Starship is Go...

louis · 2020-05-30 18:45:21

Do you mean Scots English Void? Some consider Scots/Scots English to be more than a dialect, a separate language. Or do you mean his English as spoken by Scottish people has been Americanised?

Void wrote:

Maybe I will get a spanking, but I am amused.
Although I am not that much lowland Scottish, they had a perfectly legitimate form of English, as Anglo-Saxons were there as well.
Just for fun, Scott Manley does not have spoken proper Scottish English.
https://www.bing.com/videos/search?q=Sc … &FORM=VIRE
It is hard for me not to be amused, as I am Swedish and Scottish among other things, as per genetic heritage.
I will cease to profane this thread with this off topic stuff. A little smile

louis · 2020-05-30 18:51:44

Leaving aside the amusing language debate, I must say it was a total relief that the Crew Dragon mission went well today. Had there been an inflight abort that would have been a real disaster for Space X after the Starship explosion.

Showing that they can safely get humans to orbit is a major step forward for Space X, since it is step 1 of a Mars Mission. They've got maybe 8 significant steps thereafter (transit, landing on Mars, survival on Mars, propellant production, fuelling of return Starship, launch to LMO of Starship, return transit and safe landing on Earth).

Void · 2020-05-30 18:59:50

I am so glad as well for that success. I really understand that Starship is going to be a real grunt. If you want to discuss any other thing Louis, you may start an appropriate thread for it. Else, I am satisfied.

Void · 2020-06-02 07:10:12

Elon Musk explains the probable cause of the SN4 explosion.
https://www.teslarati.com/spacex-starsh … elon-musk/

Apparently the quick disconnect for the fuel line did not seat correctly when the tried to re-insert it.

Probably best if you want to know more that you read the article.

GW Johnson · 2020-06-02 08:32:12

I got pretty much the same story talking to a McGregor Spacex employee yesterday afternoon. They weren't "for sure", but that was before Musk's story.

Handling liquid methane is more like handling hydrogen than anything else. Both are lighter than air as gases, both ignite in air at the slightest provocation, and both will mass-detonate with air if even partially mixed. LOX does none of that, only acting to make fires (lots) brighter. RP1 isn't even a cryogen.

Somehow, when stepping outside your prior experience base, running into serious troubles should NOT be surprising. Nor should it be surprising to any of the correspondents on this forum.

GW

louis · 2020-06-02 08:41:51

Lol, I'm still constantly surprised! Maybe all the safety conscious engineers go to companies like Boeing and Lockheed and all the risk takers end up at Space X?

GW Johnson wrote:

I got pretty much the same story talking to a McGregor Spacex employee yesterday afternoon. They weren't "for sure", but that was before Musk's story.
Handling liquid methane is more like handling hydrogen than anything else. Both are lighter than air as gases, both ignite in air at the slightest provocation, and both will mass-detonate with air if even partially mixed. LOX does none of that, only acting to make fires (lots) brighter. RP1 isn't even a cryogen.
Somehow, when stepping outside your prior experience base, running into serious troubles should NOT be surprising. Nor should it be surprising to any of the correspondents on this forum.
GW

louis · 2020-06-02 08:56:12

SN7 already in production at Boca Chica.

https://www.youtube.com/watch?v=YUVxWq9l6mc

Last edited by louis (2020-06-02 08:56:28)

SpaceNut · 2020-06-02 16:26:12

Keep building more and breaking them it's not a conference builder for wanting to take a ride on one.

GW Johnson · 2020-06-02 17:31:10

Building and breaking articles should not detract from anyone's confidence. Breaking an article you intended to fly, before you ever fly it, is another matter entirely. That speaks to unanticipated problems cropping up. When problems arise that are unanticipated, that speaks toward not being ready to attempt what they said they want to attempt.

And THAT should reduce confidence. A little. NOT a lot. Not for exploratory development. Because QUITE OFTEN in exploratory development, unanticipated problems show up. That's just life, when you do exploratory development. Been there and done that, myself. More than once.

