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Rocket ride-shares could make going to space like catching a bus

October 9, 2019 | MIT Technology Review

Rocket launches that leave on a regular schedule will make it much cheaper and easier to get small satellites into orbit.

Think about how you normally take a bus out of town. The schedule tells you when the next one leaves. You buy a ticket that gets you on board. The bus goes once it’s time to depart, whether it’s sold out or nearly empty. It then heads out on a route, dropping off passengers along the way.

Welcome to the future of space launches. The “ride-share” model of trips into orbit, in which firms buy a spot on rockets that launch on a regular schedule, is going to shake up the industry. Already, SpaceX has scheduled a ride-share mission into orbit next March and plans to run these types of missions once a month. Arianespace, the multinational spaceflight firm, plans to hold a ride-share mission to low Earth orbit in May and head to geostationary orbit (GEO) in 2022. Companies like Rocket Lab and Spaceflight are also planning ride-share schemes. “They’re the key to moving the satellite industry forward,” says Asal Naseri, the head of small satellite technologies at the Space Dynamics Laboratory in Logan, Utah.

Ride-share launches aren’t a completely new concept. NASA has been launching its version for nearly 30 years now, beginning with the space shuttle. But a ride-share flight has typically meant just the addition of minor payloads to bigger missions whose launch costs were already paid for. Until fairly recently, these “piggyback payloads” were also uncommon.

But as the space industry has pushed to maximize bang for buck, secondary payloads have become the norm. Meanwhile, the proliferation of small satellite firms has encouraged launch providers to start considering the economics of sending multiple small payloads on a single mission, with several customers covering the launch cost between them.

For satellite companies, this model offers advantages over hitching a ride as a secondary payload. “Satellite providers like to go on the ride-shares because they get better service,” says Charles Swenson, a spaceflight engineer at Utah State University. They can have their satellites deployed at specific orbital “stops” along the mission route, they’re more involved with shaping mission strategies, and they have an easier time getting any special requests fulfilled.

Ride-share launches, in turn, are affecting how manufacturers approach satellite design. Instead of launching a handful of powerful, expensive satellites for a single application, companies are now designing large constellations made of hundreds, or even thousands, of smaller satellites to do the same job. In addition, manufacturers are now thinking about how to build a satellite that snugly and safely fits into ride-share payloads with many other objects. Swenson likens it to the way steel containers revolutionized the shipping industry by forcing customers to strategize about how to fill a large rectangular box with all their wares. People began manufacturing goods that were stackable, space efficient, and safe to ship within these standard containers.

Where ride-shares can make the biggest impact is in making it much easier and cheaper to send satellites into higher and more elongated orbits. Traditional launches don’t deploy payloads directly into regions like GEO (22,236 miles or 35,786 kilometers in altitude). Like a bus that stops miles from your destination, those launches typically drop satellites off in lower orbits; they have to make their own way up using onboard propulsion systems that are either costly and bulky, or so weak that they don’t get the satellite to its target orbit until months later.

But a ride-share launch that heads directly to GEO, as Arianespace’s GO-1 mission is expected to in 2022, eliminates the need for heavy, expensive propulsion systems. “We expect to be able to offer something like the GO-1 mission at least once a year,” says Wiener Kernisan, the president of Arianespace’s US subsidiary. He says he’s already heard from a few customers who are eager to build GEO satellites that weigh only 600 to 1,100 pounds (270 to 500 kilograms)—generally unheard-of for satellites going into such a high orbit. He anticipates that some manufacturers might even go as low as 330 pounds.

Telecom companies that rely on GEO-based systems will be eager to take advantage of these savings, but ride-sharing could be useful in other applications too. Earth observation satellites like NASA’s Geostationary Air Quality constellation, due to launch over the next several years, could be slimmed down and made lighter. Most science experiments have been barred from reaching GEO because of the high costs, but that might now change. Swenson, for example, is involved with an experimental NASA mission called Excited that wants to launch several satellites into a high orbital inclination to study plasma interactions in the ionosphere and thermosphere. The satellites need to be oriented in an “L” shape, and Swenson thinks a ride-share launch could easily make the stops to drop off these satellites into that formation.

There are, of course, challenges to making ride-share launches work. Preparing, storing, and managing half a dozen or more satellites for a single launch requires an intense amount of work. Just as some people miss their bus, some satellite customers might miss their launch. It could be quite easy, says Swenson, to lose track of which satellite is your own when there are multiple deployments at a given moment.

Yet “for business to keep moving forward, we need to find new solutions,” says Kernisan. Launch service providers like Arianespace and SpaceX are already thinking about whether upper-stage boosters can be engineered to fire on and off to accommodate more complex ride-share mission routes and drop payloads off in more extreme orbits.

And while ride-shares hew to a one-size-fits-all approach, some services will undoubtedly seek to customize missions for customers who will pay for it. Naseri in particular wants to see if launch providers can ensure safe release of a more diverse array of payloads. “We’re already seeing a demand for new innovations from customers,” she says. “The ride-share market is already here, and it’s here to stay.”