitude

    Earth-Mars Trajectory Analysis Sensitivity Study

    IMLEO vs. Earth Return Orbit Altitude

    305

    Mars Orbit

    Mars Stay: 37.0 days

    Altitudes

    Mars Spiral: 54.5 days

    17200km

    10000km

    300

    Mars Stay: 37.0 days

    Mars Spiral: 53.6 days

    5000km

    Mars Stay: 37.0 days

    Mars Spiral: 53.0 days

    500km

    Mars Stay: 37.0 days

    Mars Spiral: 52.7 days

    295

    Mars Stay: 37.0 days

    Mars Spiral: 52.4 days

    Mars Stay: 60.0 days

    290

    Mars Spiral: 30.6 days

    IMLEO (mt)

    Mars Stay: 60.0 days

    Mars Spiral: 30.1 days

    Mars Stay: 70.0 days

    Mars Stay: 60.0 days

    285

    Mars Spiral: 20.4 days

    Mars Spiral: 29.8 days

    Mars Stay: 60.0 days

    Mars Spiral: 29.6 days

    Mars Stay: 70.0 days

    Mars Stay: 37.0 days

    Mars Spiral: 20.0 days

    Mars Spiral: 29.4 days

    Mars Stay: 70.0 days

    Mars Spiral: 19.8 days

    280

    Mars Stay: 70.0 days

    Mars Spiral: 19.7 days

    Mars Stay: 70.0 days

    Mars Stay: 77.0 days

    Mars Spiral: 19.6 days

    Mars Spiral: 13.0 days

    Mars Stay: 77.0 days

    275

    Mars Spiral: 12.8 days

    Mars Stay: 77.0 days

    Mars Spiral: 12.6 days

    Mars Stay: 77.0 days

    Mars Spiral: 12.5 days

    Mars Stay: 77.0 days

    Mars Spiral: 12.4 days

    270

    30000

    40000

    50000

    60000

    70000

    80000

    90000

    Earth Departure/Return Orbit Altitude (km)

    Courtesy: Melissa McGuire/GRC, Rob Falck/GRC


    Total and crewed mission time vs earth return orbit radius

    Earth-Mars Trajectory Analysis Sensitivity Study

    Total and Crewed Mission Timevs. Earth Return Orbit Radius

    Courtesy: Melissa McGuire/GRC, Rob Falck/GRC


    Low thrust nep trajectory trade space raw data

    Earth-Mars Trajectory Analysis Sensitivity Study

    Low Thrust NEP Trajectory Trade Space Raw Data

    Courtesy:

    Melissa McGuire/GRC

    Rob Falck/GRC


    Observations

    Missions of 700 round trip are possible with limits on Earth and Mars orbit altitude choices

    Total trip time does not equal total crew time

    Note: The astronauts will ascend to the NEP vehicle once it’s in the high earth altitude via a crew taxi

    Trade studies needed to evaluate choice of Mars parking orbit with respect to Ascent/Descent vehicle versus NEP vehicle performance

    Note: Appendix D provides some preliminary data

    Further analysis needed to evaluate proximity to Sun on return leg

    Earth-Mars Trajectory Analysis Sensitivity Study

    Observations


    Study 2 sun earth l2 libration point se l2 mission

    Study 2Sun-Earth L2 Libration Point (SE-L2) Mission


    Assumptions1

    Sun-Earth Libration Point (L2) Mission

    Assumptions

    • Satellite constellation deploy/maintenance mission

      • Also, dress rehearsal for Mars mission

    • Single vehicle - NEP Mars transfer vehicle

      • No rendezvous at SE-L2

    • Target => SE-L2

    • Use same vehicle specifications as last year study for Mars transfer vehicle

      • Power = 6 Mw

      • Engine efficiency = 0.6

      • Isp = 4000 sec

      • No thrust vector turning constraints

    • Final mass target (back at Earth) =89mt

    • Mission

      • Opportunity independent - selectable stay time at SE-L2 (independent of Earth departure time)

      • Crew transfer altitude designed to keep crew out of trapped proton radiation belt


    Mission overview2

    Sun-Earth Libration Point (L2) Mission

    Mission Overview

    SE-L2 Operations

    Sun-Earth L2 Libration Point (SE-L2)

