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Cited by 6Spacecraft Design and TechnologySpacecraft Dynamics and ControlRocket and propulsion systems research

NASA GRC Compass Team conceptual point design and trades of a hybrid Solar Electric Propulsion (SEP)/Chemical Propulsion Human Mars Deep Space Transport (DST) Vehicle

Open access
McGuire, Melissa L., Oleson, Steven R., Burke, Laura, McCarty, Steven, Newman, J. Michael, Martini, Michael, Smith, David·2018·2018 AIAA SPACE and Astronautics Forum and Exposition
DOI 10.2514/6.2018-5141
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Abstract

NASA has long been conducting studies which apply different in-space propulsion technology assumptions to the mission of sending humans to Mars. Two of the technologies under study that are considered to be the most near-term with respect to technology readiness level (TRL) are traditional chemical propulsion systems and high-power Solar Electric Propulsion (SEP) systems. The benefit of relatively low trip times inherent in using impulsive chemical propulsion systems to perform the full round-trip delta V is hampered by the large propellant mass required to perform these burns for human Mars missions. SEP systems offer the benefit of much lower propellant requirements to perform the same round-trip missions, at the cost of longer trip times. Traditionally, impulsive chemical systems are better suited than SEP when used in a gravity well, and SEP systems are more efficient than traditional impulsive systems when used in interplanetary space. A mission to Mars includes both of these scenarios, and thus several NASA architecture studies performed over the last few years have looked to combine the use of both SEP and chemical propulsion systems where they are the most beneficial to human Mars missions. This combined propulsion system concept has been referred to as a SEP/Chem hybrid Mars Transfer Vehicle and is currently shown as the concept Deep Space Transport (DST) in the March 2017 NASA presentation to the National Aerospace Council (NAC).

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Crossref · 10.2514/6.2018-5141

Cites

10 of 10 references verified0 citation errors · 0 not checkable

Statistics

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Claims the paper makes

0 of 11 cited sources checked · 0 supported · 0 flagged

  • Findingnone given

    The chemical propulsion system performs a 138 m/s MOI burn to capture into the desired 5 Sol orbit.

    “uses the chemical propulsion system to perform a 138 m/s MOI burn to capture into the desired 5 Sol orbit.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The DST docks to Gateway in a 9:2 NRHO during initial outfitting and for refit and refueling after completed missions.
  • Findingnone given

    The crewed vehicle reaches Mars on August 7, 2038.

    “The crewed vehicle arrives at Mars on August 7, 2038”
    Quote in the paperNot a substantial claim
  • Findingown data

    The BOL solar array power for baseline Case 1, and for Case 2, operating at 120 V was 485 kW.

    “The BOL solar array power for the baseline Case 1 (and for Case 2 as well) operating at 120 V was 485 kW.”
    Quote in the paperNot a substantial claim
  • Findingreasoning

    With margin included, 44,680 kg of propellant is loaded onto the DST while it is in the NRHO.

    “Including margin, a total of 44,680 kg of propellant is loaded onto DST while in the NRHO, as seen on line 10.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The DST is launched with enough propellant to reach the NRHO and then needs refueling to complete the round-trip Earth-Mars mission.
  • Findingreasoning

    Because the EP system cannot provide enough initial acceleration after the LGAs to reach Mars while allowing a 300-day surface stay, the chemical system must perform a 360 m/s TMI burn.

    “Because the EP system cannot provide sufficient initial acceleration following the LGAs to reach Mars while enabling a 300-day surface stay, the chemical system must perform a 360 m/s TMI burn.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: For crewed missions, the SEP-Hybrid performs a 6-month near-ballistic WSB transfer from the NRHO to the LDHEO to await crew rendezvous.
  • Classified as probably not a substantial claim. 27
  • May combine two claims. 44

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The crew transfers 8,700 kg of logistics from the logistics module to the DST.

