Specifications.pdf

Specifications for Design and Fabrication of a Thrust Stand

November 8, 2016

A. Shall be of modular construction, each component shall be manufactured, calibrated and ship as modules. Installation shall not require more than two shifts of work by two experienced aerospace mechanics (32 man hours) and after installation, the thrust stand shall be capable of removal and reinstallation without affecting the thrust system characteristic or alignment and shall not require more than one shift of work by two experienced Aerospace mechanics (16 man hours).

B. Shall operate over three thrust ranges with an accuracy equal to or better than 0.5% of each operational range.

a. The contractor shall provide calibration and run load cells for operation in the 0.5 N to 5

N thrust range.

b. The contractor shall provide calibration and run load cell for operation in the 3 N to 15 N thrust range.

c. The contractor shall provide calibration and run load cell for operation in the 10 N to 30

N thrust range.

C. Shall operate and measure in two modes of thruster operation, steady state and pulsed modes.

a. Steady state mode results in continuous operation of the thruster up to 4500 sec

b. Pulsed mode results when the thruster is repetitively fired in an on/off cycle with a minimum of a 10ms on/10ms off pulse width.

c. Shall provide a frequency analysis to insure stand will operate without resonating.

D. Shall conform to the Design Envelope shown in the attached Sketch A, page 3 is attached.

a. The thrust Stand shall be configured to bolt direct to four hard point penetration in the altitude Test chamber

b. The outside dimension shall not exceed the dimension shown but can be smaller.

c. Thrust stand longitudinal axis shall align with center of the four hard point penetration in the altitude test chamber in a horizontal orientation

d. Weight shall not exceed 800 lbs.

E. Shall have provisions for attaching to an overhead crane for removal and installation by the

Government.

F. Shall use universal flexure as flex points. The use of ball and socket joint is prohibited.

G. Shall provide a universal mounting plate with a removable interface plate to allow for adaption of a variety of thruster mount interfaces

a. The expected thruster interface is expected not to exceed 8” in diameter

b. The design must allow for an axial fuel line.

H. Shall have a calibration system that can be remotely operated outside the altitude Test Chamber and is a self- contained, integral part of the basic thrust stand.

a. The only penetrations needed to operate the calibration system shall be pneumatic lines and/or electrical lines.

b. Calibration system shall have provisions to prevent overloading the run load cell and operate at altitude conditions.

c. Calibration shall be performed in situ at altitude conditions.

I. Shall be operational in an altitude environment at pressures ranging from 0.05 psia to 0.5 psia.

J. Shall be designed to minimize impacts of heat soak back during long duration testing. External cooling shall be integrated into the design if required by analysis to maintain temperatures within the thermally compensated range of key components.

K. Shall have provisions for mechanically or optically aligning the rocket engine to with 0.3 degrees of the longitudinal axis of the Altitude test chamber: Contractor shall provide any special tooling for accomplishing this.

L. Shall use run and calibration strain gauge load cells. Dual bridge strain gauge load cells are preferable. Load Cells to be calibrated and certified by a reliable agency which can accomplish

0.25% full scale certification that is traceable to the National Institute of Standards and

Technology, USA.

M. Contractor shall provide drawings required for NASA approval within 30 days of effective contract date

a. Schedule for first submittal

b. Schedule for approval, approved as noted or disapproved

c. Response schedule

d. Responsibility for errors.

N. Contractor shall provide at time of delivery Production level drawings including

a. Parts list and cut sheets

b. Detail and assembly drawings

c. Interface control data

d. Diagrams including wiring and connectors

e. Performance characteristic

f. Critical manufacturing limits

g. Details of material and processes.

O. The contractor shall provide a complete operations and installation manual in triplicate.

P. At time of quotation the bidder shall provide documentation that demonstrates relative experience in the design and fabrication of thrust stand of this size and application. Three references shall be furnished, at least one shall demonstrate thrust stand design in this range.

Q. Delivery shall be made within 180 calendar days after contract effective date to NASA Glenn

Research Center.

R. Shall include an initial site visit to assess test chamber interface issues and a site visit to support initial installation and integration.

S. Final inspection and acceptance will be performed at delivery destination.