Abstract: One example includes an altitude control system arranged in a balloon. The system includes a transparent outer chamber configured to receive incident infrared radiation. The system also includes an inner chamber comprising suspended particles configured to change the optical transmission of the inner chamber between a first state having a first transmissivity and a second state having a second transmissivity. The first transmissivity is greater than the second transmissivity. The system further includes a state controller configured to electrically activate the suspended particles to change the optical transmission of the inner chamber from the first state to the second state to change an altitude of the balloon based on the incident infrared radiation.

Abstract: One example includes an altitude control system arranged in a balloon. The system includes a transparent outer chamber configured to receive incident infrared radiation. The system also includes an inner chamber comprising suspended particles configured to change the optical transmission of the inner chamber between a first state having a first transmissivity and a second state having a second transmissivity. The first transmissivity is greater than the second transmissivity. The system further includes a state controller configured to electrically activate the suspended particles to change the optical transmission of the inner chamber from the first state to the second state to change an altitude of the balloon based on the incident infrared radiation.

Abstract: A high altitude balloon including a payload, a balloon film with lifting gas disposed within the balloon film, a sealing ring operably coupled to the balloon film, a retention element configured to retain the payload in contact with the sealing ring, and a release element configured to cause the retention element to release the payload.

Abstract: An apparatus for launching an aircraft secured to a balloon by a tether includes a support member and a launch arm connected to the support member and rotatable relative to the support member about an axis. At least one mechanism releasably connects the aircraft to the launch arm and has a first condition securing the aircraft to the launch arm when the aircraft has a first orientation relative to the launch arm. The release mechanism has a second condition automatically releasing the aircraft from the launch arm when the aircraft has a second orientation relative to the launch arm different from the first orientation.

Abstract: A high altitude balloon including a balloon film, a lifting gas disposed within the balloon film, a payload operably coupled to the balloon film, and a heat transfer element operably coupled between the payload and the balloon film configured to transfer heat from the payload to the lifting gas causing a change in buoyancy of the high altitude balloon.

Abstract: A high altitude balloon including a balloon film, a lifting gas disposed within the balloon film, a payload operably coupled to the balloon film, and a heat transfer element operably coupled between the payload and the balloon film configured to transfer heat from the payload to the lifting gas causing a change in buoyancy of the high altitude balloon.

Abstract: A high altitude balloon including a payload, a balloon film with lifting gas disposed within the balloon film, a sealing ring operably coupled to the balloon film, a retention element configured to retain the payload in contact with the sealing ring, and a release element configured to cause the retention element to release the payload.

Abstract: An apparatus for launching an aircraft secured to a balloon by a tether includes a support member and a launch arm connected to the support member and rotatable relative to the support member about an axis. At least one mechanism releasably connects the aircraft to the launch arm and has a first condition securing the aircraft to the launch arm when the aircraft has a first orientation relative to the launch arm. The release mechanism has a second condition automatically releasing the aircraft from the launch arm when the aircraft has a second orientation relative to the launch arm different from the first orientation.