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#1301 2021-07-10 12:11:11

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
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Re: Starship is Go...

TH:

Trusses are a fairly well-known solution in space,  with the construction of the ISS.  It has multiple trusses. 

ISS does not have any significant propelled motion (other than dodging debris and raising a decaying orbit).  Trusses can be fairly lightweight if strength requirements are not very high,  but their mass is not trivial.  For a propelled vehicle (such as a Starship going to Mars),  it adds directly to inert mass only,  which means it comes directly out of carriable payload,  ton for ton.

Starship's design,  as currently published by Spacex,  uses all but about 20 tons (of its 1200 tons) of propellants to leave Earth orbit and conduct course corrections on the way to Mars.  That "about 20 tons" is required to land on Mars,  from a direct atmospheric entry at a speed above Mars escape.  There is no other propellant remaining on board a ship that carries useful amounts of payload,  with which to conduct a burn into Mars orbit.

A ship carrying little or no payload uses substantially less of that 1200 tons to leave Earth and conduct course corrections.  If fully filled,  it then has much more than 20 tons on board at Mars arrival (if we ignore boiloff for propellants outside the enclosed header tanks,  which is a bad engineering assumption),  and so could decelerate into Mars orbit.  But with little or no payload,  what would be the point?

And that previous paragraph is EXACTLY why Spacex always projects a direct entry at Mars with its Starship,  and NEVER a stop in Mars orbit at arrival.

It could stop in orbit on the return flight to Earth,  but that is NOT the same thing at all!

GW

PS:

Mars surface escape velocity is right at 5 km/s.  Low circular orbit velocity is right at 3.5 km/s.  Allowing for the gravity of Mars accelerating the ship toward it upon arrival,  velocities near low orbit or entry interface altitude at Mars are about 5.4 km/s off of Hohmann min energy transfer,  and right at 7.4 km/s off of the much faster 2-year period abort transfer orbit. 

The difference between arrival speed at low altitude and orbit speed at low altitude is what you have to have for an orbital entry burn delta-vee. If instead you do direct entry,  you can kill almost all the low-altitude arrival speed with atmospheric drag,  excepting that which you need to pull-up,  flip,  and retropropulsively land.  That landing allowance is about 0.3-0.5 km/s until you factor it up for uncertainties,  hover,  and divert requirements. 

You basically need 1 to 1.1 km/s delta-vee capability to land on Mars.  Because of the thin air,  you come out of deceleration hypersonics at Mach 3 about 8-12 km above the surface,  still doing around Mach 3,  and headed slanted downward.  Mere seconds from surface impact.
Spacex's current simulations show a low-supersonic pull-up at around Mach 1.5+ about 3-5 km above the surface,  without thrust,  but I think they will find they need to add thrust to get it to pull up.  That is why my landing delta-vee requirement looks bigger than theirs.

Last edited by GW Johnson (2021-07-10 12:35:32)


GW Johnson
McGregor,  Texas

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

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#1302 2021-07-10 12:17:41

louis
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Re: Starship is Go...

I'm with you on the last para, GW. And it's why in my view we won't see it used on Mission One. But, I could see it might be developed to facilitate tourism, so people might have a zero G "joyride" at the beginning and end of their orbital vacation but otherwise be in 1G.

Once concern - am I right in thinking with the tether system there's no way you could maintain a relatively "fixed view of Earth below.  It would have to be coming in and out of view...wouldn't that be nausea-inducing? Maybe not so good for orbital tourism after all.


GW Johnson wrote:

I see lots of proposals to use cable-tethers for spin gravity,  but I have NEVER,  EVER seen any experimental results to back them up,  at useful gee levels (which would be 0.1 to 1 gee).  Such are therefore BY DEFINITION not an off-the-shelf,  ready-to-apply technology for design purposes.  Not until the necessary experiments at useful gee levels have been successfully run.  And the odds favor failure first time up.

GW


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#1303 2021-07-10 21:50:09

GW Johnson
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Re: Starship is Go...

