Crew Dragon Demo-2: Launch success

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Summary:

Crewed spaceflight returns to the US

Main Question or Discussion Point

It doesn't happen every day decade that people are being launched to orbit in a new spacecraft. The last time it happened was 2003 (Shenzhou), and the last time before that was the Space Shuttle in 1981. The next time will be in 12 hours, if the weather stays good. And for the first time it is a private spacecraft. Going to orbit is no longer the exclusive domain of governments. You can call SpaceX if you want a ride (and have maybe 100 million dollars).

The first crewed launch of Dragon 2 is scheduled for today 20:33 UTC, in 11.5 hours. There is a detailed timeline here. The crew will enter Dragon 2.5 hours before take-off, fueling the rocket will begin 35 minutes before. After take-off the astronauts will need 9 minutes to reach orbit and about 19 hours to reach the ISS. The largest concern currently is the weather, the latest forecast sees a 60% chance that the weather will be good. If the launch needs to be delayed there are backup dates 3 and 4 days later.

Live coverage is about everywhere, most will start a few hours before the launch. NASA, SpaceX will have one, at Spaceflight Now, from the "Everyday Astronaut", from "Space Videos", from Florida Today

It hasn't been decided yet how long the crew will stay at the ISS, but the general expectation is 1-3 months. NASA has suggested to make the first routine flight (for long-term stays at the ISS) end of August, this demonstration mission should land before that.

There is a long list of conditions for the weather (that page is a summary) - for the launch site, but also for sites where the astronauts might land in case of an abort during the launch.

Historic coincidences: Doug Hurley and Bob Behnken will launch from same pad as the last Shuttle launch in 2011. The crew of that Shuttle launch left a US flag on the ISS, to be returned by the next crewed flight from the US. One of the crew members of that last Shuttle launch? Doug Hurley. He can now pick up the flag again. Oh, it's also the pad used for all Apollo flights apart from Apollo 10, and for the first Shuttle launch.

The crew will enter Dragon before the rocket is fueled. It allows SpaceX to load colder - more dense - propellant and launch while it is still cold, which means the rocket takes off with more propellant and more thrust, so it can put more mass into orbit while still recovering its first stage. This is an unusual procedure, and NASA was initially concerned about it. There are many things that can go wrong during fueling. On the other hand: Their capsule has an abort system that can get the astronauts away from the rocket quickly if they are in danger. This procedure also means they don't need astronauts and support crew to be outside near the fully fueled rocket (without an abort system).
 
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Answers and Replies

  • #2
.Scott
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This may also be the first manned US mission with an "instantaneous" launch window.
If weather isn't good at 4:35pm local time, then it'll be scrubbed for the day.
And the crew is aboard.
 
  • #3
berkeman
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with an "instantaneous" launch window
Why is the launch window so tight?
 
  • #4
.Scott
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Why is the launch window so tight?
I believe it's to arrive in orbit already synced with the ISS orbit - thus shortening the rendevous time. That is the most common reason.
I will see if I can check that.
 
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  • #6
.Scott
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The crew was just told that a weather front over Orlando - and heading their way - appears to be eroding.

So the weather is looking better.
 
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  • #7
.Scott
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I believe it's to arrive in orbit already synced with the ISS orbit - thus shortening the rendezvous time. That is the most common reason.
I will see if I can check that.
It's more specific than that.
The launch site will cross the ISS orbital plane moments after the launch time.
Live ISS Orbit

Also, this verifies that this confirms this as the first human US flight with an instantaneous launch window:
https://blogs.nasa.gov/spacex/2015/06/28/launch-window-instantaneous-today/ said:
The now-retired space shuttle had 10 minutes and the Orbital ATK Antares rocket has had between five and 10 minutes.
 
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  • #8
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They could make something like a 3 minute launch window in terms of rocket performance - but if anything delays the launch then it won't be fixed in 3 minutes. No one is going to trust that 3 minute fix.

Weather is still a concern, but for the chance that it will be good they will continue to prepare for launch. The launch escape system is armed, propellant loading has started just now.

Edit: We'll get a (final?) weather update ~20:14.
 
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  • #9
.Scott
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At T-20:00
Scrubbed for weather: Low clouds and lightning energy dissipation.
Hmmm - but they're hedging.
 
  • #11
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At T-20:00
Scrubbed for weather: Low clouds and lightning energy dissipation.
Hmmm - but they're hedging.
Huh? NASA's stream still counts down, even though it doesn't look promising.

Edit: Now it has been scrubbed. t-17:00
 
  • #12
.Scott
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They're giving it until T-17:00 - but they don't expect it to clear.
Launch abort just started.
 
  • #13
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Weather forecast in 3 days is better.
 
  • #15
.Scott
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Why is the launch site in wet Florida and not somewhere more dry?
Closer to the equator - a little boost with Earth rotation.
And a safe place for East-bound boosters to fall.
 
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  • #16
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It needs to be at the east coast as (nearly all) launches go east. For the ISS it could be further north, but for geostationary satellites (=most commercial launches) a launch site needs to be as close to the equator as possible, and having two sites would cost more. Three, actually, as SpaceX also launches from Vandenberg (west coast) for sun-synchronous ("polar") orbits.
 
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  • #17
robphy
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Maybe SpaceX needed some RainX.
:-p
 
  • #18
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20 minute interview with Elon Musk and Jim Bridenstine the day before the launch attempt. NASA administrator Jim Bridenstine called it "dawn of a new era in spaceflight" (17:15). Generally the way NASA talks about commercial spaceflight changed a lot recently. From "this is something we can try, let's see if it works out" to "this changes the whole way we run NASA".
 
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  • #20
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t-5 minutes, weather is good, everything is ready for launch
 
  • #22
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Successful launch. Dragon is in orbit. It will need 19 hours until it docks with the ISS.
The first stage landed on the drone ship in order to be reused on a future flight.
 
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  • #24
Klystron
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Minor mishap when the Dragon commander banged his forehead while entering the ISS. Probably due to muscles attuned to 1G operating in free fall and general excitement of a successful demo.

Inspiring flight and docking.
 
  • #25
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SpaceX got the permission to reuse boosters and capsules for crewed flights
For cargo missions they got that permission a while ago, for crew it is new. It is again demonstrating that people learned to trust reused boosters. It's the safer long-term strategy for sure. Would you prefer to fly with an airplane that was never flown before, or one that made several successful flights?
 
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