New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: This forum is accepting new registrations by emailing newmarsmember * gmail.com become a registered member. Read the Recruiting expertise for NewMars Forum topic in Meta New Mars for other information for this process.

#1826 2024-04-15 16:53:50

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

Nasa has learned its lesson of having its eggs all in one basket I would hope as the commercial industry has given similar types of lift even if pricing is more for the launcher purpose that its needing.

Offline

#1827 2024-05-14 10:56:40

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

From AIAA’s “Daily Launch” for 5-14-2024:

SPACE
SpaceX Starship's next launch 'probably 3 to 5 weeks' away, Elon Musk says

We're likely still a month or so away from the next launch of SpaceX's Starship megarocket. That was the timeline Elon Musk offered in a post on X over the weekend, saying Starship's next test flight is "probably 3 to 5 weeks" away. "Objective is for the ship to get past max heating, or at least further than last time," the billionaire entrepreneur added.

My take:

Hopefully,  the FAA permit is not a problem,  or else the “3-5 weeks” will need to be multiplied by the ratio of real time to Musk time.  In the past,  that has been factor 3,   or even more,  depending upon whether the regulators get PO’d by prior permit violations.

Clearly,  the loss of attitude control going into entry on the last test flight (that caused vehicle breakup during entry) is the real problem they have been trying to solve!  The wording in the quote suggests that breakup on that last flight occurred before even reaching peak heating,  which precedes peak deceleration.  All of that took place at near-orbital speeds,  because it is the deceleration pulse where the speed drops sharply,  and that occurs near the end of the process.

GW

Last edited by GW Johnson (2024-05-14 10:57:51)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1828 2024-05-22 08:34:21

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

Today's AIAA "Daily Launch" says test flight 4 might fly 1st week in June.  It also says the top priority goal for this flight is surviving entry.  We'll see if they fixed the total loss of attitude control during flight 3,  which "Daily Launch" says is also why they elected not to do the engine restart demo.  No heat shield can save you if you enter tumbling,  unless it protects you at all attitudes. But if you have such a thing (and Starship does NOT),  and you do reach peak gees tumbling,  that's somewhere between very rough and fatal for any occupants.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1829 2024-05-22 13:16:10

RGClark
Member
From: Philadelphia, PA
Registered: 2006-07-05
Posts: 756
Website

Re: Starship is Go...

SpaceX apparently wants the FAA to grant a license for the next Starship launch without them submitting a mishap report on the last flight. This just released video by “Angry Astronaut” discusses this:

SpaceX asks the FAA to bend the rules and return Starship to flight NOW! PLUS RFA ONE static fire!!
https://www.youtube.com/watch?v=nG8T2HUe-Lo

Points out the point I’ve been making. The reason SpaceX still has not released a mishap report is they do not want to acknowledge the reason the booster failed on landing is the Raptor still has the problem observed previously of leaking fuel on relights:

Starship SN8 SN9 SN10 SN11 SN15 High Altitude Flight test synced.
https://m.youtube.com/watch?v=Ww83pSeuGuA

  But I don’t agree with “Angry Astronaut” in his video where he says, IFT-3 offered no danger to the public, so Starship can be recertified by the FAA to fly without a mishap report. The booster landed far outside the expected landing zone, probably because of flaws in the Raptor firing during the boostback burn. It should have landed 30 km off shore, but actually landed ca. 100 km off shore:

Starship Booster 10 Descent Simulation.
https://m.youtube.com/watch?v=O6a10KbkGro

It could have been a danger to fishing or shipping in the area where it landed unexpectedly.

  Bob Clark

Last edited by RGClark (2024-05-22 13:17:03)


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

#1830 2024-05-22 17:05:49

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

I agree so long as the engine problem exists over water, but it may not always once it attempts to land it for recovery.

Offline

#1831 2024-05-22 17:36:11

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,975

Re: Starship is Go...

For RGClark ... if you are interested, there is a presentation on how the FAA prepares for launches available on the Internet. A team from the agency gave a talk for the North Houston chapter of National Space Society.

Regarding your concern about fisherpeople .... the area would have been cleared before the flight, and the area  cleared is huge, for the reason you cited. Debris can fall far from it's intended path.

(th)

Offline

#1832 2024-05-28 12:40:23

RGClark
Member
From: Philadelphia, PA
Registered: 2006-07-05
Posts: 756
Website

Re: Starship is Go...

SpaceX has released the suspected causes of the IFT-3 mishaps:

MAY 24, 2024
ON THE PATH TO RAPID REUSABILITY
Following stage separation, Super Heavy initiated its boostback burn, which sends commands to 13 of the vehicle’s 33 Raptor engines to propel the rocket toward its intended landing location. All 13 engines ran successfully until six engines began shutting down, triggering a benign early boostback shutdown.

The booster then continued to descend until attempting its landing burn, which commands the same 13 engines used during boostback to perform the planned final slowing for the rocket before a soft touchdown in the water, but the six engines that shut down early in the boostback burn were disabled from attempting the landing burn startup, leaving seven engines commanded to start up with two successfully reaching mainstage ignition. The booster had lower than expected landing burn thrust when contact was lost at approximately 462 meters in altitude over the Gulf of Mexico and just under seven minutes into the mission.