    Mars Crew Transfer Vehicle

    Constant Thrust

    Power = 6 MW

    Efficiency = 60%

    Isp = 4000 sec

    Mass Return to Earth = 89 mt

    Trans SE-L2 Flight

    Trans-Earth Flight

    Crew Delivery Taxi

    (Possible Emergency Return Vehicle)

    HEO

    30,000 –> 90,000 km

    (Circular Orbits)

    Crew

    Return

    Rendezvous/Dock Of Crew Taxi and

    Mars Transfer Vehicle

    LEO (700 km)

    On-orbit Construction

    of Transfer Vehicle

    Launch of NEP

    Transfer Vehicle

    Launch Of

    Crew Taxi

    Launch for

    Crew Pickup

    Courtesy: Jerry Condon / JSC/EG5


    Mission overview3

    Sun-Earth Libration Point (L2) Mission

    Mission Overview

    • Spiral NEP ‘Mars’ transfer vehicle from LEO (700 km) to selected crew transfer orbit (flight crew not onboard)

      • Note: The Mars transfer vehicle is used for this mission to Sun-Earth L2 (SE-L2)

        • In addition to meeting planned objectives, the SE-L2 mission could provide a proving ground for future Mars missions

    • Crew taxi launches from ground to Mars transfer vehicle (30,000 – 90,000 km)

      • Crewed mission begins with crew transferred to Mars transfer vehicle above the trapped proton radiation belt

        • Avoids crew spiral through proton radiation belt

        • Crew will, however, spiral through the larger trapped electron belt

    • Mars transfer vehicle spirals from crew transfer orbit to SE-L2

    • Variable stay time at L2

    • Mars transfer vehicle returns crew from SE-L2 to original crew transfer orbit at Earth (30,000 – 90,000 km) for crew pick-up with crew taxi


    Study methodology

    Sun-Earth Libration Point (L2) Mission

    Study Methodology

    • Trajectory tool used: Copernicus

      • Multi-body, multi-spacecraft, continuous thrust trajectory tool in development at University of Texas – Center for Space Research

    • Mission - trajectories were solved backwards (from end of mission to beginning) in order to determine required IMLEO needed to conclude mission with an 89 mt mass

      • Mission segments:

        • Return trip from SE-L2 to crew transfer altitude (30,000 – 90,000 km)

        • Outbound trip from 100,000 km to SE-L2

        • Spiral up from 700 km initial circular Earth parking orbit to 100,000 km circular orbit

          • Mass matching performed for the vehicle at 100,000 km altitude


    Imleo and trip time vs crew altitude

    Sun-Earth Libration Point (L2) Mission

    IMLEO and Trip Time vs. Crew Altitude


    Tabular trajectory data

    Sun-Earth Libration Point (L2) Mission

    Tabular Trajectory Data


    Future work

    Future Work

    • Complete RAPTOR mission set

      • Compare and contrast results with VariTOP

    • Review Mars parking orbit parametric study

      • Evaluate sudden change in eccentricity at 38,000 km altitude range


    Appendices

    Appendices


    Appendix a

    Appendix A

    Mars Arrival Parking Orbit Analysis

    Earth-Mars Round Trip Mission

    Comparison of Elliptical vs. Circular Mars Parking Orbit Arrival

    Kyle Brewer / JSC/EG5

    March 3, 2003


    Purpose

    Mars Arrival Parking Orbit Analysis

    Purpose

    • Provide a comparison of insertion into Circular vs. Elliptical orbits at Mars based on a state vector from a fully integrated roundtrip mission provided by JPL


    Assumptions2

    Mars Arrival Parking Orbit Analysis

    Assumptions

    • Same Vehicle specifications as previous study

    • The JPL mission is optimized for the following roundtrip mission:

      • Depart 30,000 km Earth orbit

      • Arrive/Stay Depart Aerosynchronous (17,048 km alt) orbit

      • Arrive 30,000 km Earth orbit

    • Initial state vector and mass taken from beginning of Mars approach burn (see next slide)

    • Given that the state and mass are not optimized for the variety of orbits analyzed, the resulting data should be considered for comparative purposes only.


