15-16 June 2005 1

.THEMIS

Propellant Offload Concept

M. Sholl (UCB)

M. McCoullough (SAI)

P. Turin (UCB)

15-16 June 2005 MIWG/GOWG(TIM)

Space Sciences Laboratory

Berkeley, CA

(Revision A, 2 June 2005)

15-16 June 2005

EWR127.1-Chapter 3Launch Vehicle, Payload, and Ground Support Equipment Documentation, Design, and Test Requirements

3.12.1.3 Flight Hardware Pressure System Offloadinga. Hazardous pressure systems shall be designed so that

depressurization and drain fittings are accessible and do not create a personnel or equipment hazard for off-loading hazardous fluids at the launch complex. NOTE: This requirement is intended for contingency safing operations.

b. The design goal is to be able to offload these pressure systems at any point after pressurization or loading, including the ability to offload all systems at the launch pad without demating of the spacecraft from the launch vehicle or any other disassembly of vehicle systems.

c. In cases in which the Range User and Range Safety decide that design prohibits offload capability of a mated spacecraft at the launch pad, offload shall be possible within the launch complex.

15-16 June 2005

P5 Access

• P5 is located centrally on PC

• Fifth door (2ft x 2ft) requested on fairing for access to P5

• Accessible via standard “diving board”, defined in ICD

• Access difficult in SCAPE suit

15-16 June 2005

Defuel Panel

• Regulated N2 supply

• Valve allows fuel tanks to be drained individually, with minimal reconfiguration

• EWR-dictated pressure relief valves, scrubbers, and facility vents required

15-16 June 2005

Defuel Tank 1

RV1

CV

G1

P1

V1

V4

RV2

DOT 4BW

G3

V3 P3

V2 P2 SV2

THEMIS Probe

Facility Vent

Propellant Offload Panel

Facility Vent

SV1

Tank 1 Tank 2

G2

SV3

Scrubber

Cylinder

Regulated GN2 Source

20 gal min cap

Scale

15-16 June 2005

Defuel Tank 2

Tank 1 Tank 2Facility Vent

V1 RV1 RV2

P1

CV

G1

Regulated GN2 Source

Propellant Offload Panel

V4

V2

V3

G2

G3

P2

P3

DOT 4BWCylinder20 gal min cap

Scale

SV1

SV2

SV3

THEMIS Probe

Facility Vent

Scrubber

15-16 June 2005

Technique for propellant offload in SCAPE suit

• Propellant offload lines remain attached to P5, coiled and stowed until final fairing closeout. During final closeout, technician uses ICD-defined diving board to remove lines.

• Propellant valve may be opened, and line removed after offload, while in SCAPE suit from fairing exterior using offload extension tool

• Standard safety practices apply (tethering, etc.)

15-16 June 2005

Fill/vent panel

Open/close valve

Drain line or cap

15-16 June 2005

HOSE PASSED THROUGH FAIRING

DOOR DURING ENCAPSULATION

HOSE ATTACHMENT

FITTING

PROBE FUELING

VALVE

Drawings: P. Turin

15-16 June 2005

FAIRING DOOR

15-16 June 2005

VALVE OPENING WRENCH IS SLID

DOWN HOSE WHICH ACTS AS GUIDE

15-16 June 2005

FLANGE ON WRENCH PREVENTS WRENCH

FROM SLIDING BEYOND NUT

WRENCH IS TURNED TO OPEN VALVE

15-16 June 2005

HOSE REMOVING WRENCH IS SLID

DOWN HOSE, WHICH ACTS AS GUIDE

15-16 June 2005

REMOVABLE FLANGE ON WRENCH

PREVENTS WRENCH FROM SLIDING

BEYOND NUT

WRENCH IS TURNED TO

REMOVE HOSE

15-16 June 2005

FLANGE ON NUT PREVENTS HOSE

FROM FALLING THROUGH WRENCH

DURING WITHDRAWAL

15-16 June 2005

Conclusions

• P5 may be defueled by SCAPE suited technicians, using aforementioned tools

• EWR-127.1, 3.12.1.3b describes this defuel capability as a goal

• Range and Boeing to decide whether this should be baselined, or to invoke EWR-127.1, 3.12.1.3c, which allows defueling after fairing removal