GW

Last edited by GW Johnson (2020-06-02 17:31:35)

louis · 2020-06-05 20:16:42

I was going to post this video with the focus on the cause of the SN4 explosion - failure to reconnect an "umbilical cord" after discharge...

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

But what most interested me was the firm statement that Musk has not yet abandoned the target of a 2022 cargo mission!

I guess that is still possible on the basis that you aren't risking any lives. If you've shown the Starship can fly and land on rocky terrain. why not go for a 2022 landing?

SpaceNut · 2020-06-06 08:44:52

No work has been performed to build a first stage, so a 2022 cargo seems moot as work for a first stage is required to what I would assume would be before bring the cargo to the only destination in orbit in the ISS but that's after a trial run or 2 to the orbit with approach and landing on earth being successful as in the Falcon 9 Dragon has been through. The starship booster is quite a bit greater of an achievement than for a falcon 9 landing gear in comparison due to the greater size of the would be first stage.
A 2022 landing to, where?

GW Johnson · 2020-06-06 09:30:07

He's talking about landing on Mars in 2022, Spacenut.

Louis:

My understanding is that the hold-down clamp is also the umbilical connection. Those connections are complex, being communications as well as propellant load/unload connections. That particular test had a problem, after disconnecting, the methane connection failed to reconnect properly. Upon the command to de-fuel methane from the vehicle, the methane gushed out onto the surface below the vehicle, instead of following the plumbing back to storage.

To me, this says there was no way to detect the failure in connection integrity in how they currently go about this. I hope they fix that, because Murphy's Law says this will happen again. It is obviously not frequent, but it did happen.

And methane is unlike RP-1 or even LOX. Handling it is far more akin to handling hydrogen. They leak at the drop of a hat, the vapors mix quickly with air and are explosive over a wide range of mixture ratios, ignition occurs at the drop of a hat or even just a hard look, and they very easily go into full supersonic-shock detonation.

As for sending one of these to Mars in 2022, I think that is arrant nonsense. They have to demonstrate a number of critical steps in order to do that. Each involves uncovering and correcting a number of problems. Probably with significant design changes along the way.

1. Demonstrate vehicle control, vehicle and a whole slew of component integrities, and quantify actual component performances, in a series of ever-more-demanding suborbital hops.

2. Demonstrate the heat shield, the belly-flop maneuver, and the controllability into a retropropulsive touchdown in that part of the suborbital tests wherein the burnout speeds are sufficiently hypersonic as to stress the heat shield (that would likely be above Mach 5).

3. Demonstrate that they can safely manage 37 Raptor engines firing simultaneously in the SuperHeavy booster. This is important because inability to safely run 30-something engines at once was the reason the Russian N-1 moon rocket failed every single flight test attempt (in massive explosions).

4. Demonstrate orbital operation and recovery of both stages with the Starship/SuperHeavy combined vehicle. Do this several times in succession without a fatal failure of anything significant. Fix every less-than-significant failure between these flights. And believe me, they WILL occur! That's just Murphy's Law!

5. Demonstrate on-orbit propellant refilling with tanker flights, which in turn requires demonstrating the tail-to-tail docking that no one has ever done before, demonstrating fluid ullage and transfer by means of thruster-based micro-acceleration (which no one has ever done before, only the ullage part), and demonstrate maintenance of sub-cooled extra-dense cryogens for long durations on the ground and on space (something no one has ever done before). All these are fraught with peril, precisely because no one has ever done them before.

6. Demonstrate maintenance of subcooled extra-dense cryogens in space for 6-9 months at a time. No one has ever done that before.

7. Demonstrate how to land Starship safely on soft, uneven, and rocky surfaces. This ought to be done during the early suborbital hop tests, with deliberate off-site landings, to cover the orbit-abort possibilities of even routine LEO operations. But I bet they don't do it then. And if they don't get it done, that first landing on Mars will ALMOST CERTAINLY be a crash. They not only need to demonstrate this capability, they need to demonstrate it half-a-hundred times, to get a sense of how reliable it really is. And not just for Mars and moon landings, Earthly off-site abort landings, too. Landing on soft sand dunes, beaches, rocky desert sands, soft plowed farm fields, cow pastures, scrub brush, tree lines, etc. Nothing I have ever seen out of any of Musk's presentations suggests they have even thought about that issue! They certainly haven't addressed it in their designs so far.