    Initial state from jpl

    Mars Arrival Parking Orbit Analysis

    Initial State from JPL

    Initial State taken from this point


    Methodology

    Mars Arrival Parking Orbit Analysis

    Methodology

    • Trajectory tool used: Copernicus

      • Multi-body, multi-spacecraft, continuous thrust trajectory tool in development at University of Texas – Center for Space Research

    • Trajectories to circular orbits were computed by specifying the desired orbit radius and constraining the eccentricity to 0.0 and solving for minimum thrusting time

    • Optimum eccentricity orbits were determined by holding only the desired Semi-Major Axis constant and solving for minimum thrusting time to meet that SMA constraint


    Prop usage for circular and opt ecc orbits

    Mars Arrival Parking Orbit Analysis

    Prop Usage for Circular and Opt. Ecc Orbits


    Optimum eccentricity and ha hp

    Mars Arrival Parking Orbit Analysis

    Optimum Eccentricity and Ha/Hp


    Observations1

    SMA = 30000 km

    SMA = 39600 km

    SMA = 42000 km

    Mars Arrival Parking Orbit Analysis

    Observations

    • A large jump in optimum eccentricity is seen around the target SMA of 39,000 km

      • This is the target about which the powered trajectory makes it’s first complete pass around the planet

    (SMA shown is an altitude)


    Tabular trajectory data1

    Mars Arrival Parking Orbit Analysis

    Tabular Trajectory Data


    Appendix b

    Appendix B

    Mars Parking Orbit Lifetime

    Carlos Westhelle / EG5

    March 3, 2003


    Orbit lifetime at mars introduction

    Mars Parking Orbit Lifetime

    Orbit Lifetime at Mars - Introduction

    • Current Mars ascent vehicle targeted to 200 km temporary parking orbit

    • Off-nominal situations (e.g. failure of subsequent engine firing) may require extended stay in this orbit

    • This lifetime study takes a quick look at the parking orbit lifetime as a function of altitude range (130-200 km) for a range of possible vehicle ballistic numbers (150-1500 kg/m2)


    Orbit lifetime at mars methodology

    Mars Parking Orbit Lifetime

    Orbit Lifetime at Mars - Methodology

    • STK-Astrogator was used to propagate the vehicle with a Mars GRAM atmosphere model

    • Orbit was propagated until it decayed to a 125 km altitude (Mars entry interface) up to a maximum time cutoff of 365 days

    • For orbit propagations reaching this 365 day limit, the resulting orbit altitudes are noted on the plot on the next slide


    Orbit lifetime at mars

    Mars Parking Orbit Lifetime

    Orbit Lifetime at Mars

    Courtesy: Carlos Westhelle / JSC-EG5


    Orbit lifetime at mars observations

    Mars Parking Orbit Lifetime

    Orbit Lifetime at Mars – Observations

    • A 200 km circular Mars parking orbit provides sufficient time (> 365 days) for an extended stay for a worst-case ballistic number (i.e., 150 kg/m2)

      • Note: For this case the vehicle will decay to Mars entry interface (125 km) in approximately another 40 days


    Appendix c

    Appendix C

    Integrated Reference Mission – JPL

    Greg Whiffen/JPL

    February 23, 2003


    Mission design and results

    Mission Design and Results

    • Single end to end multi-body integrated trajectory using Mystic

    • Trajectory characteristics:

      • Start escape spiral at 30,000 km altitude Earth orbit, 224 metric tons, September 8, 2026

      • Escape Earth, 209.9 metric tons, October 24, 2026

      • Capture Mars-begin spiral, 178.1 metric tons,July 18, 2027

      • Areosynchronous orbit 40 days, 173.3 metric tons, July 30 through Sept 8, 2027

      • Mars escape, 171.4 metric tons, September 19, 2027

      • Earth capture, 104.1 metric tons, July 10, 2028

      • Earth 30,000 km altitude orbit, 97.6 metric tons, July 26, 2028

    • Vehicle characteristics:

      • Power = 6 MW, Efficiency = 60%, Isp = 4000 seconds

    • Trajectory results:

      • Total flight time is 687 days from 30,000 km altitude Earth orbit to a return 30,000 km altitude Earth orbit

      • Time spent in low mars orbit is 40 days.

