RatSat or DemoSat is an aluminum mass simulator on the fourth flight of the Falcon 1 rocket, launched on 28 September 2008. Ratsat remained bolted to the second stage of the carrier rocket after reaching low Earth orbit. It is an aluminium alloy chamber in hexagonal prism shape with 1.5 m (5 ft) length. The Falcon 1 launch that carried Ratsat to orbit was the first successful orbital launch of any privately funded and developed, liquid-propellant carrier rocket, the SpaceX Falcon 1, something only six nations had successfully accomplished previously. The launch, identified as Falcon 1 Flight 4, was conducted by SpaceX, and also marked the first time the Falcon 1 rocket successfully achieved orbit, after three consecutive failures on the three previous launch attempts.
Background Prior to Ratsat's launch, three consecutive flights of the Falcon 1 rocket had ended in failure. In particular, during the third launch of the Falcon 1 in August 2008, the first stage of the rocket after stage separation exhibited residual thrust and slammed into its second stage, resulting in catastrophic damage to the second stage's Kestrel engine. Though the fix for the problem was simple – add a time delay between main engine cut off and stage separation – SpaceX was running out of money and there was much uncertainty as to whether or not there would be a fourth flight for the company. SpaceX's CEO, Elon Musk, was under immense stress financially and personally, as both of his ventures, SpaceX and Tesla Inc., were at risk of bankruptcy due to a series of failures. Compounding his financial stress was his recent divorce with Justine Musk - the resulting property settlement left him homeless, as well as having lost their first son due to SIDS.
Preparation
Shipping to Omelek Right after the third launch failure, Musk made an encouraging speech for the SpaceX employees and told them to launch another rocket in six weeks. According to Musk, this tight schedule was necessary or else the company would be overrun by operational fundings and at risk being in bankruptcy. The rocket was hastily built out of rocket spare parts in the factory. The fourth launch of the Falcon 1 was supposed to deliver the Malaysian government's RazakSAT satellite, but the Malaysian government has backed out and no other customer was willing to launch on a thrice-failed rocket. Therefore, the SpaceX team had to make a non-functional aluminum boilerplate to simulate the rocket's payload. The boilerplate weighed 165 kg (364 lb) and was named "RatSat" after the last names of Jeff Richichi, Ray Amador and Chris Thompson, who were part of the company's structures team. The design for RatSat's logo was inspired by Ed Roth t-shirts, whom Thompson admired.
Normally, Falcon 1's first stage would have been shipped by container to Omelek Island, Kwajalein Atoll, U.S. (where SpaceX launched the rocket) and Falcon 1's second stage would fly out to the island using the Douglas DC-8 aircraft. The first stage was too big to be flown out using a DC-8. However, the tight schedule mandated the first stage to be shipped over air, so after scrambling with military contacts, a SpaceX employee was able to book a flight on the U.S. Air Force's Boeing C-17 Globemaster III with a price of $500,000. Being much larger than the DC-8, the C-17 can easily fit the rocket's first stage (which its dry mass weighs 1,800 kg (4,000 lb) compared to the C-17 carrying capacity of 77,000 kg or 170,000 lb) and twenty supporting employees.On 3 September, the C-17 landed at the Los Angeles International Airport near SpaceX's headquarters, loaded up, and took off without issues. An intentional small opening in the Falcon 1's oxygen tank fuel pressurization line was made to equalize the rocket's internal pressure with the surroundings. This approach worked well enough for the rocket tanks to slowly release its pressure while the plane was ascending. However, when it was time for the plane to descend to Hawaii and the cabin depressurized, the small opening did not allow air to pass into the rocket tanks fast enough. Thus, the Falcon 1 imploded, right next to the supporting crew. Had SpaceX crews not been onboard the flight, the Falcon 1 would have been ditched into the sea. With only 30 minutes of fuel left and the rocket continuing to crumble, the crew cut the shrink wraps with their knives and set to work fixing the problem. A member of the crew crawled inside the Falcon 1's interstage with a wrench and detached a pressurization line inside, allowing air to pass inside. The crumbling oxygen tank was inflated back to shape, though it had sustained damage to its structure. The C-17 landed at the Hickam Air Force Base, Hawaii at midnight. The next morning, the crew and rocket took off from Hawaii and landed on an airstrip in the Kwajalein Atoll. A barge then carried the first stage of the rocket to Omelek Island.
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