8. Somebody is going to have to figure out what the first cargo sent to Mars is really going to be. It ought to be a pilot plant demonstrator for making propellant, but getting the water during an unmanned mission will be difficult at best, and likely impossible at worst. But if it is a propellant plant demonstrator, then who is going to build it for them? How is that builder going to verify how it really works under Martian conditions? How can anybody get all that done by 2022?

Each one of those things in that list of 8 could take several months to a year or so, to solve individually. The changes in the design that are required to address each one will impact the results that the revised design will get for the other 7, requiring continuous re-testing of all those things, until the design successfully (and reliably!!!) addresses all of them simultaneously! If you don't do that, you will NOT succeed with your unmanned missions, and you will NEVER successfully man-rate the thing! There's not two years' work there, there's several-to-many years' work, even if nothing ever goes wrong. And it WILL go wrong, believe me!

Which is exactly why I think the 2022 goal of a cargo flight to Mars is utter nonsense. Unrealistic wishful thinking. You have to have a demanding goal to spur an organization forward to make progress. There's nothing wrong with having a very demanding goal, but it's an error for outside observers to mistake a desired goal for a statement about what might really be done. The "Musk time" vs actual time track record with Falcon-1, Falcon-9, and Falcon-Heavy should tell you that. Actual time/Musk time has been running about 3 to 4. Yet he does what he sets out to do. It just takes him longer than he ever wanted. Because space is HARD!

GW

Last edited by GW Johnson (2020-06-06 09:35:34)

SpaceNut · 2020-06-06 12:02:41

Thanks GW so SpaceX Mars 2022 Launch Speculation

Since it 2020 and a cycle to build even a cheap robotic rover is about 2 years with plans there would be nothing on the vehicle when it lands by the end of the year with a launching any time idea which we know is false as the alignment only happens every 2 years.

NASA’s Mars Perseverance Launch Period: July 17 - Aug. 11, 2020 with an eventual Landing: Feb. 18, 2021 with the next launch window is

Void · 2020-06-11 15:28:11

I regard this topic to be chaired by Louis, but in the absence of posting, I will add to it. I will also avoid speculative thinking, beyond what is closely related to the topic.

https://www.inverse.com/innovation/spac … o-the-moon

I failed to copy a quote.

For the Moon versions:
-More or less, upper thrusters needed for stabilization in wind, gone.
-Legs: wider stance, automatic leveling.
-Early cargo ships likely to be left on the Moon as part of the base.

I am happy. I have to say, that although I can thinks of instances of Starship which might be valuable in LEO, I much prefer a presence on another world, any world, the Moon being available.

If there will be such a thing as quality control for Starships, and also continuing updating development, the Moon would perhaps be a good place to send the less quality ones during development, particularly if they are for cargo and not crew.

I am going to post speculation in an alternate location.

Done.

Last edited by Void (2020-06-11 15:33:43)

louis · 2020-06-12 13:11:34

Super-Heavy coming soon...

https://www.youtube.com/watch?v=cC6JiuTCG6Q

Void · 2020-06-16 07:45:23

Super Heavy is going to be cool. It will probably will not be just for a re-usable Starship. They may also send mega-probes out to the planets at high speed, say Jupiter, maybe Titan.

By the way, SpaceX was pressure testing SN7, (A test tank), yesterday. I think they got to 7.5 bar so far.

Done.

louis · 2020-06-16 18:21:37

Yes it will be a new era in space exploration.

Isn't 8.6 the industry standard...or did I make that up?

