The Space Congress® Proceedings 1990 (27th) 90's - Decade Of Opportunity

Apr 25th, 2:00 PM - 5:00 PM

Paper Session II-A - Space Station Assured Crew Return Vehicle (ACRV) System and Operational Considerations

George F. Fraser Space Transportation Systems Division Rockwell International Downey, California

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Scholarly Commons Citation Fraser, George F., "Paper Session II-A - Space Station Assured Crew Return Vehicle (ACRV) System and Operational Considerations" (1990). The Space Congress® Proceedings. 17. https://commons.erau.edu/space-congress-proceedings/proceedings-1990-27th/april-25-1990/17

This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. SPACE STATION ASSURED CREW RETURN VEHICLE (ACRV) SYSTEM AND OPERATIONAL CONSIDERATIONS

George F. Fraser Space Transportation Systems Division Rockwell International Downey, California

January 1990

ABSTRACT The Space Station currently is being designed to maximize crew safety through fault tolerance, safe- haven provisions, and crew delivery and return using the Space Transportation System (STS). Studies have identified the need for assured crew return capability through a space-based "lifeboat" that is always available for use in contingencies encompassing (1) medical emergencies, (2) Space Station failures, and (3) interruption of STS services. This paper reviews major mission, operational, and system requirements and the process for evaluating a range of practical vehicle and operational options. It describes flight and ground system design concepts and the major trade studies being performed to select the best end-to-end system that will provide a basis for design and development. Flight vehicles include capsules with ballistic and low lift/drag characteristics and aerodynamic-shaped designs. Ground systems emphasize the use of existing resources.

1. INTRODUCTION 2. NASA ACRV STUDY PROCURE- MENT PLANS BEING During Space Station Phase B studies, con­ IMPLEMENTED sideration was given to enhancement of crew safety through the use of a space-based crew As a result of studies that identified the need return vehicle. NASA initiated assured crew for a space-based rescue system, NASA is con­ return capability studies in 1986 and assessed tracting for ACRV systems studies. space- and ground-based crew rescue approaches. The NASA studies concluded that Two contracts for combined Phase A1 and space-based rescue was required; this conclusion optional Phase B studies are planned with dura­ was supported by several major independent tions of 6 and 12 months, respectively. These study groups, including the National Research contract studies, each valued at $6 million, com­ Council, Aerospace Safety Advisory Panel, and mence in April 1990 under the management of the NASA Critical Evaluation Task Force activity the NASA JSC Project Office. at the . • COMBINED PHASE A' & PHASE B OPTION ON ONE CONTRACT

• OBJECTIVE - TO DEFINE AN ASSURED MEANS OF CREW RETURN FROM SPACE • PHASE A' FIRST 8 MONTHS TO SUPPORT SPACE STATION PERMANENT MANNED PRESENCE

• PHASE B "HARD" OPTION ADDITIONAL 12 MONTHS » ACRC STUDIES INITIATED IN FY 1986 FINALIZED FY 1988

• EXERCISE OPTION DURING PHASE A' > TWO APPROACHES ADDRESSED * SPACE-BASED ~ RESPOND IN MINUTES/HOURS * GROUND-BASED - RESPOND IN WEEKS/MONTHS • FIRM FIXED-PRICE CONTRACTS PLANNED

• IN-HOUSE ACRC STUDY CONCLUDED SPACE-BASED RESCUE SYSTEM WAS • ESTIMATED VALUE $6M (PER CONTRACT) NECESSARY FOR DEFINED MISSIONS * CREW RETURN FOR MEDICAL REASONS • PHASE A' - $1.5M * NEED FOR STATION EVACUATION « PHASE B - $4.5M * NSTS SERVICE INTERRUPTION

• CONCURRENT STUDIES BY VARIOUS INDEPENDENT GROUPS SUPPORTED THE • START APRIL 1990 NEED FOR SPACE-BASED RESCUE SYSTEM * 1987 NATIONAL RESEARCH COUNCIL REPORT * 1989 AEROSPACE SAFETY ADVISORY PANEL REPORT • RESPONSIBLE ORGANIZATION: ACRV PROJECT OFFICE - * CRITICAL EVALUATION TASK FORCE, ETC,

