Radiation Detection and Dosimety Workshop John Connolly Manager, Lunar Lander Pre-Project CxPO/Advanced Projects Office CONSTELLATION Slide 2 Topics . ESAS Architecture . Changes Since ESAS . Lunar Sortie Design Reference Mission . Lunar Outpost Design Reference Mission . The Radiation Risk Challenge Slide 3 Immediate Answers to Big Questions ESAS was chartered by the NASA Administrator to answer 4 immediate questions: • (1) Complete assessment of the top-level Crew Exploration Vehicle (CEV) requirements and plans to enable the CEV to provide crew transport to the ISS and to accelerate the development of the CEV and crew-launch system to reduce the gap between Shuttle retirement and CEV IOC. • (2) Definition of top-level requirements and configurations for crew and cargo launch systems to support the lunar and Mars exploration programs. • (3) Development of a reference exploration architecture concept to support sustained human and robotic lunar exploration operations. • (4) Identification of key technologies required to enable and significantly enhance these reference exploration systems and a reprioritization of near-term and far-term technology investments. Slide 4 CEV Overview - Crew Module Functions • CM attitude control propulsion (GO2/Ethanol) • Docking system (LIDS) • Contingency EVA • Crew Accommodations • Avionics: DMS, C&T, GN&C, VHM • Life Support and Thermal Control • Earth Atmospheric Entry and Recovery Design of Crew Module Design of Crew Module Design of Crew Module Slide 5 CEV Overview – Service Module Design of Service Module • Avionics • Health sensors, embedded processors • ECLSS/ATCS • 60% propylene glycol / 40% H2O single-phase fluid loop, 4 x 7 m2 body-mounted radiator • Power • 2 x 4.5 kW Solar Arrays • Propulsion • 1 x 15,000 lbf pressure-fed LOX/Methane OMS engine @ 362 s Isp, 24 x 100 lbf Lox/Methane RCS engines @ 315 s Isp, Al-Li graphite wrapped Lox/Methane tanks @ 325 psia, He pressurization • Structure • Graphite epoxy composite skin & stringer/ring frames construction • Thermal Protection • Insulation Slide 6 Launch System Selection • NASA will continue to rely on the EELV fleet for scientific and International Space Station cargo missions in the 5-20 metric ton range to the maximum extent possible. • Commercial capabilities will be allowed to compete. • The safest, most reliable, and most affordable way to meet exploration crew launch requirements ia a 25 metric ton system derived from the current Shuttle solid rocket booster and liquid propulsion system. • Capitalizes on human rated systems and 85% of existing facilities. • The most straightforward growth path to later exploration super heavy launch. • 125 metric ton cargo lift capacity required to minimize on-orbit assembly and complexity - increasing mission success • A clean-sheet-of-papaer design incurs high expense and risk. • EELV-based designs require development of two core stages plus boosters - increasing and decreasing safety/reliability. • Current shuttle lifts 100 metric tons to orbit on every launch. Design of rockets Slide 7 2-stage LOR LSAM with Single Crew Cabin and Integral Airlock images of singe crew module Lunar Surface Access Module (LSAM) • 2-stage, expendable • LOX/H2 Descent Stage performs LOI, nodal plane change and lunar descent • RL-10 derivative throttleable engines • LOX/Methane ascent stage • Same engine as CEV SM • ISRU compatible • Single volume cabin with integral airlock • 2700 kg + cargo capability Slide 8 “1.5 Launch” EOR-LOR Vehicles are not to scale Design of Launch EOR-LOR with labels: Ascent Stage Expended LSAM Performs LOI 100 km Low Lunar Orbit Direct Entry Land Landing Low Earth Orbit EDS, LSAM CEV Earth Departure Stage Expended MOON MOON EARTH EARTH Service Module Expended Slide 9 Potential Lunar Exploration Sites chart of potential lunar exploration sites Landing Site Latitude Longitude Notes ------------------------------------------------------------------------------------------------------------------------------------------------- A. South Pole 89.9 S 180 W (LAC 144) rim of Shackleton B. Far side SBA floor 54 S 162 W (LAC 133) near Bose C. Orientale basin floor 19 S 88 W (LAC 91) near Kopff D. Oceanus Procellarum 3 S 43 W (LAC 75) inside Flamsteed P E. Mare Smythii 2.5 N 86.5 E (LAC 63) near Peek F. W/NW Tranquilitatis 8 N 21 E (LAC 60) north of Arago G. Rima Bode 13 N 3.9 W (LAC 59) near Bode vent system H. Aristarchus plateau 26 N 49 W (LAC 39) north of Cobra Head I. Central far side highlands 26 N 178 