A world team of watchful observers caught the camera of an American robotic space plane X-37 B, which carried out its fourth mission on Earth.
Unmanned X-37 B was launched on May 20 at the top of the United Launch Alliance Atlas V rocket from Cape Canaveral in Florida. Detailed information about the mission, known as Orbital Test Vehicle-4, or OTV-4, is classified, but new satellite observations shed light on the activities of the spacecraft.
“This rocket is lower than normal, so it confused us first, because I thought it would be a standard orbit,” said tracker Greg Roberts, who lives in South Africa, Space.com. “The slope is also lower than it was before.”
Roberts captured photographs of a space plane with two second long exposures through what he calls “damn phone lines and power lines.”
X-37 B was designed and developed by Boeing Network & Space Systems, a division that also creates and distributes satellites used for weather forecasting, navigation services, communications and reconnaissance. The robotic car looks like a mini version of the NASA space shuttle, which is now retired. The Air Force has two spacecraft X-37 B, which together flew three missions before launch on May 20. OTV-1 was launched in April 2010 and landed in December, after 224 days in orbit. OTV-2 was launched in March 2011 and landed in June 2012, after 468 days in orbit. OTV-3 landed in October 2014, after spending 675 days in space.
All of these X-37 B missions have intrigued amateur astronomers: Roberts and Ted Molkan from Toronto, who are eager to see exactly where a space plane is flying.
Molktsan heads a group of amateurs who like to watch satellites. Together with Roberts, he organized a team of amateur astronomers scattered around the world, whose work revealed the X-37 B at the very opening of the visibility window, immediately after the launch of the OTV-4.
“Launch tracking is highly dependent on the organization of the analysis of the orbit. A single observer can be clouded by clouds for several days, ”Molktsan told Space.com. This may push the discovery forward a few days.
For example, Molktsan said that the slope of the OTV-4 by 38 degrees is the lowest of the programs X-37 B. The previous slope of the OTV-1 is 40 degrees. The OTV-4 also has the lowest initial altitude — 198 miles (318 kilometers) —when the X-37 B was launched. The previous low OTV-2 was 205 miles (330 km). “The only thing that OTV-4 has in common with its predecessors is that the track of the earth repeats every 31 turns, which takes two days,” says Molktsan.
“In previous missions of OTV, the interval between repetitions of earth tracks varied from two to six days,” says Molktsan. “Thus, we will not be surprised when we see that the OTV-4 behaves in the same way.
“Such changes are easy to carry out by maneuvering a vehicle in order to slightly correct the orbital period,” added Molktsan.
The Air Force did not report how long the OTV-4 will be in the air. When the ship goes down, it can land on the program X-37 B, which has not yet been used: at the NASA Kennedy Space Center in Florida. Those previous missions landed on the Vandenberg Air Force Bas in California.