SpaceX Starship : First Flight : Starbase, TX : 20 April 2023 - DISCUSSION

[Lee Jay]

Are the vehicles pressurized (like with N2) during stacking?

[meekGee]

Gentlemen, please: the OLIT has stairs. Even if whatever falling doodad prevents use of the elevator, do you really think there are no SpaceXers willing to risk thigh chafing to perform any tasks out of manlift reach in order to avoid a delay?

It's not the grunt's willingness to grind that matters, it's the willingness of the company to let this go uninvestigated until the conclusion of the flight test or their willingness to get this i vestigated and cleared out before continuing to use stage 0.

You’ve obviously never worked in construction or health and safety. If there was no injuries then all SpaceX have to do is cease using that piece of equipment and carry out their own investigation, add remedial measures and fix. It shouldn’t prevent anything else from going  ahead. That’s assuming nobody was injured and there is no further risk of injury.

That's what I'm saying. What they *have* to do doesn't necessarily match with what they want to do or should do considering all eyes on them.

I think they'll need to have a rationale.

For example, if it was the counterweight(s) and if the fall path remained contained, (and the car remained latched) then it can be argued that the backup systems worked and so there's no damage expected outside of the elevator system.

Maybe look for why the counterweight separated, to make sure it wasn't caused by something outside the elevator system.

Both things can be done today towards a Monday launch.

If they find something wrong, plenty time to stand down on Sunday.

[sferrin]

Doesn’t sound or look great:

Wonderful.  Now OSHA will shut it down for three weeks for an "investigation".

Do you prefer a fatal accident or injury?

How'd you get that from my statement?

Because, OSHA exists for a very clear reason...

No SS.  I work in manufacturing.  I know all about OSHA.

[meekGee]

orbital flight with making less than one orbit

That's exactly what it is.

People calling it suborbital are the same people calling a 100 (82...) km up-and-down hop "going to space"

Using legalese to intentionally miss the point is all fun and games, but has never helped anyone do anything constructive.

Not even repeating that likely this is a fully-legal orbital flight too, because that hair splitting is entirely inconsequential.

[meekGee]

BTW we're used to it by now but remember all the talk about how stacking the rocket takes so much time, as a limiter to potential flight rate?

I mean we're watching a giant rocket being put together as if nothing. Wham bam thank you ma'am. Lego rocket FTW.

And it just seems natural, we almost take it for granted.

[TheRadicalModerate]

To have perigee below sea level and be able to do 3/4 of the circle around the Earth after standard rocket launch ... you must have apogee at ~320km or higher. Otherwise your trajectory would be too shallow.

... for example - insert directly into an orbit with an apogee above your current altitude and descending, and thus never reach apogee.

Sure, but your example trajectory would have its perigee <1/2 an orbit away from SECO, right?

No, it's more complicated than that.  If you're trying to maximize energy, yes, your burnout would be at either perigee or apogee, with a flight path angle of zero.  But you can also have burnouts with non-zero flight path angles, where the apse line is somewhere else.  This is pretty likely when you're aiming for a particular spot in the Pacific, which is roughly 85% of an orbit.  I also did a rough Google Earth propagation of the NOTMAR debris hazard box (azimuth = ~93º) and an energy-maximized orbit would cross a few hundred km below the Big Island, not north of Kauai, where the landing zone is.  Some of that is because of Earth's rotation, but I suspect that there's some RAAN rotation baked in there as well, which is yet another indication of a funny flight path angle at burnout.

Discussion about suborbital/orbital or not first need to decide on the definition of orbital as there is not one that is obvious and universally used.

Some candidates:

Specific energy >= -μ/2R (lowest circular orbit above the surface).
Specific energy >= -μ/2r for some r>R.
Perigee above surface.
Perigee above some height h.

r and h could be 50 km, 80 km, 100 km or some spacecraft dependent value guaranteeing more than a full orbit is possible.