    “The crew transfer 8,700 kg of logistics from the logistics module to the DST.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The DST launch mass is 44,756 kg, made up of 23,813 kg inert Transport Module, 19,760 kg inert Habitat, 1,074 kg usable RCS/ACS, and 108 kg usable xenon.

    “The launch includes a 23,813 kg inert Transport Module (the propulsion and power portion of the DST), a 19,760 kg inert Habitat mass, along with 1,074 kg usable RCS/ACS and 108 kg of usable xenon, for a total launch mass of 44,756 kg.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The DST is launched on a single SLS and delivered to an orbit about Earth.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The DST performs phasing burns to target a two-LGA sequence that raises outgoing C3 to 2 km2/s2.

    “The DST performs phasing burns to target the 2 LGA sequence to increase the outgoing C3 to a value of 2 km 2 /s 2 .”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Findingnone given

    The docking maneuver back to Gateway requires 859 kg of propellant.

    “Rather than carry all of the required propellant to perform this docking maneuver (859 kg) all the way to Mars and back”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: A commercial flight brings the propellant required for the docking maneuver to the DST and transfers it before the DST docks with Gateway.

  • May combine two claims.

    Findingreasoning

    The usable propellant needed for the remaining mission includes 21,118 kg xenon, 21,246 kg main chemical propellant, and 180 kg RCS/ACS propellant.

    “The usable propellant includes 21,118 kg of xenon, 21,246 kg of main chemical propellant, and 180 kg of RCS/ACS propellant.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The DST is launched with enough propellant to reach the NRHO and then needs refueling to complete the round-trip Earth-Mars mission.

  • May combine two claims.

    Findingreasoning

    Inability to operate the AEPS at a lower voltage reduced SEP thrust for the outbound leg, leading to a need for a chemical TMI burn requiring about 10 t of chemical propellant.

    “Being unable to operate at a lower voltage reduced the SEP thrust level for the outbound leg of the trajectory leading to the need for a chemical TMI burn requiring ~10 t of chemical propellant.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    In the analyzed trajectory, the DST leaves Earth on July 18, 2037.

    “In this analysis, the DST escapes Earth on July 18, 2037.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The two solar array panels are each 39.09 m by 28.46 m.

    “The two solar array panels are each 39.09m x 28.46m.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    Orion brings a 13,000 kg co-manifested logistics module and docks to the DST in the LDHEO.

    “Orion brings a 13,000 kg co-manifested logistics module and docks to the DST in the LDHEO.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: For crewed missions, the SEP-Hybrid performs a 6-month near-ballistic WSB transfer from the NRHO to the LDHEO to await crew rendezvous.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    Waste mass drops depend on mission duration and consumption rate and occur at several points in the mission.

    “The waste mass drops are functions of mission duration and consumption rate and occur at several points in the mission.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingnone given

    The primary SEP system had two pallets of twelve 13.3 kW Hall thrusters each and twelve cylindrical xenon tanks carrying the 22 t of xenon propellant needed for the roundtrip trajectory.

    “The primary SEP system consisted of two pallets of twelve 13.3 kW Hall thrusters each and twelve cylindrical xenon tanks carrying the 22 t of xenon propellant required to perform the roundtrip trajectory.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The xenon propellant is refueled on-orbit before each use and reuse of the DST.

  • May combine two claims.

    Findingown data

    The solar arrays had a total area of 1029.7 m2 and a total mass of 1650 kg.

    “The solar arrays were a total area of 1029.7 m 2 and total mass of 1650 kg.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    The SEP system is used during the Earth inbound transit to reduce the departure burn near Mars and to keep the arrival C3 at Earth below 2 km2/s2.

    “The SEP system is used during the Earth inbound interplanetary transit to reduce the departure burn done near Mars and to ensure that the arrival C3 at Earth remains under 2 km 2 /s 2.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    The thermal control system had roughly 119 m2 of deployed radiators able to radiate about 32,000 Wth from the SEP, PMAD and module systems.

