Launch Delays: Why Satellite Launches Slip and How to Plan for Them

Launch dates move. Every satellite operator learns this sooner or later, and the best way to deal with it is to plan for it from the start. This guide explains the main reasons why launches and returns slip, shows real examples from NASA missions, explains what delays cost under typical contract terms, and gives practical steps to protect your schedule.

What "no earlier than" means

Launch dates are usually announced as "no earlier than", often shortened to NET. It is the earliest possible date, not a promise. NASA used exactly this wording in October 2026 for the return of Crew-12 from the International Space Station: undocking was targeted for "no earlier than" 7 October, and the exact splashdown time could still adjust depending on the return location selected.

The main reasons launches slip

1. Weather

Weather is the most visible cause. Two NASA examples:

On 27 May 2020, the first crewed launch of Crew Dragon, the Demo-2 mission, was scrubbed due to weather and moved to 30 May.
On 31 July 2025, the Crew-11 launch was scrubbed due to weather and moved to the next day, 1 August. The cover image shows the rocket on the pad after that scrub.

Weather does not only affect launches. For returns, conditions in the landing or splashdown area matter as well. When NASA and SpaceX planned Crew-12's return, they monitored weather off the California coast. On 2 October, NASA said Crew-12 could begin its trip home as early as Monday, 5 October. On 3 October, after reviewing weather and splashdown conditions, the target moved to no earlier than 7 October. By 5 October, the planned undocking time had changed again, from 1:05 a.m. to 8:05 a.m. EDT on 7 October. NASA named spacecraft readiness, recovery team readiness, weather, sea states and other factors as conditions for undocking.

2. Launch vehicle and spacecraft readiness

Technical issues on the rocket, the ground systems or the spacecraft can stop a countdown or push a launch by days or weeks. NASA's wording for Crew-12 lists spacecraft readiness first among the conditions for departure.

3. Your own satellite is late

For small satellite operators, the most common delay is on their own side: testing takes longer, a component arrives late or a problem appears in thermal vacuum. On a rideshare, the rocket will not wait. SpaceX's rideshare terms show how this is handled: if a payload is delayed, 100% of the money paid can be applied toward rebooking on a future mission, subject to a 5 to 10% rebooking fee.

4. The primary mission or the rideshare schedule

NASA's Small Spacecraft Technology report explains that on rideshares with a primary spacecraft, the primary mission determines the requirements, including orbit and schedule. If the primary payload slips, every secondary payload slips with it.

5. Missed integration deadlines

Launch integration is a chain of deadlines. In SpaceX's typical rideshare schedule, mission analysis inputs are due around eight months before launch, range safety submissions start around six months before launch, and the launch campaign readiness review takes place about two months before launch. Missing one of them can cost you the slot.

6. Licenses and export approvals

NASA notes that launch providers require proof of licensing before integration. SpaceX's guide adds that if a required export license cannot be obtained within a reasonable time, SpaceX may rebook the customer with rebooking fees or terminate the agreement and refund all amounts paid without interest. See export control for satellites and spectrum licensing.

7. Range and traffic constraints

Range safety approvals are required for every launch campaign. Hazardous operations at the launch site, for example, require 72 hours' advance notice to the range safety authorities in SpaceX's process. See range safety and launch licensing.

What delays cost

Rebooking fees: for SpaceX rideshare, 5 to 10% of the money paid. On a $350,000 base slot, that is $17,500 to $35,000.
Team costs: engineers and launch campaign staff who wait on site or must travel again.
Storage and environment: SpaceX's guide limits how long payloads stay in each processing phase, for example up to 45 days in processing and up to 40 days encapsulated in the hangar.
Business impact: a later start of service, delayed revenue, and in some cases penalties toward your own customers.
Battery and consumables: SpaceX requires payloads that use pad charging to stay disconnected for at least 72 hours, so long holds need to be part of your power planning.

How to plan for delays

Build buffers backward from delivery. SpaceX receives rideshare payloads about 30 days before launch. Add buffers for testing, shipping and customs before that date.
Start licenses first. Spectrum, national licenses and export approvals are often the longest lead items.
Read the delay clauses. Check rebooking fees, refund rules and what happens if the provider delays. See launch service agreement explained.
Keep alternatives. Know which other missions or providers could take your satellite if you miss a slot. Our rideshare booking guide explains the options.
Design for waiting. Make sure your satellite can stay safely powered down and stored within the provider's environmental limits for longer than planned.
Communicate early. SpaceX asks customers for an updated processing schedule every working day during the launch campaign. The earlier a problem is flagged, the more options remain.

Frequently asked questions

Why do rocket launches get delayed?

Mainly because of weather, technical readiness of the rocket, spacecraft or ground systems, late payloads, schedule changes of the primary mission, and missing licenses or approvals.

What does NET mean in spaceflight?

No earlier than. It marks the earliest possible date, which can still move.

What happens if my satellite misses its rideshare?

It depends on the contract. SpaceX lets customers apply all payments to a future mission, subject to a 5 to 10% rebooking fee.

Can a launch be delayed by the primary payload?

Yes. NASA notes that on rideshares with a primary spacecraft, the primary mission determines the schedule.

Do returns from space get delayed too?

Yes. Crew-12's return from the ISS moved from as early as 5 October to no earlier than 7 October 2026 because of weather and splashdown conditions.

Sources

Cover image: Falcon 9 with Dragon on the pad at Launch Complex 39A after the Crew-11 launch attempt was scrubbed due to weather, 31 July 2025. Credit: NASA/Joel Kowsky (NHQ202507310025), public domain.