US Federal definition of suborbital is a trajectory whose vacuum instantaneous impact point does not leave the Earth's surface. Mount Everest is under 9km tall, so a rocket with perigee of >9km (worst case) is orbital (or one way to deep space).

https://www.law.cornell.edu/uscode/text/51/50902#24

Unfortunately there's no definition for "vacuum instantaneous impact point", which is a bit ambiguous.  Does this mean the impact point if Earth had no atmosphere, or the ground track expected from an uncontrolled reentry?

I'm gonna guess that the orbit is actually about 235 x 100km, since things with perigees below the Karman Line are going to reenter is short order (i.e. a fraction of an orbit).  That would be a semi-major axis (altitude) of 168km, and also the equivalent circular orbit.  That's probably OK for an orbit or two, but not much more than that.

Update:

I found a set of USSF range safety manuals:

Volume 1 (range safety and requirements procedures)
Volume 2 (flight safety requirements)
Volume 3 (ground support systems)
Volume 4 (flight safety, FTS, etc.)
Volume 5 (reentry vehicle location)
Volume 6 (personnel safety)
Volume 7 (glossary)

Sadly, while there's a definition of instantaneous impact point, there's still no definition of the "vacuum" version of that term.  However, in volume 2 (p. 81), there's a time-of-flight definition that's as follows:

Time of flight (2D) remaining to instantaneous vacuum impact point in seconds (TIIP).

Definition. The time of flight is the flight time remaining to an instantaneous vacuum
impact point assuming that all vehicle thrust is terminated at some time after launch.
The instantaneous vacuum impact point is a Keplerian solution only. The
instantaneous impact point is the location at which the vehicle would meet the
spheroid and is measured in the downrange direction from the launch point in the
flight plane.

So I think that makes the "suborbital" definition the atmosphere-free version, which invalidates my guess.

Update to the Update:

Here's an FAA rulemaking for reusable suborbital vehicles with the following definition:

The reusable suborbital rocket must also be flown on a suborbital trajectory, which the CSLAA defines as the intentional flight path of a launch vehicle, reentry vehicle, or any portion thereof, whose vacuum instantaneous impact point (the location on Earth where a vehicle would impact if it were to fail, calculated in the absence of atmospheric drag effects) does not leave the surface of the Earth.

Done deal.  So if SpaceX and/or the FAA is calling the flight suborbital, then the perigee is consistent with lithobraking.

[pedz]

More questions about the "Starbase Launch Keep Out Zone":  Is Highway 4 closed before or after the border patrol check point?  The diagram has two "Check Point".  One is next to Richardson Avenue.  Is it possible for me to get at that point with my cameras?  Is it possible to see the launch pad from that point?

That point is only 4 miles away rather than 6 miles which is the distance from Port Isabel.  But, you would be shooting straight into the rising sun -- although that could look cool if done properly.

As I recall, there is still a lot of scrub at that point and you can't actually see the launch site except whatever pokes out above the scrub.

As far as I'm aware, general public has to stay out of the outer checkpoint (and will be escorted if found between outer and inner checkpoint) while spacex personnel is allowed between the checkpoints, but nobody past the inner checkpoint(Eichorn Blvd.?) Tim dodd's boca chica visiting guide had some mention of that

Thank you.  I watched that video and saw that but later in the same video he says “this is where the check point is” and it is at Starbase itself.  Slightly confusing.

[DigitalMan]

Given the shape of the trajectory, does anyone know the velocity at EI?

[Tywin]

Doesn’t sound or look great:

Wonderful.  Now OSHA will shut it down for three weeks for an "investigation".

Do you prefer a fatal accident or injury?

How'd you get that from my statement?

Because, OSHA exists for a very clear reason...

No SS.  I work in manufacturing.  I know all about OSHA.

I was working in construction, so I know OSHA well too....

[Tywin]

orbital flight with making less than one orbit

That's exactly what it is.

People calling it suborbital are the same people calling a 100 (82...) km up-and-down hop "going to space"

Using legalese to intentionally miss the point is all fun and games, but has never helped anyone do anything constructive.

Not even repeating that likely this is a fully-legal orbital flight too, because that hair splitting is entirely inconsequential.

We can twist reality as much as we want at our will, but the definitions are clear...

[meekGee]

orbital flight with making less than one orbit

That's exactly what it is.