      • Dry mass with tankage is 97.567 metric tons

      • Total propellant used is 126.433 metric tons

      • 5% tankage is 6.322 metric tons

      • Net Mass without tankage 91.245 metric tons


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen/JPL


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen/JPL


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen/JPL


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen/JPL


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen/JPL


    Earth mars artificial g nep architecture sun earth l2 architecture 3 week parametric trade study

    Courtesy: Greg Whiffen / JPL


    Appendix d

    Appendix D

    Effects of Parking Orbit Geometry on Mars Lander Mass

    Dave Lee JSC/EG5

    March 3, 2003


    Effects of mars parking orbit geometry on lander mass

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Effects of Mars Parking Orbit Geometry on Lander Mass

    • Comparison of lander mass trends for circular vs. elliptical orbits

    • Payload mass cases based on:

      • Previous Dual Lander Study

      • JSC/EX/Jim Geffre 6 crew/30 day case

      • Light descent payload case for illustration

    • Delivery method not considered

      • Delivery method would amplify mass trends

      • No periapse raise after aerobrake budgeted

      • High ellipse more suited to aerobrake delivery


    Orbital maneuvers

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Orbital Maneuvers

    Drop periapse for aerobraking

    1

    Parking

    Orbit

    Parking

    Orbit

    Descent

    Ascent

    Raise orbit to PO periapse

    Deorbit

    Circularize in 300 X 300 km

    4

    2

    3

    Ascent to

    200 X 200 km

    Entry, Descent, and Landing

    1

    5

    2

    Aerobraking

    3

    Raise orbit to PO apoapse


    Dual lander case

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Dual Lander Case

    Descent/Ascent Stack

    • Masses:

      • Descent Only Payload = 15314 kg

      • Ascent Payload (w/ crew) = 2624 kg

      • 6 Crew (93 kg each) = 558 kg total

      • Aeroshell mass 10% of total vehicle mass

    • Delta-V’s:

      • Terminal descent = 632 m/s

      • Ascent to 200 km circ = 3900 m/s

      • Rendezvous = 45 m/s

    • Single stage and two stage ascent modeled (same delta-V)

    • Stage Mass fractions calculated per historical model

      • except terminal descent stage (Mass Fraction = 0.58)

    • Specific Impulse for all stages 379 s

    Ascent Payload

    Ascent Stage

    Descent Payload

    Descent Stage

    Circ/Deorbit Stage

    Aeroshell

    Figure intended to show payloads and staging order only.

    No relative scale should be inferred.

    Stage location and orientation should not be inferred.


    Lander mass vs mars parking orbit semi major axis

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis

    110000

    Dual Lander:

    Single Stage Ascent

    100000

    Circular Orbits

    20000 km periapse

    10000 km periapse

    90000

    34%

    5000 km periapse

    80000

    Vehicle Mass (kg)

    2000 km periapse

    70000

    400 km periapse

    60000

    50000

    40000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)


    Lander mass vs mars parking orbit semi major axis1

    110000

    Dual Lander:

    Two Stage Ascent

    100000

    90000

    80000

    Circular Orbits

    Vehicle Mass (kg)

    20000 km periapse

    70000

    10000 km periapse

    28%

    5000 km periapse

    60000

    2000 km periapse

    400 km periapse

    50000

    40000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis


    6 crew 30 day case staging is different

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    6 crew/30 day case* (staging is different)

    Descent/Ascent Stack

    • Masses:

      • Descent Only Payload = 17266.8 kg

      • Ascent Payload (w/ crew) = 5345.5 kg

      • 6 Crew (82 kg each) = 492 kg total

      • Aeroshell mass 14% of total vehicle mass

    • Delta-V’s:

      • Terminal descent = 632 m/s

      • Ascent to 200 km circ = 3931 m/s

      • Rendezvous = 45 m/s

    • Single stage and two stage ascent modeled (same delta-V)

    • Stage Mass fractions calculated per historical model

      • except terminal descent stage (Mass Fraction = 0.58)

    • Specific Impulse for all stages 379 s

    Ascent Payload

    Ascent Stage

    Descent Payload

    Descent Stage

    Circ/Deorbit Stage

    Aeroshell

    Figure intended to show payloads and staging order only.

    No relative scale should be inferred.

    Stage location and orientation should not be inferred.

