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#1 2023-12-06 13:18:52

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Bets on Staging Remedy for Starship/Booster Flight 3

The top post of this topic will be used to hold the bets and to show the results.

The entries for bets are:

1) GW Johnson solid rocket ullage motors in booster
2) Oldfart1939 Redesigned hardware in inter-stage to reduce force on booster stage
3) RobertDyck drop hot staging and use helium piston
4) GW Johnson solid rocket ullage motors in Starship
5) SpaceNut suggestion - smaller tanks for the landing
6) Parachute to pull booster upright after staging
.... more entries are welcome .... add them as posts in this topic

Rules: Each NewMars member has 100 chips to allocate to the various entries
Show your allocations in posts to this topic.

Results will be totaled up after the third launch, and after details of what SpaceX actually did are made public.

If there is a non-member reader who would like to take part, see Recruiting topic for procedure.

Update: tahanson43206: 80 chips on #1 and 20 chips on #5

(th)

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#2 2023-12-06 13:21:40

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Opening chip allocation by tahanson43206

I'm putting all 100 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
0 chips to Oldfart1939 change inter-stage hardware option
0 chips to replace hot staging with something else option

The above allocations may change as new information arrives ahead of the third launch

(th)

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#3 2023-12-06 20:40:43

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

I've just added SpaceNut's interesting suggestion, to keep the landing propellant tanks full during launch, so there is no sloshing at stage separation.

This solution would require more tankage and piping, but it would not require solid ullage motors.

Interesting !!!

(th)

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#4 2023-12-06 20:42:34

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

With SpaceNut's entry to the Flight 3 Sweepstakes, I'm changing my chip allocaiton:

tahanson43206 wrote:

I've just added SpaceNut's interesting suggestion, to keep the landing propellant tanks full during launch, so there is no sloshing at stage separation.

This solution would require more tankage and piping, but it would not require solid ullage motors.

Interesting !!!

(th)

New allocation: 50 GW solid ullage rockets
and 50 SpaceNut separate tanks for landing

(th)

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#5 2023-12-07 16:31:11

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Based upon discussion in the Starship launch topic, I'm revising my chip allocation:

80 solids

20 dedicated tanks for return flight

(th)

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#6 2023-12-08 12:54:18

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 9,312

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Tahanson sometimes people have an honest bet and not a 'House Always Wins', but hosting a bet or hold the bets are usually designed so that the house i.e. the casino owners will always net a profit.

Gamble while you can, if religion gets to Mars these Gambler 'Vice' might be banned outright wink

Why have people got taken you up on the current bet? its like the Kenny Rogers song says ...You've got to know when to hold 'em, know when to fold 'em, Know when to walk away, know when to run.

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#7 2023-12-09 08:42:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

For Mars_B4_Moon re #6

Your comments on the morality of betting are interesting and might be appropriate on another topic.

This topic is available for those NewMars members who would like to predict ahead of time, what solution SpaceX is going to find for the staging problem they have encountered. 

SpaceX has already solved the staging problem with their much small Falcon 9 rocket system, including the three booster Falcon Heavy configuration.

SpaceX ** MUST ** solve the staging problem in order for the Starship enterprise to continue.

Investors have placed many millions of dollars (USD) in the service of achieving the SpaceX goals, and many more will be on the table before the first dollar of return comes in.

It is possible you come from a culture where betting is discouraged.  America is NOT such a culture.  American was built on a series of bets, starting with the folks who took the risk of crossing the land bridge from other continents.

Elon Musk, Jeff Bezos, Bill Gates and many other Americans have made a series of successful bets that led to large scale winnings for millions of people, and in the case of Bill Gates in particular, billions of people.

A culture that cannot place bets is a culture that will not survive, because Nature is constantly working to find weaknesses in any structure, physical or psychological. 

I expect today's meeting of the North Houston chapter of the National Space Society to provide additional information that will help me to improve my allocation of chips ahead of the next launch of Starship.

SpaceX ** will ** solve the staging problem.  The people of SpaceX will sort through the options, and place million dollar bets on one or perhaps two of the options, and we (observers) will eventually learn what the solution is.

(th)

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#8 2023-12-09 10:50:00

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,440

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Can the booster stage use its grid fins to perform a loop after separating?

