By Leonard David and Space.com
The U.S. Air Force's secretive X-37B space plane apparently boosted itself into a new orbit Aug. 9, according to reports from seasoned satellite trackers around the world, SPACE.com has learned.
The rest of the copyrighted story is available at
http://www.space.com/spacewatch/x-37b-space-plane-new-orbit-skywatchers-100823.html
Our original story on this spacecraft appeared on this blog on April 11, 2010 at the link http://mt-milcom.blogspot.com/2010/04/new-unmanned-spacecraft-set-to-launch.html
Little is known about the classified duties of the X-37B. However, Air Force officials did make it clear in pre-launch statements that the craft's first mission would focus on proving technologies necessary for long-duration reusable space vehicles with autonomous re-entry and landing capabilities. According to the Pentagon, a second X-37B is under construction.
Built by Boeing's Phantom Works division, the X-37B space plane is just over 29 feet (9 meters) long and weighs about 11,000 pounds (5,000 kg). It stands slightly more than 9.5 feet (3 meters) high and has a wingspan of just over 14 feet (4.3 meters).
The spacecraft's new mission is overseen by the Air Force Rapid Capabilities Office. The X-37B is believed to be operated by contractors under the direction of Air Force Space Command's 3rd Space Experimentation Squadron at Schriever Air Force Base.
The X-37B is designed to orbit Earth at altitudes of up to 500 nautical miles, loiter in orbit for up to 270 days, then re-enter the atmosphere to make an automated landing at Vandenberg.
"After the test objectives are satisfied, we look forward to a successful re-entry and recovery at Vandenberg Air Force Base, California, and post-landing refurbishment of the vehicle," said Air Force spokesman Andy Roake. "No landing date has been scheduled."
And then we have this from the dean of the SEESAT-L observers and list owner, Ted Molczan, who provides some technical details of the obital shift by the winged DoD spacecraft.
"Leonard David has nicely documented X-37B OTV-1's orbit-raising of Aug 9, including the involvement of several SeeSat-L members in the subsequent tracking and orbit analysis:
"One of the findings reported in the article is the apparent timing of the two orbit-raising manoeuvres to enable nearly continuous monitoring by several Air Force Satellite Control Network (AFSCN) tracking stations. Since that fact may be useful in understanding future manoeuvres, I want to provide some technical details that are not appropriate for a news article, but well-suited to this forum.
"Propagating the new orbit backward to the time of its closest separation from the original orbit, revealed the mid-point between the manoeuvres, which were performed on opposite sides of the Earth, near a perigee and an apogee.
"The first manoeuvre occurred on Aug 09, about 17:12 UTC, near 40 S, 98 E. The spacecraft was near the apogee of its original 403 X 420 km orbit, and manoeuvred to raise its perigee by 42 km, resulting in a 420 X 445 km orbit. Since the new perigee was greater than the original apogee, the line of apsides was effectively rotated 180 deg.
"About 16 minutes later, the spacecraft came within range of the Air Force Satellite Control Network (AFSCN) tracking station at Hawaii, the first of five AFSCN stations in a position to monitor it throughout the remainder of the manoeuvre sequence.
"The final manoeuvre occurred half an orbit after the first one, near the new apogee, at about 17:58 UTC, near 40 N, 100 W. The perigee was raised 12 km, resulting in a 432 x 445 km orbit. This was just before LOS by the AFSCN station at VAFB, and well above the horizon of the Colorado AFSCN station. Depending on the duration of the burn, the New Hampshire station may also have been able to monitor it directly; it certainly would have been able to monitor the results.
"Below are the estimated AOS/LOS times of the AFSCN tracking stations that OTV-1 passed during the manoeuvre sequence:
AOS LOS
17:38:28 - 17:48:29 AFSCN Hawaii Tracking Station, Kaena Point, Oahu, Hawaii
17:40:14 - 17:49:36 AFSCN Guam Tracking Station, Andersen AFB, Guam
17:47:42 - 17:58:13 AFSCN Vandenberg Tracking Station, Vandenberg AFB, California
17:51:24 - 18:01:56 AFSCN Colorado Tracking Station, Schriever AFB, Colorado
17:58:15 - 18:08:31 AFSCN New Hampshire Tracking Station, New Boston Air Station, New Hampshire
"AOS and LOS correspond to estimated time of rise/set, 2 deg above the horizon; actual AOS/LOS depend on local terrain, not considered in this analysis.
"Below are elsets documenting the manoeuvre. The pre-manoeuvre elset is derived from our last observations of the original orbit, on July 29. The two manoeuvre elsets are accurate estimates; their epochs correspond to the manoeuvre times."
Pre-manoeuvre orbit 403 X 420 km
1 36514U 10015A 10210.09309780 .00000000 00000-0 00000-0 0 09
2 36514 39.9851 119.3456 0012533 356.3806 3.6913 15.52766118 04
First manoeuvre 420 X 445 km
1 36514U 10015A 10221.71696759 .00000000 00000-0 00000-0 0 05
2 36514 39.9851 47.8421 0018773 266.6117 0.6500 15.45484000 09
Final manoeuvre 432 X 445 km
1 36514U 10015A 10221.74841435 .00000000 00000-0 00000-0 0 01
2 36514 39.9851 47.6508 0009598 266.8531 175.6000 15.43360000 09
