India’s space agency successfully tests prototype for controlling descent of spent 1st stages
India’s space agency ISRO on September 3, 2022 successfully used a suborbital sounding rocket to test a prototype of an inflatable airbag, which it dubs an Inflatable Aerodynamic Decelerator (IAD), that can inflate at the top of a 1st stage and slow and control its descent back to Earth after launch.
The graphic to the right was adapted from the mission brochure [pdf]. According to ISRO:
The IAD was initially folded and kept inside the payload bay of the rocket. At around 84 km altitude, the IAD was inflated and it descended through atmosphere with the payload part of sounding rocket. The pneumatic system for inflation was developed by LPSC. The IAD has systematically reduced the velocity of the payload through aerodynamic drag and followed the predicted trajectory. This is first time that an IAD is designed specifically for spent stage recovery. All the objectives of the mission were successfully demonstrated
ISRO claims this design can not only facilitate the reuse of first stages, it can also be used for science payloads to Mars and Venus.
I look at this and wonder, wouldn’t parachutes or parasails, already developed and used numerous times in similar applications, do the same job? In fact, Rocket Lab has already successfully used parachutes to control the re-entry of its Electron first stages. Meanwhile, SpaceX uses simple and lightweight grid fins to control the descent of its Falcon 9 first stages, and simply fires that stage’s engines twice to slow it down for landing.
While there may be engineer advantages to this airbag design, the whole thing smacks of many of NASA’S complex test programs that never made it past prototype tests. The ideas always looked good, but they never were practical or cost effective.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
India’s space agency ISRO on September 3, 2022 successfully used a suborbital sounding rocket to test a prototype of an inflatable airbag, which it dubs an Inflatable Aerodynamic Decelerator (IAD), that can inflate at the top of a 1st stage and slow and control its descent back to Earth after launch.
The graphic to the right was adapted from the mission brochure [pdf]. According to ISRO:
The IAD was initially folded and kept inside the payload bay of the rocket. At around 84 km altitude, the IAD was inflated and it descended through atmosphere with the payload part of sounding rocket. The pneumatic system for inflation was developed by LPSC. The IAD has systematically reduced the velocity of the payload through aerodynamic drag and followed the predicted trajectory. This is first time that an IAD is designed specifically for spent stage recovery. All the objectives of the mission were successfully demonstrated
ISRO claims this design can not only facilitate the reuse of first stages, it can also be used for science payloads to Mars and Venus.
I look at this and wonder, wouldn’t parachutes or parasails, already developed and used numerous times in similar applications, do the same job? In fact, Rocket Lab has already successfully used parachutes to control the re-entry of its Electron first stages. Meanwhile, SpaceX uses simple and lightweight grid fins to control the descent of its Falcon 9 first stages, and simply fires that stage’s engines twice to slow it down for landing.
While there may be engineer advantages to this airbag design, the whole thing smacks of many of NASA’S complex test programs that never made it past prototype tests. The ideas always looked good, but they never were practical or cost effective.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Parachutes flap in the wind. Also they need to be of some strong material (Zylon?) to keep from ripping apart if they are holding a cargo of empty booster-rocket.
Maybe they’re hoping to control the surface-area better than a non-inflatable parachute is controllable.
I can see it being used as a first drag ability to keep the first stage upright at very high speeds were chute do no work well.
Then set it free and use the chutes.
It would not take as much material and energy as the grid fin system.
Something like the solid rocket boosters on the shuttle/SLS if they were thinking of recovering them for re-use.
Phil Bono’s ROOST was to be similar, as detailed at “No Shortage Of Dreams.” Ballutes can serve as heat shields and floats.
Once the base of the rocket touches down, perhaps with a retro rocket firing at the very end, maybe the rocket can then fall over on its side and the top will rest in the balloon. Ugly but it might work
This isn’t exactly a new idea. NASA thought of doing something similar for reentry at Mars:
https://www.nasa.gov/feature/inflatable-heat-shield-one-step-closer-to-2022-demonstration
From the article:
It seems that the Indian engineers think that they can develop a technology to economically recover booster stages.
It is possible that it does not work out and they merely test technologies that don’t get used, as NASA had done in the 1960s, such as the NERVA engine and the Rogallo wing.
https://en.wikipedia.org/wiki/Rogallo_wing
https://en.wikipedia.org/wiki/NERVA
You go to space with the resources you have.
Bob expressed doubts on the John Batchelor Show. The technology is called a ballute” used by the military to slow bombs from low flying aircraft to escape the effects of the bombs. Again, not new, the US was using ParaFrags (PARAchute retarded FRAGmentation bombs) in WW2 and used the Snakeye retarded bomb in Vietnam https://www.reddit.com/r/wwiipics/comments/pa0mjy/a_b25s_payload_of_parafrag_bombs_fall_toward_a/ and https://www.bing.com/videos/search?q=snakeye+bombs+mk83&qpvt=snakeye+bombs+mk83&view=detail&mid=3818FA17175FD3313CB63818FA17175FD3313CB6&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dsnakeye%2Bbombs%2Bmk83%26qpvt%3Dsnakeye%2Bbombs%2Bmk83%26FORM%3DVDRE and https://www.bing.com/videos/search?q=ballute&&view=detail&mid=8195B44CB305A14D0EA78195B44CB305A14D0EA7&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dballute%26FORM%3DHDRSC3 and https://en.wikipedia.org/wiki/Ballute