Author Topic: SpaceX Falcon 9 / Dragon 2 : SpX-DM1 : March 2, 2019 : DISCUSSION  (Read 591447 times)

Offline Comga

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SpaceX Demo-1 Dragon Spacecraft - Welcoming Ceremony at the International Space Station
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=6662

Great words by astronaut Anne McClain:

"Our sincere congratulations to all Earthlings who have enabled the opening of this next chapter in space exploration. To the International Space Station teams, past and present, who stand guard 24 hours a day at control centers from Moskow to Japan to Houston. Congratulations to the teams at SpaceX and Boeing, who have been working diligently to define what this new era of commercial spaceflight will look like. And congratulations to all nations, private space firms and individuals, who work up every day, driven by the magic of exploration. This day belongs to all of us.

Spaceflight gives us a chance to reflect on the context of our existence. We are reminded that we are human, before any of our differences, before all of the lines that are drawn by dividers. And we are reminded that we are at our best when we are part of something bigger than ourselves. In 1957, just over 60 years ago, history changed when Russia launched Sputnik, the worldís first artificial satellite. People across the globe gathered in backyards and looked up at the night sky, hoping to catch a glimpse. A few years later, people of all nationalities grabbed hands, hoping and praying for Yuri Gagarinís successful launch, as he became the first human in space. And in 1969 every TV across the globe was tuned in as Buzz, Michael and Neil embarked on the first human journey to the moon.

Today, human advancement of exploration continues, as the first new space vehicle designed for humans in over 40 years arrived at our front door, welcomed by our crew of one Russian, one Canadian and one American, who have been living together as family for three months onboard the International Space Station. These events remind us that we are more alike than different; that we can be united by a cause that is not based on fear, threat or common enemy, but rather on a bold endeavour, an insatiable curiosity to go beyond what is known, and to do what has never been done. We humans were built for exploration, and we are built to do it together."

I agree with the previous comments that this speech was stilted and perfunctory.  More befitting a political appointee than an astronaut.

"Earthlings"? Really?

Congratulations equally to SpaceX and Boeing?  (For an extra $1.6B, using an existing rocket, with a head start, Boeing's OFT-1 is months behind SpaceX's DM-1.)  This day doesn't belong to all of us.  It belongs primarily to SpaceX.

People in the west didn't look for Sputnik in awe.  It was terrifying.  Launched by a Soviet ICBM, playing their national anthem, and flying unstoppably overhead. 

We weren't cheering for Gargarin because NOBODY KNEW.  It was secret.  It was Soviet.

All the world's TVs weren't tuned to Apollo 11.  I know.  I was in a third world country and missed it.  Sorry.  Too "poetic" and grandiose.

Today is the 50th anniversary of the launch of Apollo 9.  Rusty Schweikart made those observations about invisible boundaries after that flight.  It was enough to get him labeled the "hippie astronaut".  Now they are platitudes.


Some of us ARE sounding like grumpy old men today. 
And it's a GREAT day!  Dragon at ISS!
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Comga

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Will they in future be using the Dragon 2 when itís docked to the ISS as part of the living space of the station being as unlike Soyuz it is quite roomy?
With a little screen they could probably use the Dragon for two sleeping quarters.

How about the big screens, the video screens?
Astronauts could go in there to watch movies, like the new Apollo 11 documentary
(Wouldn't that be ironic.)
Just being in that clean, uncluttered volume should be a break from the intensely hardware saturated modules.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Online theinternetftw

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This day doesn't belong to all of us.  It belongs primarily to SpaceX.

It certainly belongs to SpaceX.  It also belongs to NASA for directing the effort, especially to those who got the ball rolling in the late 2000s and kept it rolling after.

And it belongs to all Americans, as we paid the billions necessary to accomplish it.

Online theinternetftw

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The age of commercial human orbital spaceflight, however, will not belong to America, NASA, or SpaceX.

That will belong to all of us.

This is for the same reason that the Information Age doesn't belong to Tim Berners-Lee and our modern world of aviation doesn't belong to the Curtiss-Wright Corporation.  You can't hoard a revolution.

I will note that I don't think we're quite yet at that revolution.  Billions in government funds does not commercial viability make.

But this is certainly a day of portent for that coming era.
« Last Edit: 03/03/2019 11:49 pm by theinternetftw »

Offline punder

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McClain, a civil servant, said what she was told to say. Problem solved.

Edit, political rant deleted.




« Last Edit: 03/04/2019 12:15 am by punder »

Offline edkyle99

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The DM-1 Crew Dragon's mass is 12055kg it is literally a 12+ metric ton spacecraft
At docking it was predicted to be 12055 kg.  That means that at liftoff it was hundreds of kg heavier.  I've guessed 12,500-ish kg.  JCM has guessed 13,000 kg.  Someone else estimated about 12,425 kg.  Of course it will be heavier on future missions with crew and/or cargo.