Be aware that this is nothing but speculation on my part.  I am guessing that partial gee is way better than no gee at all,  in terms of human health effects.  There will be fluid gradients,  even at lunar gravity levels.  There will be some demand on bones and muscles. 

I suspect that passengers subjected to months at 0.38 gee will arrive at Mars more-or-less healthy for living at 0.38 gee,  but not healthy enough to live at 1 full gee.  But I also suspect that the drastic bone and muscle losses that we have to fight so hard,  the heart and circulatory problems that we fight so hard,  the eyesight damage we seem unable to prevent,  and the immune system deterioration that we cannot understand much less prevent that we see at 0 gee,  won't happen at partial gee,  or at least not nearly as bad.

I think the way it works out is that people headed to Mars to live,  need only acclimatize at 0.38 gee during transit,  as long as the entry and landing gee forces are not too high (probably never above 3-ish gees on short transients).

But,  by the same token,  those returning to Earth need to acclimatize at 1 full gee during the transit home,  in order to cope with 1 full gee on Earth,  and the rather higher gee levels to be endured during the entry and landing transients (perhaps 10+ gees). 

So,  it's a double-edged sword in all likelihood.  It's going to bite both ways.  Somebody acclimatized to 0.38 gee on Mars is going to have very serious health problems if he returns to Earth.  It will take months to readjust bones,  muscles,  etc to that.  Easy to go down in gee,  but very,  very hard to go up in gee. 

However,  until we humans have actually gone there and done these things,  we cannot know for sure,  because we never built a spinning-wheel space station where we could try partial gee out,  at multiple levels.  Rather stupid in hindsight,  that.

GW


GW Johnson
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#1304 2021-07-11 00:15:45

Oldfart1939
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Re: Starship is Go...

GW-
Your analysis is very similar to mine. I only speculated on the outbound to Mars being 0.4g. I'm using the 0.4 figure as a crude number, because the two Starships tethered together nose to nose will have different artificial gravities depending on which level within the ship at a given number of RPM.
My suggestion for the return flight is a incremental increase in the spin rate over time, gradually increasing from 0.4g to 1.0 over a 6 month interval. If the return flight is 8 months, that would give the travelers a full 2 months at Earth gravity.

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#1305 2021-07-11 06:41:32

SpaceNut
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Re: Starship is Go...

So far there is no mention of an air lock for the starship to allow for a space walk to connect a truss to a two ship mission with AG of any level. The attachment points would be a minor budget mass reduction in payload but it adds a another level of complexity as we approach mars we then would need another space walk to remove that truss from use and is gone from the stand point of a return flight back to earth.

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#1306 2021-07-11 08:05:36

Void
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Re: Starship is Go...

So, the whole system is in flux to a degree, with options to be speculated on....

I have not seen report of a 9 engine Starship so far on this site.  Perhaps I missed it, and it has been discussed.

https://www.teslarati.com/spacex-elon-m … ades-2021/

Quote:

SpaceX CEO Elon Musk teases nine-engine Starship, Raptor upgrades

I have seen glimpses of reasons for this possible variant in the article.  However, I consider myself to be outside of my strengths to comment much on it.  Perhaps others feel they can explain this possible option.

I would be interested.

Done.

Last edited by Void (2021-07-11 08:08:54)


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#1307 2021-07-11 10:05:33

tahanson43206
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Re: Starship is Go...

For SpaceNut re #1305

Spacewalks are so 20th Century !!!

we then would need another space walk to remove that truss from use and is gone from the stand point of a return flight back to earth.

Why would a spacewalk be necessary?

(th)

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#1308 2021-07-11 10:13:07

GW Johnson
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Re: Starship is Go...

Spacewalks are the fun part!  And they always will be.  A chance to leave confinement and go outside and look around!  Any excuse is a good excuse for a spacewalk.

GW


GW Johnson
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#1309 2021-07-11 10:22:05

tahanson43206
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Re: Starship is Go...