    “The Thermal Control system consisted of roughly 119 m 2 of deployed radiators capable of radiating ~32,000 Wth from the SEP, PMAD and module systems.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The Habitat has its own thermal systems and the propulsion and power module is not responsible for thermal control of the Habitat.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The solar array booms provide 10.91 m of distance between the DST power and propulsion module and the solar array.

    “The solar array booms offer 10.91m distance between the DST power and propulsion module nad the solar array”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    When fully deployed, the longest dimension across the solar arrays is 84.01 m.

    “When fully deployed, longest dimension across the solar arrays is 84.01m.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The chemical system performs a TMI burn to further increase departure energy after the LGA maneuvers.

    “The chemical system performs a TMI burn to further increase the departure energy following the LGA maneuvers.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    For cases using HERMeS' thrusters, eight total thrusters were placed on the SEP-Chem bus, resulting in a maximum power of approximately 400 kW usable by the thrusters.

    “For cases using the HERMeS' thrusters, eight total thrusters were placed on the SEP-Chem bus resulting in a maximum power of approximately 400 kW usable by the thrusters.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The HERMeS' thruster will be designed to operate near 50 kW at the lower 300 V/2000 s setpoint, necessitating a ~150 A cathode compared to the AEPS ~20 A cathode.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    During uncrewed periods in the LDHEO, the SEP-Hybrid must perform 10 m/s orbit maintenance burns each orbit to maintain perigee altitude.

    “During uncrewed periods in the LDHEO the SEP-Hybrid must perform 10 m/s orbit maintenance burns during each orbit to maintain perigee altitude.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: For crewed missions, the SEP-Hybrid performs a 6-month near-ballistic WSB transfer from the NRHO to the LDHEO to await crew rendezvous.

  • May combine two claims.

    Findingnone given

    For cases using AEPS thruster strings, 24 total thrusters were placed on the DST Transport module, resulting in a maximum power of approximately 319 kW usable by the thrusters.

    “For cases using the AEPS thruster strings, 24 total thrusters were placed on the DST Transport module resulting in a maximum power of approximately 319 kW usable by the thrusters.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Besides propellant, 14,040 kg of logistics and 1,896 kg of items offloaded from the Habitat at launch are loaded onto the DST in the NRHO.

    “In addition to propellant, 14,040 kg of logistics, as well as 1,896 kg of items that were offloaded from the Habitat at launch are also loaded on DST, as seen on lines 11 and 12 in Table 2.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The DST is launched with enough propellant to reach the NRHO and then needs refueling to complete the round-trip Earth-Mars mission.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    The trajectory design required about 15 t of cryogenic LOX/LCH4.

    “The trajectory design required ~ 15 t of cryogenic LOX/LCH4.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Inbound SEP delta-v for Case 1 was 3056.4 m/s, Case 2 3084.9 m/s, and Case 3 3063.1 m/s.

    “Inbound SEP DV (m/s) 3056.4 3084.9 3063.1”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Total SEP delta-v for Case 1 was 6264 m/s, Case 2 6317.1 m/s, and Case 3 6557.8 m/s.

    “Total SEP DV (m/s) 6264 6317.1 6557.8”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total chemical delta-v for Case 1 was 717.9 m/s, Case 2 704.7 m/s, and Case 3 359.9 m/s.

    “Total Chem DV (m/s) 717.9 704.7 359.9”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Total payload wet mass with growth was 19760 kg.

    “Total Wet Mass with Growth 19760 0 19760”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    MOI delta-v for Case 1 was 137.8 m/s, Case 2 136.5 m/s, and Case 3 139.3 m/s.

    “MOI DV (m/s) 137.8 136.5 139.3”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    DST total mass for Case 1 was 42395 kg, Case 2 41192 kg, and Case 3 40511 kg.

    “DST Total Mass 42395 41192 40511”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total xenon propellant for Case 1 was 20.2 t, Case 2 20.2 t, and Case 3 24.9 t.

    “Total Xenon Propellant (t) 20.2 20.2 24.9”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Mass at Earth return for Case 1 was 63 t, Case 2 62 t, and Case 3 61 t.