 - Ed Kyle

Online LouScheffer

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At booster separation, DM-1 was at 6774 km/hr = 1882 m/s.   This is much closer to the RTLS missions such as X-37 (1629 m/s) than any of the GTO ASDS landings (2260-2360 m/s).  It also had a quite long (32 second) 3-engine re-entry burn.    This will be a lightly used core.

Offline Alexphysics

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Why barge and not land landing for the first stage?

I thought it would have enough performance for coming back to cape canaveral on this kind of payload.

This kind of payload? What do you expect with a +12 metric ton spacecraft on top of the rocket?


It's not a 12+-tonne spacecraft. I'ts closer to 11 tonnes.

So it should be about 11.5 tonnes.

Quote
This is the heaviest thing a Falcon 9 has ever launched to ANY orbit.

This is the EASIEST orbit of practically any F9 launches. Most other orbits have been either GTO or polar, which both require more delta-v.

The DM-1 Crew Dragon's mass is 12055kg it is literally a 12+ metric ton spacecraft

The Block 5 does have enough performance to return to the launch site, even with a Dragon 2, but for this mission, NASA stipulated that the booster stage remain ignited for a longer period, in order to apply a safety margin of performance for the upper stage. I believe that this was mentioned in one of the NSF articles covering this mission.

Didn't Scott Manley post a video comparison between the Dragons with a flatter flight profile for crewed Dragon to limit the (I assume down range) accelerations in case of abort?  I don't see why NASA would be concerned with US performance as much as with test-as-you-fly scenarios.

EDIT: Spelling.

Funny thing is that the actual launch profile was a lofted trajectory, you just have to see the numbers on the webcast and compare to other missions. I'm still trying to understand why NASA would like that but...

Offline Comga

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Funny thing is that the actual launch profile was a lofted trajectory, you just have to see the numbers on the webcast and compare to other missions. I'm still trying to understand why NASA would like that but..

We see Stephen's still at T+2:42 with 6693 km/hr at 90.5 km for DM-1 just after MECO
Stephen posted a still at T+2:32 with 5716 km/hr at 73.6 km for SpX-16 just after S1/S2 separation

                 DM-1                        SpX-16
T(sec)   V(km,/hr)  H(km)    V(km,/hr)  H(km)
1:00        1022          8.2         1122     8.5
1:30/2     1982         19.5        2156   21.6
2:00        3733         40.8        3721   40.9
2:32        6281         76.2        5716   73.6    (DM-1 values from replay)
2:42        6693         90.5

So DM-1 was both higher and faster at MECO.
At 2:32 it looks like DM-1 was significantly faster but not much higher.
Is that sufficient to conclude that it was lofted?
Having it lofted despite the statements to the contrary would be very interesting.

(There was someone on the forum who managed to extract and plot the entire data sets)
edit: typo corrected
« Last Edit: 03/04/2019 03:39 am by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Steven Pietrobon

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Quote from: Anne McClain
Today, human advancement of exploration continues, as the first new space vehicle designed for humans in over 40 years arrived at our front door,...

The author of that speech forgot about Shenzhou, New Glenn, SpaceShipOne and SpaceShipTwo!

Quote from: Anne McClain
A few years later, people of all nationalities grabbed hands, hoping and praying for Yuri Gagarinís successful launch, as he became the first human in space.

As pointed out above, Vostok 1 was launched in secret, so the only ones who were praying (and in secret) were the religious Soviet's who knew about the flight!
« Last Edit: 03/05/2019 01:14 am by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline alang

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Quote from: Anne McClain
Today, human advancement of exploration continues, as the first new space vehicle designed for humans in over 40 years arrived at our front door,...

The author of that speech forgot about Shenzhou, New Glenn, SpaceShipOne and SpaceShipTwo!

Quote
A few years later, people of all nationalities grabbed hands, hoping and praying for Yuri Gagarinís successful launch, as he became the first human in space.

As pointed out above, Vostok 1 was launched in secret, so the only ones who were praying (and in secret) were the religious Soviet's who knew about the flight!

This stuff washes over me. Elected politicians say stupider things.
I suppose that people focussed enough to become astronauts don't have time to learn 'fripperies' like history. I was shocked that Hadfield could play guitar.
I seem to recall once reading that the Soviet Union kept Gagarin's planned ejection seat landing secret for years, supposedly because of fears it might not meet some international institution's definition of a successful spaceflight. If true it seems very strange today.
« Last Edit: 03/10/2019 09:56 am by alang »

Offline meekGee

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Today, human advancement of exploration continues, as the first new space vehicle designed for humans in over 40 years arrived at our front door,...

The author of that speech forgot about Shenzhou, New Glenn, SpaceShipOne and SpaceShipTwo!

Quote
A few years later, people of all nationalities grabbed hands, hoping and praying for Yuri Gagarinís successful launch, as he became the first human in space.

As pointed out above, Vostok 1 was launched in secret, so the only ones who were praying (and in secret) were the religious Soviet's who knew about the flight!

I think they meant "real spacecraft that go to space for real".

