Astronauts experience changes in vestibular function while in a microgravity environment, which leads to illusory motion causing spatial disorientation upon g-level transitions. This impairs piloting performance during landing and will pose further safety risks in future lunar and planetary missions while landing and performing tasks post-g-level transitions. We propose a wearable device that applies galvanic vestibular stimulation (GVS) to induce spatial disorientation in response to head-tilt, to artificially replicate the sensation astronauts experience upon g-level transitions. GVS waveform parameters will depend upon tilt orientation and angular velocity as detected by an IMU. The device will comprise multiple electrodes capable of inducing illusory motion in both pitch and roll axes. It will be used by NASA and other government and private agencies to train astronauts in performing shuttle landings and other tasks while experiencing head-tilt contingent spatial disorientation. During Phase-1 we will adapt an existing portable constant current stimulation design (that incorporates an in-built IMU) into a first functional GVS disorientation trainer. The current prototype is single channel, wirelessly charged, has data logging capability and provides full control via a bluetooth connected smartphone app. We will adapt it into a 2-channel version to allow simulating pitch and roll tilt and incorporate additional features to fully meet the stated deliverables of the solicitation. Phase-1 will establish a laboratory version of the disorientation trainer culminating in pilot testing with up to 3 participants. We expect a TRL of 4 by the end of Phase-1 and TLR 6 by the end of Phase-2. This technology addresses NASAs Human Research Programs need for improving human behavioral performance and risk reduction. It will improve astronauts performance during landing and tasks post-g-level transitions. Potential NASA Applications (Limit 1500 characters, approximately 150 words): We expect NASA to use our device for training astronauts as well as intermittently afterwards for performance maintenance, since all other proposed solutions for spatial disorientation (e.g. preconditioning astronauts for landing by creating artificial gravity in space using a centrifuge) are impractical for multiple reasons. Efforts are underway to form a permanent human presence on the Moon. This will require many well-trained shuttle crew members, increasing the usefulness of our technology. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): In the advent of a lunar economy, private companies will train astronauts with our device to perform landings and post-g-level transition tasks. Also, our technology will be used for training military and commercial pilots for spatially disorienting flight maneuvers. Furthermore, our programmable GVS-IMU device can be developed into a balance prosthesis for those with certain vestibular disorders. Duration: 6