People calling it suborbital are the same people calling a 100 (82...) km up-and-down hop "going to space"

Using legalese to intentionally miss the point is all fun and games, but has never helped anyone do anything constructive.

Not even repeating that likely this is a fully-legal orbital flight too, because that hair splitting is entirely inconsequential.

We can twist reality as much as we want at our will, but the definitions are clear...

You're not listening.

The definitions are clear, and yet you can apply them to arrive at the wrong conclusions.

This flight is equivalent to any LEO flight (sans circularization) and entirely different from what's normally referred to as a suborbital flight.

Plus, reading upthread, it may even formally be fully orbital, depending on the flavor of the definition.

THAT is the reality.   Good luck with the hair splitting - it doesn't change a thing except give some folks the illusion that a certain suborbital launcher is "ready to catch up" or even "leap frog" SpaceX.

[Alberto-Girardi]

To have perigee below sea level and be able to do 3/4 of the circle around the Earth after standard rocket launch ... you must have apogee at ~320km or higher. Otherwise your trajectory would be too shallow.

... for example - insert directly into an orbit with an apogee above your current altitude and descending, and thus never reach apogee.

Sure, but your example trajectory would have its perigee <1/2 an orbit away from SECO, right?

No, it's more complicated than that.  If you're trying to maximize energy, yes, your burnout would be at either perigee or apogee, with a flight path angle of zero.  But you can also have burnouts with non-zero flight path angles, where the apse line is somewhere else.  This is pretty likely when you're aiming for a particular spot in the Pacific, which is roughly 85% of an orbit.  I also did a rough Google Earth propagation of the NOTMAR debris hazard box (azimuth = ~93º) and an energy-maximized orbit would cross a few hundred km below the Big Island, not north of Kauai, where the landing zone is.  Some of that is because of Earth's rotation, but I suspect that there's some RAAN rotation baked in there as well, which is yet another indication of a funny flight path angle at burnout.

Discussion about suborbital/orbital or not first need to decide on the definition of orbital as there is not one that is obvious and universally used.

Some candidates:

Specific energy >= -μ/2R (lowest circular orbit above the surface).
Specific energy >= -μ/2r for some r>R.
Perigee above surface.
Perigee above some height h.

r and h could be 50 km, 80 km, 100 km or some spacecraft dependent value guaranteeing more than a full orbit is possible.

US Federal definition of suborbital is a trajectory whose vacuum instantaneous impact point does not leave the Earth's surface. Mount Everest is under 9km tall, so a rocket with perigee of >9km (worst case) is orbital (or one way to deep space).

https://www.law.cornell.edu/uscode/text/51/50902#24

Unfortunately there's no definition for "vacuum instantaneous impact point", which is a bit ambiguous.  Does this mean the impact point if Earth had no atmosphere, or the ground track expected from an uncontrolled reentry?

I'm gonna guess that the orbit is actually about 235 x 100km, since things with perigees below the Karman Line are going to reenter is short order (i.e. a fraction of an orbit).  That would be a semi-major axis (altitude) of 168km, and also the equivalent circular orbit.  That's probably OK for an orbit or two, but not much more than that.

Update:

I found a set of USSF range safety manuals:

Volume 1 (range safety and requirements procedures)
Volume 2 (flight safety requirements)
Volume 3 (ground support systems)
Volume 4 (flight safety, FTS, etc.)
Volume 5 (reentry vehicle location)
Volume 6 (personnel safety)
Volume 7 (glossary)

Sadly, while there's a definition of instantaneous impact point, there's still no definition of the "vacuum" version of that term.  However, in volume 2 (p. 81), there's a time-of-flight definition that's as follows:

Time of flight (2D) remaining to instantaneous vacuum impact point in seconds (TIIP).

Definition. The time of flight is the flight time remaining to an instantaneous vacuum
impact point assuming that all vehicle thrust is terminated at some time after launch.
The instantaneous vacuum impact point is a Keplerian solution only. The
instantaneous impact point is the location at which the vehicle would meet the
spheroid and is measured in the downrange direction from the launch point in the
flight plane.

