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#160
by
BrianPeterson
on 04 Aug, 2019 22:11
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I see it like this Starship first, then tankers. When Starship is fueled another tanker full to run in parallel with Starship. Two Falcon 9s with Dragons and a crew of seven each from 39a and 40 to dock and board Starship. That gives you 14 Troopers with carry on luggage and a quick turn around fuel supply and will leave a Tanker on the surface after a month stay.
This really doesn't make much sense. Why would you launch a starship and two completely redundant F9s when you can do the same thing with the one starship launch?
The way I see it, is that if it's a manned mission, then the tankers get launched and hang out in Leo and the crew starship then launches. The consumption of resources to have whatever crew compliment hang out in LEO waiting 5 days for fueling is a killer. You want them to get fueled and be on with their mission. The shortest duration would be the manned ship pulling up the rear of the launches.
There is also the what if you have crew hanging out in LEO and one of the Tankers fail, worst case scenario, a RUD? Since there isn't a foreseeable time when NASA and the FAA wouldn't just ground all rockets (it may come one day but not for a while) you will have people in space now on an aborted mission. Wouldn't you rather have them on the ground in that scenario?
Of course it's Musk, who knows what he will actually do.
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#161
by
joek
on 04 Aug, 2019 23:13
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This really doesn't make much sense. Why would you launch a starship and two completely redundant F9s when you can do the same thing with the one starship launch?
...
It might be an alternative depending on the regulatory hurdles-time-effort-cost to human rate Starship for launch: use Commercial Crew (CC) vehicles for Earth-LEO transport in the interim. Of course that would also require adding NDS/IDA docking port(s) to Starship. There are also potential hurdles for human rating Starship Earth EDL (that propulsive landing thing). If we have CC vehicles in the mix, they might also be used to address the Starship Earth EDL issues. Apollo redux anyone?[1]
In any case, many potential options if CC vehicles are introduced; discussion of those options-tradeoffs probably best addressed in another thread.
[1] edit: Except all the components are reusable (at least the most significant ones).
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#162
by
oiorionsbelt
on 05 Aug, 2019 01:35
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Assuming the FAA is OK with crew, why wouldn't SpaceX just launch SS with crew? If NASA doesn't want their astros onboard for whatever reason, so be it. They're going anyway, either you get onboard or you stay put.
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#163
by
DistantTemple
on 05 Aug, 2019 01:50
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Assuming the FAA is OK with crew, why wouldn't SpaceX just launch SS with crew? If NASA doesn't want their astros onboard for whatever reason, so be it. They're going anyway, either you get onboard or you stay put.
Ar first I thought this just blunt inappropriate and unlikely to be reasoning that works on NASA. However....
Assuming dozens of successful cargo and fuel launchings, refuellings wtc and successful landing and take off from the Moon.... And that buss-load of artists having circled the Moon, as well as some SX test-pilots!! The next step would be NASA and possibly international astronauts... NASA would be the odd one out if France, Japan, Canada etc all sent an astronaut but NASA said.... no we haven't completed our safety audit! we're not riding!
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#164
by
Chris Bergin
on 05 Aug, 2019 01:56
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Guys, we have all these threads. You don't need to be discussing things like Starship to the Moon/Mars, when there's threads.
This is about the pad on 39A. Only posts on that here, per the report.
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#165
by
Dave G
on 05 Aug, 2019 08:50
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The sonic boom thing is starting to worry me.
The Draft EA says:
In general, booms in the 0.2 to 0.3 psf range could be heard by someone who is expecting it and listening
for it, but usually would not be noticed. Booms of 0.5 psf are more likely to be noticed, and booms of 1.0
psf are certain to be noticed. Therefore, people west of KSC are likely to notice booms from Starship
landings...
Looking at the map from the EA (first picture below), the area > 1.0 psf (light blue) covers around 1/3 of the state of Florida, including Tampa, St. Petersburg, and Clearwater. The area > 2.0 psf (green) encompasses the whole Orlando metro area.
Now let's compare that with the
sonic boom area for Falcon 9 (second picture below).
Note that the color scale is completely different.
The worst case is only 0.2 to 0.4 psf (blue and light-blue), and that's only in Titusville and Daytona Beach.
The area > 1.0 psf is completely over the Atlantic ocean.
Orlando and West isn't affected at all.
Isn't this what killed the
Concorde?
If they'd been able to offer super-sonic domestic flights, e.g. New York to L.A., they may have been profitable.
In any case,
governments banning Concord super-sonic flights over land due to sonic booms has set a precedent.
Breaking that precedent could prove difficult.
This could be a serious issue for landing orbital Starship missions in Florida and Texas.