Void wrote:

Super Heavy is going to be cool. It will probably will not be just for a re-usable Starship. They may also send mega-probes out to the planets at high speed, say Jupiter, maybe Titan.
By the way, SpaceX was pressure testing SN7, (A test tank), yesterday. I think they got to 7.5 bar so far.
Done.

louis · 2020-06-16 18:32:55

I agree a 2022 cargo mission to Mars is unlikely but impossible? I'm not so sure.

Take a look at 21:20 in Ryan McDonald's video...

https://www.youtube.com/watch?v=bmcr2FaoWoU&t=805s

He's not ruling out an orbital flight in 2020. NASA went v. quickly from orbital to circumlunar to lunar landing flights - I think it was within 2 years wasn't it?

So, if Space X can hit the 2020 orbital flight target, then I don't think you can rule out a Mars cargo mission in 2022. That will leave enough time for development of landing techniques and working out what to put on board and how to do it...

I think the propellant plant can go with the 2024 crew...that will give time for failsafe testing of this most crucial aspect of the mission.

The 2022 cargo run could include medical supplies, dried food, canned food, water, hydrogen feedstock, chemical batteries, methane-oxygen electricity generators, experimental farm hab and space-rated PV panelling.

GW Johnson wrote:

He's talking about landing on Mars in 2022, Spacenut.
Louis:
My understanding is that the hold-down clamp is also the umbilical connection. Those connections are complex, being communications as well as propellant load/unload connections. That particular test had a problem, after disconnecting, the methane connection failed to reconnect properly. Upon the command to de-fuel methane from the vehicle, the methane gushed out onto the surface below the vehicle, instead of following the plumbing back to storage.
To me, this says there was no way to detect the failure in connection integrity in how they currently go about this. I hope they fix that, because Murphy's Law says this will happen again. It is obviously not frequent, but it did happen.
And methane is unlike RP-1 or even LOX. Handling it is far more akin to handling hydrogen. They leak at the drop of a hat, the vapors mix quickly with air and are explosive over a wide range of mixture ratios, ignition occurs at the drop of a hat or even just a hard look, and they very easily go into full supersonic-shock detonation.
As for sending one of these to Mars in 2022, I think that is arrant nonsense. They have to demonstrate a number of critical steps in order to do that. Each involves uncovering and correcting a number of problems. Probably with significant design changes along the way.
1. Demonstrate vehicle control, vehicle and a whole slew of component integrities, and quantify actual component performances, in a series of ever-more-demanding suborbital hops.
2. Demonstrate the heat shield, the belly-flop maneuver, and the controllability into a retropropulsive touchdown in that part of the suborbital tests wherein the burnout speeds are sufficiently hypersonic as to stress the heat shield (that would likely be above Mach 5).
3. Demonstrate that they can safely manage 37 Raptor engines firing simultaneously in the SuperHeavy booster. This is important because inability to safely run 30-something engines at once was the reason the Russian N-1 moon rocket failed every single flight test attempt (in massive explosions).
4. Demonstrate orbital operation and recovery of both stages with the Starship/SuperHeavy combined vehicle. Do this several times in succession without a fatal failure of anything significant. Fix every less-than-significant failure between these flights. And believe me, they WILL occur! That's just Murphy's Law!
5. Demonstrate on-orbit propellant refilling with tanker flights, which in turn requires demonstrating the tail-to-tail docking that no one has ever done before, demonstrating fluid ullage and transfer by means of thruster-based micro-acceleration (which no one has ever done before, only the ullage part), and demonstrate maintenance of sub-cooled extra-dense cryogens for long durations on the ground and on space (something no one has ever done before). All these are fraught with peril, precisely because no one has ever done them before.
6. Demonstrate maintenance of subcooled extra-dense cryogens in space for 6-9 months at a time. No one has ever done that before.
7. Demonstrate how to land Starship safely on soft, uneven, and rocky surfaces. This ought to be done during the early suborbital hop tests, with deliberate off-site landings, to cover the orbit-abort possibilities of even routine LEO operations. But I bet they don't do it then. And if they don't get it done, that first landing on Mars will ALMOST CERTAINLY be a crash. They not only need to demonstrate this capability, they need to demonstrate it half-a-hundred times, to get a sense of how reliable it really is. And not just for Mars and moon landings, Earthly off-site abort landings, too. Landing on soft sand dunes, beaches, rocky desert sands, soft plowed farm fields, cow pastures, scrub brush, tree lines, etc. Nothing I have ever seen out of any of Musk's presentations suggests they have even thought about that issue! They certainly haven't addressed it in their designs so far.
8. Somebody is going to have to figure out what the first cargo sent to Mars is really going to be. It ought to be a pilot plant demonstrator for making propellant, but getting the water during an unmanned mission will be difficult at best, and likely impossible at worst. But if it is a propellant plant demonstrator, then who is going to build it for them? How is that builder going to verify how it really works under Martian conditions? How can anybody get all that done by 2022?
Each one of those things in that list of 8 could take several months to a year or so, to solve individually. The changes in the design that are required to address each one will impact the results that the revised design will get for the other 7, requiring continuous re-testing of all those things, until the design successfully (and reliably!!!) addresses all of them simultaneously! If you don't do that, you will NOT succeed with your unmanned missions, and you will NEVER successfully man-rate the thing! There's not two years' work there, there's several-to-many years' work, even if nothing ever goes wrong. And it WILL go wrong, believe me!
Which is exactly why I think the 2022 goal of a cargo flight to Mars is utter nonsense. Unrealistic wishful thinking. You have to have a demanding goal to spur an organization forward to make progress. There's nothing wrong with having a very demanding goal, but it's an error for outside observers to mistake a desired goal for a statement about what might really be done. The "Musk time" vs actual time track record with Falcon-1, Falcon-9, and Falcon-Heavy should tell you that. Actual time/Musk time has been running about 3 to 4. Yet he does what he sets out to do. It just takes him longer than he ever wanted. Because space is HARD!
GW

