People across most of the eastern United States have a great opportunity, weather permitting, to witness a SpaceX rocket launch four astronauts to the International Space Station early Friday (April 23). It may be an amazing spectacle, but you'll have to wake up before dawn to see it.
SpaceX's upcoming Crew-2 astronaut mission for NASA will launch a Falcon 9 rocket nearly parallel to the U.S. East Coast. Liftoff is set for 5:49:02 a.m. EDT (2249:02 GMT) from Pad 39A of NASA's Kennedy Space Center in Cape Canaveral, Florida, to send the Falcon 9 and its Crew Dragon spacecraft on the right course to reach the space station.
You can watch the launch online here and on the Space.com homepage, courtesy of NASA and SpaceX, starting at 1:30 a.m. EDT (0630 GMT). You'll also be able to watch it directly from NASA and SpaceX webcasts. But if you want to see the launch with your own eyes, you'll have to know when and where to look (and have good weather, as well).
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What to expect
From the southeastern United States, depending on a viewer's distance from Cape Canaveral, the Falcon 9 should be easily followed in the predawn sky thanks to the fiery output of its first stage, consisting of nine Merlin 1D engines. The light emitted by these engines will be visible for the first 2 minutes and 36 seconds of the launch out to a radius of some 300 statute miles from the Kennedy Space Center.
Depending on where you are located relative to Cape Canaveral (see map), the Falcon 9 will become visible anywhere from a few seconds to just over 2.5 minutes after it leaves historic Launch Complex 39A.
Three seconds after main engine cutoff (MECO), the first and second stages separate. Two minutes and 47 seconds after launch, the second stage, consisting of a single Merlin 1D rocket engine is ignited, accelerating the Crew Dragon capsule (called Endeavour) and its crew of four astronauts to orbital velocity.
The main show
As the Falcon 9's second stage rises high enough into the atmosphere to catch the light of the sun, it should evolve into an eye-catching sight.
For observers on the ground, the sun will still lie below the horizon, giving a twilight feel to the predawn sky. But at the altitude of the ascending rocket, the sun will already be above the horizon for both the Dragon capsule and the exhaust contrail produced by the Falcon 9's second stage engine. The sunlight reflecting off the rocket's exhaust will illuminate it, creating a long and expanding plume.
During an earlier SpaceX launch on March 14, when a different Falcon 9 rocket also lifted off before sunrise to deliver 60 Starlink satellites into Earth orbit. The result was a spectacular sight for those who were up during the predawn hours.
On Long Island, amateur astronomer, Tom Penino witnessed the display. On the Internet Hot Line of the Astronomical Society of Long Island (ASLI) that morning, he noted: "Approximately 7 minutes into flight, was able to observe a 'huge fan shape cone' moving from the south towards the east. What amazed me was 'how fast' it was traveling!! It bolted across the S-SE-E skies in a matter of 10 to 15 seconds. I could see the engine itself thrusting (2nd stage), followed by this large fan shaped cloud trailing it. The cone encompassed tens of degrees in the southeast sky. Upon 2nd stage shutdown, the point of [the] plume pulled away from the huge fan shaped cloud, & continued as a point of light to the east. Eventually this point faded & I was just left with the aftermath of the remaining fan shaped cloud."
Another Long Island amateur, John Vogt, was out doing a 10K run when he was taken by surprise and also saw the launch.
"Beautiful sight!" Vogt reported on the ASLI Hotline. "I guess the plume was about 4 to 5 degrees across and 10 degrees long." For comparison, the "pointer stars" (Dubhe and Merak) of the Big Dipper, are roughly 5 degrees apart while your clenched fist held at arm's length measures about 10 degrees.
Many others reported the cosmic contrail sighting as a UFO, a fireball or a "space jellyfish."
When and where to look:
Southeast U.S. coastline: Anywhere north of Cape Canaveral, I suggest viewers initially concentrate on the south-southeast horizon. If you are south of the Cape, look low toward the north-northeast. If you're west of the Cape, look low toward the east.
Carolinas to Virginias: Look toward the south-southeast about 3 to 6 minutes after launch.
Delaware/Maryland to southern New York: Concentrate your gaze low toward the south-southeast about 6 to 8 minutes after launch. For places to the east (right) of a line running from Massena, NY to Riverhead, NY, the sun will be above the horizon making it rather difficult or perhaps impossible to see the Falcon-9 against the bright blue daylight sky.
It's important to note that in some cases, Falcon 9 will appear to literally skim the horizon, so be sure there are no buildings or trees to obstruct your view. Check our map for regions of visibility; the closer you are to the coast, the higher the rocket will appear. Depending upon your distance from the coastline, Falcon 9 will be somewhat low to the horizon (at an altitude of 15 to 25 degrees).
If you're positioned near the edge of a circle, Falcon 9 will barely come above the horizon and could be obscured by low clouds or haze.
Falcon 9's second stage will shut down 8 minutes and 47 seconds after launch at a point about 770 statute miles up range (to the northeast) of Cape Canaveral and some 300 statute miles southeast of New York City. At that moment, the Dragon capsule will have risen to an altitude of 653,560 feet (123.8 statute miles), while moving at 16,256 mph (26,161 kph) and should be visible for a radius of about 900 statute miles from the point of Second Engine Cut Off (SECO).
And, of course, before you head out to look for the rocket, make sure it has actually left the launch pad by watching the online broadcasts.
What happens in case of a scrub?
Should the launch be postponed, the next launch attempt would come on Monday, April 26. Liftoff would come at 4:38 a.m. EDT (0838 GMT).
However, this would be a full night launch with no chance of the sun illuminating the Crew Dragon capsule or the Falcon 9 rocket's exhaust trail.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook.