New Mars Forums
You are not logged in.
- Topics: Active | Unanswered
Announcement
#1976 2024-11-26 15:06:19
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 5,836
- Website
Re: Starship is Go...
Supersonic retropropulsion is not the brand new area of investigation that the Angry Astronaut says it is. It's only new if current people at NASA and SpaceX do not understand or appreciate history. Which is apparently the case!
My 1965-vintage edition of Sighard F. Hoerner's opus "Fluid Dynamic Drag" has a plot of drag coefficient versus jet thrust, for a retrorocket plume emanating from the heat shield center of a Mercury capsule shape, tested at Mach 2 in a wind tunnel in 8.2-inch diameter size. The reference Hoerner cites for this plot is a NASA Tech note titled "Thin Retro Jet", TN-D-751, dated to 1961, written by Charczenko. He also gives two other closely-related refences: Wasko "From a Sphere" TN-D-1535, and Peterson "Four Retrorockets" TN-D-1300. These citations did not give a date. The 3 relevant citations (numbers 22a, b, and c) are listed on page 20-9 of this edition of Hoerner's book. The plot is Figure 27 in Chapter 20, located on page 20-11 in Hoerner's book.
It is very clear that NASA was doing serious engineering testing of retropropulsion effects in supersonic flow, way back in the early 1960's.
The modern "experts" seem to be unaware of it. Some "experts" they are!
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#1977 2024-11-28 13:26:10
Re: Starship is Go...
Here's a link to the SpaceX notes stating the tower was definitely the issue, as the tower initiated the landing abort into the ocean.
https://youtube.com/clip/Ugkx3e2Q0dB6CM … PdrbjRLeLA
The launch video prior to hotstaging says the tower was go for catch. Then later they decided to divert. The tower issue wasn’t known immediately? Also, The voiceover says the boostback back burn should last another approximately 30 seconds, but then it ends immediately after she says this. Did the boostback end early?
Bob Clark
Last edited by RGClark (2024-11-28 13:33:11)
Old Space rule of acquisition (with a nod to Star Trek - the Next Generation):
“Anything worth doing is worth doing for a billion dollars.”
Offline
Like button can go here
#1978 2024-11-28 14:25:08
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 19,949
Re: Starship is Go...
For RGClark....
Your question about the diversion may be of interest to others.
Gemini is a Google extension to it's search engine. I decided to ask Gemini but the result was disappointing.
My expectation is that the diversion was performed entirely by the automation. No human could possibly process the avalanche of data that is flowing as the booster approaches the tower.
That said, there is sure to be someone who thinks a human could have been involved.
Here is what Gemini offered:
Conversation with Gemini
Hi Gemini! Thanks (again) for the assistance you have provided in the past. Today I'm hoping you can do a little detective work. A small group of supporters of the US space program, and particularly Starship, are wondering if anything more has been published about the diversion of the Super Heavy from the landing tower. There is at least one report that a computer made the decision to divert the ship to the Gulf of Mexico because the antenna was damaged by the liftoff. I'm sure no humans were involved in making the decision, but can you confirm that?
There have been reports that the Super Heavy booster's diversion to the Gulf of Mexico was triggered by a computer due to damage to the antenna during liftoff. However, SpaceX has not released an official statement confirming the cause of the diversion. It is possible that the decision was made by a combination of automated systems and human operators.
Thanks for your response. What is the cutoff for the information you reviewed?
My knowledge is constantly being updated, so I don't have a specific cutoff date. However, it's important to note that I rely on information that is publicly available. SpaceX hasn't officially confirmed the cause of the Super Heavy booster's diversion, so there might be more details that haven't been released yet.
Thank you for this update. We'll just have to be patient. Do you have any details about the damage to the antenna system?
There have been reports of damage to the antenna system on the Super Heavy booster during liftoff. However, SpaceX has not released an official statement confirming the cause of the damage or the extent of the damage. It is possible that the damage was caused by the extreme heat and pressure of the rocket engines.
(th)
Offline
Like button can go here
#1979 2024-11-28 15:46:11
Re: Starship is Go...
Robert Zubrin’s made a key statement in this SpaceWatch.Global interview that Elon told him SpaceX could build Starship for $10 million, https://x.com/spacewatchgl/status/18559 … 41756?s=61.
This leads to a surprising conclusion:
SpaceX can build a Moon or Mars rocket for ca. $10 million. Now.
Such a rocket could offer costs of $100/kilo to orbit. Now.
SpaceX routine orbital passenger flights imminent.
http://exoscientist.blogspot.com/2024/1 … enger.html
Bob Clark
Last edited by RGClark (2024-11-28 15:46:34)
Old Space rule of acquisition (with a nod to Star Trek - the Next Generation):
“Anything worth doing is worth doing for a billion dollars.”
Offline
Like button can go here
#1980 2024-11-29 09:19:52
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 5,836
- Website
Re: Starship is Go...
Well, they do have to make it all work, and then they must show it all to be reliable, before people ride it. We do that same process with new airplane designs, because it is the right thing to do.
Myself, I take claims like that with a bucket of salt. Musk dollars to do things seem to be off from reality by a similar large factor as Musk time to get something done.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#1981 2024-12-01 11:56:49
- Void
- Member
- Registered: 2011-12-29
- Posts: 7,961
Re: Starship is Go...
You have to tolerate a lot of off topic stuff in this video to get the heat shield stuff, but it is interesting. Apparently, SpaceX is looking into various types of active cooling. I like that as the attitude apparently is "Whatever Works".
https://www.youtube.com/watch?v=ANITE9MFlGA
Quote:
Elon Musk REVEALS New UPDATE: Metallic Heat Shield Will END Ceramic Tiles!
Space Frontier
3.88K subscribers
They mention several types of active cooling.
Gas, Liquids, and then evaporating films.
I am glad that they did everything they could to fix the flaps hinge problem, without resorting to a gas flow, but I have felt that they could flow Ullage gas into the hinges to cool them. They even might flow gas though the flaps themselves. I have even felt that they could have a "Cold Gas Thruster" incorporated into the flaps themselves. This might be OK if the hinges do not leak too much, so that at least part of the flow would go through the flaps. In this way the flaps as thrusters could be pointed. Then they may be useful even before entering the atmosphere.
In the interest of making a machine that can fly repeatedly with reduced maintenance they will likely use a variety of methods.
Ending Pending 
Last edited by Void (2024-12-01 12:16:47)
End
Offline
Like button can go here
#1982 2024-12-01 19:22:43
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 19,949
Re: Starship is Go...
For Void re #1981
kbd512 and I are just curious ... you may have been logged in when kbd512 pulled the plug on the old system.
Did you notice anything, or were you safely logged off when that happened?
(th)
Offline
Like button can go here
#1983 2024-12-01 19:56:19
- Void
- Member
- Registered: 2011-12-29
- Posts: 7,961
Re: Starship is Go...
I did OK. I discovered I could not get in, there was a message about service of the system.
Ending Pending
End
Offline
Like button can go here