    “Mass at Earth Return (t) 63 62 61”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Using the higher power SEP system in Case 3 removed the chemical departure burn and cut total round-trip mission propellant requirements by more than 10 t of chemical propellant.

    “Using the higher power SEP system eliminated the need for a chemical departure burn and therefore reduced the total round-trip mission propellant requirements by >10 t of chemical propellant.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The HERMeS' thruster will be designed to operate near 50 kW at the lower 300 V/2000 s setpoint, necessitating a ~150 A cathode compared to the AEPS ~20 A cathode.

  • May combine two claims.

    Findingown data

    EP system power for Case 1 was 319 kW, Case 2 319 kW, and Case 3 400 kW.

    “EP system power (kW) 319 319 400”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Number of EP thruster strings for Case 1 was 24, Case 2 24, and Case 3 8.

    “Number of EP Thruster Strings 24 24 8”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Acceleration following TMI for Case 1 was 1.318×10^-7 km/s^2, Case 2 1.322×10^-7 km/s^2, and Case 3 1.894×10^-7 km/s^2.

    “Acceleration following TMI (km/s 2 ) 1.318×10 -7 1.322×10 -7 1.894×10 -7”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Outbound SEP delta-v for Case 1 was 3196 m/s, Case 2 3221.0 m/s, and Case 3 3485.2 m/s.

    “Outbound SEP DV (m/s) 3196 3221.0 3485.2”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Total interplanetary time of flight for Case 1 was 1036 days, and for Cases 2 and 3 was 1035 days.

    “Total Interplanetary TOF (d) 1036 1035 1035”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    TMI delta-v for Case 1 was 360.2 m/s, Case 2 353.6 m/s, and Case 3 0.0 m/s.

    “TMI DV (m/s) 360.2 353.6 0.0”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Re-orientation SEP delta-v for Case 1 was 11.4 m/s, Case 2 11.2 m/s, and Case 3 9.5 m/s.

    “Re-orientation SEP DV (m/s) 11.4 11.2 9.5”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Total chemical propellant for Case 1 was 19.4 t, Case 2 21.1 t, and Case 3 8.0 t.

    “Total Chemical Propellant (t) 19.4 21.1 8.0”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Mass at Earth escape for Case 1 was 111.9 t, Case 2 112.7 t, and Case 3 103.3 t.

    “Mass at Earth Escape (t) 111.9 112.7 103.3”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Case 2 used the same near-term SEP as Case 1 but utilized Orion's storable chemical propulsion systems instead of the lower TRL LOX/LCH4 systems, allowing for even more dry mass launch margin.

    “The second design case, Case 2, which included the use of the same near-term SEP as Case 1 but utilized Orion's storable chemical propellant propulsion systems (thrusters, tanks, etc.) instead of the lower TRL LOX/LCH4 systems, allowed for even more dry mass launch margin.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Less chemical propellant and smaller tanks made the concept vehicle about 2 m shorter.

    “The reduction in chemical propellant required to perform the mission, and subsequent reduction in tank size, shortened the concept vehicle by about 2 m.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The Compass baseline DST design Case 1, assuming near-term SEP and advanced LOX/LCH4, successfully fit on a single SLS launch with 104 kg of launch margin but had a slightly larger departure wet mass (112 mt) compared to Cases 2 and 3.

    “The Compass baseline DST design Case 1, which assumed near term SEP and advanced LOX/LCH4 successfully fit on a single SLS launch (104 kg of launch margin) but had a slightly larger departure wet mass (112 mt) compared to Case 2 and Case 3.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    TEI delta-v for Case 1 was 219.9 m/s, Case 2 214.6 m/s, and Case 3 220.6 m/s.

    “TEI DV (m/s) 219.9 214.6 220.6”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingown data

    EP thruster power for Case 1 was 13.3 kW, Case 2 13.3 kW, and Case 3 50 kW.