For GW Johnson ... Point taken (re Post #1308)

However, re SpaceNut's concept ... a spacewalk for fun is one thing.  A spacewalk that is completely unnecessary, to fit a girder to the nose of a Starship, is another.

My recommendation to anyone thinking about designing equipment for on-orbit assembly is to avoid spacewalks, except as backup when purpose designed equipment fails.

To SpaceNut's point about reducing payload to add a truss ... why would ** that ** be necessary?

The truss should be in space already, fully tested and ready for automatic attachment to the noses of the two Starships.

***
For RobertDyck ... how is Unreal Engine coming along?

It should be possible to adapt the organizing principles of the Large Ship to this opportunity.

It should be possible to design a truss system for rotation of two (or more) Starships to provide the Mars Gravity at 20 second rotation times you've been advocating in the Large Ship topic.

The model would show the way for a ** real ** Large Ship, by showing the advantages of your recommended operating parameters.

(th)

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#1310 2021-07-11 11:42:10

GW Johnson
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Re: Starship is Go...

What are you going to do with the truss when you get to Mars? 

Starship hasn't the delta-vee capability to stop in Mars orbit (some 2 to 5 km/s delta vee).  It can only do a direct entry from the interplanetary trajectory (at 5.4 to 7.4 km/s velocity at entry interface),  and then land (about 1 km/s delta vee). 

If you let the truss also enter and therefore burn up,  then you have no spin truss for any voyage back to Earth.

Starship can enter low Mars orbit,  but it carries almost no payload doing that,  while still requiring the full 1200 tons of propellant on board at LEO departure.

Any truss mass comes out of payload mass,  ton for ton.

GW

Last edited by GW Johnson (2021-07-11 11:46:22)


GW Johnson
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#1311 2021-07-11 12:03:32

SpaceNut
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Re: Starship is Go...

Tethered AG is also the same problem of attachment and getting rid of it once we approach mars as a truss would be. We need to face it that starship is a taxi to LEO and is in trouble beyond the lunar use....

Void thanks for the article muse from Musk on the use of more engines on the starship as well as for the BFR booster. Going from 32 engines is sort of minor if the engine compartment can take it as that just a compensation.

going from 3 + 3 on the starship is a different issue as what type of the engines are going in 3 vaccumn or 3 atmospheric as the later would be made use of for landing most likely to aid. Where are 3 vaccumn would be used for a lunar or mars landing...

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#1312 2021-07-12 08:29:09

GW Johnson
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Re: Starship is Go...

Re post 1309 question about the truss reducing payload:

1. Getting the truss to LEO from Earth's surface means it (or its components) are payload for the ride up. 

2. When Starship arrives in LEO,  it is out of propellant except for around 20 tons in the header tanks,  which goes for the deorbit burn,  and then for the flip and retropropulsive landing.  That does presume it was carrying significant payload,  but that is a good assumption,  because what would be the point of the flight with no payload,  excepting only tanker flights?

3. Any Starship that travels anywhere at all outside of LEO (including just to higher orbits) must be refilled to one extent or another by tanker craft (planned to be other Starships).  Spacex is planning a tanker version,  but a Starship flown with zero payload arrives with enough unused propellant to be almost as good a tanker as the dedicated tanker design.

4. The burn to leave LEO for an interplanetary trajectory to Mars requires somewhere between 4 and 5+ km/s delta-vee,  including course corrections,  which is all of the propellant on board,  less only the crudely-20-tons-landing allowance at Mars in the header tanks.  You will NOT arrive at Mars with the propellant needed to decelerate into Mars orbit,  unless you are carrying almost no payload,  and you were filled to the full 1200 tons propellant capacity for departure.  Even so,  propellant in excess of header tank capacity is at risk of solar-driven evaporation over the months of the voyage.

