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MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Thu Dec 28, 2017 10:50 pm

Image
 
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moo
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 2:41 am

It wouldn't surprise me if SpaceX did the test firing with the payload attached - the payload is worthless, but the demating and mating process takes time and money, so if that cost is greater than the cost of the fairings then why do it?
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 8:04 am

Do people have advice on where to check for schedule updates? I'd love to watch both the test fire and launch if they're played live.
 
ZaphodHarkonnen
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 10:35 am

I would be shocked if the launch is not live streamed. Doubt any test firing will be live streamed, just video after the fact.

As for schedule? No idea other than no earlier than January 2018.. https://www.kennedyspacecenter.com/laun ... lcon-heavy
 
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flyingturtle
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 11:20 am

MatthewDB wrote:
Do people have advice on where to check for schedule updates? I'd love to watch both the test fire and launch if they're played live.


I'm checking the launches daily on https://spaceflightnow.com/launch-schedule/


David
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 11:20 am

Here's a better photo of the Falcon Heavy:

Image
https://forum.nasaspaceflight.com/index ... msg1765265
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 11:49 am

I like to think that most of my comments on this website are mature and controlled.But I do have to admit a childish excitement over this launch.Whilst I remember them ,I was way too young to physically see a Saturn5 and never took the considerable time off (live in UK) to see the Shuttle launch (which must have been mega with the visual effect of the SRB's).
So I do want at some stage to 'come over' and watch one of these babies take off!
I fully understand that the FH has become somewhat of a commercial sideshow for SpaceX but equally (if it works well) could be so useful to test out the concepts required for the BFR programme .
So fingers and toes crossed!
 
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flyingturtle
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 1:14 pm

parapente wrote:
But I do have to admit a childish excitement over this launch.


So do I!

It's a new era to begin. Born in 1981, I was young enough to be excited about the Space Shuttle (which I called "Spatzenschüttler", literally "sparrow shaker" - notice the similarity between "Space Shuttle" and the German word). We all dreamed that the Space Shuttle will finally make space much, much more accessible. But it fizzled out. But then comes Elon Musk, takes what is working, and reinvents the rest.

David
 
GDB
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Re: SpaceX - Tests, Launches, Developments

Fri Dec 29, 2017 4:37 pm

parapente wrote:
I like to think that most of my comments on this website are mature and controlled.But I do have to admit a childish excitement over this launch.Whilst I remember them ,I was way too young to physically see a Saturn5 and never took the considerable time off (live in UK) to see the Shuttle launch (which must have been mega with the visual effect of the SRB's).
So I do want at some stage to 'come over' and watch one of these babies take off!
I fully understand that the FH has become somewhat of a commercial sideshow for SpaceX but equally (if it works well) could be so useful to test out the concepts required for the BFR programme .
So fingers and toes crossed!


The same is true for me, I was too young to directly remember Apollo, though I was around!
My first memory of a launch was at our Junior (Elementary) school where our aviation and space fan of a teacher got a TV in for us to watch the last Apollo, with the link up with Soyuz in 1975. A few months later he'd herd us up to the top (of 3) floors of our school, a couple of miles from LHR, to watch the first BA Concorde service take off. (21 years later I would join the BA Concorde Engineering Operation).
I've been in FLA twice near to when a Shuttle was due to go, which it didn't though never the purpose of the trip but being as launches were very often delayed with that complex beast, it seemed a long way to go to not see it!

So I too an excited about FH, maybe I'll make the trip when Musk puts a crew on top of a launch.
Or maybe for the SLS.
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 4:56 am

parapente wrote:
I like to think that most of my comments on this website are mature and controlled.But I do have to admit a childish excitement over this launch.Whilst I remember them ,I was way too young to physically see a Saturn5 and never took the considerable time off (live in UK) to see the Shuttle launch (which must have been mega with the visual effect of the SRB's).
So I do want at some stage to 'come over' and watch one of these babies take off!


My wife has been asking me for a while why I'm so fascinated / fixated on what SpaceX is doing. The thought of them pulling off three booster returns, two simultaneously, is incredible. I'm on the same page with you, I must get myself to a launch and watch it. After the last Iridium launch, I'm thinking I want to see a night launch too, particularly if it is a booster return.

