The Star Wars stage was completed in early May. It was too small to house the Rebel hangar and Dagobah sets, and an extension had to be funded and built. The producers mandated filming begin on the stage on May 18, regardless of its state. The hangar scene involved 77 rebel extras, which cost £2,000 per day. Around of dendritic salt, mixed with magnesium sulfate for a sparkle effect, were used for the snowy sets; this combination of substances gave the cast and crew headaches. Second unit director John Barry died suddenly in early June; Harley Cokeliss replaced him a week later. The typical purpose of the second unit was to do time-consuming filming for special effects shots, but they were now filming main scenes—including Luke's ice cave imprisonment—because the schedule had overrun by around 26 days. Hamill was unavailable for several days after injuring his hand during a stunt jump from a speeder bike. Having been called in for the stunt the same day his son was born, aggravated by the salt-laden setting, and exhausted, he angrily chastised Kurtz for not using a double for the scene. Kershner's hands-on directing style, which included him acting out how he wanted a scene performed, agitated Hamill; Kershner, for his part, was frustrated that Hamill was not following his advice.
The Star Wars stage was completed in early May. It was too small to house the Rebel hangar and Dagobah sets, and an extension had to be funded and built. The producers mandated filming begin on the stage on May 18, regardless of its state. The hangar scene involved 77 rebel extras, which cost £2,000 per day. Around of dendritic salt, mixed with magnesium sulfate for a sparkle effect, were used for the snowy sets; this combination of substances gave the cast and crew headaches. Second unit director John Barry died suddenly in early June; Harley Cokeliss replaced him a week later. The typical purpose of the second unit was to do time-consuming filming for special effects shots, but they were now filming main scenes—including Luke's ice cave imprisonment—because the schedule had overrun by around 26 days. Hamill was unavailable for several days after injuring his hand during a stunt jump from a speeder bike. Having been called in for the stunt the same day his son was born, aggravated by the salt-laden setting, and exhausted, he angrily chastised Kurtz for not using a double for the scene. Kershner's hands-on directing style, which included him acting out how he wanted a scene performed, agitated Hamill; Kershner, for his part, was frustrated that Hamill was not following his advice.