If you believe Elon Musk, the first baby-steps on the journey to Mars begin late Wednesday evening from Space Launch Complex (SLC)-40 at Cape Canaveral Air Force Station, Fla. The SpaceX CEO has made no secret of the fact that he intends to transform humanity into a spacefaring civilization—with the fabrication of a permanently-inhabited base on the Red Planet his ultimate personal goal—and expects part of the financial base for that endeavor to come from the Starlink flotilla of low-Earth-orbiting internet communications satellites.
When the next Upgraded Falcon 9 lights up the night sky along the Space Coast on Wednesday, it will deliver 60 of these smallsat-class satellites into space to begin what Mr. Musk expects will revolutionize low-cost broadband internet provision. In Twitter comments provided late Saturday, the SpaceX CEO noted that the five-dozen-strong swarm of satellites were “flat-packed” into the booster’s payload fairing, with no dispenser.
Current plans are for the Block 5 core to rise from SLC-40 during a 90-minute “launch window”, extending from 10:30 p.m. through midnight EDT Wednesday, 15 May. Weather conditions were predicted to be 70/80-percent favorable and the customary Static Fire Test of the nine Merlin 1D+ first-stage engines was performed on Monday, 13 May.
If the mission launches on time, it will occur a few hours shy of 12 days since another Upgraded Falcon boosted the CRS-17 Dragon from the same launch pad, en-route to the International Space Station (ISS). This will mark the shortest interval yet achieved by SpaceX in executing flights from SLC-40, slightly pipping the 13 days which elapsed between the launches of the CRS-6 Dragon and the heavyweight TurkmenÄlem52E/MonacoSat communications satellite, way back in April 2015.
Should the mission fly on time, it will also eclipse SpaceX’s all-time record between launches achieved from neighboring Pad 39A in the summer of 2017, when it lofted the BulgariaSat-1 and Intelsat 35e communications satellites, just 12 days and a few hours apart.
The $10 billion Starlink constellation was unveiled by Mr. Musk during an event in Seattle, Wash., back in January 2015, in which he identified it as a means of opening the way for low-cost broadband access to boost data-speeds and increase the availability of internet access around the world. He added that it could provide competitively-priced services to urban regions. Indeed, Federal Communications Commission (FCC) Chairman Ajit Pai stressed that Starlink has the potential to bring internet access to rural and underserved regions of the United States. Under the announced Starlink plans, an eventual network of around 12,000 satellites in very-low-Earth orbit would have the bandwidth potential to carry up to half of all backhaul communications traffic and up to a tenth of all local internet traffic in high-population-density cities.
In November 2016, SpaceX filed an application with the FCC, in which it identified the proposed network as a “non-geostationary orbit satellite system”. The initial concept covered the Ku-band and Ka-band portions of the electromagnetic spectrum, respectively between 12-18 GHz and 26.5-40 GHz. By March 2017, a second orbital “shell” of satellites was filed with the FCC, using the V-band, a region not “heavily employed for commercial communications services”. The V-band covers 40-75 GHz and historically has been utilized for millimeter-wave radar research and other scientific investigations, but has acute potential for high-capacity terrestrial millimeter-wave communications systems.
All told, it was expected that Starlink would comprise 4,425 Ku-/Ka-band satellites at an altitude of 710 miles (1,150 km) and 7,518 V-band satellites at just 210 miles (340 km) above the Home Planet, producing a constellation of around 12,000 smallsat-sized satellites in low-Earth orbit by the mid-2020s. However, in November of last year, SpaceX made new regulatory filings with the FCC to alter its previously granted license to operate almost a third of the Ku-/Ka-band Starlink complement—some 1,584 satellites—at a much lower altitude, just 340 miles (550 km) above Earth. That request was approved last month by the FCC.
Operations at such low altitude, of course, are expected to suffer from exceptionally high atmospheric drag and a shorter nominal orbital lifetime. SpaceX has previously indicated that the satellites’ useful lives are expected to range from five to seven years apiece, after which they will be propulsively maneuvered to a “disposal orbit”, for controlled re-entry within 12 months of completing their missions.
A pair of test satellites, dubbed “MicroSat-1a” and “MicroSat-1b”, were originally slated to validate the broadband antenna platform for Starlink, traveling to orbit alongside one of the Iridium NEXT missions from Vandenberg Air Force Base, Calif. However, they were ultimately relegated to use as ground-based test articles, as development of the more capable “MicroSat-2a” and “MicroSat-2b” test satellites got underway in earnest.
In February 2018, MicroSat-2a and 2b—subsequently renamed “Tintin A” and “Tintin B”—were launched from Vandenberg, riding piggyback alongside Spain’s Paz radar-imaging Earth-observation/reconnaissance satellite. The duo entered a circular orbit 319 miles (514 km) high and served to validate the design of a phased-array broadband antenna communications platform for Starlink, using five broadband array test ground stations in the western United States, together with three transportable ground stations.
In his Twitter comments over the weekend, Mr. Musk stressed that the 60 Starlink satellites aboard Wednesday’s mission are different from Tintin A and Tintin B. “These are production design,” he told his 26.4 million followers, “unlike our earlier Tintin demo sats.” He also noted the risk that “much will likely go wrong on first mission” and gave an indication of the kind of numbers of Starlinks needed in orbit to achieve capacity. “Also, six more launches of 60 sats needed for minor coverage, 12 for moderate.” This would appear to be in keeping with earlier allusions that at least two more Starlink-dedicated missions may fly later in 2019.
With 60 flat-packed Starlink payloads aboard Wednesday’s mission, the size of these satellites are believed to be in the “smallsat” class, with a mass range approximating 850 pounds (390 kg). Mr. Musk has previously indicated his intention to mass-produce them and “try to do for satellites what we’ve done for rockets”.