The most likely root cause for the early boostback burn shutdown was determined to be continued filter blockage where liquid oxygen is supplied to the engines, leading to a loss of inlet pressure in engine oxygen turbopumps. SpaceX implemented hardware changes ahead of Flight 3 to mitigate this issue, which resulted in the booster progressing to its first ever landing burn attempt. Super Heavy boosters for Flight 4 and beyond will get additional hardware inside oxygen tanks to further improve propellant filtration capabilities. And utilizing data gathered from Super Heavy’s first ever landing burn attempt, additional hardware and software changes are being implemented to increase startup reliability of the Raptor engines in landing conditions.

During Starship’s coast phase, the vehicle accomplished several of the flight test’s additional objectives, including the first ever test of its payload door in space. The vehicle also successfully completed a propellant transfer demonstration, moving liquid oxygen from a header tank into the main tank. This test provided valuable data for eventual ship-to-ship propellant transfers that will enable missions like returning astronauts to the Moon under NASA’s Artemis program.

Several minutes after Starship began its coast phase, the vehicle began losing the ability to control its attitude. Starship continued flying its nominal trajectory but given the loss of attitude control, the vehicle automatically triggered a pre-planned command to skip its planned on-orbit relight of a single Raptor engine.
https://www.spacex.com/updates/#flight-3-report


So they are pointing the finger away from the Raptor engine itself. But IF the fuel venting seen for both the booster and ship after their burns was real, that suggests the problem is with the Raptor itself:

https://x.com/djsnm/status/1768268571531235669?s=61

https://x.com/nricolas360/status/178576 … 46057?s=61

https://x.com/goingballistic5/status/17 … 79764?s=61

  Bob Clark

Last edited by RGClark (2024-05-28 12:42:57)


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

#1833 2024-05-28 18:02:04

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

Engines that are not reliable to go the duration of flight is a huge problem.

Offline

#1834 2024-05-30 08:58:49

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

On May 23,  SpaceX McGregor suffered some sort of fireball incident on its tower thrust stand.  That with a photo was in today's Waco "Tribune-Herald" newspaper.  Based on few if any hearing a "boom",  this was more of a fast burn than an actual explosion,  which matches the appearance of the fireball in the photo.  This was only several seconds into a Raptor-2 test being conducted on the tower stand. The story was entirely unclear about the source of a leak,  saying only "vapors" from somewhere.  Could be an engine leak,  could be in the test plumbing,  could be in the tanks located atop the tower.  Who knows?

I will say this:  the tower stand tests are the loud ones heard all over the county,  being way up in the air like that.  The other test stands on the ground fire into flame tunnels with water deluge.  Between that and being down in a hole,  they are nowhere near as noisy.  SpaceX inherited the tower stand from Andy Beal's earlier operation out on that site.  When they first started,  that was their only thrust stand.  Even the Merlins are noisy when fired up there.

As for the fireball,  that had to be a methane leak,  creating an unintended fuel-air deflagration.  It is entirely unclear if it came from the engine,  or if the engine was still running when the fireball occurred.  Unlike LOX and kerosene,  methane is very prone to leakage,  like hydrogen,  just not as bad,  because of the small size of the molecules. It is really easy to have leaks at any sort of plumbing joints. 

All I know for sure is that the tower stand is "down" for repairs.  The testing continues,  but it has been less noisy of late.

GW

PS - fueling tests of the big rocket are in progress at Boca Chica.  I don't know of FAA has granted a launch license yet.  But they should,  soon.  As near as I can tell,  they met the terms of the last one,  despite losing both the booster and the upper stage.

Last edited by GW Johnson (2024-05-30 09:02:43)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1835 2024-06-01 17:17:47

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

Offline

#1836 2024-06-03 17:54:12

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

SpaceX fourth Starship launch: how and where to watch it in the US on TV and online? tentative date for the fourth test is set for next Thursday, June 6, provided FFA approval is obtained.

at 7:00 a.m. CT / 8:00 a.m. ET / 5:00 a.m. PT

Offline

#1837 2024-06-05 09:59:15

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,431

Re: Starship is Go...

The FAA license has been approved and the launch of IFT-4 is "go." Tomorrow, and is available for viewing on lots of YouTube channels--too many to list here. The SpaceX livestream is only on X.

Offline

#1838 2024-06-05 10:08:27

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

I saw that the license has been granted on this morning's AIAA "Daily Launch". 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1839 2024-06-06 07:10:46

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,431

Re: Starship is Go...

A very successful launch and water landing of the Super Heavy booster!

Here's the video from Everyday Astronaut: https://www.youtube.com/watch?v=8VESowgMbjA

Offline

#1840 2024-06-06 07:57:33

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,777

Re: Starship is Go...

Success!

Edit:
Soft landing of Super Heavy booster and Starship was achieved.  Although Starship looked pretty rough, it made it.