Not sub orbital, not on paper.

This still leaves Shenzhou tho, that's correct.  (Unless they want to claim it's a soyuz derivative)
« Last Edit: 03/04/2019 02:30 pm by meekGee »
ABCD - Always Be Counting Down

Offline tea monster

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"the first new space vehicle designed for humans in over 40 years"

America designed plenty of space vehicles in the past 40 years. All of them got cancelled though - some while actually in flight testing (X-38). If America had the determination and foresight to actually follow through on one of these designs, then they wouldn't be in the ridiculous situation they found themselves in till now.

Offline CorvusCorax

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"the first new space vehicle designed for humans in over 40 years"

America designed plenty of space vehicles in the past 40 years. All of them got cancelled though - some while actually in flight testing (X-38). If America had the determination and foresight to actually follow through on one of these designs, then they wouldn't be in the ridiculous situation they found themselves in till now.

Also, Orion already had 1 testflight, although on a non human-rated launch vehicle. One could argue that that was designed over the last 40 years.

Offline Alexphysics

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Funny thing is that the actual launch profile was a lofted trajectory, you just have to see the numbers on the webcast and compare to other missions. I'm still trying to understand why NASA would like that but..

We see Stephen's still at T+2:42 with 6693 km/hr at 90.5 km for DM-1 just after MECO
Stephen posted a still at T+2:32 with 5716 km/hr at 73.6 km for SpX-16 just after S1/S2 separation

                 DM-1                        SpX-16
T(sec)   V(km,/hr)  H(km)    V(km,/hr)  H(km)
1:00        1022          8.2         1122     8.5
1:30/2     1982         19.5        2156   21.6
2:00        3733         40.8        3721   40.9
2:32        6281         76.2        5716   73.6    (DM-1 values from replay)
2:42        6693         90.5

So DM-1 was both higher and faster at MECO.
At 2:32 it looks like DM-1 was significantly faster but not much higher.
Is that sufficient to conclude that it was lofted?
Having it lofted despite the statements to the contrary would be very interesting.

(There was someone on the forum who managed to extract and plot the entire data sets)
edit: typo corrected

It was what I told you the other day. Even though we were told this was not a lofted trajectory it was indeed a lofted trajectory. Compare any of those numbers with a GTO mission and you'll see those go lower and faster which means they fly a shallower trajectory.

Offline Star One

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Will they in future be using the Dragon 2 when it’s docked to the ISS as part of the living space of the station being as unlike Soyuz it is quite roomy?

The Soyuz is quite roomy with the orbital module.

I thought it being put into orbital hibernation precluded its use.

Offline su27k

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It was what I told you the other day. Even though we were told this was not a lofted trajectory it was indeed a lofted trajectory. Compare any of those numbers with a GTO mission and you'll see those go lower and faster which means they fly a shallower trajectory.

I don't think anyone official told us this was not a lofted trajectory, in fact Hans made it clear it is a lofted trajectory in the press conference, it's just nobody here believes him...

Offline woods170

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It was what I told you the other day. Even though we were told this was not a lofted trajectory it was indeed a lofted trajectory. Compare any of those numbers with a GTO mission and you'll see those go lower and faster which means they fly a shallower trajectory.

I don't think anyone official told us this was not a lofted trajectory, in fact Hans made it clear it is a lofted trajectory in the press conference, it's just nobody here believes him...

Folks here only need to compare the Stage 2 telemetry numbers with those of the average GTO mission. In doing so it will become quite clear that Demo-1 very much flew a lofted trajectory: the average GTO mission stages at an altitude of ~ 68 km with a velocity of ~ 8300 km/h, whereas Demo-1 staged at an altitude of 88 km and a velocity of just ~ 6700 km/h. So, staging was 20 km higher than a GTO mission and 1600 km/h slower than a GTO mission.

So yes, very much a lofted trajectory: trading speed for altitude in the early phase of the mission.

Offline daedalus1

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Will they in future be using the Dragon 2 when itís docked to the ISS as part of the living space of the station being as unlike Soyuz it is quite roomy?

The Soyuz is quite roomy with the orbital module.

I thought it being put into orbital hibernation precluded its use.

I'm just responding to someone who implied that the Soyuz wasn't roomy. I have no idea wether either spacecraft can be used when docked.

Offline ugordan

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Folks here only need to compare the Stage 2 telemetry numbers with those of the average GTO mission. In doing so it will become quite clear that Demo-1 very much flew a lofted trajectory: the average GTO mission stages at an altitude of ~ 68 km with a velocity of ~ 8300 km/h, whereas Demo-1 staged at an altitude of 88 km and a velocity of just ~ 6700 km/h. So, staging was 20 km higher than a GTO mission and 1600 km/h slower than a GTO mission.

So yes, very much a lofted trajectory: trading speed for altitude in the early phase of the mission.

There's also the fact that the 1st stage landed 10 minutes after launch, which IIRC is the longest delay ever, additional hint that it was flying a lofted trajectory.

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