The first satellite in a nearly $ 1 billion program that provides the German military with enhanced radar surveillance images from space will be launched into polar orbit on Saturday off the central coast of California with a SpaceX Falcon 9 launch vehicle.
The synthetic aperture radar image satellite, called SARah 1, is tucked into the nose cone of the 229-foot (70-meter) high Falcon 9 rocket to take off at 7:19 a.m. PDT (10:19 EDT; 14:19 GMT) Saturday from base of the Vandenberg Space Force in California, located on the Pacific coast between Los Angeles and San Francisco.
SARAh 1 is the first of three radar imaging satellites commissioned by the German government from the industry in 2013. The Bremen-based OHB is a leading contractor in the SARah program and is building the second and third satellites in the series. Airbus teams in southern Germany have produced the first and largest satellite in the program, called SARAh 1, which is expected to launch on Saturday from California.
When the development contracts were signed in 2013, SARAh satellites were scheduled to be launched in 2018 and 2019. But satellite-related technical problems, efforts to improve spacecraft encryption and delays caused by the COVID-19 pandemic repelled the first Launch of the SARAh spacecraft by 2022
SpaceX will deliver the SARAh 1 satellite into orbit a few hundred miles above Earth, where it will begin a 10-year mission to provide reconnaissance images of the Bundeswehr, the German army.
The Falcon 9 rocket will ascend from Space Launch Complex 4-East in Vandenberg, powered by nine kerosene-powered Merlin 1D engines, generating more than 1.7 million pounds of thrust. The engines will steer the rocket down south over the Pacific Ocean before the first and second stages of the Falcon 9 split more than two minutes after the mission.
The boost phase will pulsate the cold throttle pushers to turn first and fly in a queue, then restart three of its reverse combustion boost engines to reverse the course and begin the journey back to Vandenberg. The backward maneuver will take place while the first stage of the Falcon 9 flies to the edge of space at an altitude of about 350,000 feet or more than 100 kilometers.
The return maneuvers will culminate in the propulsive landing of the acceleration phase in landing zone 4, just a quarter of a mile west of the Falcon 9 launch site in Vandenberg. The landing is expected about eight minutes after takeoff to complete the third space flight for this accelerator, packing number B1071.
The flight plan for the upper stage of the Falcon 9 after the launch of the rocket’s payload remains a mystery. SpaceX did not list any additional flight events from the second phase or the time of deployment of the spacecraft in the online schedule of the mission.
The second stage will probably be triggered twice to inject the SARAh 1 satellite into the correct separation orbit.
The SARAh 1 satellite weighs about four tons, according to its manufacturer Airbus. The contractor said in a statement that the SARAh 1 satellite carries “the latest high-resolution radar technology” to collect images in all weather conditions, day and night, at sites around the world for the German military.
The German Defense Public Procurement Agency manages the development of the SARAh satellites. The Airbus-built ship, which launches on Saturday, carries an active phased array radar antenna based on technology developed for civilian surveillance satellites TerraSAR, TanDEM-X and Paz.
“This technology offers the benefits of very fast targeting and very flexible beamforming to deliver images in record time,” Airbus said in a statement.
Two smaller SARAh spacecraft, built by OHB, will fly with passive synthetic aperture radar reflectors. The German military says the second and third SARAh satellites will fly the Falcon 9 rocket later this year.
Radar imaging satellites have the advantage of resolving the earth’s surface through darkness and cloud cover, which prevents optical spy satellites from always seeing the earth.
The three SARah satellites replace the SAR-Lupe constellation of five German Army spacecraft, which launched from 2006 to 2008.
“Today, without satellites, intelligence, communication and navigation are almost impossible,” the German army said in a press release earlier this month.
“The new SARAh satellites ensure that the Bundeswehr has global intelligence capabilities, regardless of the time of day or the weather,” said the German military. “At the same time, they provide support for early detection and crisis management.”
The launch on Saturday from California is the second of three Falcon 9 missions planned for about 36 hours.
The Falcon 9 rocket took off on Friday at 12:09 PM EDT (1609 GMT) from the Kennedy Space Center in Florida with 53 other Starlink satellites. Following the SARah 1 mission, the SpaceX launch team in Florida will return to action for another Falcon 9 launch from Cape Canaveral Space Station at 12:27 PM EDT (04:27 GMT) on Sunday, carrying a backup commercial communications satellite and transmit Globalstar data into orbit.
The launches mark SpaceX’s 24th, 25th and 26th missions of the year. Saturday’s flight from California will be the 159th launch of the Falcon 9 rocket as a whole and the 24th from Vandenberg.
The weather forecast looks favorable for the start on Saturday, with a 90% chance of good weather in Vandenberg. The only slight concern about the weather is the earth’s winds.
At the start, forecasters predict scattered fog and fog, a deck of scattered layered clouds from 1,100 feet to 1,300 feet above sea level, with launch site temperatures as low as 50 degrees Fahrenheit. There is a 100% chance of an acceptable start time on the spare day on Sunday.
Follow Stephen Clark on Twitter: @ StephenClark1.