When I first started working after college, I worked with an engineer who worked for Grumman on the LEM. He told me about how they all went to the Cape to watch the launch, then were glued to the TV to watch every bit of coverage while on the moon. At the time, I was thinking "what could I ever work on that is as cool as that?" I think making a rocket land on it's back end like they showed in the '50s science fiction movies is pretty darn close.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 12:06 pm

Of course if you believe Elon's timings he will have something even bigger and better to show us in a few short years.Sadly I don't.A decade would be optimistic.Love to be wrong though.But it will be an exciting time with the FH and then NASA's SLS.If I could see that it really would be a Saturn 5 replay!
But it is all rather odd.With Saturn 5 there was a clear mission for exactly why it was what it was.Now here are 2 giant rockets.One about to T/o hopefully and the other in assembly.
But neither (as far as I can tell) has a mission plan!
Ok the FH has a few heavy Sat loads booked (3-4?) but there really is little commercial call for such power.Oh and a round the moon and back trip!
SLS? Vague words about the moon and Mars and Asteroids.But nothing concrete as far as I can tell.
It's all rather odd.Even New Shepherd only vaguely takes about mining and stuff with no obvious reason why as far as I can tell.
 
ZaphodHarkonnen
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 1:45 pm

I think it also becomes one of those things of having the capability will bring some demand. Especially for the right price. While the Delta IV could throw some pretty heavy payloads it simply cost to much to make it commercially worthwhile. But bring that cost down and we'll probably see even larger geostationary sattallites. Or launch a truly huge flock of cubesats.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 1:59 pm

I don't wish to sound perverse but I am not sure the above it true.Indeed possibly the reverse.You (only) need 'X' amount of satellites for (say) digital global coverage - not more not less it's maths.The same goes for GSO says.However digitisation means they (on the whole) get smaller not bigger.
Now missions to foreign planets,that might be different (not sure).The one thing that doesn't get any smaller are humans! Nor all the energy they consume and the life support systems they need.Whether it's in LEO or off to somewhere else.
NASA recognises that those are the only things their SMS is good for (and would rather private enterprise kept out of 'their' space!).

Having said that there are some commercial Payloads -and obviously some military ones (note the upper stage development with military money)that the FH will be good for.But it's one hell of an investment 'just' for that.(can't think what it leaves for Boeing or The Glenn rocket frankly).Perhaps that's the idea -squeeze everybody else out?
Anyway I hope to read about some interesting new and exciting uses over the next year if it works as scheduled.
 
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Tugger
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 6:07 pm

Ultimately travel, methods of travel, needs to become ubiquitous for it to truly succeed and grow. Look at ships and aircraft, when they started they were for adventurers and people of daring and risk taking. Once they became "normal" it opened them to millions ( and billions) of people and just moving regular things around.

Imagine how amazing it would be (will be) if launching into orbit and space beyond is just as boring as airplane travel is for the majority of travelers today (having to hunt for the cheapest ticket that gets you close enough to your destination in the style you want, the stress of packing properly, getting to the airport/transport hub, checking yours bags and finding out you are overweight, the grind of going through security, waiting in the boarding area only to hear your flight is delayed and is now at a different gate, standing waiting to have your boarding group called and crowding to get on first, having to do that slow walk into the jetway that you can see nothing out of and entering the random aircraft you will travel on, having to find your seat - telling the person in you seat that no their seat is in front/behind/across the aisle.... all the fun and joy of travel as we know it! By the way, I do encourage you to go and just listen to the Blue Origin launch and land video I posted in that thread and get an inkling of what this might be like when we all get to do it someday.).

It will be an amazing time when it becomes boring....

Tugg
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 10:14 pm

parapente wrote:
I don't wish to sound perverse but I am not sure the above it true.Indeed possibly the reverse.You (only) need 'X' amount of satellites for (say) digital global coverage - not more not less it's maths.The same goes for GSO says.


Not if prices drop. Lower prices means that there is more opportunity for competition. More competition will drive prices for services down, and then more people utilize the satellites for ever more services.

parapente wrote:
However digitisation means they (on the whole) get smaller not bigger.


That ignores transmission power. Digitization doesn't reduce the size of the solar panels and batteries needed to transmit with more power. More power means larger coverage area, smaller receivers on the ground, or both.
 