Oldfart1939 · 2020-06-16 18:46:03

Louis-

I applaud your undying enthusiasm and support of SpaceX, but there is a point where reality intervenes. The road to space for Starship is fraught with difficulty and many perils. Every test of the Starship prototypes is a major learning experience, and even Elon commented in passing that the span of the landing legs is being redesigned and widened.

GW is simply passing along a reality check against unbridled enthusiasm. I would personally love to see a Mars landing in 2022, but the chances are roughly 20% at best that the mission will launch, and with maybe a 5 % chance of overall success. These are my very optimistic estimates. I would love to be proved wrong.

GW Johnson · 2020-06-17 16:11:19

It's not "the right landing techniques", it's the right landing hardware designs, which they still do not have! By about a factor of 10 for launch weight support pressure on Mars, and by about a factor of 2 or 3 on landing pad span for the cg height. And the numbers do NOT lie! The incorporation of proper designs will affect the vehicle inert weight, ascent and entry aerodynamics, and required hydraulics and controls, at the very least.

GW

SpaceNut · 2020-06-17 17:06:11

repost

GW Johnson wrote:

I just dunno about putting Starship into low Earth orbit without a Superheavy booster. I think that is an unrealistic notion. My numbers say the mass ratio to do that is just not there, even at zero payload. And the thrust ain't there to lift off at all, unless you install all 6 engines as sea level Raptors, and even then you are still too short to lift off on thrust, relative to fully fueled but zero payload weight. I went through all that doing my 2019 and 2020 reverse-engineering estimates.
GW

tahanson43206 wrote:

For GW Johnson re #49
Thank you for your review of the notion of putting a Starship into orbit as its own "payload".
The traditional way of building an expedition vehicle is to replicate the building of the ISS, with as many launches as are needed to put the components in place.
With the SpaceX progress with re-usability of first stage boosters, it seems (to me at least) quite likely the components can be shipped to LEO with only modest second stage propulsion, and that can be down with vacuum qualified engines, which can ** then ** be put into long term service moving the expedition vehicle where it needs to go.
SpaceX has been throwing away perfectly good Merlin engines for quite a while now.
I'm reminded of the policy to throw away perfectly good aluminum tanks for the Space Shuttle. There are quite a few of them littering the floor of the Atlantic, because NASA decided to resist the many appeals for a long term use.
(th)