5. If you send 2 Starships to Mars simultaneously,  intending to spin them for artificial gravity by means of a connecting truss,  then the truss must be riding on one or the other of them (or parts of it aboard both of them) at departure.  The truss is therefore by definition a part of the payload being sent to Mars.  You must therefore reduce the otherwise-useful payload mass sent to Mars by the mass of the truss.   

6. You WILL LOSE the truss upon arrival at Mars,  because you must make a direct entry into its atmosphere off the interplanetary trajectory,  there is no "dropping anything off" into Mars orbit.  EXCEPTION:  go EVA very far from Earth with no hope of help or rescue,  disassemble the truss,  and store it inside the cargo holds of the two Starships,  thus carrying it down to the surface,  reducing useful payload a bit further by adding inert mass to the landing burn. 

7. The upshot of all this is:  yes,  you can take a truss and spin two Starships for artificial gravity.  But,  it will cost you a reduction in useful payload sent to Mars,  by the amount of the mass of the truss.  Further,  you will take a very serious EVA risk saving the truss for any return to Earth.  So,  is the artificial gravity worth the cost of the truss?  Depends upon the length of the voyage:  just how much microgravity disease can you tolerate?

8.  Consider:  average Hohmann transfer 8.6 months one-way is the longest.  Likely,  the shortest would be using the 2-year abort orbit,  which is on average 4.3 months one way.  The 6-month one-way trajectories currently being considered lie in between those extremes,  but offer no free-return abort capability. 

9.  Myself,  I'd send unmanned cargo via Hohmann to maximize delivered payload.  I'd send crewed vehicles at lower on-board payload via one of the faster trajectories,  but no longer than 6 months exposure to zero-gee.  Crews arriving at Mars will be "good" for 3-4 gee hypersonic deceleration transients,  and living at 0.38 gee.  Very similar to what ISS astronauts do coming home. 

10. The problem will be for crews returning to Earth after years on Mars.  A 6 month flight in zero gee just makes the 10-ish gee entry transients and sudden adjustment to 1-gee living rather threatening.  Perhaps lethally so.  Artificial gravity is much more important for returning personnel than it is for crews going out to Mars.  It should be done just like OF39 suggested:  start out at 0.38 gee,  gradually increase to 1.0 gee before you arrive at Earth.

GW

Last edited by GW Johnson (2021-07-12 08:31:03)


GW Johnson
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#1313 2021-07-12 10:07:10

RobertDyck
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Re: Starship is Go...

I have said NASA needs to complete 2 experiments *RIGHT NOW*! These are overdue.

  • launch the Centrifuge Accommodation Module for ISS, and attach it

  • attach a manned capsule to a cargo ship with a tether and spin

The first can be done with an Altas V or Falcon Heavy, using a Cygnus service module to rendezvous with ISS.

The second is relevant to this discussion. Use a tether, not a truss. The capsule could be Crew Dragon aka Dragon 2, or Boeing Starliner. The cargo ship could be Cygnus, or Cargo Dragon, or Japanese HTV. The idea is to use vehicles that travel to ISS anyway. Before they return to Earth, do one more experiment. Separate from ISS a safe distance, connect the tether and spin. Whether it's spun for Earth level gravity or Mars level gravity is detail I'll leave to others, but it must be significant gravity. And change orbit while spinning. Do *NOT* stop spinning to change orbit. The orbital manoeuvre doesn't have to be a lot, just enough to simulate a mid-course correct enroute to Mars. The cargo ship should be filled with garbage. With any experiment, you have to prepare for the possibility of complete success, but you also have to prepare for problems. If you have to sacrifice one spacecraft to save the other, then if one has astronauts while the other holds nothing but garbage, which to sacrifice is a no-brainer. Cargo Dragon is usually used to return experiments to Earth, it isn't destroyed upon re-entry. Using Cargo Dragon could be problematic because controllers may hesitate to sacrifice the cargo ship should a problem arise. For that reason I would prefer either Cygnus or HTV. This experiment could also be done with a Russian Soyuz and Progress, but I assume American politicians will want American hardware.

