SpaceX looks set for another record for its personal-best books this month, having launched a third Falcon 9 in just two weeks to deliver another batch of Starlink internet communications satellites to low-Earth orbit. Liftoff of the previously-flown B1059 core—making its third foray into space, having previously lofted a pair of Dragon cargo missions to the International Space Station (ISS)—took place at 5:21 a.m. EDT Saturday from storied Space Launch Complex (SLC)-40 at Cape Canaveral Air Force Station, Fla.
With this morning’s successful launch, SpaceX intends two more flights before month’s end: another Starlink batch as soon as 22 June and a long-awaited Global Positioning System (GPS) Block III mission on the 30th. Should these two missions fly on time, it will mark the first time in SpaceX’s history that it will have scored four launches in a single calendar month.
This morning’s pre-sunrise flight was also notable in that B1059 was not put through a Static Fire Test of its nine Merlin 1D+ first-stage engines in the run-up to liftoff, an important indicator of the system’s growing maturity. Previously used in December 2019 and March 2020 to deliver the CRS-19 and CRS-20 Dragon missions to the space station as part of SpaceX’s Commercial Resupply Services contractual obligation to NASA, B1059 is the seventh Falcon 9 core in only 18 months to log a third launch. Elsewhere, the veteran Autonomous Spaceport Drone Ship (ASDS), “Of Course I Still Love”—upon which 27 Falcon 9 cores have now safely landed since April 2016, out of 35 attempts—was in action yet again for this mission. It put to sea early Tuesday and was in the targeted recovery zone, some 390 miles (630 km) downrange of the Cape by Thursday morning.
Today’s mission also boasted reused payload fairing “halves”, as SpaceX continues to push the envelope in its campaign to enhance reusability across the Falcon 9 fleet. Both of the fairing halves had seen prior service: one half on the JCSat-18/Kacific-1 launch in December 2018, the other on the first Starlink mission of 2020. Since 2018, efforts to retrieve the fairings have been made with steerable parachutes and giant “catcher nets” aboard the SpaceX-chartered vessels “Ms. Tree” (previously called “Mr. Steven”) and “Ms. Chief”. Several early attempts to catch the descending fairings achieved “close-but-no-cigar” outcomes, but in June 2019 one fairing half was successfully recovered following the third Falcon Heavy launch. More recent attempts have met with mixed success. One half was captured following the Amos-17 launch last August and another was grabbed after a Starlink flight in January. And only last November, B1048 launched with two reused fairing halves for the first time, flying again after their Falcon Heavy debut.
Weather conditions for the opening launch attempt on Saturday were predicted to be around 70-percent-favorable, deteriorating to 60 percent in the event of a 24-hour scrub and turnaround to Sunday. “A weak frontal boundary is expected to sag into the state from the north late Friday into Saturday, along with a boost in moisture from the tropics,” noted the 45th Weather Squadron at Patrick Air Force Base. “These two features will bring increasing clouds and Atlantic showers starting Friday night.” This was expected to trigger a potential violation of the Cumulus Cloud Rule on Saturday, with an increase in cloud cover on Sunday raising the possibility of more showers and storms.
And for the first time, the 45th Weather team for today’s launch was an all-female affair. Led by Maj. Emily Graves and Capt. Nancy Zimmerman, the team includes duty forecaster Hannah Mulchaey, lead officer Arlena Moses, recon officer Melody Lovin and radar office Jessica Williams.
Although this mission marked the ninth dedicated Starlink launch between May 2019 and last week, it actually carried a slightly lower number of the flat-packed satellites uphill this time around. Rather than the 60 Starlinks that we have seen loaded into the Falcon 9’s payload fairing on each mission so far, Saturday’s flight carried 58 satellites, to make room for three SkySat Earth-observation satellites being lofted on behalf of San Francisco, Calif.-headquartered Planet Labs, Inc. Founded back in December 2010, Planet Labs seeks to develop flexible, inexpensive satellites to perform daily Earth imaging as part of efforts to monitor ongoing change and pinpoint evolving trends.
