And he's pretty confident about hitting that mark. In an interview with Top Gear, Dr. Caplin said that he's comfortable with reaching that target. He had 2,000 feet (0.6 km) before the flag at 286.1 mph, which was the absolute top speed of his Tuatara in the record-breaking attempt. He believes that there's a fair bit more to come. The question now is when and where.
To put things in perspective, the Tuatara's second official run took place at the Johnny Bohmer Proving Grounds at Space Florida's Shuttle Landing Facility. It only had 2.3 mi (3.7 km) of runway to use, with the Tuatara using 1.9 mi (3 km) to reach the absolute top speed.