Crawler-Transporter 2
NASA's tracked vehicle that carries the Mobile Launcher and SLS between KSC facilities.
Last refreshed: 17 April 2026 · Appears in 1 active topic
What machine moves NASA's Moon rocket and how slowly does it travel?
Timeline for crawler-transporter 2
Carried Mobile Launcher 1 from Pad 39B toward VAB
Artemis II Moon Mission: Five open Orion items, no fix datesMentioned in: Launcher rolls back from Pad 39B
Artemis II Moon Mission- How does NASA move the Space Launch System to the launch pad?
- crawler-transporter 2 carries the fully assembled SLS and Mobile Launcher from the Vehicle Assembly Building to the launch pad at about one mile per hour.Source: briefing
- How old is NASA's crawler transporter?
- crawler-transporter 2 was built in 1966 for the Apollo programme and has been upgraded multiple times for Shuttle and SLS operations.Source: briefing
Background
crawler-transporter 2 carried Mobile Launcher 1 from Launch Pad 39B to the Vehicle Assembly Building beginning 08:11 EDT on 16 April 2026. The transit covers four miles at a maximum speed of roughly one mile per hour. Operations paused Thursday evening for crew rest and resumed 17 April.
crawler-transporter 2 is one of two giant tracked vehicles built for Apollo and operated since 1966. It weighs approximately 2,721 tonnes empty and moves on four double-tracked crawlers. Originally used to carry Saturn V rockets to the pad, it has been upgraded multiple times for Shuttle and SLS. It must carry ML-1 to the VAB, wait for Artemis III stacking, then carry the assembled vehicle back to the pad.
With a single functional crawler required to operate, the crawler's availability is a scheduling constraint on NASA's launch cadence. Any unplanned crawler maintenance during the VAB stay could delay Artemis III rollout and push the 2027 launch target.