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moo
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Re: SpaceX - Tests, Launches, Developments

Sat Dec 30, 2017 11:21 pm

One thing often missed is that satellites need propellant to keep station - even though we are talking about "space" here, we are still talking "orbits" which invariably means drag (either from gravitational changes across the orbit or atmospheric drag), plus no satellite is perfectly set in its alignment. This is true for all orbits, including geostationary.

Heavier payloads at a cheaper launch cost means more propellant can be carried, which means satellites can stay active for longer, rather than have to be disposed due to exhausting their station keeping ability.

Satellites that function longer mean more bang for your buck.

Make no mistake, there are plenty of missions for the Falcon Heavy.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Sun Dec 31, 2017 9:50 am

Once again well made point Moo never considered that.Obviously (long term) bad news for satellite manufacturers if they could (say) double the life of a GSO satellite .But clearly It would be worth it.
But I still hope he uses the FH for learning work over the next 6-10 years (there will be slippage just like F9's and FH) whilst the BFR system is being developed.There are so many Moon/Mars/LEO development programmes he could run over this period so that he is on the ground running when the game time comes.
I read somewhere that a non return FH could take 15 tons to Mars orbit.Not sure if that's true but if it is it's a very useful payload.
 
WIederling
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Re: SpaceX - Tests, Launches, Developments

Sun Dec 31, 2017 1:58 pm

moo wrote:
Satellites that function longer mean more bang for your buck.
Make no mistake, there are plenty of missions for the Falcon Heavy.


station keeping fuel isn't really an issue.
SOHO in one of the more difficult positions still has fuel
though the attitude system has been shot / massively degraded for quite some time.
Stil, SOHO continues to provide good data.

Comms Sats have lost mass.
Ariane V has enough payload to bring two payoads into a GEO position.
( inclusive of stacking infrastructure "under the hood" )
But in most cases you then need to bring two customers together. PITA!

Another lifetime issue is obsolecense.
What good is a Comms Sat that is good at stuff nobody any longer requires.
Things move on.
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Sun Dec 31, 2017 9:12 pm

parapente wrote:
I read somewhere that a non return FH could take 15 tons to Mars orbit.Not sure if that's true but if it is it's a very useful payload.


I find that unlikely. Maybe possible with crossfeed, but that's not happening right now.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Mon Jan 01, 2018 11:35 am

I think it was stated in lbs somewhere on their site.They used to post rocket capabilities both in terms of Earth (LEO and GEO) and for some odd reason Mars!
But thinking of the now cancelled Red Dragon mission.That was to take ta craft from Earth to Mars,inject into orbit.Then release Red Dragon for surface soft landing.Scoop up some Mars put into a rocket (inside the R Dragon capsule).Then blast off from Mars,escape gravity and further boost to Earth and inject into orbit (think that's right).15 Tons? Well I would have thought it would have needed all of that!But only a guess.
 
WIederling
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Re: SpaceX - Tests, Launches, Developments

Mon Jan 01, 2018 1:06 pm

Image
( imu minimun energy values )

going to Mars takes much more time but not that much more energy.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Mon Jan 01, 2018 2:43 pm

I'll take your word for it!
My hope for the new year (or two).
That the FH works like clockwork.
That Elon is encouraged to try a few things out (after all 2018 is a 'Mars' year).
And hopefully the Moon as well-With it being a 'Google X prize year' it's certainly going to be in the news.
JV with NASA?? No more silly Tesla cars!
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Mon Jan 01, 2018 11:23 pm

WIederling wrote:
Image
( imu minimun energy values )

going to Mars takes much more time but not that much more energy.


Interesting chart. At the risk of a thread jack - two questions.

Why is the delta-V to reach low orbit around Venus so high? Venus is 0.8 of the Earth's mass - shouldn't it be a bit lower than Earth's?

What exactly is a Earth - Sun transfer orbit? Aren't all orbits outside the orbit around any object orbiting the sun a solar orbit?
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 4:15 am

SpaceX is claiming on their website that the FH capability is 16.2 metric tons for "Mars payload". I'm not sure if that's Mars transfer obit, Mars orbit or surface.

http://www.spacex.com/about/capabilities
 
meecrob
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 8:24 am

MatthewDB wrote:
WIederling wrote:
Image
( imu minimun energy values )

going to Mars takes much more time but not that much more energy.


