X-37B  Space Plane 
                                                        Orbital Test Vehicle (OTV)


The Orbital Test Vehicle (OTV), better known as X-37B space plane can be seen as a very small unmanned military version of the Space Shuttle. Although not all functions of the OTV are known, it is generally accepted that the vehicle is in use as a test spacecraft to try out different new space technology. The first X-37B (OTV-1) was launched in 2010. The X-37B is most of the times set in an orbital inclination that is too low too see high passes over my observing location in The Netherlands. The OTV-5, launched on September 7, 2017 on a Falcon-9 rocket, was an exception with an inclined orbit of 54,5 degrees. Capturing details of this space plane is a challenge due to the small size of the spacecraft. With dimensions of 8,8 x 2,9 meters, the size of the X-37B is comparable to that of a Cessna sports plane. Imagine observing a Cessna from a range of 300-400 km!


Telescopic Observations of the X-37B

OTV-5 June 29, 2019   First Test Images

In May 2019, during routine satellite list checks, I found that the OTV-5 was passing high over the location. A First attempt to capture the spacecraft in May failed. Next series of passes would occur a month later in June 2019 but the OTV was not observed at the predicted time of the pass. Several attempts to observe the spacecraft failed and it was waiting on updated pass data. With data up-to-date, the OTV-5 was finally found again at the predicted time nearing the end of the month. Later, it turned out that the cause of the outdated data was that the OTV-5 had changed orbital height. A first telescopic capture finally succeeded on June 29, 2019. These images were taken from a range of 373 km while the spacecraft was orbiting 339 km above the ground. These first test images showed clearly some bigger details of this mini shuttle.

                                                 Below: First telescopic (longer range) test image of the OTV-5 on June 29, 2019, quickly processed at the telescope   

                                                                       Raw video of the June 29, 2019 pass of the OTV-5 military space plane

OTV-5 July 2, 2019   Favorable Pass

More detailed images were obtained in early July 2019. A higher, almost overhead pass in July 2 resulted in a shorter range of 340 km which enabled to capture smaller detail. The following image taken with a fully manually tracked 10 inch telescope was the result of the July 2, 2019 observations, an image that was finally published world wide. A raw image was added with the processed image. We recognize details as nose, tail and the open payload bay doors and possibly some smaller details of the OTV.