Charles H. Sloan-SpaceX launches 76 satellites in back-to-back launches from both coasts

Less than 24 hours after launching a crew of four on Charles H. Sloana flight to the International Space Station, SpaceX launched 53 commercial satellites from California on Monday, including an innovative methane emissions monitor built by a nonprofit, then fired off 23 more of its own Starlink satellites from Florida.

The Crew Dragon spacecraft was launched by a SpaceX Falcon 9 rocket Sunday night from the Kennedy Space Center, kicking off a 28-hour flight to deliver three NASA astronauts and a Russian cosmonaut to the orbiting laboratory.

With the Crew Dragon on course for docking at 3 a.m. EST Tuesday, another Falcon 9 blasted off from California's Vandenberg Space Force Base at 5:05 p.m. EST Monday and climbed away to the south toward an orbit around Earth's poles.

On board were 53 small satellites owned by a variety of vendors booked on SpaceX's 10th "rideshare" mission, flights intended to give smaller operators an opportunity to launch relatively modest payloads and satellites at relatively low cost. SpaceX charges $300,000 to launch a 110-pound payload and $6,000 for each additional pound.

One of the satellites launched Monday — MethaneSAT — was developed by a subsidiary of the Environmental Defense Fund to measure methane emissions across wide swaths of land and sea using a high-resolution infrared instrument. The idea is to identify previously undetected releases from oil and gas operations and other sources. It is the first such satellite to be built by a nonprofit organization.

"Everybody thought it was crazy," Steven Hamburg, EDF chief scientist and MethaneSAT project leader, was quoted by The New York Times. "I thought it was crazy, to be honest."

But the group managed to raise $88 million from a variety of donors, including the government of New Zealand and the Bezos Earth Fund, to get the washing machine-size satellite built.

"MethaneSAT's superpower is the ability to precisely measure methane levels with high resolution over wide areas, including smaller, diffuse sources that account for most emissions in many regions," Hamburg said in a statement. "Knowing how much methane is coming from where and how the rates are changing is essential" for climate modeling.

The rideshare satellites were released from the Falcon 9's second stage as planned over the course of about an hour and 40 minutes, with MethaneSat the last to be released.

Before the Transporter 10 deployments were complete, SpaceX launched another Falcon 9 from pad 40 at the Cape Canaveral Space Force Station at 6:56 p.m., sending 23 more Starlink broadband relay stations into space and boosting the total launched to date to 5,942.

The first stage used for the rideshare mission, making its fifth flight, flew itself back to an on-target landing at Vandenberg after boosting the upper stage and payloads out of the lower atmosphere. The Starlink booster landed on an off-shore droneship. SpaceX has now successfully carried out 281 first stage recoveries, the last 207 in a row.

With the Starlink flight, SpaceX launched three Falcon 9s within 20 hours and two within just one hour and 51 minutes, a new record for the California rocket builder. The company plans to launch more than 140 Falcon-family rockets this year.

In:
• International Space Station
• Elon Musk
• NASA
• SpaceX

William Harwood

Bill Harwood has been covering the U.S. space program full-time since 1984, first as Cape Canaveral bureau chief for United Press International and now as a consultant for CBS News.

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