Interesting chart. At the risk of a thread jack - two questions.

Why is the delta-V to reach low orbit around Venus so high? Venus is 0.8 of the Earth's mass - shouldn't it be a bit lower than Earth's?

What exactly is a Earth - Sun transfer orbit? Aren't all orbits outside the orbit around any object orbiting the sun a solar orbit?


I'll leave your first question to someone more qualified than me since my orbital mechanics knowledge is quite frankly layman, but I can help with your second one until someone totally blows my answer away. They specify the dV to sun orbit because they mean "an orbit closer to the sun than Mercury." You are correct that any object who has the Sun as its largest influence gravity-wise is in orbit around the sun (save for collision courses, etc), but think of that chart like a roadmap. Say you are going to a corner store for milk. You want to know how far it is to the corner store, not how far it is so everytime you look, its in the same place. You can stand on the corner 3 blocks from the store, but that doesn't help much when you want to buy some milk. In this scenario, all you did was get off the bus a few stops too early.

P.S. Had a thought about your Venus Question - I'm guessing the reason the dV is so high is Venus' atmosphere is extremely thick and trying to escape it would be more dV intense than Earth. I don't know, however, if this could be counter-acted by using parachutes instead of engines to land, therefore saving dV on the descent. Hate to land in a sea of whatever boiling elements are scattered around unguided using parachutes than use an engine to guide me to a safe landing.
 
WIederling
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 9:00 am

Venus Question: "27km/s" This could be a typo. ( 33km/s is what you need to get out of jupiter gravity well.)
https://en.wikipedia.org/wiki/Escape_ve ... velocities
( Earth is ~11, Venus ~10km/s ) Venus by virtue of its (retrograde) very slow rotation does give no assist to orbit. ( earth: .46km/s )
 
WIederling
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 9:06 am

MatthewDB wrote:
SpaceX is claiming on their website that the FH capability is 16.2 metric tons for "Mars payload". I'm not sure if that's Mars transfer obit, Mars orbit or surface.

http://www.spacex.com/about/capabilities


tag says "16t payload to Mars" i.e. at least a stable Mars orbit. ( only question is that a minimum energy Hohmann
or some faster transfer. Afaik you can do a fling via Venus.)

( 26t to GT(ransfer)O , needs another 1.5km/s for insertion into GEO.)
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 9:22 am

Was watching an interesting YouTube on FH by an enthusiast (in an orange spacesuit??).However what he had to say was very enlightening.Whist there has been a 4 year delay in FH things have hardly stood still in the meantime.F9 today is now 40% (I think he said) more powerful than originally conceived.Indeed a 'full power' can (and has) launched a heavy satellite into geostationary orbit!This was the original perceived job of the FH.
As people have stated above I am sure there are still uses for the FH (certainly Military by their continued sponsorship of improvements).But it doesn't surprise me can it can take 16.2 metric tons of something to Mars.The question is what?
Mr Boeing wants a race to Mars.Elon says 'do it'.Mmmmm.
I also can't help feeling that the Moon will become an objective (will need a bigger fairing perhaps).One good reason is that the politicians are all talking about a return to the Moon.Follow the politicians and you follow the money.Elon's not stupid.I am not sure Trump cares whether it's Spacex or NASA frankly.
If this rocket works well (it's man rated too) you do have to start wondering about the SLS-no?
 
Nicoeddf
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 10:38 am

Interestingly enough, Space flight yields by far the most civilized discussions on this board. It is a great reading here guys, thanks for that and happy new year.

Too bad my understanding of the mechanics of space flight are more than layman-like.
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 10:42 am

parapente wrote:
As people have stated above I am sure there are still uses for the FH (certainly Military by their continued sponsorship of improvements).But it doesn't surprise me can it can take 16.2 metric tons of something to Mars.The question is what?
Mr Boeing wants a race to Mars.Elon says 'do it'.Mmmmm.


A race, and then what? In order to put a handful people on Mars, you need to uplift a much bigger payload than 16t. For reference, the Apollo missions that sent 3 people to the moon was good for a payload of 40t. Sending a rover is one thing. Once you start adding people, the requirements will balloon.

Reality is that you need something like Saturn V to get the job done.

If this rocket works well (it's man rated too) you do have to start wondering about the SLS-no?


