SpaceX Manned Launch TO ISS

[rhd]

Today, for the first time a private company's rocket launched men into space. The SpaceX launch from Florida went off pretty much w/o a hitch and the rocket also returned to Earth (on a drone ship in the Atlantic) successfully to be reused in a later launch. The two NASA astronauts on board, Bob Behnken and Doug Hurley, will rendezvous w the International Space Station tomorrow.

This is a big deal. First of all, it's so great to have something very positive to happen in 2020 and also something for the US to be very proud of these days. But more importantly, this is a big step forward for space travel. Using SpaceX rockets, which are reusable, cuts the cost of launching into space by 75%. NASA plans to return humans to the moon in the next 4 years, and presumably in the mid-term future to Mars for the first time. Glad to hear it.

Before the launch, Elon Musk (head of SpaceX) said that if the launch was successful it's to the credit of his engineers but if it fails then it's his fault. If only our political leaders (notably our Emperor, I mean USA CEO, I mean our President) would take this attitude at least on occasion. I dont know about you, but to me, in spite of his shortcomings, Elon Musk is a hero.

The launch time of mid-afternoon was very unusual. I've never heard of any rocket being launched into space at that time. It's always been in the morning around sunrise. This is because the rocket gets the most boost from the Earth's momentum thru space at sunrise. Launching in the afternoon is almost the worst time because then the rocket has to do all the work.

Also, in the near future it is planned that Tom Cruise will star in a movie filmed from the International Space Station, meaning that he will be launched into space. I am looking forward to this! Maybe it will inspire the next Elon Musk!

[The Feral Slasher]

Today, for the first time a private company's rocket launched men into space. The SpaceX launch from Florida went off pretty much w/o a hitch and the rocket also returned to Earth (on a drone ship in the Atlantic) successfully to be reused in a later launch. The two NASA astronauts on board, Bob Behnken and Doug Hurley, will rendezvous w the International Space Station tomorrow.

This is a big deal. First of all, it's so great to have something very positive to happen in 2020 and also something for the US to be very proud of these days. But more importantly, this is a big step forward for space travel. Using SpaceX rockets, which are reusable, cuts the cost of launching into space by 75%. NASA plans to return humans to the moon in the next 4 years, and presumably in the mid-term future to Mars for the first time. Glad to hear it.

Before the launch, Elon Musk (head of SpaceX) said that if the launch was successful it's to the credit of his engineers but if it fails then it's his fault. If only our political leaders (notably our Emperor, I mean USA CEO, I mean our President) would take this attitude at least on occasion. I dont know about you, but to me, in spite of his shortcomings, Elon Musk is a hero.

The launch time of mid-afternoon was very unusual. I've never heard of any rocket being launched into space at that time. It's always been in the morning around sunrise. This is because the rocket gets the most boost from the Earth's momentum thru space at sunrise. Launching in the afternoon is almost the worst time because then the rocket has to do all the work.

Also, in the near future it is planned that Tom Cruise will star in a movie filmed from the International Space Station, meaning that he will be launched into space. I am looking forward to this! Maybe it will inspire the next Elon Musk!

I have never heard about the launch time affecting the power/thrust required. Do you have any more info about that ?

[rhd]

I have never heard about the launch time affecting the power/thrust required. Do you have any more info about that ?

Good question. Since just about every launch I've watched or heard about was in the morning, typically near sunrise, I had assumed that this was the optimal time, which also happens to be the time when the Earth is pointing in the same direction as its orbit around the Sun. The Earth is traveling about 67,000 mph in its orbit so an object launched in the same direction would have this same momentum, plus the momentum supplied by the rocket. AFter thinking about this, this added momentum would be beneficial for spacecraft leaving the Earth's orbit but not for those remaining in Earth's orbit, which is what this mission will be doing. So, this factor shouldnt matter for this launch so my statement was wrong. What mattered for this launch, among other things, was the position of the ISS so the launch was timed to make it easiest to rendezvous w the ISS based on its position at the time in question.