Rather than attempting an almost immediate boosting back maneuver following stage separation, which causes a brief but significant change in gravitational force (transient period of less than 1g), the vehicle changes direction by performing a loop first, the booster continues to pitch nose up while exiting the bottom of the loop, the remaining propellant has settled at the bottom of the tanks (actually, it never left the bottom of the tanks as a result of the force exerted by said maneuver), and then the boost back burn is performed at a lower altitude while the vehicle is heading in the correct direction and with gravity forcing the propellant to the bottom of the tanks.

In aircraft that are not specifically rated for aerobatic maneuvers, you can still perform loops and rolls, as long as positive gravity is exerted on the engine oil and fuel.  You're using gravity and momentum to ensure that the engine oil and fuel remain settled on the bottom of the tanks, so the intake or pickup / feed lines for those fluids remain submerged in fluid throughout the maneuver.  This suggestion is purely from a pilot's perspective flying normal / utility category aircraft.  There may be any number of reasons why this cannot be done with a Starship booster stage.  However, this works rather well for non-aerobatic aircraft that do not have pressurized oil and fuel feed systems, so I thought it might be worth considering.

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#9 2023-12-12 21:10:34

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Revised chip allocation by tahanson43206

I'm putting 79 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
0 chips to Oldfart1939 change inter-stage hardware option
0 chips to replace hot staging with something else option
20 chips to SpaceNut's separate tanks for staging recovery
1 chip to drogue chute to pull booster upright after staging

The above allocations may change as new information arrives ahead of the third launch

(th)

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#10 2023-12-13 18:27:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,957

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Gw's solids for either purpose means controlling the thrust and burn rate so as to keep it going forward in motion.

Changing the section of the interchange section might require PICA panels over the tank to reduce heat coming in contact with teh stages tank.

The BFR after stage separation falls back the arc that the ship rose with no tilt unless something pushes the nose towards earth. Yes, a parachute would need to wait and then be launch with drogue chutes to pull them outward to keep the speed of fall back slowed but that means all forward motion is gone.

Online

#11 2023-12-13 18:40:26

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

For SpaceNut re #10

Question for you .... if you want to return to the launch site, wouldn't you want to stop forward motion?

I appreciate your giving the drogue chute some air time.

You have a multi-ton booster in flight ... the drogue chute would have almost no effect on such a massive vehicle.

It's purpose would be to provide just enough drag at the nose to slide the propellant toward the base of the tanks.

(th)

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#12 2023-12-15 18:30:13

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Chip allocation by tahanson43206 - holding steady

Nothing published by active NewMars members has convinced me to change my bet at this point.

SpaceX ** will ** solve the problem of sloshing propellants!  The only question is how, and we've seen some speculation in the forum.

I'm putting 78 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
1 chip to Oldfart1939 change inter-stage hardware option - whatever change is made will be cosmetic
0 chips to replace hot staging with something else option - The success of the first test insures it will remain the preferred solution
20 chips to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
1 chip to drogue chute to pull booster upright after staging - I think this is a ** very ** long shot, but it would definitely work

The above allocations may change as new information arrives ahead of the third launch

NewMars members are welcome to contribute new ideas. 

Some of the smartest people on Planet Earth are working the problem. 

I think odds of a solution at the next launch are at least 51/49 in favor.

(th)

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#13 2023-12-16 08:54:39

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Chip allocation by tahanson43206 - adding a new category: Check Valve

SpaceX ** will ** solve the problem of sloshing propellants!  The only question is how, and we've seen some speculation in the forum.

I'm putting 77 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
1 chip to Oldfart1939 change inter-stage hardware option - whatever change is made will be cosmetic
0 chips to replace hot staging with something else option - The success of the first test insures it will remain the preferred solution
1 chip to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
0 chips to drogue chute to pull booster upright after staging - I think this is a ** very ** long shot, but it would definitely work
1 chip to kbd512's suggestion of using the fins at the nose of the booster to drag the vehicle just enough to settle the tanks
20 chips to a new suggestion: Check valves inside the LOX and LCH4 tanks would prevent sloshing

The above allocations may change as new information arrives ahead of the third launch

NewMars members are welcome to contribute new ideas. 

Some of the smartest people on Planet Earth are working the problem. 

I think odds of a solution at the next launch are at least 51/49 in favor.

(th)

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#14 2023-12-17 07:18:14

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Chip allocation by tahanson43206 - revising a new category: Smart Baffle

SpaceX ** will ** solve the problem of sloshing propellants!  The only question is how, and we've seen some speculation in the forum.