GW Johnson wrote:

Well, remember, the baseline design job of Starship/Superheavy is as a fully reusable freighter to LEO. That's where they started, and with some extras, you can do those other jobs.
Point-to-point on Earth requires Superheavy, but can carry larger payload, as it need only attain high suborbital speed. Say 6.5-7 km/s instead of 7.9 km/s.
Going outside LEO (such as to the moon) merely requires refueling on-orbit. It also requires rough-field landing and takeoff capability.
"Merely"? We'll see. I hope they can do it.
Coming home from Mars merely requires propellant manufacture and all the logistics of liquifaction and storage and sub-cooling on Mars. Plus rough-field landing and takeoff capability. And refueling while in LEO. "Merely" again? Tall order, that one!
Aside from that, they merely have to get broadside entry to work, their new ceramic heat shield tiles to work, to verify there are not any hot plasma jets striking the windows during entry, and achieve landing and recovery with objects larger and more massive than anyone has ever dealt with before. Any one of those issues can cause complete vehicle loss in flight test. "Merely"? And that's just to make the basic LEO freighter application work.
Which assumes they don't crash during an off-site abort, since they have yet to even conceive a landing leg system that would work on uneven, soft, and/or rocky ground. Murphy's Law says that an off-site abort crash WILL happen! The stand-down to correct what went wrong will take 6-18 months, and cost $millions, if not $billions (if the lost vehicle was crewed; there is NOTHING as expensive as a dead crew). They'll essentially have to start flight-testing over again, because much of the bird will be a new design.
Getting all that done successfully is why I skoff at the notion of successful orbital flight anytime during 2020, or even the remote possibility of a cargo flight to Mars in 2022.
GW

louis · 2020-06-17 17:45:12

Brilliant video from Felix explaining very well what's going on at Boca Chica - now a maze of incredible activity. Looks like we won't have too long to wait before we are into the SuperHeavy era.

https://www.youtube.com/watch?v=cnidBG9l63k&t=19s

louis · 2020-06-17 17:56:57

I wouldn't disagree with your 20%/5% assessment. No one really knows but as things stand it's not 0%/0%! They've probably got to about maybe Feb. 2021 to get a Starship to LEO. Beyond that, I don't think they can really meet the 2022 launch target.

I have been a longtime Space X enthusiast, since the early Kwajalein days, but my support for them is entirely rational. It just so happens that in Elon Musk we have a Mars-obsessive who cannot be out-obsessed by anyone else on our planet! - so I don't think we could do better for a rocket company that can, potentially, get to Mars. So, yes, I am rooting for them but I realise the scale of the challenge. But Apollo showed once you have the capability to go to LEO then a lot more follows on. No one had tried the lunar landing before - that was all based on purely theoretical knowledge, albeit drawing on Earth-based modelling and circumlunar flight. So, it's not like they have to practice a series of Mars landings before they embark on the Mission. "Follow Apollo" would be my motto for this mission.

Oldfart1939 wrote:

Louis-
I applaud your undying enthusiasm and support of SpaceX, but there is a point where reality intervenes. The road to space for Starship is fraught with difficulty and many perils. Every test of the Starship prototypes is a major learning experience, and even Elon commented in passing that the span of the landing legs is being redesigned and widened.
GW is simply passing along a reality check against unbridled enthusiasm. I would personally love to see a Mars landing in 2022, but the chances are roughly 20% at best that the mission will launch, and with maybe a 5 % chance of overall success. These are my very optimistic estimates. I would love to be proved wrong.

GW Johnson · 2020-06-18 08:20:13

Well, I like the notion "follow Apollo", but before you go too far with it, bear in mind what nearly all the Apollo flights really were. Especially Apollo 8.

