Comments on: Elon Musk hints at using a “giant party balloon” to recover Falcon 9 upper stages

By: wayne

wayne — Wed, 18 Apr 2018 03:12:42 +0000

Curiosity’s Landing on Mars; How It Unfolded
>side-by-side Animation & actual Mars Descent Imager video
NASA JPL CalTech
https://youtu.be/W7e_k-_jzZg
4:05

By: wayne

wayne — Wed, 18 Apr 2018 02:54:55 +0000

geoffc-
check these out

“How we landed on Mars with NASA Spirit”
https://youtu.be/6t3IARmIdOI
6:32

and the companion piece–
Mars Rover Opportunity Landing
[https://youtu.be/daiUW_O6gOM]
(8:09)

Do we know how many times each of them bounced?

By: Mark

Mark — Wed, 18 Apr 2018 00:54:14 +0000

It has to be a ballute. https://en.wikipedia.org/wiki/Ballute

Armadillo Aerospace used a ballute in their suborbital-class rocket, last launched about six years ago. https://www.universetoday.com/93281/armadillo-launches-a-stig-a-rocket-captures-awesome-image-of-ballute/

Video of the ill-fated launch. They had problems with the attachment plate breaking. https://www.youtube.com/watch?v=Aw11NFz14sA Deployment at about 3:25, failure at about 4:55.

A few months ago, Elon Musk openly tweeted out his personal phone number. He intended it to be a private message sent to John Carmack. Carmack was the owner and chief designer for Armadillo, and it is likely that Mr. Carmack has contributed to the Falcon 9 design, to some small degree. I have heard that the use of grid fins was due to his suggestion.

One other area where there could be contribution is through the usage of GPS guided parachutes. This was still an experimental procedure when AA and Wamore achieved this landing. https://www.youtube.com/watch?v=UV7zL07Tof8 I don’t know if SpaceX is using Wamore or someone else, or developing within house, but this type of system has to be what is used with the current faring recovery attempts. It is also what would be used to guide the 2nd stage back to a landing site.

By: Robert Zimmerman

Robert Zimmerman — Tue, 17 Apr 2018 17:47:12 +0000

In reply to geoffc. geoffc: The balloons were used on both Mars and the Moon to provide cushioning on impact. The spacecraft bounced numerous times before settling on the surface unharmed. Granted, SpaceX's plan seems to involve an inflated balloon. Different engineering.

By: geoffc

geoffc — Tue, 17 Apr 2018 17:34:27 +0000

You wrote: “The balloon idea has some merit, as it has been successfully used to land landers and rovers on the Moon and Mars.”

How would you use a balloon on the Moon? No atmosphere? Mars, sure, and there is a NASA program to test a ballute for this purpose (with no real success, they keep tearing it). But if SpaceX decides to do this, tetsing different ideas on otherwise normal launches odds of their licking it with dozens-30 tests a year seems more likely than NASA with a total of 2 or 3 tries and lack of success.

SpaceX is so much more interesting for their willingness to try and fail until they succeed.