Yes, you can perform manoeuvres while spinning with a tether. Just time thruster bursts so you always pull the tether, never push. You can't push on a string.

There will be some people in NASA who think this tether experiment is far too advanced. But it isn't. Gemini 11 connected to an Agena Target Vehicle in 1966, and spun. Yes, there were astronauts in the Gemini capsule. It spun at a low rate, and didn't try to manoeuvre while spinning. The experiment I propose is the next logical step after Gemini 11. Anyone who claims it's too difficult or too advanced has completely lost all knowledge gained by Gemini.
260px-Gemini_11_Agena.jpg

This is ideal for Mars Direct. However, this could be used for SpaceX Starship. Instead of a truss, use a tether. The tether could be retracted with a winch after the two vehicles separate. That way it could be reused for return.

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#1314 2021-07-12 12:51:24

tahanson43206
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Re: Starship is Go...

For GW Johnson re #1312

It is good to have you back in the flow of discussion ...

While you were away, I suggested that there is NO reason ** whatsoever ** for any vehicle to leave Earth (LEO) without full tanks.

Refueling on orbit changes the "way of doing things", but it is (obviously) difficult to get used to the implications of the technology.

I know ... it doen't exist yet.

That said, and assuming it comes to pass, then vehicles headed to Mars (or anywhere) can be topped off before departure, and they can be given all the impetus they need by pusher tugs dedicated for the purpose.

The truss does NOT need to be brought up on one of the expedition vehicles.  It can (and certainly will) be brought up on dedicated freighters.

The OLD way of doing things was based upon limitations of human capability that still exist.  I understand that.  But since refueling is part of Elon's planning, then the implications of having the capability can and (in my opinion ** should ** ) be taken into account.

For RobertDyck about a tether ... I would recommend a tether inside the truss that is present for safety purposes.  It is possible for the truss to fail, and a safety tether would increase the safety margin for the two vehicles involved.

(th)

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#1315 2021-07-12 16:31:44

Oldfart1939
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Re: Starship is Go...

I am in complete agreement with Robert about the tether. I would envision it as a permanent part of the ship and would be fully retractable onto a rotary drum. Each ship would need to carry only half of the necessary tether cable. Using the freighters as cable carriers is also with merit. Using trusses might seem good at first glance, but having a system with flexibility would win in the end.

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#1316 2021-07-13 00:09:38

kbd512
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Re: Starship is Go...

Why not simply admit that we need real interplanetary transports of the type that RobertDyck proposed using?

If we can design Starship for 200 reentries, then surely we can design a ship that stays in space for 20+ years, as ISS already has.  Use chemical propulsion to help break orbit at Earth, then use electric propulsion and a common propellant, like N2 or O2 or Ar to provide cruise propulsion and braking at Mars.

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#1317 2021-07-13 12:29:08

GW Johnson
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Re: Starship is Go...

Well,  you use what you have on-hand.  We currently have nothing in the way of a large crewed transport vessel,  but the one that might become "real" soonest looks to be Spacex's Starship/Superheavy.  That's why it was the scenario for spin gravity discussions.   

Myself,  I think Robert is right to suggest using cable tethers,  once the experiments have been done to verify functionality.  If feasible, they would be a lot more adaptable and lighter weight than trusses.  But that's a big "if".   The experiments were never done.

I just worry about instabilities and oscillations excited by thruster pulses when connected nonrigidly.  We have a lot more experience with the dynamics of rigid bodies than we do cable-connected things.  It's only a worry,  but I fear the experiments will show that cable-connected spin at useful gee levels is a bit more difficult to do,  than Robert thinks. 

And trying to conduct delta-vee operations with a spinning cable-connected object might prove impossible.  Either way,  it all has to be verified before we can use it on a mission.  The verification path is a lot shorter with fewer milestones,  for a rigid body approach.