    *Based on JSC/EX/Jim Geffre design


    Lander mass vs mars parking orbit semi major axis2

    170000

    Geffre 6 crew/30 day:

    Single Stage Ascent

    160000

    Circular Orbits

    20000 km periapse

    10000 km periapse

    150000

    35%

    140000

    5000 km periapse

    130000

    Vehicle Mass (kg)

    120000

    2000 km periapse

    110000

    400 km periapse

    100000

    90000

    80000

    70000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis

    Courtesy: Dave Lee/JSC


    Lander mass vs mars parking orbit semi major axis3

    170000

    Geffre 6 crew/30 day:

    Two Stage Ascent

    160000

    150000

    140000

    130000

    Circular Orbits

    20000 km periapse

    Vehicle Mass (kg)

    120000

    30%

    10000 km periapse

    110000

    5000 km periapse

    100000

    2000 km periapse

    90000

    400 km periapse

    80000

    70000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis

    Courtesy: Dave Lee/JSC


    Light descent payload case

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Light Descent Payload Case

    Descent/Ascent Stack

    • Masses:

      • Descent Only Payload = 500 kg

      • Ascent Payload (w/ crew) = 5345.5 kg

      • 6 Crew (82 kg each) = 492 kg total

      • Aeroshell mass 10% of total vehicle mass

    • Delta-V’s:

      • Terminal descent = 632 m/s

      • Ascent to 200 km circ = 3931 m/s

      • Rendezvous = 45 m/s

    • Single stage and two stage ascent modeled (same delta-V)

    • Stage Mass fractions calculated per historical model

      • except terminal descent stage (Mass Fraction = 0.58)

    • Specific Impulse for all stages 379 s

    Ascent Payload

    Ascent Stage

    Descent Payload

    Descent Stage

    Circ/Deorbit Stage

    Aeroshell

    Figure intended to show payloads and staging order only.

    No relative scale should be inferred.

    Stage location and orientation should not be inferred.


    Lander mass vs mars parking orbit semi major axis4

    130000

    Light Descent:

    Single Stage Ascent

    120000

    20000 km periapse

    Circular Orbits

    10000 km periapse

    110000

    37%

    5000 km periapse

    100000

    90000

    2000 km periapse

    Vehicle Mass (kg)

    80000

    400 km periapse

    70000

    60000

    50000

    40000

    30000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis

    Courtesy: Dave Lee/JSC


    Lander mass vs mars parking orbit semi major axis5

    130000

    Light Descent:

    Two Stage Ascent

    120000

    110000

    100000

    90000

    Circular Orbits

    20000 km periapse

    Vehicle Mass (kg)

    80000

    10000 km periapse

    33%

    5000 km periapse

    70000

    2000 km periapse

    60000

    400 km periapse

    50000

    40000

    30000

    0

    5000

    10000

    15000

    20000

    25000

    30000

    35000

    Mars Parking Orbit Semi-Major Axis (km)

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Lander Mass vs. Mars Parking Orbit Semi-Major Axis

    Courtesy: Dave Lee/JSC


    Conclusions

    Effects of Mars Parking Orbit Geometry on Mars Lander Mass

    Conclusions

    • Elliptical orbits offer major mass advantages for large SMAs as compared to circular orbits

      • Up to 37% lander mass savings for some large SMA cases

      • Most pronounced for Single Stage Ascent (but still significant for Two Stage)

      • If aerobraking delivery were desired, elliptical orbits would offer additional mass advantage

    • Two stage ascent offers major mass advantages for high orbits

      • Over 25% lander mass difference for some higher orbit cases

      • Less than 10% for lowest orbits

      • Most pronounced for Light Descent case and Circular orbits

    • If we consider the mass impact of delivering the lander/ascent vehicle to the Mars parking orbit, these mass trends would be amplified


    Appendix e

    Appendix E

    Van Allen Radiation Belt Data

    Trapped Proton Belt Data

    Jerry Condon / JSC/EG5


    Trapped proton radiation belt dosage vs altitude

    Van Allen Radiation Belt (Trapped Proton) Data

    Trapped Proton Radiation Belt – Dosage vs. Altitude

    Courtesy: Jerry Condon/JSC


    Trapped proton radiation belt effect of orbit orientation

    Van Allen Radiation Belt (Trapped Proton) Data

    Trapped Proton Radiation Belt - Effect of Orbit Orientation

    Courtesy: Jerry Condon/JSC


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