E (LAC 50) near nearDante J. North Pole 89.5 N 91 E (LAC 1) rim of Peary B Note: Contours represent LOI delta-V (m/sec) required to access that point on the lunar globe Slide 10 Lunar Sortie Crew Missions Surface Operations Concept • Sorties do not depend on pre-deployed assets and can land at any location on the Moon • Four crew members lives out of landed spacecraft for up to 7 days • EVAscan be conducted every day with all crewmembers • Crew can work as two separate teams simultaneously • Unpressurizedrovers for surface mobility (2 for simultaneous but separate EVA ops) gives crew approximately 15-20 km range from lander • Sortie mission surface activities focus on three activities • Lunar science (geology, geophysics, low frequency radio astronomy, Earth observations, astrobiology) • Resource identification and utilization (Abundance, form and distribution of lunar hydrogen/water deposits near lunar poles; geotechnical characteristics of lunar regolith) • Mars-forward technology demonstrations and operational testing (autonomous operations, partial gravity systems, EVA, surface mobility) Slide 11 Candidate Lunar Outpost Site - Lunar South Pole Lunar South Pole (from Bussey et al, 1999) image Robotic Lunar Program (RLEP) must answer the open issues with the lunar south pole • Advantages • Lunar South Pole is a candidate for outpost site based on its greatest ‘potential’over other sites • Elevated quantities of hydrogen, possibly water ice (e.g., Shackelton Crater) • Areas with greater than 50% sunlight - Area (A) exists with approx. 80% illumination, with the longest darkness period of approximately 50 hours - Areas B and C have more than 70% illumination, with longest dark periods of 188 and 140 hours, respectively • Less extreme diurnal temperatures - Avg. for sunlit areas -53 °C ± 10 °C - Avg. for shadowed areas -223 °C(?) • Disadvantages • Undulating highland terrain (e.g., Apollo 16) - Outpost layout, ISRU • Extreme environment in shadowed craters - Operating machinery at -223 °C - Nature of ‘frozen’regolith • Low sun angle, long shadows • No constant sight communications with Earth Slide 12 Architecture Recommendations • CEV • 5.5 meter diameter blunt body, Apollo-derivative capsule • 32.5 degree SWA • Nominal Land Landing (Water Back-up) Mode • CEV Reusable for 10 Missions, Expendable Heatshield • Pressure-fed LOX/Methane SM propulsion, sized for lunar mission (1450 m/sec TEI delta V) • Crew Launch Vehicle • 4 Segment RSRB • 1 SSME Upper Stage • Cargo Launch Vehicle • Shuttle-derived, in-line ET-diameter with 5 Block II SSMEs • 5 Segment RSRBs • Upper Stage/ Earth Departure Stage w/ 2 J-2S+ • EOR-LOR Mission Mode, "1.5 launch" • Global Lunar Access with Anytime Return • South Pole Lunar Outpost Using an Incremental Build Approach • 2-stage LSAM • LOX-Hydrogen descent propulsion (1100 m/sec + 1850m/sec Descent delta V) • Pressure-fed LOX-Methane ascent propulsion • Airlock • Up to 7 day surface sortie capability Slide 13 PROJECT ESAS diagram of lunar landing flight techniques Direct Lunar Orbit Rendezvous EOR-LOR Slide 14 ISS – Moon –Mars Architecture Linkages design of Mars Architecture linkages with labels: • Mars 6 crew departure and return • 3 to 6 crew + payload • Crew rotation • ISS cargo Operations and Systems • Autonomous operations • Partial gravity systems • EVA, Surface mobility Crew Exploration Vehicle • 4 crew • Earth-moon transfer • Autonomous operations • Partial gravity systems • EVA, Surface mobility •AR&D • Autonomous operations • Safe crew launch Technology Maturation • ISRU Systems • Oxygen-Methane propulsion • Oxygen-Methane propulsion • ISRU Systems • Oxygen-Methane propulsion Earth-to-Orbit Transportation • Safe crew launch • Heavy Payload: 125mt • Large Volume: 8m dia • Safe crew launch • Multiple, Heavy Payload Launches • Large Volume Payloads Slide 15 Changes Since ESAS - Crew Exploration Vehicle (CEV) • CEV Command Module • Mold Line: Apollo-Derived Capsule • Crew: 6 for ISS & Mars, 4 for Moon • Size: 5 Meter Diameter • Docking Mechanism: APAS or LIDS • CEV Service Module • Propulsion: Hypergolic (MMH/NTO) • Some Capability for Delivering Unpressurized Cargo • UnpressurizedCargo Variant No Longer Required • Ongoing Analysis • Impact of Reducing CEV Volume • Trading Functionality between Command nd Service Module • Eventual Migration to Non-Toxic Propellants Design of CEV Design of CEV Slide 16 Changes Since ESAS - Crew Launch Vehicle (CLV) & Heavy Launch Vehicle (HLLV) • Crew Launch Vehicle • Single 