SpaceX will make its second attempt to launch 60 Starlink satellites

Even though the weather was in its launch window on Wednesday night, SpaceX missed an attempt to launch its first batch of Starlink satellites. The winds at altitude simply did not cooperate, so the company stopped the launch attempt.

Thursday, the rocket is again on the launching pad. This time, weather conditions have improved and winds in the upper part of the atmosphere seem more conducive to launch. SpaceX will therefore continue with the historic launch and unconventional deployment of 60 satellites that will provide Internet access. The deployment, about an hour after launch, will be fascinating to watch and we are eager to see how well the company and the Air Force will connect to and track these satellites.

Below you will find an integrated webcast, which should begin around 10:15 pm (Thursday at 2:15 pm), as well as an edited copy of our article explaining the Starlink constellation, which was originally published prior to Wednesday's launch attempt.

Most heavy payload

With a mass of 18.5 tons, Thursday's launch will be the heaviest yet of the Falcon 9 or Falcon Heavy rocket. The rocket will propel 60 Starlink satellites, each weighing 227 kg, at an altitude of 440 km.

This is the first block of Starlink satellites for what should eventually be a much larger constellation. They will help SpaceX evaluate its performance and test several key systems. In the coming months, these first satellites will be joined by six additional launches carrying payloads of similar size. These launches will bring the constellation an initial "operational" capability.

There is no guarantee that everything will be all right, SpaceX founder Elon Musk told reporters on Wednesday night. "It's very difficult," said Musk. "There are a lot of new technologies, so it's possible that some of these satellites are not working, there's a small possibility that not all of these satellites will work."

Launch and release

The first part of the launch will be familiar to people who have already watched a SpaceX launch. This first leg of the Falcon 9 has already flown twice before and will attempt to land on the Of course I still love you droneship in the Atlantic Ocean. The actual action will occur approximately 1 hour 2 minutes after launch, when the second stage will begin StarLink satellite deployment.

First 60 @SpaceX Starlink satellites loaded into the Falcon fairing. Tight fit. pic.twitter.com/gZq8gHg9uK

– Elon Musk (@elonmusk) May 12, 2019

In order to save the mass, each of the 60 satellites will not have its own release mechanism, such as a spring. Instead, Musk explained that the upper stage of the Falcon rocket will begin a very slow rotation and that each of the satellites will be released in turn with a different amount of rotational inertia.

"It will almost look like spreading a deck of cards on a table," said Musk. There may be contacts between Starlink satellites, he added, but they are designed to handle it.

Power

After deployment, the satellites will power their ionic readers and open their solar panels. They will move to an altitude of 550 km on their own. Musk said he was concerned about the deployment of solar panels and said there are two different deployment mechanisms on the satellites for this purpose. He also said that the satellites had incorporated a new technology with thrusters as well as phased array antennas that had not yet been tested in space.

Satellites are designed to control costs. For example, everyone will maneuver with Hall effect thrusters (they are ionic thrusters in which the thruster is accelerated by an electric field). The classic fuel for such a propellant is xenon, which offers high performance. Starlink satellites, however, will use a different noble gas: krypton. Its density is lower, the fuel tanks of the satellites must be larger and its performance is lower than that of xenon. But krypton can be bought at one-tenth the cost of xenon, which counts if a company wants to power thousands of satellites.

"It costs a lot less than xenon," Musk said of krypton. (He also joked, in response to a question from Ars about this fuel, that the satellites would be immune to the invasion of Superman's home world.)

During the conversation, Musk said that the delivery of each Starlink satellite into orbit is more expensive than manufacturing. The list price for a Falcon 9 launch is $ 62 million. With reuse discounts and wholesale rates, StarLink satellite construction costs well under $ 1 million.

Plan of business

SpaceX is competing with about half a dozen other companies to develop a low latency and broadband Internet. One competitor, OneWeb, launched six of its own satellites in February. But SpaceX seems to be well ahead of most other players.

With six other launches and a total of about 400 satellites, Musk said the constellation would reach the point of being able to offer initial connectivity to ground users. A dozen launches would bring "significant" connectivity, he said, and 24 launches would provide a near-global service.

After several recent fundraisers, SpaceX has enough capital to launch the first 400 satellites and start selling the service to telecommunication companies and governments wishing to serve densely populated areas. If there are any significant issues with the deployment or performance of the first 400 satellites, he said that SpaceX should probably return to the capital markets.

Musk believes that with time, Starlink will become a commercial success for SpaceX and will enable it to achieve its goal of building an autonomous city on Mars. Potential start-up revenues reach about $ 3 billion a year for the company, he said, but capturing just 3% of the global Internet market could yield about $ 30 billion. "We see this as a way for SpaceX to generate revenue that can be used to develop more and more advanced rockets," he said.

Musk has recognized the validity of the concerns about the orbital debris of so many satellites (SpaceX is allowed to launch more than 11,000 Starlink satellites, well above the current total of around 2,000 in orbit). But he also said that the chosen 500 km altitude and satellite design would help ensure that the constellation gets cleansed because of its interaction with the Earth's atmosphere.