4-21 3. MISSION REQUIREMENTS AND time constraints (including return of crew to a SYSTEM IMPACT DEFINED medical facility), and crew life support and accel­ eration limits. These key requirements influence The NASA studies identified three missions the landing site selection; entry and landing requiring return of the Space Station crew using modes; and the vehicle shape, size, number, and an ACRV. The missions that are combined into subsystem designs. sets to develop requirements encompass: MISSION REQUIREMENT SYSTEM IMPACT MEDICAL MISSION • TIME LIMIT LANDING SITE SELECTION & SAR • 24 HR FROM DECISION * Return of a sick or injured crew member • 6 HR MISSION * CREW ACCELERATION LIMITS • ENTRY CONTROLLED ENTRY MODERATE LID CAPSULE OR LIFTING BODY * Return of the complete Space Station » LANDING IMPACT VELOCITY CONTROL • SICK CREW MINIMUM CREW SIZE - 2 crew following a need for evacuation MEDICAL & EGRESS PROVISIONS SS FREEDOM CONTINGENCY • EVACUATION TIME LIMIT GROUND SUPPORT & CHECKOUT * Return of the crew following interruption ON-ORBIT OR GROUND LOITER CAPABILITY • STATION CONDITIONS CONTROLLED SEPARATION of STS services • CREW SIZE - 8 VEHICLE SIZE/NUMBER OF VEHICLES . STS SERVICES INTERRUPTED • CREW SIZE - 8 \ . VEHICLE SIZE/NUMBER OF VEHICLES AS FOR The most significant mission requirements STATION CONTINGENCY that impact the system design include crew size, COMBINED MISSIONS NUMBER OF USES OVER 30 YEARS

4. WIDE RANGE OF CONCEPTS has been assessed relative to the ability of these CONSIDERED systems to satisfy key mission requirements. Concepts have also been evaluated in terms of A wide range of concept options encompass­ maturity and program impact to converge on the ing ballistic entry compatible shapes, controllable most promising representative configurations. capsules, and aerodynamic lifting body vehicles

DROPOUT: i NOW REENTRY \ INFLATABLE DEP LOVABLE LIFTING BODY

SHUTTLE (SMALL) RUSSIAN

SHUTTLE (LARGE) RUSSIAN

SHUTTLE JAPANESE

NASP (NATIONAL AEROSPACE PLANE)

HOTOL (HORIZONTAL TAKEOFF & LANDING)

SHAPES SINGLE-PERSON ESCAPE CAPSULES BALLISTIC SHAPES LIFTING-BODY DEFICIENT IN CRITICAL AREAS STRONG CONTENDERS STRONG CONTENDERS

4-22 5 . STUDIES PLANNED TO VALIDATE mission requirements and assure crew safety in MISSION REQUIREMENTS AND an affordable system. A range of operating ASSESS OPTIONS modes and system designs will be considered, encompassing ballistic and controlled entry; con­ Representative vehicle configurations in a ventional parachute and parasail deceleration range of aerodynamic performance categories are systems; and land terrain, water, or runway being evaluated in terms of their ability to satisfy landings.

DELIVERY TO SPACE STATION

EMERGENCY ACRV MISSIONS TO RETURN CREW IF: 1. MEDICAL EMERGENCIES REQUIRE IMMEDIATE RETURN OR EXCEED SPACE STATION CAPABILITIES 2. ACCIDENT/FAILURE CONTINGENCY EXCEEDS SPACE STATION SAFETY CAPABILITIES 3. NSTS LAUNCHES INTERRUPTED

LAND OR & LAND-BASED ELV HELICOPTER DELIVERY RECOVERY (OPTION) SPACE TITAN 4 SHUTTLE OR OTHERS 6. REPRESENTATIVE VEHICLES encompass aerodynamic shape, automation, and ASSESSED RELATIVE TO control. REQUIREMENTS Representative systems are being assessed. Significant discriminators are the abilities to The assessment of representative vehicles is satisfy entry constraints, site access, complexity, based on their merit relative to meeting mission and cost. or programmatic requirements and providing desirable system attributes. Of the candidate representative designs, only the ballistic entry capsule is incompatible with defined requirements due to the excessive accel­ Key mission requirements—including time eration experienced on entry. Major factors influ­ constraints, crew size, and acceleration limits— encing the evaluation of remaining concepts are combined with the needs for simplicity, reli­ include degree of complexity, maturity of the ability, and cost effectiveness to establish desired knowledge base and its impact on program risk, system characteristics. These characteristics and the relative development and life-cycle costs.

MISSION REQUIREMENTS CREW SAFETY SYSTEM CHARACTERISTICS DESIRED CREW MEDICAL SPACE STATION STS SERVICES MINIMUM LCC SIMPLE • AVAILABLE MAINTAINABLE EVACUATION INTERRUPTED & AFFORDABLE RELIABLE • ROBUST COST-EFFECTIVE

CREW: 2 CREW: 441 • SICK CREW INFLUENCES AUTOMATION MISSION: 24 HR EVAC:15-30M • CONFIGURATION PACKAGING SENSITIVE TRANSPORT: SHR DECONDtnONINO INFLUENCES AUTOMATION ENTRY fl: «4 ENTRY (j:<4 ENTRY g:<4 • ENTRY 0 REQUIRES ENTRY LIFT LANDING: 2-10 LANDING: 5-15 LANDING: 5-15 • CONTROLLED LANDING REQUIRED

