NNX17A608338Q_Questions_and_Answers.pdf

Questions and Answers:

1. Please provide the maximum engine and adapter weight that will be mounted to the live bed of the thrust stand for each of the three thrust ranges (0.5N-5N, 3N-15N, 10N-30N).

Answer:

Flight weight hardware estimate

Heavy weight hardware estimate

Mounting interface plate estimate

Thrust Range Mass, kg kg kg

0.5-5N 0.9 2.7 0.5-1

3-15N 1.4 4.2 0.5-1

10-30N 2.2 6.6 0.5-1

2. Question: Please provide the amount of heating that will occur during the long duration testing to determine if active cooling is necessary.

Answer: For cooling requirements heavy weight hardware is estimated at 500 W of heat rejection for the smaller thruster up 1000 W for the larger thruster. Flight hardware should be less.

3. Does there need to be a clearance hole down the centerline of the thrust stand for a fuel line;

Is that the 6” Diameter hole in section C-C view?

Answer: For clarification the 6” hole is a for universal flange, 8” dia OD with a 7” Bolt circle kind of a drop in plate that is a mating surface designed based on a specific thruster. The sketch does not show well that there would be smaller diameter edge towards the fixed head that the universal plate would back up against. A center hole is needed due to the nature of the single fuel line of these thrusters, if the thought is to mount directly to the universal plate. That could be < 1”. However, if the thruster can be mounted away (by extension) from the universal plate and allow for an inlet tubing bend into the thruster valve, then not necessarily. The plan was that only the universal plate could be built specifically from thruster to thruster, rather than major alterations to the actual thrust stand as every thruster will have its’ own unique mounting scheme. As the universal mounting flange is actually part of the thrust stand design, alternative dimensions and sizes can be proposed. For example the plate could be square not round. The sketch is intended to provide the envelope of the existing thrust stand mounting feature and the size of the test chamber and a starting point for the universal plate.