    “EP Thruster Power 13.3 kW 13.3 kW 50 kW”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The HERMeS' thruster will be designed to operate near 50 kW at the lower 300 V/2000 s setpoint, necessitating a ~150 A cathode compared to the AEPS ~20 A cathode.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The 13.3 kW AEPS thruster string, also called HERMeS, will be demonstrated on NASA's upcoming PPE, which will provide propulsive capability for Gateway.

    “The 13.3 kW AEPS thruster string, also referred to as the HERMeS thruster [18], will be demonstrated on NASA's upcoming PPE which will provide propulsive capability for Gateway.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] Huang, 2017

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    The paper's trajectories were modeled with the Copernicus trajectory tool.

    “The trajectories documented in this paper are modeled using the high-fidelity trajectory tool, Copernicus.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Increased thruster string power reduced the required number of thruster strings from twenty-four down to eight, thereby reducing the overall complexity of the EP system.

    “The increased thruster string power also reduced the required number of thruster strings from twenty-four down to eight, thereby reducing the overall complexity of the EP system.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The HERMeS' thruster will be designed to operate near 50 kW at the lower 300 V/2000 s setpoint, necessitating a ~150 A cathode compared to the AEPS ~20 A cathode.

  • May combine two claims.

    Interpretationnone given

    For Mars opportunities from 2033 through 2045, the SEP/Chem hybrid vehicle would be outfitted and refueled in NRHO and could deliver a pressurized Habitat with a crew of four to an orbit about Mars.

    “For Mars opportunities starting in 2033, and extending through to 2045, this SEP/Chem hybrid vehicle, also referred to as DST, would be outfitted and refueled in a lunar near rectilinear halo orbit (NRHO) and be capable of delivering a pressurized Habitat with a crew of four to an orbit about Mars.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The DST is a single integrated vehicle made of a pressurized crew Habitat and a power and propulsion Transport module.
    • The authors state this as an assumption: The DST is launched on a single SLS and delivered to an orbit about Earth.
    • The authors state this as an assumption: The DST is launched with enough propellant to reach the NRHO and then needs refueling to complete the round-trip Earth-Mars mission.
    • The authors state this as an assumption: The DST docks to Gateway in a 9:2 NRHO during initial outfitting and for refit and refueling after completed missions.
    • The authors state this as an assumption: For crewed missions, the SEP-Hybrid performs a 6-month near-ballistic WSB transfer from the NRHO to the LDHEO to await crew rendezvous.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Using LOX/LCH4 and storable NTO/MMH systems on the DST in addition to landed assets could allow cost and technology development savings in the overall Mars architecture.

    “Utilizing these systems on the DST in addition to the landed assets could allow for cost and technology development savings in the overall Mars architecture.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Solar radiation pressure was not modeled in this analysis.

    “Solar radiation pressure has not been modeled at this time.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Compass uses AIAA S-120-2006 as the guideline for its mass growth calculations.

    “The Compass Team utilizes the AIAA S-120-2006, “Standard Mass Properties Control for Space Systems,” as the guideline for its mass growth calculations.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites AIAA S-120-2006

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    An optimized end-to-end trajectory was developed for the baseline design and for each propulsion system trade case.

    “In order to fully understand the impact of propulsion system technologies on the round-trip mission, an optimized end-to-end trajectory was developed for the baseline design, as well as for each of the propulsion system trade cases.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Margin was carried on all propellants: an extra 5% usable xenon, 5% usable main chemical propellant, and 10% usable RCS/ACS propellant, included in the vehicle inert mass summary.

    “Margin was carried on all propellants; An additional 5% of usable xenon, 5% of useable main chemical propellant, and 10% of usable RCS/ACS propellant, and is included in the vehicle inert mass summary.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The DST concept was built on previous Compass analyses and designed to combine low-thrust and high-thrust propulsion for round-trip delivery of a crew of four from Earth to Mars.

