Update: 12 PM EDT Saturday

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.

Due to unfavorable weather, we are standing down from today's launch of @northropgrumman's NG-21 mission. Next launch opportunity is Sunday, August 4 → https://t.co/bsNx0Xb6I3

— SpaceX (@SpaceX) August 3, 2024

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.

—————-

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.

At A Glance

• Mission: Northrup Grumman NG-21
• Date: NET August 3, 2024
• Launch Window: 11:28AM EDT (1528 Zulu)
• Weather: 50% GO at launch time
• Organization: SpaceX
• Rocket: Falcon 9
• Trajectory: Northeastward
• Launch Site: SLC-40, Cape Canaveral Space Force Station
• Booster Landing: Landing Zone 1, CCSFS
• Payload: Cygnus CRS-2 NG-21 (S.S. Francis R. “Dick” Scobee)
• Destination: International Space Station

Payload

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:

• Test articles to evaluate liquid and gas flow through porous media found in space station life support systems.
• A balloon, penny, and hexnut for a new STEMonstration on centripetal force.
• Microorganisms known as Rotifers to examine the effects of spaceflight on DNA repair mechanisms.
• A bioreactor to demonstrate the production of many high-quality blood and immune stem cells.
• Vascularized liver tissue to analyze the development of blood vessels in engineered tissue flown to the space station.

Weather

General Forecast

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

Official Launch Forecast

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.

Trajectory

Northeastwards.

Landing

The booster used for this mission, B1080, will land at Landing Zone 1 at Cape Canaveral Space Force Station.

Online Viewing

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.

Launch Viewing: In Person

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.

Indirect Views

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.

• Jetty Park, Port Canaveral
  • Fee required, much be purchased in advance: Port Canaveral Store
  • It’s very possible to see a cruise ship coming or going.
  • The pier especially has great views of the landing — probably the best that the public can get to. The launch view is indirect.
• Cocoa Beach
  • Parking fees (probably). Pay with your smartphone on the parking app. There are signs everywhere telling you how.
  • Further away, but still good views. Launch and landing is indirect.
• Northern Titusville Parks
  • Further away, but really nice views after liftoff.
  • You won’t see the landing directly, but instead from a good distance away.

Playalinda Beach

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.

• Get there at least two hours early, or better, earlier than that. Lines are long at the entry gate and they will only allow as many spectator vehicles as there are parking space available.
• Cape Canaveral National Seashore has a fee to get in and cash is not accepted. Debit and credit cards are okay, or if you have one of the National Park Service’s passes for the Seashore or the National Parks, that will work as well.
• Cellphone service is spotty at best and often non-existent at Playalinda. Don’t count on your cellphone to keep up with the launch; you might get a signal, or you might not.
• You are not allowed to view from the pullouts on Beach Road. Stanchions will block them. You’ll have to park and go to the beach.
• Refreshments are not available. There are no stores at Cape Canaveral National Seashore, so you’ll need to bring drinks and food if you want any while you’re there.
• Rangers will keep you back a certain distance from the launch area on the beach. Even if the beach is open, you’ll still be unable to go down to the fence that demarcates the normal security zone. There’s a line that spectators can’t go past somewhat north of the fence. That’s for safety and security.

Be prepared for potential changes or pushbacks in the launch schedule, and keep up by monitoring the live stream links mentioned above.

Booster: B0180

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

Countdown Timeline

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

Launch, Landing and Deployment

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