There is no doubt at all that everything through Apollo 11 classifies as engineering flight test. One can make a pretty good case that everything from Apollo 12 through Apollo 16 or 17 also qualifies as engineering flight test. I say that because all crew members on all the flights, save one, were engineering test pilots. Only Harrison Schmidt, on Apollo 17, was a geologist, and not an engineering test pilot.

Apollo 8 was the first manned flight test of Saturn 5. It was originally slated to be an LEO flight test. There had been only two previous flights of Saturn 5 at all, and both of those suffered near-fatal problems. Apollo 7 was a manned flight test in LEO of the Apollo CSM cluster, launched by Saturn 1. All the previous flights of Apollo were unmanned tests using the Saturn 1. Apollo 9 was an LEO test of both the Saturn 5 and the lunar module.

Apollo-8 was still a flight test of the Saturn 5, but they deliberately took the risk of flying to lunar orbit with it, instead of the LEO test they originally planned, in order to "beat the Russians". The idea was to send astronauts to the moon first, even if they did not land. There was intelligence that the Russians might launch their N-1 rocket with men to around, or on, the moon. As it turned out, the N-1 launch was an unmanned test, and it blew up shortly after launch, during the first stage burn.

The lunar lander got one flight test in LEO on Apollo 9, and the all-up Saturn 5/Apollo CSM/lunar lander got one more flight test at the moon in Apollo 10. Then we attempted the landing with Apollo 11, and just barely succeeded. Two reprises (Apollo 12 and 13) got mixed results: Apollo 13 failed, and we very nearly lost that crew. Success with Apollos 14-16 gave them enough confidence to send a real geologist on Apollo 17. Then Nixon stupidly cancelled all out-of-LEO human spaceflight before we could send Apollos 18-22, for which all the hardware had already been built.

For the most part, that is an engineering flight test program. One in which the concept of demonstrating reliability by repeat flights was ignored until the end. That was a huge risk taken precisely to "beat the Russians". I really don't recommend that procedure to Spacex with its Starship/Superheavy, Musk's obsession with Mars notwithstanding. You need to include the demonstrations of reliability with repeat flights at each major step as you go along. That's how flight test really works. If you don't, the testing record at places like Edwards AFB show that you will fail a lot more than you will succeed.

GW

Last edited by GW Johnson (2020-06-18 08:26:33)

tahanson43206 · 2020-06-18 10:35:47

For Louis re topic ... Congratulations for the ongoing success of this topic! Started on [2018-12-23 17:12:56], it has reached 273 posts, and shows no signs of slowing down, as SpaceX itself continues building momentum, experience and on-the-job skill.

For GW Johnson ... I decided to go back to 2009, when you started ExRocketman, and was delighted to find your remarks critical of Nixon for his inexplicable decision to kill the pending Apollo flights. I read somewhere that he was afraid the success would not continue, and he would have lost crew on his watch.

I appreciated (as well) your observations about the NASA nuclear rocket research, which was ended at around the same time.

SpaceNut has suggested a new (actually already available) topic for discussion of a full scale human expedition to Mars, which (in my proposal) would be formed around your multiple posts which touch on how that would/could be done, safely and reliably, and with better than even chances of safe return of an exploration team.

The available topic is set up in Human Missions (Index level), with the title: Human Business and Flight Plan for Mars

I invite you to drop off a message in that topic, to help start activity there.

Meanwhile, I'm looking (somewhat subdued) at the collection of articles you recommended for study in the Solving Mars Mission Docking with Phobos topic.

The writing style comes across to me as approachable and often entertaining, while adroitly avoiding excesses that are so tempting in the modern period.

I could (and do) imagine a document/book/multimedia/animation coming out of the development of SpaceNut's Flight Plan topic.

(th)

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Re: Starship is Go...

#720 2020-06-17 16:11:19

Re: Starship is Go...

#721 2020-06-17 17:06:11

Re: Starship is Go...

#722 2020-06-17 17:45:12

Re: Starship is Go...

#723 2020-06-17 17:56:57

Re: Starship is Go...

#724 2020-06-18 08:20:13

Re: Starship is Go...

#725 2020-06-18 10:35:47

Re: Starship is Go...

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