I'm putting 67 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
1 chip to Oldfart1939 change inter-stage hardware option - whatever change is made will be cosmetic
0 chips to replace hot staging with something else option - The success of the first test insures it will remain the preferred solution
1 chip to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
0 chips to drogue chute to pull booster upright after staging - I think this is a ** very ** long shot, but it would definitely work
1 chip to kbd512's suggestion of using the fins at the nose of the booster to drag the vehicle just enough to settle the tanks
30 chips to a new suggestion: Smart One-Way Baffle inside the LOX and LCH4 tanks would prevent sloshing

The above allocations may change as new information arrives ahead of the third launch

NewMars members are welcome to contribute new ideas. 

Some of the smartest people on Planet Earth are working the problem. 

I think odds of a solution at the next launch are at least 51/49 in favor.

Note: The Smart One-Way Baffle would span the interior of the two propellant tanks, at a location below where the liquid level will be at stage separation. Thanks to input from GW Johnson, SpaceNut and RobertDyck.

The Baffle Plates would be open during ascent to stage separation.  They would close before stage separation, and open again after the booster regains forward momentum and a stable positive artificial gravity and terrestrial gravity combination is measured by sensors.

(th)

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#15 2023-12-17 18:32:46

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Chip allocation by tahanson43206 - revising a new category: More engines on Super Heavy at Stage Separation

SpaceX ** will ** solve the problem of sloshing propellants!  The only question is how, and we've seen some speculation in the forum.

I'm putting 2 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
1 chip to Oldfart1939 change inter-stage hardware option - whatever change is made will be cosmetic
0 chips to replace hot staging with something else option - The success of the first test insures it will remain the preferred solution
1 chip to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
0 chips to drogue chute to pull booster upright after staging - I think this is a ** very ** long shot, but it would definitely work
1 chip to kbd512's suggestion of using the fins at the nose of the booster to drag the vehicle just enough to settle the tanks
40 chips to a new suggestion: Smart One-Way Baffle inside the LOX and LCH4 tanks would prevent sloshing
Balance of chips on GW Johnson's suggestion to fine tune the force generated by the Heavy Booster engines at staging time

As I read GW Johnson's recent post about adjusting the force produced by the booster engines, it may not be necessary to use any additional measures, if the software controlling the engine thrust can be fine tuned at staging time to keep the liquid in the booster tanks settled at the base of their respective tanks.

The above allocations may change as new information arrives ahead of the third launch

NewMars members are welcome to contribute new ideas. 

Some of the smartest people on Planet Earth are working the problem. 

I think odds of a solution at the next launch are at least 51/49 in favor.

Note: The Smart One-Way Baffle would span the interior of the two propellant tanks, at a location below where the liquid level will be at stage separation. Thanks to input from GW Johnson, SpaceNut and RobertDyck.

The Baffle Plates would be open during ascent to stage separation.  They would close before stage separation, and open again after the booster regains forward momentum and a stable positive artificial gravity and terrestrial gravity combination is measured by sensors.

(th)

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#16 2023-12-17 20:23:41

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

This evening's Google Meeting spent a lot of time on the SpaceX stage separation problem.

I didn't take notes so will be depending on memory, but there was at least one new idea to add to the Staging Remedy list, and possibly two.

The first (and most compelling) was to use the existing system and just make software adjustments.

This is the option that (it seems likely) will be most attractive to the SpaceX team, although they won't be afraid to try hardware changes.

We ended up with a combination of kbd512's suggestion to use the four grid fins to help to orient the booster to a vertical posture with respect to the Earth below, and GW's suggestion to throttle the booster engines much more adroitly, to minimize the amount of negative G experienced by the booster as the Starship pushes against the top of the booster.

I'll add the software-only option to the list of choices.

I asked our two resident Texans why we don't have their participation in the SpaceX State Separation Sweepstakes, and with any luck, we might get their participation before the next launch.

You are given 100 chips to work with, and you can use one or more of the existing options, or add new ones.

Whatever you decide will be weighed in the balance when we see what SpaceX actually ** does **.

The NewMars member with the best score will win the title of "Best Prognosticator" until we set up another competition.

(th)

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#17 2023-12-17 20:29:22

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

A new item to add to the list of options to be  considered by SpaceX ahead of the next launch is:

Sensors to measure fluid pressure near the engine intake ports.

There might already be such sensors in the system, but if they are not their now, they would be helpful to guide the software that is managing the post separation problem.  There needs to be fluid resting calmly in the bottoms of both tanks, before the engines are started, and there are at least two ways to achieve that, per the discussion in this evening's Google Meeting.