REPRESENTATIVE VEHICLES

BALLISTIC WITH SEPARATE LOW L/D WITH INTEGRAL MODERATE L/D WITH SEPARATE HIGH L/D WITH INTEGRAL PROPULSION PROPULSION PROPULSION PROPULSION

• AUTOMATION DESIRABLE • ENTRY CONTROL • GOOD CROSS RANGE • MARGIN ON ENTRY • AUTOMATION DESIRABLE - AUTOMATION DESIRABLE • MATURE DATA BASE • ENTRY/LANDING CONTROL - ENTRY fl INCOMPATIBLE • AUTOMATION DESIRABLE • MAN-RATED CONFIGURATION • LOW DECELERATION LOADS - LANDING CONTROL REQUIRED •ENTRY CONTROL • EXTENDED ON-ORBIT LOITER WITH • MAXIMUM CROSS RANGE/SITE • LOW COST • MODERATE CROSS RANGE SERVICE MODULE ACCESS • SIMPLE SYSTEMS • GOOD NSTS PACKAGING • 2 EGRESS PASSAGES • HORIZONTAL LANDING • LOITER WITH SERVICE MODULE • LANDING CONTROL REQUIRED • LANDING CONTROL REQUIRED • MODS TO RAISE LANDING L/D

4-24 7. RELATIVE PERFORMANCE entry g, higher temperatures, and larger recovery ESTABLISHED AS A FUNCTION target dispersion, possibly necessitating water OF AERODYNAMIC SHAPE AND landing. Low to moderate L/D capsules with ENTRY MODE controlled entry offer the opportunity for lower entry g's and temperatures, and smaller recovery The significant performance discriminators targets with a resulting moderate increase in have been identified for the representative candi­ complexity and cost. date concepts as a function of their hypersonic lift-to-drag ratio (L/D) and entry mode. High L/D configurations provide lower entry g's and temperature, excellent recovery target Ballistic entry capsule concepts offer potential accuracy, and site access, but with significant for simplicity and low cost but are subject to high increase in complexity and cost.

RANGE OF L/D

VEHICLE L/D = 0 BALLISTIC L/D < 0.25 L/D < 0.5 L/D < 0.75 L/D > 1.1 OR SYSTEM FACTOR HIGH-G CONFIGURATIONS LOW-G CONFIGURATIONS

ENTRY (g's) ~ 8 >4 <4 <3 <2

GUIDANCE SIMPLE, SPIN VEHICLE BANK ANGLE CONTROL REQUIREMENT • BANK ANGLE & a CONTROL REQUIRED COMPLEXITY FOR ENTRY • 3-AXIS CONTROL REQUIRED FOR RUN­ WAY LANDING

TRAJECTORY LARGE = 30 NMI L/D>0.1 1-NMI SPOT SIZE ACHIEVABLE RUNWAY ACCURACY ACHIEVABLE DISPERSIONS REQUIRED FOR GOOD TRAJEC­ TORY CONTROL

LANDING WATER ONLY LAND OR WATER OPTION RUNWAY LANDING IF SUBSONIC AERO IMPLICATIONS CHARACTERISTICS ACCEPTABLE

CROSS RANGE EXTRA AV REQUIRED TO ACQUIRE LAND AT L/D > 0.5 AT L/D > 0.75 ALL ALLOWANCE OF EXTRA SITE ACCESS IMPLICATIONS SITES, AERO CROSS RANGE INSUFFICIENT SOME SITES SITES & CONUS: OPPORTUNITIES BY LARGE CROSS ACCESSIBLE ACCESSIBLE RANGE WITHOUT WITHOUT EXTRA EXTRA AV AV

HEATING ———————————————————- INCREASING HEAT LOAD IMPLICATIONS INCREASING PEAK TEMPE MATURE ———————————————— nirLEASING CONFIGURATION COMPLEXITY

COST rhUIVI UtoluN IMPLICATIONS FROM OPERATIONS ———————————————————————

4-25 8. WATER IMPACT WITH zontal impact velocity components, parachute •PARACHUTE EECOVERY swing, roll orientation, and wave state. POTENTIALLY EXCEEDS CREW ACCELERATION LIMITS Experience with previous manned capsule programs using parachute recovery indicates that Decisions on water or land landing and the nominal acceleration on the order of 10 g's m&y landing system design are impacted by crew be expected, with a range from 5 to 30 g's. physiological acceleration limits that are orientatiOE-depaident As this range of acceleration with a parachute If ;i. vdiAcb Is landed in water, the induced recovery exceeds NASA-specified sick crew acceleration environment is governed by vehicle acceleration limits, controlled impact becomes shapf water penetration angle, vertical, and hori­ necessary.

