If Ship 24 was fully fueled and launched...

[E_T]

As Ship 24 has just completed a full 6 raptor static fire, successfully, what would it's likely suborbital performance be if it was fully fueled and then launched (without a booster)? Assuming keeping enough fuel to do a water soft landing, how high and how far downrange would it be able to get to? 

Would it be good enough to get some significant date on TPS performance?  As well as how well the ships handling is in the hyper-sonic ranges?  Could a ship that is like 'Mighty Servant 1' be used to retrieve it fairly quickly from the splashdown area so that further visual inspection of how the ship had flown could possibly make it available?

Even if it wasn't carrying any payloads, it's better than just sitting around a rocket garden... 

[StarshipTrooper]

After ignition it would sit on the pad, burning at full thrust, and if it didn't explode it would burn until enough fuel burnt off that it was light enough to start climbing ever so slowly up into the sky. When it got light enough it would gradually and painfully pick up speed. It would get up pretty high, but nowhere near orbital velocity, and fall into the ocean.

[StarshipTrooper]

Now if it had 9 raptor engines, then it would take right off. It wouldn't make it to orbit but I would travel a long way across the globe. In fact they may use it like this for point to point suborbital flights.

[E_T]

After ignition it would sit on the pad, burning at full thrust, and if it didn't explode it would burn until enough fuel burnt off that it was light enough to start climbing ever so slowly up into the sky. When it got light enough it would gradually and painfully pick up speed. It would get up pretty high, but nowhere near orbital velocity, and fall into the ocean.

I'm not talking about it getting into orbit. 

And it should have more than 1:1 lift while using all 6 engines, even though 3 of them are vacuum optimized.

[daavery]

and the obvious problem - the test pads are no longer equipped to launch starships - the QDs are not launch QDs and the hold down clamps are not quick release clamps

[E_T]

o.k., so let's say that IF those were not issues AND I know that the TPS is a possible issue, post static fire; would it be able to launch and if so, approximately how high would it get, how far downrange and how fast would it get to before engine cut off? 

[StarshipTrooper]

I'm not talking about it getting into orbit. 

And it should have more than 1:1 lift while using all 6 engines, even though 3 of them are vacuum optimized.

Well you did say "fully fueled." That would be 150 metric tons for the starship and 1200 metric tons of fuel. So that would equate to approximately 1:1 thrust to weight ratio with 3 raptor 2 and 3 raptor vacs.

[AC in NC]

I'm not talking about it getting into orbit. 

And it should have more than 1:1 lift while using all 6 engines, even though 3 of them are vacuum optimized.

Well you did say "fully fueled." That would be 150 metric tons for the starship and 1200 metric tons of fuel. So that would equate to approximately 1:1 thrust to weight ratio with 3 raptor 2 and 3 raptor vacs.

Would you mind explaining the point that I think is troubling E_T and, admittedly, myself as well.  I suspect the math is what it is but there's an element that seems on 1st blush to not make sense.

You are citing 150mt SS + 1200mt props.  But assuming Elon's most optimistic optimization, it should be 100mt SS + 150mt payload + 1200mt props if we are considering the general case.  So even assuming your numbers, less than 1:1 TWR incurs significant gravity losses at staging.  If we assume mine, significant moves toward massive?  Can it be the case that the RVac efficiencies at staging altitude bring TWR > 1?  Or is it the case that at staging, you can take the gravity losses with < 1:1 TWR for gaining horizontal velocity?

Or are we misunderstanding, in that the typical SS as 2nd stage would not be fully fueled?  Perhaps fully fueled is only on return trips but seems like they would still suffer the <1:1TWR problem.

Hope it's clear why this is confusing to a layman.  Can you bridge the gap and help us understand?

[AlesH]

The rocket's second stage may initially have a TW ratio less than 1:1, because it is no longer ascending vertically during the stagging period, but is flying at an angle of about 45°, so it is only partially overcoming gravity and still accelerating. A number of rockets are constructed this way.

However, this does not mean that the fully fueled second stage could lift itself from the ground (vertically). Not even a Starship can do it (without a Super Heavy). But we can consider that for this special test the Starship would be only partially fueled, e.g. with 1000 tons of fuel. Then it could probably take off, and according to my rough calculations and simulations, with a suitable trajectory, it could reach a height of over 200 km, a speed of around 5 km/s and a downrange of perhaps up to 4000 km. Maybe even a little more.

I don't know if it makes sense for EDL testing, but even for me it would be better than if Starship just ended up in "Rocket Garden".

[DanClemmensen]

The rocket's second stage may initially have a TW ratio less than 1:1, because it is no longer ascending vertically during the stagging period, but is flying at an angle of about 45°, so it is only partially overcoming gravity and still accelerating. A number of rockets are constructed this way.

However, this does not mean that the fully fueled second stage could lift itself from the ground (vertically). Not even a Starship can do it (without a Super Heavy). But we can consider that for this special test the Starship would be only partially fueled, e.g. with 1000 tons of fuel. Then it could probably take off, and according to my rough calculations and simulations, with a suitable trajectory, it could reach a height of over 200 km, a speed of around 5 km/s and a downrange of perhaps up to 4000 km.

I don't know if it makes sense for EDL testing, but even for me it would be better than if Starship just ended up in "Rocket Garden".

Don't know about S24 and EDL testing, but it's a nice way to ship SS to KSC in the future. 

[E_T]

The rocket's second stage may initially have a TW ratio less than 1:1, because it is no longer ascending vertically during the stagging period, but is flying at an angle of about 45°, so it is only partially overcoming gravity and still accelerating. A number of rockets are constructed this way.

However, this does not mean that the fully fueled second stage could lift itself from the ground (vertically). Not even a Starship can do it (without a Super Heavy). But we can consider that for this special test the Starship would be only partially fueled, e.g. with 1000 tons of fuel. Then it could probably take off, and according to my rough calculations and simulations, with a suitable trajectory, it could reach a height of over 200 km, a speed of around 5 km/s and a downrange of perhaps up to 4000 km. Maybe even a little more.

And assuming that there was enough left over propellant to possibly do a post bellyflop, soft water landing, it should put it around the same area. 

I don't know if it makes sense for EDL testing, but even for me it would be better than if Starship just ended up in "Rocket Garden".

Now, seeing the amount of lower vehicle damage the was sustained to S24, post static fire, they will very likely need to redesign the sub-orbital pads as it is, so as to get the vehicle up away from any possible sonic reflective and pad debris damage to the vehicle.

As the idea (initially - but we know how things change in all this) is to take it from a static fire almost directly to the OLT and mounting on the booster and firing off into space, not having any debris/sonic damage to the loser portion of the vehicle is not optimal.

[kevin-rf]

Firing vac optimized engines at sea level leads to rapid shredding of the nozzle...  So it would really be a nonstarter.

[r8ix]

Firing vac optimized engines at sea level leads to rapid shredding of the nozzle...  So it would really be a nonstarter.

They're not "fully" optimized; they just fired them at sea level last week...

[Hog]

Firing vac optimized engines at sea level leads to rapid shredding of the nozzle...  So it would really be a nonstarter.

They're not "fully" optimized; they just fired them at sea level last week...

Like the RS25.