just posted this video depicting two Canberra jets in early stage proof-of-concept flight test with small scale airships prior to more useful ones for missile defence.
The LTA vehicle is air-launched because going to just 80,000 feet MSL results in 2600% gas volume expansion. Here, the airship is not being used to lift all the rocket fuel weight. When burnt off at high altitude, that is less weight for the airship to lift. At 300,000 feet the airship will not want to stay up and very little gas ported to the lift bags will result in tremendous expansion with considerable lift.
The reason for the airship at high altitude is to get into the thin air and near zero drag. At this height, any form of propulsion has the best efficacy in producing velocity. Meanwhile, the least bit of gas can go a long way toward offsetting altitude loss. The name of the game is long-duration and heavy lift.
Being able to speed up greatly provides considerable advantage over the 747 carried Airborne Laser of the USAF. Airship times aloft can potentially exceed that of the 747 even with rotating crews and aerial refueling. But, mostly, an airship provides a stable optical and laser platform while the ability to push for hypersonic speeds enables bringing those systems into the enemy theater sooner than a lower flying jet can arrive there. Thus, boost phase missile intercept is better enabled someday.
Commercially, there is a large sector of the aerospace market which does not need costly orbital launch. Right now, their options are costly Low Earth Orbit and Geosynchronus options….or the booming new suborbital launchers of fairly low duration. With high altitude airships of various form, that gap is bridged.
Much is still in early stage discussion, but the B-57’s are 3 to 6 months work to pull out of mothball. These versatile work horses provide us with global delivery options on airships, bat wings, rockets, UAS, and also are equipped for weather and imaging.
Source: YouTube