Last edited by kbd512 (2024-06-06 07:58:45)

Offline

#1841 2024-06-06 08:16:50

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,776

Re: Starship is Go...

'Starship: Elon Musk’s SpaceX successfully launches and lands most powerful rocket ever made'

https://www.independent.co.uk/tech/star … 58012.html

Offline

#1842 2024-06-06 08:37:15

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,776

Re: Starship is Go...

Despite loss of many tiles and a damaged flap, Starship made it all the way to a soft landing in the ocean!
https://x.com/elonmusk/status/1798718549307109867

'Super Heavy has splashed down in the Gulf of Mexico'
https://x.com/SpaceX/status/1798701489097183286

Offline

#1843 2024-06-06 09:20:40

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

As near as I can tell,  the booster worked pretty much as desired,  excepting 1 engine out going up,  and another engine out for the return burn.  It seemed to land on the water and topple over as planned.

Starship went into entry under proper attitude control,  which kept the air from stripping off tiles like flight 3.  It made it through most of entry intact,  until at least one flap showed severe burn-through damage at the aft end of its hinge  There apparently was some sort of leakage path into that part of the hinge.  They'll have to fix that.  As near as I could tell from the SpaceX site video,  the water landing was apparently successful.  I could not tell if all 3 SL engines lit up,  but apparently it flipped up,  and made at least some sort of successful landing burn. 

Actually,  all in all,  a rather good flight test. 

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#1844 2024-06-06 11:13:18

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,776

Re: Starship is Go...

a very good tough ship like those Thunderbolt A-10 Warthogs it can survive a few punches

The SpaceX Starship Launch #4 was a HUGE success.
https://x.com/krassenstein/status/1798715585896833295

quote

Re-entry went better than most expected. As you can see, approximately 5 minutes before splashdown some of the heat seals malfunctioned and the heat caused the camera to crack and lose a clear view, but the StarShip continued to slow down and make it’s way to Earth before performing a flip and a successful splashdown in the Indian Ocean.

AMAZING!

Offline

#1845 2024-06-06 12:56:00

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,776

Re: Starship is Go...

'We did switch to a passive (mostly) glass heat shield, rather than actively-cooled steel, as the latter was heavier, at least according to initial calculations'

https://x.com/elonmusk/status/1798745564898840872

Offline

#1846 2024-06-06 13:37:00

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,431

Re: Starship is Go...

I'm wondering whether or not they had any video recording from Starbase of the booster reentry and splashdown--or drone recordings? That would have been something that they should have done.
My 2 cents about the next test flight: continue working on the engines and ensure that they are 100% reliable; achieve orbit and do a reentry burn; improve the thermal protection in the hinges.
Overall, this was a fantastic performance and a magnificent feat of engineering.
Kudos to the entire SpaceX team!

Offline

#1847 2024-06-06 15:57:28

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,777

Re: Starship is Go...

GW,

The engine shut down on the booster was an intentional "engine out" test, that was called-out during the flight as a testing point for IFT-4.

Offline

#1848 2024-06-06 16:32:35

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,777

Re: Starship is Go...

At $20M per copy, SpaceX can afford to "blow up" 7 Starships and Super Heavy boosters before they reach the cost of a single RS-25E engine for the Space Launch System.  Nominally, SpaceX would not blow up any vehicles, but if that is what they must do to learn and push the hardware to its limits, then I think NASA and the US Air Force are getting their money's worth out of the test program.  Sometimes you have to "break things" to learn what not to do.  The flight testing phase of development is the correct time to intentionally try to break everything.

Offline

#1849 2024-06-06 19:49:59

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Starship is Go...

See Elon Musk's Starship shredding apart as it descends to Earth, with a whole fin almost ripping off

Seems more structural mass will be taken from the payload that it might one day show that it can haul to orbit.

Offline

#1850 2024-06-07 07:21:10

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,737
Website

Re: Starship is Go...

I kind of skipped through the long stretches of the video posted on SpaceX's site.  That's the one I saw,  and not live,  but a few minutes after. It showed 1 engine-out on the booster (in its outer ring of engines) during the ascent.  Whether that was deliberate or not,  I do not know.  There was also one out in the middle row of 10 just outside the inner 3 during the boost-back burn.  Again,  I saw or heard nothing about whether that was deliberate or not.  But it was 2 different engines that were out during 2 different burns. 

What I saw on the starboard forward flap was a hot spot developing near the aft end of the hinge as entry got closer to peak heating.  That grew into an unmistakable burn-through of that aft inner corner of the flap.  There was clearly plasma infiltrating inside the flap in that location.  I was pleased and surprised the flap did not depart the spacecraft;  indeed,  it remained functional.  That initially was not the only camera view,  but after entry began,  it was the only one they showed.  The other was on the aft edge of the portside forward flap,  looking aft toward the portside aft flap.  That one worked for while into the peak heating,  you could see the shocked plasma layer under the body and aft flap quite clearly.  And always n the same geometry,  so attitude control was quite good this time.

GW

Last edited by GW Johnson (2024-06-07 07:21:40)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

Board footer

Powered by FluxBB