VEHICLE PIAIC €*d RESULTANT ACCELERATION (g's)

TO

IMPACT ANGLE (TYPICAL)

9oMPACT HUTCH PARAMETER FOOTPRINT

10 m m « VERTICAL

4-tft 9 . LAND IMPACT WITH PARACHUTE tion; and vehicle shape and attenuation through RECOVERY POTENTIALLY vehicle and ground. EXCEEDS CREW ACCELERATION LIMITS Experience with the program indicates A vehicle that is recovered on land will be that potential accelerations imposed on vehicle subject to acceleration influenced by vertical and and crew will exceed the NASA-defined crew horizontal velocity components; dynamics on physiological limits. This indicates a need for landing considering velocities, terrain, orienta­ reduction in velocity on impact.

COUCH 12.0 DROP I INPUT 18.0 MO. 47 |

4-27 10. ACRV OPERATIONS SUPPORT Freedom, expendable launch vehicles, payload WILL EMPHASIZE USE OF processing facilities and resources, and existing EXISTING OR PLANNED search and rescue forces for ACRV recovery. RESOURCES Mission support availability can be assured Key to effective and affordable operation of through shared use of existing and planned the ACRV are availability and cost effectiveness support resources, plans, and training programs. of operations resources for ground processing, mission support, and flight and recovery. Support to the flight segment will emphasize Ground segment affordability can be operational simplicity through use of existing achieved through effective use of NSTS, SS support equipment inventories and technology.

MISSION SUPPORT LOGISTICS & MAINTENANCE LOGISTICS & MAINTENANCE REAL-TIME PREMISSION TRAINING GROUND PROCESSING FLIGHT OPERATIONS CONTINOUS ONE TIME PERIODIC LAUNCH POSTMISSION . ATTACHED OPERATIONS PROCESSING OPERATIONS -FLIGHT RULES > FLIGHT SSCC/FLT • TECH­ CONTROLLERS NOLOGY CREW ACTIVITY VV PLANNING

FSW PRODUCTION

COMMUNICATIONS FLIGHT PLANNING SPACE STATION INTERFACE SYSTEM & DESIGN FREEDOM DRILLS

4-28 11. MISSION AND SYSTEM TRADE operation decisions have been defined, as illus­ STUDIES WILL RESULT IN trated in the matrix. These studies will be used in SELECTION OF THE BEST ACRV the derivation and definitization of ACRV SYSTEM requirements. The selection of the best ACRV system to A consistent set of evaluation criteria are used satisfy mission requirements in an affordable to assess options to facilitate trade study deci­ manner requires integrated trade studies to assess sions. These key evaluation criteria are satisfac­ a range of system and operational options. tion of mission requirements, crew safety, and life-cycle cost; affordability; simplicity; availabil­ Major trade studies that influence system and ity; reliability; and robustness. DAYTIME VEHICLE 4-9 REUSABLEvs LANDvs ONLYvs INTEGRATED VEHICLE CREW CORRELATION EXPENDABLE WATER ANYTIME ON-ORBITvs TRADES CONFIGURATION CAPACITY ASSESSMENT VEHICLE LANDING LANDING LAND OR WATER LOITER

CAPSULE RECOVERY SITES

=11

CONFIGURATIONS

CAPSULE • BALLISTIC • LOW L/D • MODERATE L/D

LIFTING BODY

• SATISFIES MISSION REQUIREMENTS • CREW SAFETY • LIFE CYCLE COST • AFFORDABLE • SIMPLE • AVAILABLE • RELIABLE • ROBUST.

SYSTEM & OPERATION SELECTION

12. ACRV WILL ENHANCE SPACE requirements and the application of consistent STATION CREW SAFETY criteria to select the best end-to-end ACRV THROUGH ASSURING A system and operations that assure crew safety RETURN CAPABILITY and cost and operational effectiveness.

It is considered that a space-based rescue • ACRV REQUIRED TO ASSURE SPACE STATION CREW SAFETY system will provide an effective means of assur­ • LOSS OF SPACE STATION OR NSTS CREW WOULD HAVE MAJOR ing Space Station crew return. ADVERSE AFFECT ON OUR MANNED SPACE PROGRAM • ACRV SYSTEMS DO NOT REQUIRE TECHNOLOGY ADVANCEMENT Initial studies indicate that the ACRV system • PROGRAM COST MAY BE MINIMIZED THROUGH USE OF can be developed with current technology. AVAILABLE HARDWARE, SOFTWARE, & OPERATIONS SUPPORT RESOURCES

System cost may be minimized through use • CONCEPT SELECTION DRIVEN BY MISSION REQUIREMENTS, of available hardware and operations support CREW CONSTRAINTS, & COST

resources. • ACRV STUDIES SUPPORT SPACE STATION DECISIONS

of the best system to satisfy • BUDGET DECISIONS REQUIRED FOR FY 1991 & Key to selection ACTIVITIES needs are derivation and validation of mission FY 1992

4-29