https://zephalto.com/en/
Zephalto is a start-up backed by the French spatial agency CNES that positions itself on low-carbon and safe "space" travel in the stratosphere at 25 km. I couldn't find what low carbon means on their web site, but I've read a French media quoting 27 t CO2eq per passenger for one trip up to 25 km (it doesn't sound that low ?!). Could this be a vehicle for delivering SO2 or some other aerosol precursor to the stratosphere? The payload must be fairly small and the cost pretty high. Smith and Wagner (2018, https://iopscience.iop.org/article/10.1088/1748-9326/aae98d) give a cost of 40,000 $/ton for balloons. It's worth a comparison: Zephalto annouces a ticket price of 5000 € per passenger. Assuming a passenger weighs 80 kg, that's about 60,000 $/ton but there is probably a huge potential for saving when scaling this up. Worth considering if low carbon and reusable ? Olivier -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/1869838873.46965456.1672255369897.JavaMail.zimbra%40ipsl.fr.