Now,  Kbd512 might well be onto something for a large transport other than Starship.  He suggested chemical propulsion to leave LEO,  which would be required to transit the Van Allen radiation belts quickly.  The effectiveness of that was demonstrated long ago with Apollo.  Then use low-thrust electrics to speed-up the transit to Mars,  and to decelerate at Mars (spiral-in) to orbit about Mars,  since it has no radiation belts the way Earth does. 

The return trip would just the reverse:  depart and transit with electrics,  then use chemical to decelerate back into LEO quickly transiting the radiation belts,  with a big reusable orbit-to-orbit transport. 

A really good use for something like Starship used single stage would be as a surface to orbit and back ferry at Mars,  refilled with propellants made on Mars.  You would get several flights out of a heat shield,  before you need to replace it,  with only 3.5 km/s entries from Mars orbit.

The surface to orbit and back transport here at Earth would be the Starship/Superheavy combination,  or else somebody else's equivalent,  such as New Glenn,  perhaps.  This is the prime job Starship/Superheavy was really designed for:  an orbital transport at Earth.  It just happens to be useful for other jobs,  like going to the moon or Mars,  if refilled in-situ appropriately.

GW

Last edited by GW Johnson (2021-07-13 12:30:01)


GW Johnson
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#1318 2021-07-13 18:04:14

louis
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Re: Starship is Go...


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#1319 2021-07-14 06:38:41

Mars_B4_Moon
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Re: Starship is Go...

New article

Elon Musk's SpaceX reveals gigantic 160ft Starship rocket - bigger than the Statue of Liberty - that will be launched for its first orbital flight within weeks
https://www.dailymail.co.uk/sciencetech … ugust.html

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#1320 2021-07-14 20:12:42

SpaceNut
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Re: Starship is Go...

I do not believe that clearance has been given for the first flight to come.

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#1321 2021-07-15 08:00:33

GW Johnson
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Re: Starship is Go...

They do NOT have clearance yet.

This from 15 July's "Daily Launch" email newsletter from AIAA:

FAA Says Tower At SpaceX’s Boca Chica Launch Site Has Not Yet Been Approved
Reuters (7/14) reports that the FAA has warned SpaceX “that its environmental review of a new tower at its Boca Chica launch site in Texas is incomplete and the agency could order SpaceX to take down the tower.” A May 6 “letter from the FAA to SpaceX seen by Reuters said recent construction activity on one of the two proposed towers ‘may complicate the ongoing environmental review process for the Starship/Super Heavy Launch Vehicle Program.’” SpaceX “told the FAA in May that it did not believe the review was necessary because it only intends to use the ‘integration tower for production, research, and development purposes and not for FAA-licensed or -permitted launches,’ the FAA said.” However, the agency “said description in documents ‘indicates otherwise.’” The FAA “cited a SpaceX document that the towers would be used to integrate the Starship/Super Heavy launch vehicle.”

****************

It takes reading between the lines,  but the FAA dispute may possibly be boiling down to whether Spacex will be allowed to launch a Superheavy from the Boca Chica site.  It would appear that Spacex built the tower to put a Starship atop a Superheavy,  when they have yet no approval to fly the configuration from the site. 

If I am guessing correctly,  they could be forced to wait until the offshore platform is finished.  Depends upon which agency's bureaucrat is upset with them.  Since the problem is "environmental review process" in description,  I do believe it would be the EPA that is really involved,  with FAA approval dependent upon whether the EPA is satisfied.  We have seen that licensing processing sequence reported before.

I've warned about how unforgiving the EPA is before,  quite unlike the FAA.  This is what happens when you cavalierly piss off the wrong bureaucrats.  EPA is involved because the environmental "impact" of a Superheavy launch is enormous,  whether there is an explosion or not,  just because of the lethal noise.  The impact statement has to consider noise as well as fumes and pollution,  and also the dangers of an explosion (and fire).

GW


GW Johnson
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#1322 2021-07-15 10:02:39

tahanson43206
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Re: Starship is Go...

For GW Johnson re #1321

Thank you for the background on the situation with the tower.

I think it is reasonable to NOT trust Elon, if what you are asking him to do is to restrain himself.