    “The DST concept documented in this paper was built upon these previous analyses, and designed to combine the best of low thrust and high thrust propulsion systems for round-trip delivery of a crew of four from the Earth to Mars.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [11] Drake B.G., 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [12] Drake, B.G.(ed.)."Human ExplorationofMarsDesign ReferenceArchitecture5.0,Addendum,"NASA/SP-2009-566-ADD.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationnone given

    Optimal operation of an SEP system of this type for the SEP-Hybrid mission is higher thrust (300 V) during the outbound leg and higher Isp (600 V) during the return leg.

    “Optimal operation of an SEP system of this type for the SEP-Hybrid mission is higher thrust (300 V) during the outbound leg and higher Isp (600 V) during the return leg.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The solar array booms allow the arrays to articulate to track the Sun and provide clearance from the thruster pod plumes.

    “Likewise, the solar array booms allow for both articulation of the arrays to track the Sun and to provide clearance to keep the arrays out of the thruster pod plumes.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    The 13.3 kW Hall Effect thrusters are planned as the primary EP system for the Power and Propulsion Element of NASA's Gateway.

    “These thrusters are also planned as the primary EP system for the Power and Propulsion Element (PPE) of NASA's Gateway as the primary EP system.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Copernicus is a generalized spacecraft trajectory design and optimization tool that can design low-thrust and impulsive trajectories.

    “Copernicus is a generalized spacecraft trajectory design and optimization tool, capable of designing low thrust and impulsive trajectories.[16]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] Williams, 2016, NASA. NASA, 3

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    High-thrust systems are well suited for escaping and capturing into gravity wells, at the cost of higher propellant usage.

    “High thrust systems are well suited for use in escaping and capturing into gravity wells at the cost of higher propellant usage.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductcitation

    Copernicus is an n-body tool and is considered high fidelity.

    “Copernicus is an n-body tool and is considered high fidelity.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [15] C.OcampoandJ.Senent,"TheDesignand Developmentof COPERNICUS:A ComprehensiveTrajectory Designand Opti-mization System,"PaperIAC-06-C1.4.04, Oct. 2006.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [16] Williams, 2016, NASA. NASA, 3

  • May combine two claims.

    Premisenone given

    Low-thrust systems work best outside gravity wells and can use propellant more efficiently to provide DV, at the cost of longer trip times.

    “Low thrust systems work best outside of the gravity wells and can more efficiently use propellant to provide DV at the cost of longer trip times.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premiseown data

    The AEPS thruster is capable of operating at a lower Isp in the range of 2000 s, but it must be run at half power (~6 kW, limited by 20-A cathode) to do so.

    “While the AEPS thruster is capable of operating at a lower Isp in the range of 2000 s, it has to be run at half power (~6 kW, limited by 20-A cathode) in order to do so.”
    Quote in the paperSubstantial claim
63 of 63

  • The authors state this as an assumption.

    The DST is a single integrated vehicle made of a pressurized crew Habitat and a power and propulsion Transport module.

    “The DST was assumed to be a single integrated vehicle, composed of a pressurized crew Habitat and a power and propulsion Transport module.”

  • The authors state this as an assumption.

    The DST is launched on a single SLS and delivered to an orbit about Earth.

    “The DST was assumed to be launched on a single SLS and delivered to an orbit about the Earth.”

  • The authors state this as an assumption.

    The DST is launched with enough propellant to reach the NRHO and then needs refueling to complete the round-trip Earth-Mars mission.

    “it was assumed that the DST would be launched with propellant sufficient to deliver itself to the NRHO and would then require refueling to complete the round-trip Earth to Mars mission”

  • The authors state this as an assumption.

    The DST docks to Gateway in a 9:2 NRHO during initial outfitting and for refit and refueling after completed missions.

    “The DST was assumed to dock to the Gateway in a 9:2 near rectilinear halo orbit (NRHO) [14] during initial outfitting and for refit and refueling following completed missions.”

  • The authors state this as an assumption.

    For crewed missions, the SEP-Hybrid performs a 6-month near-ballistic WSB transfer from the NRHO to the LDHEO to await crew rendezvous.

