Earth’s atmosphere blocks many forms of radiation and other electromagnetic waves from reaching the earth’s surface.
EM spectrum blockage by the atmosphere. Image used courtesy of Science Learning Hub
While the atmosphere is absolutely essential for life to exist on earth, its presence can impede on our scientific observation of the universe.
In response, scientists have turned to something called space balloons, which carry observation equipment and electronic payloads to complete an exploration mission.
What are Space Balloons?
Balloon-bound telescopes can overcome the atmospheric veil. With this instrument, scientists can effectively observe the universe without costly and time-consuming expeditions into space.
Illustration of an upcoming NASA space balloon mission. Image used courtesy of JPL
In fact, NASA’s Scientific Balloon Program has been operating for 30 years and launches 10 to 15 missions a year from locations around the globe.
Balloon missions have both a lower cost and faster turnaround time compared to space missions. This adds the benefit of allowing more updated technology to be deployed and utilized in their missions.
The Electronics of Space Balloons
According to NASA’s JPL, a payload of a space balloon normally consists of its telescope, science instrument, and such subsystems as the cooling and electronic systems.
The electronic system is an integral part of these missions, generally in charge of managing all of the sensors and logging all of the data. Sensors can typically include GPS, altimeters, thermocouples, and inertial measurement units. Electronic systems also aid in the navigation, and safe return, of the space balloon.
Electronically-controlled landing feedback loop. Flowchart used courtesy of Berkeley STAC
Like many other space missions, space balloons have unobstructed access to the sun’s light. This makes electronic systems on these missions useful candidates for solar power, presenting many interesting design challenges and opportunities.
Design Challenges of Space-Balloon Payloads
It’s been well documented that the design of electronics for space (or high altitude) payloads offers unique challenges to engineers.
For starters, leaving the protective canopy of the earth’s atmosphere exposes the electronics to all sorts of ionizing radiation that doesn’t exist on the terrestrial surface. As discussed in a previous AAC article, this has created the need for radiation-hardened (rad-hard) electronics for space missions.
It’s also worth noting that far-infrared instruments need to be kept extremely cold, which requires the use of a liquid helium cooling system.
Student-made high altitude balloon avionics sensor board. Image used courtesy of PJRC and Kirill Safin
Space balloon missions require improved batteries to store electrical energy onboard. Long-duration balloon flights can experience 12 hours or more of darkness, and excess electrical power generated during the day from solar panels needs to be stored.
These unique demands call for means of more efficient energy generation, better energy storage, and novel low-power electronics.
NASA’s Upcoming Space-Balloon Mission
Last week, NASA announced that work has begun on a new mission that will carry a cutting-edge 8.4-foot telescope high into the stratosphere on a balloon. This balloon, dubbed ASTHROS (astrophysics stratospheric telescope for high spectral resolution observations at submillimeter-wavelengths) will launch from Antarctica and spend about three weeks in the air.
The goal of this mission is to measure the motion and speed of gas around newly-formed stars. During the flight, the system will study four main targets, including two star-forming regions in the Milky Way.
The NASA press release explains, “ASTHROS will make the first detailed 3D maps of the density, speed, and motion of gas in these regions to see how the newborn giants influence their placental material. By doing so, the team hopes to gain insight into how stellar feedback works and to provide new information to refine computer simulations of galaxy evolution.”
The beauty of unique missions like these is that they push the current state of electronics to meet the demands of space exploration.
ASTHROS will allow scientists to deploy technology for space observations that have yet to be used. Through this mission, NASA hopes to gain a deeper insight into the formation of the galaxy and, if we’re lucky, bring some technological improvements to earth as well.