5 segment RSRB/M 1st stage • Upper stage powered by a single engine derived from the Saturn J-2 • Given a 5 Meter CEV, Exploring Options for Upper Stage Diameter • Cargo Launch Vehicle • Twin 5 segment RSRB/M 1st stage (from CLV) • Core stage derived from the External Tank • First stage main engine decision forthcoming • CLV-derived avionics • Earth Departure Stage • Upper stage derived from the External Tank • Powered by a single J-2 engine - 2 burn capability • CLV-derived main propulsion system and avionics Design of HLLV Slide 17 Lunar Sortie DRM design of Lunar Sortie DRM with labels: Moon 100 km Low Lunar Orbit LSAM Performs LOI Ascent Stage Expended Earth Departure Stage Expended Low Earth Orbit EDS, LSAM CEV Direct or Skip Entry Land Landing Slide 18 Lunar Sortie DRM • Up to four crew members can explore any site on the Moon for four to seven days • Sortie missions allow for exploration of high-interest science sites or scouting of future Lunar Outpost locations. • Sortie crews have the capability to perform daily extra-vehicular activities (EVAs) with crew members egressing the vehicle through an airlock. • A Lunar Sortie mission requires the following elements: a CLV, aCEV, a CaLV(with EDS), an LSAM. • The mission mode is a combination Earth orbit Orbit Rendezvous and Lunar Oorbit Rendezvous (EOR-LOR) • LSAM and EDS are pre-deployed in a single launch to low Earth orbit using the CaLV • A second launch, with the smaller CLV, delivers the CEV and crew to Earth orbit where the two vehicles (CEV and LSAM/EDS) rendezvous and dock. • The EDS performs the TLI burn for the LSAM and CEV and is then discarded. • Upon reaching the Moon, the LSAM performs the LOI for the two mated elements. • The entire crew will transfer to the LSAM, undock from the CEV, and perform descent to the surface. • The CEV is left unoccupied in low lunar orbit. • After a four to seven day stay, the LSAM returns the crew and their cargo to lunar orbit where the LSAM and CEV dock and the crew transfers back to the CEV. • The CEV then separates the LSAM, performs the TEO maneuver and returns the crew to Earth • The LSAM is disposed via impace on the lunar surface • The CEV re-enters Earth's atmosphere via a direct or skip entry and lands in the western U.S. Slide 19 Sortie Crew Mission Timeline (1) Table of timeline: Event Active Other Event Notes CEV In- Flight CEV LSAM LSAM Element Elements Duration Active Duration Quiescent Active Quiescent (hours) (hours) Duration Duration Duration (hours) (hours) (hours) Cargo CaLV/EDS LSAM 0.8 Launch of the EDS and LSAM into the launch Earth Rendezvous Orbit. (approximately - - - 0.8 48 minutes) DS/LSA EDS and LSAM must be capable of M Loiter EDS LSAM Up to maintaining themselves in the ERO until - - - 2,280 in LEO 2,280 the crew launch, which could be as long as 95 days. (TBR-001-030) CEV, LSAM and Crew Launch of the crew to the Earth Ascent Crew in LEO 24- launch to CLV CEV 0.1 Staging Target. CEV separates from the 0.1 - - 0.1 120 hours EAST CLV at the Earth Ascent Staging Target. (approximately 8 minutes) CEV CEV performs remainder of ascent, Ascent CEV - 0.7 circularization burn, and phasing into the 0.7 - - 0.7 Earth Rendezvous Orbit. (approximately 40 minutes) endezvo CEV performs rendezvous and dock with us and 24 to 120 the EDS/LSAM stack. Includes two day Dock, CEV EDS, LSAM (TBR-001-016) rendezvous sequence and three loiter Earth days, which provides for four consecutive 120 - - 120 Orbit days of crew launch attempts. All systems Loiter are checked out and verified operational prior to TLI. Crew may also enter and run systems checks on the LSAM. CEV, LSAM Trans- EDS is the active element performing the and and Crew Lunar EDS LSAM, CEV 0.3 TLI maneuver. LSAM and CEV are considered 0.3 - - 0.3 in Earth-moon njection payloads with the CEV and ground monitoring transit 72 hours the maneuver. (approximately 15 minutes). EDS performs self-disposal post-TLI. Trans-Lunar This time reflects a balance between Coast, Mid- LSAM CEV 72 propulsive performance and the desire to 72 - - 72 Course minimize crew exposure to deep space Correction conditions. (typically three to four days) Lunar Twenty-four hours for three impulse Orbit LSAM CEV 24 capture into LLO. The CEV is placed in 24 - 6 18 nsertion, quiescent mode prior to LSAM separation. Note (3) heckout Slide 20 Sortie Crew Mission Timeline (2) Table of timeline: Event Active Other Event Notes CEV In- CEV LSAM LSAM Element Elements Duration Flight Quiescent Active Quiescent (hours) Active Duration Duration Duration Duration (hours) (hours) (hours) (hours) LSAM and Crew LSAM in LLO 25 hours eparation LSAM CEV 0.3 Crewed LSAM separates from the CEV - 0.3 0.3 - (estimated 15 minutes for separation sequence) Descent LSAM - 1 LSAM performs descent and landing to - 1 1 - and the desired landing site. Landing 96-168 hours on CEV LSAM CEV 96 to 168 Lunar Sortie mission provides from 4 to 6 160 168 - lunar surface Quiescent 7 days on the lunar surface. Both the [Note (1)] (sortie); Up to Mode. LSAM CEV and LSAM are prepared for ascent. 