There ** might ** be a way to allow the team to perform assembly testing, if skillful negotiators can participate.

The concept I have in mind is to insure that no fluids are fed into the stack after assembly.

The mechanism to enforce that might be as simple as a single member of the local police force, who (I gather) have enough clout to object when public roads are taken over by the SpaceX crew without prior agreement.

The enforcement mechanism could be something simple, like a demolition package at the base of the tower.  That might seem extreme, but with Elon, it would seem perfectly reasonable.

This situation reminded me of a story from the X-15 rocket plane test series.  (the actual vehicle might have been a precursor).  In any case, what I remember from the history of that time is that a test pilot had been asked to fly just ** under ** the speed of sound.  He could have pushed the envelope, and the temptation to do so would have been strong because it was either the last flight for that pilot, or the last flight for that particular aircraft.

The punchline for the story is that the pilot held rigorously to the test plan, so the engineers could study that incremental set of data.

Elon is ** not ** that kinda guy!

(th)

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#1323 2021-07-15 11:19:45

louis
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Re: Starship is Go...

Or it could be political interference in the guise of bureaucratic niceties. Wouldn't be the first time.

GW Johnson wrote:

They do NOT have clearance yet.

This from 15 July's "Daily Launch" email newsletter from AIAA:

FAA Says Tower At SpaceX’s Boca Chica Launch Site Has Not Yet Been Approved
Reuters (7/14) reports that the FAA has warned SpaceX “that its environmental review of a new tower at its Boca Chica launch site in Texas is incomplete and the agency could order SpaceX to take down the tower.” A May 6 “letter from the FAA to SpaceX seen by Reuters said recent construction activity on one of the two proposed towers ‘may complicate the ongoing environmental review process for the Starship/Super Heavy Launch Vehicle Program.’” SpaceX “told the FAA in May that it did not believe the review was necessary because it only intends to use the ‘integration tower for production, research, and development purposes and not for FAA-licensed or -permitted launches,’ the FAA said.” However, the agency “said description in documents ‘indicates otherwise.’” The FAA “cited a SpaceX document that the towers would be used to integrate the Starship/Super Heavy launch vehicle.”

****************

It takes reading between the lines,  but the FAA dispute may possibly be boiling down to whether Spacex will be allowed to launch a Superheavy from the Boca Chica site.  It would appear that Spacex built the tower to put a Starship atop a Superheavy,  when they have yet no approval to fly the configuration from the site. 

If I am guessing correctly,  they could be forced to wait until the offshore platform is finished.  Depends upon which agency's bureaucrat is upset with them.  Since the problem is "environmental review process" in description,  I do believe it would be the EPA that is really involved,  with FAA approval dependent upon whether the EPA is satisfied.  We have seen that licensing processing sequence reported before.

I've warned about how unforgiving the EPA is before,  quite unlike the FAA.  This is what happens when you cavalierly piss off the wrong bureaucrats.  EPA is involved because the environmental "impact" of a Superheavy launch is enormous,  whether there is an explosion or not,  just because of the lethal noise.  The impact statement has to consider noise as well as fumes and pollution,  and also the dangers of an explosion (and fire).

GW


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#1324 2021-07-15 19:30:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,084

Re: Starship is Go...

Well an explosion of the first stage would be huge since the volume of fuel is quite large in comparison to the starship even at landing that volume is still greater than a starships....

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#1325 2021-07-17 16:54:32

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,863

Re: Starship is Go...

https://www.youtube.com/watch?v=L5fsW1fcXY8

Latest from SpaceXCentric.

No let up from Musk in terms of the overall vision. Intending to make up to 1000 Raptor engines per annum to build (over a decade) the Starship fleet that can build the City on Mars, to be "completed" by 2050.

Could be a very empty city is still my view. But who would bet against Musk?

I guess we'll find out how realistic Musk's vision is when they start selling one-way tickets to Mars! More pandemic-lockdown misery could certainly help.


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