    “For crewed missions, it was assumed that the SEP-Hybrid vehicle performs a 6 month near-ballistic WSB transfer from the NRHO to a lunar distant highly elliptical orbit (LDHEO) to await rendezvous with the crew.”

  • The authors state this as an assumption.

    Gateway provides all required orbit maintenance and attitude control while the DST is docked to it in the NRHO.

    “It is assumed that Gateway provides all required orbit maintenance and attitude control while DST is docked to it in the NRHO.”

  • The authors state this as an assumption.

    The EP system performs the necessary DV to transfer into the NRHO via WSB after an LGA and provides attitude control during the transfer.

    “The EP system is assumed to perform the necessary DV to transfer into the NRHO via the WSB following an LGA, as well as provide attitude control during the transfer.”

  • The authors state this as an assumption.

    The main propulsion propellant is actively cryocooled to maintain zero boiloff and is designed to be refueled on-orbit.

    “The main propulsion system's propellant was assumed to be actively cryocooled (~ 1000 W input) to maintain zero boiloff and was assumed to be designed to be refueled on-orbit.”

  • The authors state this as an assumption.

    The xenon propellant is refueled on-orbit before each use and reuse of the DST.

    “This xenon propellant is also assumed to be refueled on-orbit before each use and reuse of”

  • The authors state this as an assumption.

    The Habitat has its own thermal systems and the propulsion and power module is not responsible for thermal control of the Habitat.

    “It was assumed that the Habitat would have its own thermal systems and the propulsion and power module of the DST would not be responsible of thermal control of the Habitat.”

  • The authors state this as an assumption.

    The Habitat computers generate the trajectory for main propulsion and command the RCS for control.

    “The Habitat computers were assumed responsible for generating the trajectory for main propulsion and commanding the RCS for control.”

  • The authors state this as an assumption.

    C&DH and communications primarily rely on larger systems assumed present on the crew Habitat for far-range communications and vehicle propulsion and attitude operations.

    “For the purpose of this concept design, the Command and Data Handling (C&DH) and communications systems primarily relied on the larger systems assumed to be present on the crew Habitat to provide far range communications and vehicle propulsion system and attitude system operations.”

  • The authors state this as an assumption.

    Two redundant X-band systems for hybrid module operation, separate from the Habitat, are assumed on the DST propulsion module for navigation while in the NRHO before crew arrival.

    “For navigation while in the NRHO, before the crew meets the DST in the Orion and transfers to the DST, two redundant X-band systems for hybrid module operation which were separate from the Habitat were assumed on the DST propulsion module.”

  • The authors state this as an assumption.

    A commercial flight brings the propellant required for the docking maneuver to the DST and transfers it before the DST docks with Gateway.

    “it was assumed that a commercial flight would bring up the required propellant, dock to DST and transfer it prior to DST docking with Gateway.”

  • The paper relies on this without support.

    NASA's Mars architecture currently under study makes wide use of performance gains of LOX/CH4 systems.

    “NASA's Mars architecture currently under study makes wide use of the performance gains of LOX/CH4 systems.”

  • The paper relies on this without support.

    HERMeS' is the next iteration of the AEPS thrusters being developed for in-space EP system applications.

    “HERMeS' is the next iteration of the AEPS thrusters being developed for in-space EP system applications.”

  • The paper relies on this without support.

    The HERMeS' development was based on an identified need for SEP thruster systems capable of operating at Isp in the 2000s range at full power.

    “This development was based on the identified need for SEP thruster systems capable of operating at Isp in the 2000s range at full power.”

  • The paper relies on this without support.

    The HERMeS' thruster will be designed to operate near 50 kW at the lower 300 V/2000 s setpoint, necessitating a ~150 A cathode compared to the AEPS ~20 A cathode.

    “The HERMeS' thruster will be designed to operate near 50kW at the lower 300V/2000s setpoint (necessitating a ~150amp cathode compared to AEPS ~20-amp cathode).”

  • The paper relies on this without support.