SLS is Saturn V ballpark, a much more powerful rocket. There is no way Falcon Heavy can send Orion spacecraft with 7 people to Lunar of Mars orbit.
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 12:02 pm

I agree with you Karel.
There is no way any version of the FH is taking anybody to Mars! Ever.Or the Moon.
But for Spacex to suggest that suddenly when they have built their BFR (6-10 years)they will land craft/people on Mars is (imho) equally ridiculous.
1.They have not been to Mars the FH can do this
2.They have not injected to orbit around Mars the FH can do this
3.They have not landed on Mars the FH can do this.
You have to prove all this first.
1.They have (yet) to put people in space the FH can do this
2.They have yet to orbit the Moon (with/without people) the FH can do this
3.They could land on the Moon (unmanned) the FH could do this.
4.Not a bad idea to do some space walks whilst they are at it with their new suits.FH could do this with capsule.

So much they need to do if they are going to be responsible -NASA will ensures they are.But so far not a word.To me the silence is deafening.
But I think we will hear something If and when the FH is a success.
 
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flyingturtle
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 1:10 pm

Nicoeddf wrote:
Too bad my understanding of the mechanics of space flight are more than layman-like.


This is a very good starter: https://www.explainxkcd.com/wiki/index. ... vity_Wells

When you move away from a gravitation source, you expend energy. When you move towards it, you expend it again - because of the braking maneuver. (In the case of Earth, though, our atmosphere does almost all of the braking.)

And if you want to move further out in the solar system (e.g. Earth to Mars), you need to expend energy. If you want to go further in (e.g. Earth to Venus), you need to expend energy too - because of the braking maneuver.

https://www.explainxkcd.com/wiki/index. ... _Mechanics :fluffy:



David
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 1:17 pm

MatthewDB wrote:
Why is the delta-V to reach low orbit around Venus so high? Venus is 0.8 of the Earth's mass - shouldn't it be a bit lower than Earth's?


meecrob wrote:
P.S. Had a thought about your Venus Question - I'm guessing the reason the dV is so high is Venus' atmosphere is extremely thick and trying to escape it would be more dV intense than Earth. I don't know, however, if this could be counter-acted by using parachutes instead of engines to land, therefore saving dV on the descent. Hate to land in a sea of whatever boiling elements are scattered around unguided using parachutes than use an engine to guide me to a safe landing.


WIederling wrote:
Venus Question: "27km/s" This could be a typo. ( 33km/s is what you need to get out of jupiter gravity well.)
https://en.wikipedia.org/wiki/Escape_ve ... velocities
( Earth is ~11, Venus ~10km/s ) Venus by virtue of its (retrograde) very slow rotation does give no assist to orbit. ( earth: .46km/s )


According to NASA, Venus escape velocity is 10.36 km/s.

See https://nssdc.gsfc.nasa.gov/planetary/f ... sfact.html
 
Nicoeddf
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 1:26 pm

Thanks @flyingturtle

very interesting! :) I guess I might play Kerbal a bit... :)
 
mxaxai
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 3:48 pm

KarelXWB wrote:
parapente wrote:
As people have stated above I am sure there are still uses for the FH (certainly Military by their continued sponsorship of improvements).But it doesn't surprise me can it can take 16.2 metric tons of something to Mars.The question is what?
Mr Boeing wants a race to Mars.Elon says 'do it'.Mmmmm.


A race, and then what? In order to put a handful people on Mars, you need to uplift a much bigger payload than 16t. For reference, the Apollo missions that sent 3 people to the moon was good for a payload of 40t. Sending a rover is one thing. Once you start adding people, the requirements will balloon.

Reality is that you need something like Saturn V to get the job done.

If this rocket works well (it's man rated too) you do have to start wondering about the SLS-no?


SLS is Saturn V ballpark, a much more powerful rocket. There is no way Falcon Heavy can send Orion spacecraft with 7 people to Lunar of Mars orbit.

SLS block 1 can lift 70 tons into LEO, vs 63.8 tons for FH (expendable). Block 2 is supposed to get 130 tons into LEO. So it can get a fair bit more payload to mars or the moon. Compare this to the Orion capsule at 25 tons and Dragon 2 with 6.4 tons. I assume the FH could get a Dragon 2 on a one-way mission to mars but probably not enough fuel and/or engines to return it (like Red Dragon was planned).

