An LTA Renaissance, 242 Years After! Pages

AN LTA RENAISSANCE, 242 YEARS LATER

Every scientific study is built on a 360-degree open-minded mentality and absolute objectivity, and I trained myself to adhere to this fundamental principle. In 2020, at the start of the epidemic, I saw an increase in the amount of glitzy news around new LTA projects in the atmosphere and the stratosphere – a term that regroups balloons, aerostats, dirigibles, and haps. I've worked in the satellite and rocket industries for 37 years, so I'm naturally sarcastic, but I found it amusing when the major companies in the space industry boasted about their plans to return to the Moon and land people on Mars so many millions of miles away from an LTA altitude! Today, all of my colleagues are currently engaged in deep space research and frequently discuss nuclear propulsion and meteoroid interception. As a result, when you discuss LTA with them, they reply with stories about their amazing balloon ride over the Kenyan savannah or about flying over a temple in Cambodia. However, don't risk telling them that a new, significant market is about to emerge. They will simply laugh out loud! Now, in 2022, the wind is changing weirdly as a result of the “ethos” around climate change. To sum up: An LTA observation platform can be launched with a small amount of helium instead of an 80 to 150-million-dollar rocket launcher that releases polluting nitrogen and methane into the atmosphere. Zero CO2 emissions and no skylight pollution. Astronomers, you may applaud. No orbital debris risks – see the Orbital Dash chronicle edition – as the LTA is brought down silently to the ground with almost no impact upon landing. The cost of the highest LTA in the stratosphere (at 20 km) is 10% or less of the launch cost of an LEO satellite. For which usage? Observation of the effects of climate change, assistance during natural disasters, telecom networks 5G/6G, border patrol, and support for warfare and intelligence are only a few examples. What are we waiting for, you're going to ask after reading that list?

Well, the disadvantage is that a single GEO satellite that covers 1/3 of the earth is extremely far away (35,000 km) from the maximum possible upper LTA location. But on the other hand, to the LTA advantage, a 300 m radius is the right size for climate control and telecom space to ground applications. The typical station-keeping lifetime of a geostationary satellite is 15 years. For maintenance and servicing, a stratospheric LTA must be brought down once a year with another replacing it in rotation. To be fair, LTAs do not have the ambition of replacing any satellite models but rather smartly propose to be a telecom relay to the ground. It would take too much time to compare LTAs with LEO satellites (like Starlink) but the comparison is to the LTA advantage even more. We won't defend LTA causes that don't need to be protected in this chronicle. You'll be surprised, like I was, at the number of applications that have sprung from the minds of these unconventional operators who have faced ridicule from their space industry colleagues but who are firmly rooted in their business models. Then, after finishing your reading, come to your own conclusion.

A climate change crucial tool, a 1500-gram weather balloon, carries instruments aloft to some 30 km in altitude in the stratosphere to send back information on atmospheric, temperature, humidity, and wind speed by means of a small, expendable measuring device called a radiosonde.