    The PPE will demonstrate and characterize the high-power SEP system utilizing the AEPS thrusters.

    “The PPE will demonstrate and characterize the high-power SEP system utilizing the AEPS thrusters.”

  • The paper relies on this without support.

    On-orbit data from PPE combined with HERMeS' ground-testing will lead to high confidence in the HERMeS' thruster string.

    “This on-orbit data from PPE combined with the HERMeS' ground-testing will lead to high-confidence in the HERMeS' thruster string.”

  • The paper relies on this without support.

    The current Mars mission CONOPS proposed that DST would be launched earlier than the other landed elements.

    “The current Mars mission CONOPS proposed that DST would be launched earlier than the other landed elements.”
21 of 21

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Case 1 is not heavier than Case 2 at Earth departure

    Minor

    The conclusion ranks Case 1 above both alternatives in departure wet mass, but Table 6 gives Case 1 as 111.9 t and Case 2 as 112.7 t.

1 of 1

Cites

Flagged first, then by citations

Research works printed but not linked: 15

  1. Mercer C.R., 2016, SPACE2013ConferenceandExposition,AIAA 2013-5492
  2. Drake B.G., 2007, NASA/TM-, 2007, C63725
  3. Percy T.K., 2015, AIAA 2015-4519
  4. Burke M., 2014, 50thAIAA/ASME/SAE/ASEE JointPropulsionConference;, 28, N16239
  5. Gefert L.P., 1999, AAS/AIAA Astrodynamics SpecialistConference, AAS, 99, 16
  6. Freeh J.E., 2015, B.K.,"ComparisonofSolarElectricandChemical PropulsionMissions,"66thInternationalAstronauticalCongress(IAC
  7. Burke L.M., NASA TM2018
  8. Borowski S.K., 2013, AIAA 2013-5354
  9. Drake B.G., 2010, HumanExploration ofMarsDesignReferenceArchitecture5.0
  10. Drake, B.G.(ed.)."Human ExplorationofMarsDesign ReferenceArchitecture5.0,Addendum,"NASA/SP-2009-566-ADD.
  11. Hambleton K., 2017, NASA. NASA, 28, y2017
  12. Williams, 2017, Space FlightMechanics Meeting,AAS17-267
  13. Williams, 2016, NASA. NASA, 3, 2017
  14. Huang, 2017, Propulsion Conference(IEPC),NASA/TM-2017-219726
  15. Stanley S., 2017, AIAA 2017-4726

Cited by

Sorted by citations

Related

Authors
McGuire, M. L., Oleson, S. R., Burke, L., McCarty, S., Newman, J. M., Martini, M., & Smith, D.
Affiliations
  • Glenn Research Center (US)
  • Vantage Partners, LLC
ORCID
Smith, David
Venue
2018 AIAA SPACE and Astronautics Forum and Exposition
Publisher
American Institute of Aeronautics and Astronautics
Published
2018-09-15
DOI
10.2514/6.2018-5141
OpenAlex
W2891335188
Semantic Scholar
72d02d8ec98d8719cb6586a0f61049a70da528d5
Cited by
6
References
7
Citations by year
2025: 1 · 2024: 1 · 2023: 1 · 2021: 1 · 2020: 1 · 2019: 1
FWCI
1.29
Type
conference paper
Language
en
Open access
Locations
  • AIAA SPACE and Astronautics Forum and Exposition (publishedVersion)
  • NASA STI Repository (National Aeronautics and Space Administration) (submittedVersion)
Topics
  • Physical Sciences › Engineering › Aerospace Engineering › Spacecraft Design and Technology
  • Physical Sciences › Engineering › Aerospace Engineering › Spacecraft Dynamics and Control
  • Physical Sciences › Engineering › Aerospace Engineering › Rocket and propulsion systems research
Keywords
chemical propulsion, human Mars missions, Mars transfer vehicle, propellant mass reduction, travel time, gravity well, interplanetary space, mission architecture

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-06.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-06.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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