On the other hand, BFR (2017) is supposed to get some 150+ tons to LEO and would likely be a fair bit simpler and cheaper than the SLS Block 2, even if expendable. I'd like to see NASA fund that (or the Blue Origin version) as the eventual SLS replacement.
 
ZaphodHarkonnen
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 4:21 pm

Nicoeddf wrote:
Thanks @flyingturtle

very interesting! :) I guess I might play Kerbal a bit... :)


Kerbal Space Program will do wonders for understanding the basics of orbital mechanics.

It helped me understand the basics of this stuff so much more. Going from ROCKETS ARE COOL to more, And this is why rockets are cool.
 
GST
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 5:15 pm

ZaphodHarkonnen wrote:
Nicoeddf wrote:
Thanks @flyingturtle

very interesting! :) I guess I might play Kerbal a bit... :)


Kerbal Space Program will do wonders for understanding the basics of orbital mechanics.

It helped me understand the basics of this stuff so much more. Going from ROCKETS ARE COOL to more, And this is why rockets are cool.


Mee too. as with most things, there's an XKCD for that:
Image
 
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flyingturtle
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 6:21 pm

ZaphodHarkonnen wrote:
Kerbal Space Program will do wonders for understanding the basics of orbital mechanics.


And you learn to approach planets from the not-so-dangerous side.

I did it wrong, once, and the gravitational slingshot maneuver catapulted the poor yellow laboratory animals into the really deep space...

And by playing KSP, you understand many design considerations. In the career mode, you have to pay for the engines you don't bring back to Earth. Which brings you to SpaceX.

And you can work with asparagus staging. And you'll learn, really the hard way, what Tsiolkovsky's rocket equation means.


David
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 6:48 pm

KarelXWB wrote:
parapente wrote:
As people have stated above I am sure there are still uses for the FH (certainly Military by their continued sponsorship of improvements).But it doesn't surprise me can it can take 16.2 metric tons of something to Mars.The question is what?
Mr Boeing wants a race to Mars.Elon says 'do it'.Mmmmm.


A race, and then what? In order to put a handful people on Mars, you need to uplift a much bigger payload than 16t. For reference, the Apollo missions that sent 3 people to the moon was good for a payload of 40t. Sending a rover is one thing. Once you start adding people, the requirements will balloon.

Reality is that you need something like Saturn V to get the job done.


Why does it have to be on the top of one rocket? The only thing that can't sit in space for a while is cryogenic fuel and people. Every thing else can go up in multiple missions. In 1969 multiple resevendous in space was risky, hence the desire to throw it all up in one launch. Now, resevendous can be done with automation. What hasn't been tried in space yet is fuel transfer, but I don't think that's too hard.
What SpaceX has achieved already is a drastic reduction in cost, the biggest barrier to these missions. Many FH trips can be had for the price of one bigger rocket (at least until there is a bigger reusable replacement).
 
parapente
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 8:58 pm

Again not to trying to perverse but - fuel transfer not hard?
But rather than argue -let's definitely add it to the list of key things to do - find out and get good at it -cos they're gonna need to!
 
mxaxai
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 9:42 pm

parapente wrote:
Again not to trying to perverse but - fuel transfer not hard?
But rather than argue -let's definitely add it to the list of key things to do - find out and get good at it -cos they're gonna need to!

How hard can it be? If you can have an automated cargo transfer vehicle that creates an airtight lock to the ISS autonomously, what's the deal with transferring fuel? It's not as if the principles of fueling lacked understanding.
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 9:53 pm

Well, at least fuel transfer was complicated enough that it didn't make it into the final Falcon Heavy design.
 
WIederling
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 10:11 pm

KarelXWB wrote:
Well, at least fuel transfer was complicated enough that it didn't make it into the final Falcon Heavy design.


Are wwe talking about

between stages
or
between different crafts ( like supply to ISS )
 
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flyingturtle
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Re: SpaceX - Tests, Launches, Developments

Tue Jan 02, 2018 10:25 pm

KarelXWB wrote:
Well, at least fuel transfer was complicated enough that it didn't make it into the final Falcon Heavy design.


Who says it's the final FH design? Falcon 9 was heavily modified all the time, after all. :praise:


David
 
ZaphodHarkonnen
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Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 12:11 am

For on orbit fuel transfer we're talking about between craft. Not between boosters during launch.

