Dual stage catalytic thruster

A catalytic thruster comprising:

• a reaction chamber that extends between a first chamber end and a second chamber end, the first chamber end including a thermal standoff cup;
• a catalyst bed in the reaction chamber, the thermal standoff cup bounding the catalyst bed;
• a feed tube that extends into the reaction chamber through the thermal standoff cup, the feed tube includes a tube end that has at least one injection port that opens into the reaction chamber;
• and
• a sacrificial flow restrictor that partially blocks the at least one injection port, wherein the sacrificial flow restrictor is formed of a material that degrades and sheds from the at least one injection port upon operation of the catalytic thruster,
• the feed tube extending a distance D1 into the reaction chamber, the distance D1 being defined from an inside surface of a narrow bottom of the thermal standoff cup where the feed tube enters to a tip of the feed tube in the reaction chamber, the reaction chamber is disposed about a central axis and has a radial dimension D2 relative to the central axis, and a penetration ratio of the distance D1 to the radial dimension D2 is greater than or equal to 1:1.