So I think that makes the "suborbital" definition the atmosphere-free version, which invalidates my guess.

Update to the Update:

Here's an FAA rulemaking for reusable suborbital vehicles with the following definition:

The reusable suborbital rocket must also be flown on a suborbital trajectory, which the CSLAA defines as the intentional flight path of a launch vehicle, reentry vehicle, or any portion thereof, whose vacuum instantaneous impact point (the location on Earth where a vehicle would impact if it were to fail, calculated in the absence of atmospheric drag effects) does not leave the surface of the Earth.

Done deal.  So if SpaceX and/or the FAA is calling the flight suborbital, then the perigee is consistent with lithobraking.

Great find. But have the FAA or SpaceX ever called the flight suborbita?

[meekGee]

To have perigee below sea level and be able to do 3/4 of the circle around the Earth after standard rocket launch ... you must have apogee at ~320km or higher. Otherwise your trajectory would be too shallow.

... for example - insert directly into an orbit with an apogee above your current altitude and descending, and thus never reach apogee.

Sure, but your example trajectory would have its perigee <1/2 an orbit away from SECO, right?

No, it's more complicated than that.  If you're trying to maximize energy, yes, your burnout would be at either perigee or apogee, with a flight path angle of zero.  But you can also have burnouts with non-zero flight path angles, where the apse line is somewhere else.  This is pretty likely when you're aiming for a particular spot in the Pacific, which is roughly 85% of an orbit.  I also did a rough Google Earth propagation of the NOTMAR debris hazard box (azimuth = ~93º) and an energy-maximized orbit would cross a few hundred km below the Big Island, not north of Kauai, where the landing zone is.  Some of that is because of Earth's rotation, but I suspect that there's some RAAN rotation baked in there as well, which is yet another indication of a funny flight path angle at burnout.

Discussion about suborbital/orbital or not first need to decide on the definition of orbital as there is not one that is obvious and universally used.

Some candidates:

Specific energy >= -μ/2R (lowest circular orbit above the surface).
Specific energy >= -μ/2r for some r>R.
Perigee above surface.
Perigee above some height h.

r and h could be 50 km, 80 km, 100 km or some spacecraft dependent value guaranteeing more than a full orbit is possible.

US Federal definition of suborbital is a trajectory whose vacuum instantaneous impact point does not leave the Earth's surface. Mount Everest is under 9km tall, so a rocket with perigee of >9km (worst case) is orbital (or one way to deep space).

https://www.law.cornell.edu/uscode/text/51/50902#24

Unfortunately there's no definition for "vacuum instantaneous impact point", which is a bit ambiguous.  Does this mean the impact point if Earth had no atmosphere, or the ground track expected from an uncontrolled reentry?

I'm gonna guess that the orbit is actually about 235 x 100km, since things with perigees below the Karman Line are going to reenter is short order (i.e. a fraction of an orbit).  That would be a semi-major axis (altitude) of 168km, and also the equivalent circular orbit.  That's probably OK for an orbit or two, but not much more than that.

Update:

I found a set of USSF range safety manuals:

Volume 1 (range safety and requirements procedures)
Volume 2 (flight safety requirements)
Volume 3 (ground support systems)
Volume 4 (flight safety, FTS, etc.)
Volume 5 (reentry vehicle location)
Volume 6 (personnel safety)
Volume 7 (glossary)

Sadly, while there's a definition of instantaneous impact point, there's still no definition of the "vacuum" version of that term.  However, in volume 2 (p. 81), there's a time-of-flight definition that's as follows:

Time of flight (2D) remaining to instantaneous vacuum impact point in seconds (TIIP).

Definition. The time of flight is the flight time remaining to an instantaneous vacuum
impact point assuming that all vehicle thrust is terminated at some time after launch.
The instantaneous vacuum impact point is a Keplerian solution only. The
instantaneous impact point is the location at which the vehicle would meet the
spheroid and is measured in the downrange direction from the launch point in the
flight plane.

So I think that makes the "suborbital" definition the atmosphere-free version, which invalidates my guess.