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#166
by
Alexphysics
on 05 Aug, 2019 11:33
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You can't compare Falcon 9 boosters reentry with Starship reentry. If you compare Starship reentry with something do it with the Space Shuttle which took a similar route towards the Cape on low inclination missions like Hubble and friends. Falcon 9 boosters don't stay too much in the air from the point they reenter to touchdown. From the EA we see that just the free-fall part takes 3 minutes. All the covered area in the sonic boom map is mainly because of that: the ship will have to bleed off more speed than what a Falcon 9 would have to bleed off and that means creating a larger sonic boom signature on the map. Also Falcon 9 boosters come from the east to west so most of the time they are over water while Starship won't. I bet Space Shuttles had a similar sonic boom map when they were coming into Florida to land.
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#167
by
philw1776
on 05 Aug, 2019 13:50
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I don't have a Shuttle boom intensity profile contour map but I recall hearing the Shuttle boom just south of Tampa FL. I wasn't expecting it but when I heard it I realized to my surprise that I'd heard the Shuttle coming in.
No big deal.
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#168
by
jpo234
on 05 Aug, 2019 14:02
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I found this
Where to Launch and Land the Space Shuttle?The Thompson Board determined that the Space Shuttle would generate its most powerful sonic boom during ascent, while the Booster and Orbiter formed a single large vehicle. The Booster's rocket plume would, for purposes of calculating sonic boom effects, make the ascending, accelerating spacecraft appear even bigger. The Shuttle's flight path characteristics - for example, the pitch-over maneuver that it would perform as it steered toward orbit - would create a roughly 10-square-mile "focal zone" for sonic boom effects about 33 nautical miles downrange of the launch site.
"Overpressure" in the focal zone would almost certainly exceed six pounds per square foot (psf) and might reach 30 psf, which would be powerful enough to damage structures (plaster and windows could suffer damage at an overpressure as low as three psf, the Board noted). Winds could unpredictably shift the focal area by several miles. The Board urged that "the severe overpressures associated with the focal zone. . .be prevented from occurring in any inhabited area."
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#169
by
whitelancer64
on 05 Aug, 2019 15:04
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The sonic boom thing is starting to worry me.
The Draft EA says:
In general, booms in the 0.2 to 0.3 psf range could be heard by someone who is expecting it and listening
for it, but usually would not be noticed. Booms of 0.5 psf are more likely to be noticed, and booms of 1.0
psf are certain to be noticed. Therefore, people west of KSC are likely to notice booms from Starship
landings...
Looking at the map from the EA (first picture below), the area > 1.0 psf (light blue) covers around 1/3 of the state of Florida, including Tampa, St. Petersburg, and Clearwater. The area > 2.0 psf (green) encompasses the whole Orlando metro area.
Now let's compare that with the sonic boom area for Falcon 9 (second picture below).
Note that the color scale is completely different.
The worst case is only 0.2 to 0.4 psf (blue and light-blue), and that's only in Titusville and Daytona Beach.
The area > 1.0 psf is completely over the Atlantic ocean.
Orlando and West isn't affected at all.
Isn't this what killed the Concorde?
If they'd been able to offer super-sonic domestic flights, e.g. New York to L.A., they may have been profitable.
In any case, governments banning Concord super-sonic flights over land due to sonic booms has set a precedent.
Breaking that precedent could prove difficult.
This could be a serious issue for landing orbital Starship missions in Florida and Texas.
Yeah, as the above comments indicate, it's no worse than the Shuttle. Also, the blue / light green are for sound levels that you probably won't notice unless you are listening for it.
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#170
by
su27k
on 05 Aug, 2019 15:10
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Here's a recording of STS-135 sonic boom over Orlando, doesn't sound too bad:
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#171
by
Machdiamond
on 05 Aug, 2019 16:35
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#172
by
ncb1397
on 05 Aug, 2019 17:03
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Here's a recording of STS-135 sonic boom over Orlando, doesn't sound too bad:
This was in jest? Because most consumer audio equipment out there can't replicate a sonic boom.
This video likely gives a better idea of the affects of a shuttle sonic boom:
Again, your laptop/desktop speakers aren't going to replicate the boom on either video.
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#173
by
su27k
on 05 Aug, 2019 17:19
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Here's a recording of STS-135 sonic boom over Orlando, doesn't sound too bad:
This was in jest? Because most consumer audio equipment out there can't replicate a sonic boom.
This video likely gives a better idea of the affects of a shuttle sonic boom:
Again, your laptop/desktop speakers aren't going to replicate the boom on either video.
Not in jest, just pointing out the fact that Shuttle does create audible sonic booms over Orlando, so Starship creates sonic booms over Orlando is not an issue.
Also your video is from Titusville, which is much closer to the center of the sonic boom than Orlando.
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#174
by
ncb1397
on 05 Aug, 2019 17:37
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Not in jest, just pointing out the fact that Shuttle does create audible sonic booms over Orlando, so Starship creates sonic booms over Orlando is not an issue.
Also your video is from Titusville, which is much closer to the center of the sonic boom than Orlando.