SkySats are based upon CubeSat technology, albeit upscaled to approximately the size of a mini-fridge. Each unit measures about 31 inches (80 cm) in length, almost three times larger than a standard CubeSat, and weighing in the region of 220 pounds (100 kg). Between November 2013 and December 2018, a total of 15 SkySats have been launched atop a range of boosters, from Russia’s Dnepr and Soyuz-2.1b to India’s Polar Satellite Launch Vehicle (PSLV)-XL and from Europe’s Vega to Northrop Grumman’s Minotaur-C and SpaceX’s Falcon 9. Accordingly, those 15 satellites have begun their journeys to observe the Home Planet from many locations across the Home Planet, from Dombarovsky in western Russia to Baikonur in Kazakhstan, from Kourou in French Guiana to Sharikota in the Andhra Pradesh region of southeastern India and from Vandenberg Air Force Base, Calif., to Cape Canaveral Air Force Station, Fla.
The satellites’ sub-meter-resolution imaging capabilities allow them to observe objects which directly impact the global economy, such as terrain, cars and shipping containers. They can capture video clips lasting up to 90 seconds at 30 frames per second and their high-definition imagery is expected to aid understanding of the movement of goods and people to afford a more “visual” perspective of supply chains, shipping, industrial activity and humanitarian relief efforts. According to Planet Labs, the optical instrumentation of the most recent SkySats has a resolution of less than 28 inches (72 cm).
The first two SkySats, launched in November 2013 and July 2014, were produced in-house by Skybox Imaging, later renamed Terra Bella following its acquisition by Google. The satellites were both equipped with a multispectral, panchromatic and video sensor with a spatial resolution as fine as 2.9 feet (0.9 meters) from their orbital altitude of about 280 miles (450 km). The next 13 SkySats were fabricated by Space Systems/Loral (SS/L)—now part of Westminster, Colo.-based Maxar Technologies—and were much larger than their predecessors, put into Sun-synchronous orbits at an altitude of 310 miles (500 km). When Planet Labs acquired Terra Bella from Google in early 2017, it entered a multi-year contract with the internet services giant to purchase SkySat imaging data.
As recently outlined by Planet Labs, a total of six more SkySats will fly as “rideshare” passengers alongside two Starlink batches, including today’s flight and another mission “in July”. All six will occupy a “mid-inclination” orbit of 53 degrees to directly complement the Sun-synchronous-orbiting fleet, doubling the average revisits over any point on the globe and providing “more targeted coverage and raw image capacity in key geographic regions”.
These six new arrivals will benefit from a rapid revisit capability to capture imagery of singular locations on Earth up to 12 times per day and a global average of seven revisits per day. It is anticipated that rapidly revisiting the same locations on Earth will allow consumers to better fulfil business and mission needs by affording shorter intervals between images to understand and properly characterize human-driven changes or unanticipated events, as well as increasing the chance of getting a cloud-free image or an image of specific shadow angles that could be important for analysis.
Planet Labs added that it worked closely with SpaceX to align its SkySat manifest into their Starlink manifest. “By dovetailing with their launch schedule, we readied the satellites, built a new rocket interface, designed a new commissioning schedule and delivered them for launch, all within six months,” it was noted.
Deployment of the three SkySats occurred at roughly 30-second intervals, beginning 12.5 minutes into Saturday’s mission. The deployment of the 58 Starlinks then got underway at 26 minutes.
This morning’s spectacular launch, just prior to sunrise, marks the tenth SpaceX mission of 2020 and its third in only two weeks. To date this year, the company has launched seven batches of Starlinks—totaling over 400 satellites—as well as the CRS-20 Dragon cargo mission to the ISS, the dramatic in-flight abort test of Crew Dragon in January and the spectacular return of U.S. astronauts to space aboard a U.S. spacecraft, atop a U.S. rocket, and from U.S. soil, for the first time since the end of the shuttle era. Coming up as soon as 22 June, another batch of Starlinks will rise from historic Pad 39A at the Kennedy Space Center (KSC) in Florida, followed by the GPS Block III mission on the 30th.
On only four prior occasions since June 2017 have Falcon 9s flown as many as three times in a single calendar month, most recently last January. If SpaceX can get another Starlink batch and the GPS Block III off the ground before the close of June, it will score a record four launches in one month and five—counting the 30 May flight of Doug Hurley and Bob Behnken aboard Dragon Endeavour—in under five weeks.