Hidden cost of operating large airships is helium perfusion as RW and I were discussing. 2% per day of 2000 cu feet is a lot smaller than 2% of 500,000 cubic feet. It becomes like a fuel cost--only helium will continually increase in price. It will help kill the LEMV IMO. So, miniaturization and UAS control are keys to having the advantages of LTA without the hidden helium cost in a post-helium world. Our eventual strats will be quite small IMO, depending upon lightweight battery technology and miniaturization of electronics.
If I were designing a large LTA craft today, I would design it for ammonia--since it is used for fertilizer it is like 1/10 the cost of helium. It also perfuses more slowly. Non-flammable but dangerous to breathe. But it is LTA so a few precautions can keep you alive when filling the envelope. Ammonia balloons are flown regularly today. Helium is still perfect for small LTA--especially if you are the company that can recycle it! Good environment for WSGI IMO. Thanks, as always, WW. IndyJonesOhio.