180 days (Outpost) Surface CEV may need to perform LLO plane change Operation to support LSAM ascent stage rendezvous. Prepare or Ascent CEV and Crew in Ascent, CEV, - 3 Represents in-plane, in-phase rendezvous. 3 - 3 - LLO 32 hours Rendezvous, LSAM Dock AS Post- CEV LSAM AS 3 Crew and cargo transfer from the LSAM 3 - 3 - Ascent to the CEV. LSAM and CEV closeout operations. Operations CEV CEV LSAM AS 0.3 Crewed CEV separates from the LSAM ascent 0.3 - 0.3 - eparation stage (estimated 15 minutes for separation sequence). LSAM LSAM - 2 LSAM performs self-disposal to the - - 2 - Disposal AS [See (4)] lunar surface post-TLI. Trans- CEV - 24 Twenty-four hours for TEI three impulse 24 - - - Earth departure from lunar orbit assuming njection significant Earth-Moon orbital misalignment. CEV and Crew Trans-Earth CEV - 84 to 108 This time reflects a balance between 108 - - - in Earth-moon Coast, propulsive performance and the desire to transit 85-109 Mid-Course minimize crew exposure to deep space hours orrection conditions. +/-12 hour variability from a nominal 4 day return trajectory is provided to allow for longitude control using Earth’s rotation. Entry, CEV CM - 1 Direct or skip entry with landing at 1 - - - Descent, CONUS landing site Landing Recovery CEV CM - 24 to 36 Recovery of crew and vehicle Note (2) - - - ontingency CEV LSAM 72 Contingency active operational time for 72 - - 72 cy the CEV. If used for post-LOI loiter in LLO, this contingency can be used to close the Sortie global access coverage without reducing the LSAM payload to the lunar surface. Total Duration (hours) 434.3 161.3 183.5 2563.9 Total Duration (days) 18.1 6.7 7.6 106.8 x hours at the end of the lunar surface phase is counted as active for the CEV to support checkout and LLO plane change (if quired) to support LSAM rendezvous. he recovery phase is not included in the CEV In-Flight total duration because it has unique unctional requirements. he LSAM is assumed to be active for two hours for each burn in the three-burn LOI sequence, or six hours total. The remainder f the 96 hours is listed as quiescent. he LSAM is assumed to be active for two hours following CEV separation to enable phasing and execution of the de-orbit burn r safe LSAM disposal to the lunar surface. Slide 21 Lunar Outpost Crew DRM • The same suite of vehicles developed to support Lunar Sortie exploration is also required for Lunar Outpost missions • Additionally, a surface habitat, power/communications systems, and other infrastructure elements are required • Outpost deployment options: • Rapidly deploy infrastructure on a few large cargo landers (20 mt per lander) • Land crewed missions repeatedly to one selected site and incrementally building upon useful infrastructure behind after the completion of each mission. • The Outpost will eventually be permanently occupied, with crews rotating every 180 days. Slide 22 Lunar Outpost Crew DRM design of outpost DRM with labels: Moon 100 km Low Lunar Orbit LSAM Performs LOI Ascent Stage Expended Earth Departure Stage Expended Low Earth Orbit EDS, LSAM CEV Direct or Skip Entry Land landing Earth Slide 23 The 3-Part Radiation Risk Challenge • We need to understand the real radiation risk to human space travelers • Better understand and characterize the environment - Lunar neutron environment - High energy proton environment - Develop reliable monitors • Better model the transport of radiation and understand how to build more inherent radiation shielding into our spacecraft designs - Integrating ALARA into the design - Use of Carbon composites in vehicle structures, shielding and components early in the design, and providing recommendations on design optimization - Long lunar stay missions will likely require increased shielding over short stay, the development of strategies to reduce chronic risk and GCR impacts • Better understand the biological effect of radiation on humans Slide 24 image of lunar landing