Not necessarily. The peak overpressure in the map that Machdiamond found is labeled at 1.75 pounds/ft
2. The map for starship says that Orlando will experience around 2. As such, it appears that the Shuttle Titusville boom in the video will be milder than the starship boom in orlando (the green contour line in Dave G's linked map). What was acceptable in Titusville that was pretty dependant economically on Shuttle may not be acceptable in Orlando with a population of nearly 1% of the United States.
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#175
by
InfraNut2
on 05 Aug, 2019 17:44
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When I try to download the document, access is blocked with the following message:
Web Page Blocked!
The page cannot be displayed. Please contact the administrator for additional information.
URL: netspublic.grc.nasa.gov/main/20190801_Final_DRAFT_EA_SpaceX_Starship.pdf
Client IP: --redacted--
Attack ID: 20000008
Has the server interpreted a high number of downloads or high bandwidth use for this file as a DoS attack and blocked it?
Anyone else have the same problem?
Does anyone know of another downloadable copy of this?
Hope someone can help me get a copy to satisfy my curiosity...
-- "InfraNut2"
(I thought this was open public info anyway...? BTW: I am located in the allied (NATO) country Norway, but I do not think country has anything to do with it, since that would be pretty meaningless in these days when many use VPNs, proxies and such)
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#176
by
RoboGoofers
on 05 Aug, 2019 17:45
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Page 8 of the attached pdf
For the reentry-descent phase of flight, the measurements were made on land with the majority
acquired in the state of California and about 25 percent in the state of Florida. The measured
boom signatures were generally N-wave in character, similar to those observed from supersonic
aircraft, with amplitudes ranging from about 0.10 psf from the vehicle at about 243,000 feet altitude
to a maximum of 2.32 psf just prior to landing. Signature periods, however, were much
greater than those observed on aircraft being on the order of about 0.40 second to about 2.5 seconds.
Predictions of the magnitude of sonic booms and ground footprints for Mach numbers to
about 6.0 compared favorably with measurements.
So a SS landing produce twice as much overpressure in Titusville. whether that translates to twice as loud or 10x as loud i don't know.
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#177
by
AnalogMan
on 05 Aug, 2019 17:53
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When I try to download the document, access is blocked with the following message:
Web Page Blocked!
The page cannot be displayed. Please contact the administrator for additional information.
URL: netspublic.grc.nasa.gov/main/20190801_Final_DRAFT_EA_SpaceX_Starship.pdf
Client IP: --redacted--
Attack ID: 20000008
Has the server interpreted a high number of downloads or high bandwidth use for this file as a DoS attack and blocked it?
Anyone else have the same problem?
Does anyone know of another downloadable copy of this?
Hope someone can help me get a copy to satisfy my curiosity...
-- "InfraNut2"
(I thought this was open public info anyway...? BTW: I am located in the allied (NATO) country Norway, but I do not think country has anything to do with it, since that would be pretty meaningless in these days when many use VPNs, proxies and such)
Link works for me just now.
Copy of report attached
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#178
by
su27k
on 05 Aug, 2019 18:04
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Not in jest, just pointing out the fact that Shuttle does create audible sonic booms over Orlando, so Starship creates sonic booms over Orlando is not an issue.
Also your video is from Titusville, which is much closer to the center of the sonic boom than Orlando.
Not necessarily. The peak overpressure in the map that Machdiamond found is labeled at 1.75 pounds/ft2. The map for starship says that Orlando will experience around 2. As such, it appears that the Shuttle Titusville boom in the video will be milder than the starship boom in orlando (the green contour line in Dave G's linked map). What was acceptable in Titusville that was pretty dependant economically on Shuttle may not be acceptable in Orlando with a population of nearly 1% of the United States.
We'll see then. But this is hardly a showstopper, worst case SpaceX needs to position a drone ship some miles off the coast for Starship to land, this is the advantage of a VTVL, it can land pretty much anywhere.
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#179
by
RoboGoofers
on 05 Aug, 2019 18:17
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Not in jest, just pointing out the fact that Shuttle does create audible sonic booms over Orlando, so Starship creates sonic booms over Orlando is not an issue.
Also your video is from Titusville, which is much closer to the center of the sonic boom than Orlando.
Not necessarily. The peak overpressure in the map that Machdiamond found is labeled at 1.75 pounds/ft2. The map for starship says that Orlando will experience around 2. As such, it appears that the Shuttle Titusville boom in the video will be milder than the starship boom in orlando (the green contour line in Dave G's linked map). What was acceptable in Titusville that was pretty dependant economically on Shuttle may not be acceptable in Orlando with a population of nearly 1% of the United States.
We'll see then. But this is hardly a showstopper, worst case SpaceX needs to position a drone ship some miles off the coast for Starship to land, this is the advantage of a VTVL, it can land pretty much anywhere.
Sounds familiar: