A $5 nut doomed SpaceX’s first rocket; its satellite crashed through a shed roof and landed beside its own shipping crate

SpaceX’s first attempt to launch was ended by a $5 aluminium nut. On 24 March 2006, the Falcon 1 rocket launched from a seven-acre island in the Pacific, leaked fuel from a cracked fitting and dropped back into the sea within about half a minute. The on-board satellite, FalconSat-2, designed by cadets from the US Air Force Academy, also failed to reach orbit. The satellite never reached orbit either. Instead, it fell through the roof of an empty storage shed and landed beside the shipping crate it had arrived in.

An island with a very small crew

Omelek, part of the Kwajalein Atoll in the Marshall Islands, about 2,500 miles southwest of Hawaii, was leased by the US Army as part of its Reagan Test Site, and was the launch site. Spaceflight Now reported in June 2005 that SpaceX had only one full time employee on Omelek. There were fewer than 25 people, managers, engineers and technicians included, supporting a Falcon 1 launch there by 2008. The rocket parts came in on a cargo freighter.


SpaceX had moved its debut to Kwajalein after the Air Force said its original pad at Vandenberg Air Force Base in California interfered with Atlas V operations nearby. The island offered open ocean in nearly every direction and paths to both polar and equatorial orbits. The rocket itself was a 70-foot, two-stage design burning kerosene and liquid oxygen, bankrolled by Elon Musk, who had co-founded PayPal.

Blaming the technician? Not so fast

Within days of the failure, SpaceX founder Elon Musk said human error was probably to blame, Brian Berger of SpaceNews reported in a story published on Space.com on 19 July 2006. SpaceX had suspected a fitting left loose by technicians who worked on the rocket the day before launch.

Then, on 18 July, DARPA, the sponsor of the flight, announced that a review board had found otherwise. The board, which included SpaceX personnel, said an aluminium B-nut on the fuel pump inlet pressure transducer had failed through corrosion cracking beneath the surface, where no one could see it. Fuel leaked onto the engine and caught fire. DARPA’s release put the end of engine thrust at 34 seconds after ignition; NBC News reported 34 seconds after liftoff.

Musk said it was “a stroke of unbelievably bad luck”: the nut broke in the 18 hours before launch. He said an inspection the day before had found it intact, Berger reported, and recovered parts showed its lock wire still attached, a sign technicians had tightened it. In a phone interview on 21 July with Braddock Gaskill of NASASpaceflight.com, Musk said telemetry showed the leak began 400 seconds before liftoff, and that a static fire a few days earlier had shown none.

Why the nut cracked was less clear. Berger reported that investigators’ leading thinking, as Musk described it, was that heat and humidity on Omelek played a part: the anodised nut may have been scratched, the rocket had stood exposed through several countdowns, and the vehicle hangar had not been climate-controlled for about three months. Musk told Gaskill the board’s finding was unanimous but called corrosion cracking the “most probable” cause, not a definitive one.

The satellite that came through a roof

The rocket crashed onto a reef less than a kilometre from the launch facility. On impact, the payload, FalconSAT-2, was thrown skyward and came down through the roof of an unoccupied storage shed, where it came to rest beside the shipping container it had travelled in, Space.com reported.

FalconSAT-2 carried an instrument designed to measure plasma in the upper atmosphere, where ionised gas can interfere with communications and GPS signals. Back in Colorado, cadets had watched the launch on a webcast. According to an Air Force Academy release, they were at first elated, then disappointed once they learned the rocket and satellite were lost. The Air Force Academy was already developing FalconSAT-3, the next project in its student satellite programme.

A cause that stayed “probable”

For a failure traced to a single part, the explanation came with caveats. Musk told NASASpaceflight.com that the board’s finding was unanimous but described stress corrosion cracking as the “most probable” cause, not a definitive one. He said SpaceX had never seen an aluminium nut crack that way in the company’s history, and that anything showing obvious corrosion had been replaced before launch. Space.com noted that why the nut cracked was still “a bit of a mystery”.

The fix, Musk said, was to replace the $5 aluminium nuts with stainless-steel ones that were cheaper still. SpaceX had planned another Falcon 1 launch for November 2006, but the schedule slipped. The second flight failed in March 2007, and a third attempt failed in August 2008. On 28 September 2008, Falcon 1 finally reached orbit on its fourth attempt.

Its first flight is remembered for a part that cost $5, and for a satellite that fell through a roof and landed beside the box it came in.