Currently, Researchers at NASA's Goddard Space Flight Center build a backpack-sized instrument to monitor Earth atmosphere from the hostile environment. This instrument is the miniaturized version of laser heterodyne radiometer or LHR, called Mini-LHR.
Mini-LHR is worked in a similar manner like LHR. In Radiometry, LHR is a technique based on the radio receiver that amplifies weak signals from a radio antenna by mixing them with a strong local oscillator.
However, this Mini-LHR is efficacious to set the stage for the possible human exploration of other worlds. Basically, this technique implements to measure the concentration level of trace gasses like methane and carbon dioxide in the atmosphere. From this measurement, Mini-LHR gets crucial info about the Earth's atmosphere.
In fact, Mini-LHR has some advantageous qualities like low-cost, Portable and nearly self-contained. Most interestingly, the device can monitor the atmosphere even in extreme hostile environment like the area near a subaerial volcano.
Regarding this, researchers are selected the region closer to Mauna Loa volcano as a test facility of Mini-LHR. Mauna Loa is one of the five active volcanoes in Hawaii and world's largest subaerial volcano in both mass and volume.
Moreover, Goddard team deployed Mini-LHR in the remote region on the Mauna Loa's saddle region in Hawaii Island. The habitat in that remote region is known as HI-SEAS (Hawai'i Space Exploration Analog and Simulation). This facility simulates an isolated Mars-like environment to prepare for the long-duration missions on the other planetary surfaces in future.
According to NASA, Mini-LHR measures the total amount of methane and carbon dioxide in the atmospheric column. Principally the device is a passive device and collecting only sunlight and nothing leaves the unit, not even stray light. However, the sensitivity of this device is one parts-per-million for CO2 and 10 parts-per-billion for Methane or CH4.
In addition, the sunlight gets mixed with a laser beam inside this Mini-LHR. However, this technique is similar to the way an FM radio receiver operates. Though the only difference is, it's equipped with telescope instead of an antenna. Like similar process in telecommunication, here also need to boost the weak using a tiny infrared laser.
The atmospheric gasses are detected in Mini-LHR by the absorption of light at particular infrared wavelengths. The pattern of this absorption is totally distinct for each gas. However, this device currently measures the methane and carbon-di-oxide but also it can detect carbon monoxide and water vapors.
Jacob Bleacher, Goddard's geologist said that Mini-LHR might be deployed around human landing sites of Mars and other planets. Moreover, the device is being maintained by crews of HI-SEAS. This is because the facility provides insufficient space, foods and power supply to simulate similar atmosphere in ISS.
HI-SEAS crews are sending the data from Mini-LHR through the mail with 20 minutes delay. This is because it simulates the signal time travel between Earth and Mars.
