A dawn view of the busiest rocket launch pad in the world, Space Launch Complex 40. A Falcon 9 rocket is 229.6 ft (70 m) tall and 12 ft (3.7 m) in diameter, or 21.2 stories — it would be a tall building in most city skylines. Unfortunately, a line of thunderstorms forced a launch scrub on this day, but still, being at a launch pad is a special thing any time.
A wave of thunderstorms passed through the Cape Canaveral area around 90 minutes before liftoff Saturday, forcing SpaceX to stand down from its launch attempt today.
The company said in a latter post on X.com that they would try again tomorrow, but with a 90% Probability of Violation and an approaching tropical system off of Florida’s west coast, the chances of that don’t seem very high. Monday’s forecast is equally squirrelly as the system is forecast to arc through northern Florida, creating storm squalls and windy conditions across the state.
On the other hand, it’s Florida and the weather here can be unpredictable. So, we’ll see when SpaceX can get this launch off of the pad.
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SpaceX is planning to launch Falcon 9 carrying the NG-21 ISS Resupply mission for Northrup Grumman. Liftoff Saturday morning is set 11:28 AM EDT (1538Z) in an instantaneous window from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida.
SpaceX plans for the booster to return and land at Landing Zone 1 in Cape Canaveral. The Space Coast will hear a sonic boom from the booster as it herald’s its return, which should happen approximately 7.5 minutes after liftoff.
Weather is a major concern for this launch, as a tropical disturbance’s passing to the west in the Gulf of Mexico is expected to bring heavy rains to the Space Coast over the weekend. Current forecasts are calling for weather to arrive sometime Saturday, so the timing of the storm coupled with the normal storm activity of Florida in summer leaves forecasters calling the chances of acceptable weather a coin flip with a 50% chance of a Probability of Violation at launch time.
Northrup Grumman’s Cygnus (S.S. Francis R. “Dick” Scobee) cargo spacecraft, loaded with scientific investigations, supplies, and equipment.
According to NASA, the payload includes:
The forecast at launch time looks relatively benign:
| Temperature | 28.9°C |
| Humidity | ~65% |
| Precipitation | None, Probably |
| Cloud cover | Variable |
| Windspeed (at ground level) | 10-15 MPH / 4.5-6.7 m/s |
| Visibility | ~16.5 miles / 27.0 km |
The 45th Weather Squadron’s discussion in their launch forecast mentions the tropical system noted above. “All eyes will remain on Potential Tropical Cyclone Four (PTC 4) as it lifts out of the Greater Antilles and into the Gulf of Mexico. The official forecast from the National Hurricane Center has the system becoming a named storm Saturday and skirting the western Florida Peninsula Sunday, potentially making landfall as a Tropical Storm anywhere from the Florida Big Bend to southwest Florida.
Regardless of where the center of the storm makes landfall, the Space Coast will be on the eastern side of the system, and weather is likely to deteriorate with time from Saturday afternoon into Sunday. For the initial launch window, scattered showers are expected to approach the coastline out of the southeast and potentially move onshore.”
Their primary concerns that could necessitate a delay are: the Cumulus Cloud Rule, Surface Electric Fields Rule, and Thick Cloud Layers Rule.
Northeastwards.
The booster used for this mission, B1080, will land at Landing Zone 1 at Cape Canaveral Space Force Station.
SpaceCoastLaunchCalendar.com will have a livestream of the launch if you’re not able to watch the launch in person: Livestream
SpaceX will have a livestream of the launch on their website: NG-21 Mission. This will also be available on the X platform. Coverage starts about five minutes before liftoff.
NASA’s launch coverage begins at 11:00 AM EDT on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website.
Spaceflight Now will have coverage of the launch starting about one hour before liftoff on Youtube: link
For official updates regarding launch times, SpaceX.com is the best source of information. Starlink launch times change from time to time, and the company generally updates their website within minutes of the decision to change the launch time. This is very handy if none of the streaming options on YouTube have started their broadcasts.
Remember that there is a delay between a launch stream and the actual countdown clock. That is simply because of physics: it takes time for the signal to travel from the launch site, through the Internet, and back down to your phone, resulting in a five to fifteen-second delay.
