A
Request for Proposal (RFP) NNA16574335R was issued, on 12 February 2016, for the delivery of a spaceflight qualified
6U CubeSat spacecraft to be operated by
NASA for its Pathfinder Technology Demonstrator (PTD) Project to accommodate
technology subsystems, hereafter referred to as the payload. One flight demonstration is planned for a low thrust propulsion system with options for four follow-on technology demonstrations. Follow‐on missions may include payloads such as higher thrust propulsion systems or payloads such as
optical communications or high precision attitude determination and control systems. Request for proposal response date: 4 April 2016. PTD-1 launched January 24th 2021 on
SpaceX rideshare Transporter-1 mission.
HYDROS Propulsion test . HYDROS is a hybrid chemical/electrical technology to provide propulsion using water. It uses an
electrolysis cell to split water propellant into gaseous hydrogen and oxygen that are stored under pressure in separate tanks. The system then burns the hydrogen and oxygen mix in a simple
thruster nozzle to provide up to 1
Newton and a
specific impulse of 258 seconds. This propulsion system is being developed by
Tethers Unlimited, Inc. In pure water, at the negatively charged cathode, a
reduction reaction takes place, with electrons (e−) from the cathode being given to hydrogen cations to form hydrogen gas. The
half reaction, balanced with acid, is: :Reduction at cathode: 2 H+ (
Aqueous solution) + 2e− → H2 (
gas) At the positively charged anode, an
oxidation reaction occurs, generating oxygen gas and giving electrons to the anode to complete the circuit: :Oxidation at anode: 2 H2O (
liquid) → O2 (
gas) + 4 H+ (
aqueous solution) + 4e− :Overall reaction: 2 H2O (
liquid) → 2 H2 (
gas) + O2 (
gas) The propulsion system uses the electricity generated by the solar arrays to power the miniature water electrolysis. The demonstration will test propulsion performance through programmed changes in spacecraft velocity and altitude. == PTD-2 ==