As for how difficult? Well no one has really tried it yet. My understanding is the ISS is periodically refueled but that's a pretty well defined and static system. https://www.universetoday.com/84546/fir ... r-mid-may/

To the best of my knowledge there's no generic standard for refueling. Probably because its never really been a consideration for most payloads and there is so much variation in propellents and electrical systems. There is work going on to build spacecraft with robotic systems that can latch to a satallite, pop off the feed caps, and refuel. But until now it just hasn't been a requirement or even nice to have.

Any refueling system would need to be system specific. And refueling a large booster will probably be very different than a small orbit kicker system for the ISS. not to mention other things like ullage motors and RCS systems.

And yeah, if SpaceX want to do the stuff they say they're going to do then in orbit refueling is a must have. So they'll have to build it into their spacecraft. But even then it will probablay be system specific with connectors being in the docking surfaces and not independent hoses. Closer to a flying boom style of system then ground hoses.
 
MatthewDB
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Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 1:20 am

flyingturtle wrote:
KarelXWB wrote:
Well, at least fuel transfer was complicated enough that it didn't make it into the final Falcon Heavy design.


Who says it's the final FH design? Falcon 9 was heavily modified all the time, after all. :praise:


David


With the benefits asparagus staging bring, I would expect FH fuel transfer on the short list to develop. I suspect the reason it was dropped is dropping it reduced the number of development risks, not that it was hard. SpaceX can get paying customers, and try the fuel transfer while simultaneously generating revenue. Perhaps make an expendable mission into a recovery mission if fuel transfer works.

mxaxai wrote:
parapente wrote:
Again not to trying to perverse but - fuel transfer not hard?
But rather than argue -let's definitely add it to the list of key things to do - find out and get good at it -cos they're gonna need to!

How hard can it be? If you can have an automated cargo transfer vehicle that creates an airtight lock to the ISS autonomously, what's the deal with transferring fuel? It's not as if the principles of fueling lacked understanding.


ISS is supplied with gaseous O2 and N2 along with UDMH and N2O4 for the thrusters. I don't think those are as hard to transfer as cryogenic fuel. The biggest problem with UDMH and N2O4 is you can't have ANY leaks because they are toxic, and put any future EVA at risk. With cryogenic fuel the problem is dealing with the cooling. Unless the tank is already chilled, cooldown and dealing with the vented gasses would be an issue to address.
 
WIederling
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Joined: Sun Sep 13, 2015 2:15 pm

Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 8:29 am

ZaphodHarkonnen wrote:
And yeah, if SpaceX want to do the stuff they say they're going to do then in orbit refueling is a must have. So they'll have to build it into their spacecraft. But even then it will probablay be system specific with connectors being in the docking surfaces and not independent hoses. Closer to a flying boom style of system then ground hoses.


jerry cans for space :-)

( less of a joke than it sounds. Having filled tanks as payload attached to an orbital ships framework..
Look into how von Braun thought about going to Mars.)
Image

only issue i see is that those would need structural strength for lifting to orbit that is not needed for the low g transfer burns.

for tank to tank transfer you'd need some artificial gravitiy help to keep fuel and fumes separated.
Cryo or "household liquids" ;-?
 
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KarelXWB
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Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 8:40 am

SpaceX released some high-res Falcon Heavy pictures:

Image
Falcon Heavy Demo Mission by SpaceX, on Flickr

Image
Falcon Heavy Demo Mission by SpaceX, on Flickr

Image
Falcon Heavy Demo Mission by SpaceX, on Flickr
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 11:21 am

what are the yellow ears sticking out of the payload fairing?
 
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flyingturtle
Posts: 6590
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Re: SpaceX - Tests, Launches, Developments

Wed Jan 03, 2018 11:25 am

In these pictures

https://mk0spaceflightnoa02a.kinstacdn. ... quick1.png

http://cbsnews2.cbsistatic.com/hub/i/r/ ... 5blow0.jpg

you see that the vapour trail separates from the rocket body in a 45 degree angle - very counter-intuitive, while in

https://i1.wp.com/www.spaceflightinside ... =350%2C200

the vapour trail is aligned with the actual air stream.


Is this higher aero-magic-dynamics?

David

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