Update to the Update:

Here's an FAA rulemaking for reusable suborbital vehicles with the following definition:

The reusable suborbital rocket must also be flown on a suborbital trajectory, which the CSLAA defines as the intentional flight path of a launch vehicle, reentry vehicle, or any portion thereof, whose vacuum instantaneous impact point (the location on Earth where a vehicle would impact if it were to fail, calculated in the absence of atmospheric drag effects) does not leave the surface of the Earth.

Done deal.  So if SpaceX and/or the FAA is calling the flight suborbital, then the perigee is consistent with lithobraking.

Great find. But have the FAA or SpaceX ever called the flight suborbita?

Neither is obliged to follow any guidelines.

The trajectory is known and agreed upon.

It's categorization as "orbital" or not is purely marketing.  There's reasons to go either way.

My guess is that there's enough obvious achievement that there's no reason for SpaceX to get into the distraction of arguing semantics.

[DigitalMan]

It's a test. The arguments are interesting to see.

Obvious minimum requirements for a first test flight in my opinion are being tested. (1) Achieving orbital velocity (2) Affects of reentry at the required entry velocity.

Sure there are other things they could add, like the flip-landing, but there is a trail of ships waiting to fly. Obvious reason for less than one orbit is risk and desire to observe entry performance from a location with adequate instrumentation.

[alugobi]

Some peeps dislike Musk so much that it makes them say funny things.

[rcoppola]

There is one overriding requirement...Clear. The. Tower.

After that...it's all good.

[joek]

Great find. But have the FAA or SpaceX ever called the flight suborbita?

FWIW... The FAA launch license is neutral. The FAA WR (published concurrently), refers to "Starship Orbital Test Flight...", and also specifically refers to booster as suborbital.

Think most of us know what a significant effort this is and what it portends--whether or not this first attempt succeeds. Trolls, ankle biters and barnyard lawyers trying to minize that based on questionable self-serving interpretations just makes them look small and is a distraction.

[baking]

Thank you.  I watched that video and saw that but later in the same video he says “this is where the check point is” and it is at Starbase itself.  Slightly confusing.

There is a checkpoint at Starbase, but that is only for non-flight tests such as cryo-tests, wet dress rehearsals, and static fires, etc.  Anything that leaves the ground (intentionally) requires FAA approval and they have a larger exclusion zone.

[joek]

There is a checkpoint at Starbase, but that is only for non-flight tests such as cryo-tests, wet dress rehearsals, and static fires, etc.  Anything that leaves the ground (intentionally) requires FAA approval and they have a larger exclusion zone.

FYI, per FAA license additional stipulations kick in well before anything might leave the ground (emphasis added)...

“Pre-flight ground operations” shall mean Space Exploration Technologies, Corp.’s pre-flight preparations of the Starship-Super Heavy vehicle at Boca Chica, Texas, beginning at the start of Autonomous Flight Termination System ordnance installation for the Starship upper stage vehicle or Super Heavy booster vehicle, whichever occurs first.

... including $48M liability coverage from those pre-flight operations. (Actual flight is $500M.)

[ChrisC]

There is one overriding requirement...Clear. The. Tower.   After that...it's all good.

Ah yes, thanks for the reminder, I wanted to whine about this.  Hey NSF guys, I was really surprised that, in your recent launch sequence video, scripted by Alex, you did not call out the point at which the stack will have flown far enough to eliminate any chance of damaging the launch pad.  That's the first major milestone that us armchair veterans will be watching for, and it typically occurs at around 25 seconds into flight.  At that point, with the altitude and more important the beginning of pitch over, the Instantaneous Impact Point (IIP) will be "outside the fenceline", and a couple more seconds after that it'll be across the beach and in the water.  It's what we were watching for during the first Falcon Heavy launch, and it's the point when Elon ran outside with a big ass grin on his face

Just "clearing the tower" isn't enough.  Once the IIP is in the water, we can breathe easy and everything after that is gravy -- max q, staging, RVac ignition, orbit*, entry, splashdown.  Put that mention of IIP into your timeline and coverage!

* OMG would you all please stop with the orbital semantics. Didn't we already do this six months ago when the Hawaii target was first news?