One option is to use the grid fins to apply force to the top of the booster as it fall through the thin atmosphere, and the other is to manage the thrust produced by the booster engines so adroitly as to avoid propellant sloshing altogether.

(th)

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#18 2023-12-17 20:35:13

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

Chip allocation by tahanson43206 - revising a new category: More engines on Super Heavy at Stage Separation

SpaceX ** will ** solve the problem of sloshing propellants!  The only question is how, and we've seen some speculation in the forum.

2 chips on the GW Johnson solid rocket ullage system mounted in the booster
0 chips to GW Johnson suggestion of solid rockets in Starship
1 chip to Oldfart1939 change inter-stage hardware option - whatever change is made will be cosmetic but it is certainly possible
0 chips to replace hot staging with something else option - The success of the first test insures it will remain the preferred solution
1 chip to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
0 chips to drogue chute to pull booster upright after staging - I think this is a ** very ** long shot, because it would take so long to work
10 chips to kbd512's suggestion of using the fins at the nose of the booster to drag the vehicle just enough to settle the tanks
10 chips to a new suggestion: Smart One-Way Baffle inside the LOX and LCH4 tanks would prevent sloshing
10 chips on GW Johnson's suggestion to fine tune the force generated by the Heavy Booster engines at staging time
7f: The balance remaining from 100 go to the general category of software solutions instead of hardware changes

As I read GW Johnson's recent post about adjusting the force produced by the booster engines, it may not be necessary to use any additional measures, if the software controlling the engine thrust can be fine tuned at staging time to keep the liquid in the booster tanks settled at the base of their respective tanks.

The above allocations may change as new information arrives ahead of the third launch

NewMars members are welcome to contribute new ideas. 

Some of the smartest people on Planet Earth are working the problem. 

I think odds of a solution at the next launch are at least 51/49 in favor.

Note: The Smart One-Way Baffle would span the interior of the two propellant tanks, at a location below where the liquid level will be at stage separation. Thanks to input from GW Johnson, SpaceNut and RobertDyck.

The Baffle Plates would be open during ascent to stage separation.  They would close before stage separation, and open again after the booster regains forward momentum and a stable positive artificial gravity and terrestrial gravity combination is measured by sensors.

(th)

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#19 2023-12-18 10:15:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,957

Re: Bets on Staging Remedy for Starship/Booster Flight 3

sensors for pressure could be an issue as the gas and liquid are under the same but the liquid versus gas electrical resistance would be different. I believe the shuttles ET used this to show how much fuel was present in the tanks as it launched.

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#20 2023-12-18 13:48:37

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

For SpaceNut .... it's good to see your post #19 in this topic.

However, your post did not include the allocation of chips that is mandatory if you are going to post in this topic.

You get 100 chips to allocate as you see fit.  You can change your allocation as the next launch approaches.

Your wisdom in allocation of chips will be tested when the ** actual ** solution found by SpaceX is revealed.

This topic is NOT about what you think SpaceX ** should ** do. It is about your prediction of what SpaceX ** will ** do.

The only folks who are ever going to see your prediction are the members of this forum. 

(th)

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#21 2023-12-20 07:59:41

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 17,298

Re: Bets on Staging Remedy for Starship/Booster Flight 3

For SpaceNut ....

Today is a good day for you to place your bets on what SpaceX is going to do to solve the staging problem.

You have 100 chips to allocate, and you have a number of interesting choices to consider, and you can add more.

This topic is not about telling SpaceX what to do ..it ** is ** about predicting what they ** will ** do!

Here are available choices, and you can add more:
? chips on the GW Johnson solid rocket ullage system mounted in the booster
? chips to GW Johnson suggestion of solid rockets in Starship
? chip to Oldfart1939 change inter-stage hardware option -
? chips to replace hot staging with something else option -
? chip to SpaceNut's separate tanks for staging recovery - this would solve the sloshing problem, at the cost of increased mass
? chips to drogue chute to pull booster upright after staging -
? chips to kbd512's suggestion of using the fins at the nose of the booster to drag the vehicle just enough to settle the tanks
? chips on Smart One-Way Baffle inside the LOX and LCH4 tanks would prevent sloshing
? chips on GW Johnson's suggestion to fine tune the force generated by the Heavy Booster engines at staging time
? general category of software solutions instead of hardware changes

(th)

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