Next Space Flight an app for iOS and Android phones, has a real-time countdown clock that is accurate to a second, give or take. The app is free. Search the App Store or Google Play. They are also on the web: nextspaceflight.com.
This morning’s planned launch is from SLC-40 at Cape Canaveral, which means that the best direct views of liftoff are:
Banana River Bridge on FL-528 W near Port Canaveral, where you will be able to see ignition, liftoff and the booster landing. Free.
Kennedy Space Center Vistor’s Center. From Apollo/Saturn V Center. Premium Launch Transportation Ticket. Bleacher seating is available, expert commentary, and closer view of the launch from across Banana Creek. Landing is pretty far away, relatively speaking. $70 for the launch viewing ticket plus entrance fees and parking. If you choose this go very early — lines will be long!
The southern parks on US-1 / S. Washington Avenue in Titusville. Kennedy Point Park and Rotary Riverview Park (among others) are your best bets for free viewing sites. These sites will be great for the launch, but not as good for the landing.
There are several excellent viewing spots for SLC-40 launches that offer indirect views — meaning you won’t see the rocket until it clears obstructions such as trees, buildings, even a storm berm in one case.
Playalinda Beach out on the Cape Canaveral National Seashore should be open to spectators until 8 PM EDT, that is if KSC Security and the National Park Service allow viewers for the launch. Generally, they have been, but security concerns can differ for each launch. It opens to visitors at 6 AM.
This is a popular place, so if you go, go early.
Call ahead to be sure they are open..
Cape Canaveral National Seashore • Playalinda Beach
Phone: (386) 428-3384 x0
Current operating hours: 6:00 AM–8:00 PM
If you are going to Playalinda, and if it is open, remember these general tips. Some may not apply to this particular launch.
Be prepared for potential changes or pushbacks in the launch schedule, and keep up by monitoring the live stream links mentioned above.
SpaceX states on their website, “This is the tenth flight of the first stage booster supporting this mission, which previously launched Ax-2, Euclid, Ax-3, CRS-30, SES ASTRA 1P, and four Starlink missions.”
That’s Booster B1080.
| Booster B1080 | ||
| Flight Number | Mission | Date |
| 1 | Axiom-2 | May 21, 2023 |
| 2 | Euclid | July 1, 2023 |
| 3 | Starlink 6-11 | August 27 2023 |
| 4 | Starlink 6-24 | October 22, 2023 |
| 5 | Axiom-3 | January 18, 2024 |
| 6 | CRS-30 | March 21, 2024 |
| 7 | Starlink 6-52 | April18, 2024 |
| 8 | Starlink 6-62 | May 23, 2024 |
| 9 | Astra 1P / SES-24 | June 20, 2024 |
| Hr/Min/Sec | Event |
|---|---|
| 00:38:00 | SpaceX Launch Director verifies go for propellant load |
| 00:35:00 | RP-1 (rocket grade kerosene) loading begins |
| 00:35:00 | 1st stage LOX (liquid oxygen) loading begins |
| 00:16:00 | 2nd stage LOX loading begins |
| 00:07:00 | Falcon 9 begins engine chill prior to launch |
| 00:01:00 | Command flight computer to begin final prelaunch checks |
| 00:01:00 | Propellant tank pressurization to flight pressure begins |
| 00:00:45 | SpaceX Launch Director verifies go for launch |
| 00:00:03 | Engine controller commands engine ignition sequence to start |
| 00:00:00 | Falcon 9 liftoff |
| Hr/Min/Sec | Event |
|---|---|
| 00:01:08 | Max Q (moment of peak mechanical stress on the rocket) |
| 00:02:18 | 1st stage main engine cutoff (MECO) |
| 00:02:22 | 1st and 2nd stages separate |
| 00:02:30 | 2nd stage engine starts (SES-1) |
| 00:02:35 | Boostback Burn Starts |
| 00:02:58 | Fairing deployment |
| 00:03:24 | Boostback Burn Ends |
| 00:06:17 | 1st stage entry burn start |
| 00:06:34 | 1st stage entry burn ends |
| 00:07:24 | 1st stage landing burn start |
| 00:07:31 | 1st stage landing |
| 00:08:33 | 2nd stage engine cutoff (SECO-1) |
| 00:14:35 | Cygnus Deploys |
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