Re: launches into outer space, I think my point about the boost from the Earth's momentum should be valid. But I couldnt find any support for this. The sources I found all mentioned other factors, like being close to the Equator and launching from the east coast, and one said it shouldnt matter what time of day you launch as long as the time was convenient for mission control. But I swear that practically every launch I've watched was in the morning and if there was a problem that they couldnt resolve w/i an hour or 2 they postponed the launch until a later date. There has to be some reason for this.

[rhd]

Today, the spacecraft docked successfully w the ISS. It was over 3 hours before the 2 astronauts entered the ISS. Part of this time was due to pressurization and thermalizations of the hatches between the 2 spacecraft and leak checks but most of it seemed to be other stuff like setting up and testing cameras and microphones. They're in the midst of a welcome ceremony now. Mission well done, fellas!

[swampdragon]

Well done

I occasionally teach rocketry to my middle schools students and when you think about it

The concept of thrust making something a rocket rise is so incredibly simple and making a manned rocket work successfully is incredibly complex.

[Kevin Seitzer]

https://www.nasa.gov/centers/kennedy/launchingrockets/launchwindows.html

https://www.airspacemag.com/flight-today/how-things-work-shuttle-launch-windows-3142572/

https://www.airspacemag.com/need-to-know/why-do-nasa-launch-times-depend-on-lighting-conditions-35403278/

https://space.stackexchange.com/questions/7986/why-do-certain-times-of-day-have-more-launches-than-others

[Kevin Seitzer]

None of those links have a definitive answer, but I thought they were all interesting. The Stack Exchange thread actually comes closest to attempting an answer to your question. Someone there offered this answer, and it makes a lot of sense to me. The best reasons may have nothing to do with orbits:

For Florida, surrounded by water and with a reputation for electric storms, weather is a big factor. Early morning and evening is preferred for stable atmospheric conditions.

The following is surmise: Whatever the launch site, the economic factors mentionned in the other answers would favorize a night-time or early morning launch. Human factors such as the sleep cycle would tend to an early morning launch. Any launch emergency would be better dealt with in daytime.

[rhd]

None of those links have a definitive answer, but I thought they were all interesting. The Stack Exchange thread actually comes closest to attempting an answer to your question. Someone there offered this answer, and it makes a lot of sense to me. The best reasons may have nothing to do with orbits:

Thanx. I read the StackExchange link. The data from different launch sites did show a preference for morning launches. Weather seems to be one of the biggest factors determining launch time. I was surprised that the data from the Florida launches showed a greater preference for evening launches, as late afternoon/evening is the time of highest electrical storm activity in Florida.

After thinking about this more, for space voyages beyond the Earth's orbit, spacecraft dont go directly into outer space, rather they orbit the Earth for a while in order to build up speed and then they leave Earth's orbit. So regarding getting a boost from Earth's momentum, it shouldnt matter much when the launch occurs. What matters more is when the spacecraft leaves Earth's orbit. When the spacecraft is ready to do this, doing it around sunrise for where the spacecraft is is when the Earth's momentum would give it a boost.

[Steve 2.0]

Every time I see the title of this thread I read ISS as ISIS. Am I the only one?

[Ken]

Every time I see the title of this thread I read ISS as ISIS. Am I the only one?

You are the only one.




(that's why you have to do all the heavy lifting around here)

[Kevin Seitzer]

Every time I see the title of this thread I read ISS as ISIS. Am I the only one?

You, and the Falcon 9 rocket, have to do all the heavy lifting around here.

[TranaGreg]

must be an oklahoma thing.

[Gregg]

Every time I see the title of this thread I read ISS as ISIS. Am I the only one?

ISIS a trick question?

[Ken]

ISIS a trick question?

Depends

[swampdragon]

check this out - https://spotthestation.nasa.gov/