Monday, June 13, 2022

Can SpaceX launch version 2 Starlink satellites this year?

A Starship spacecraft being lifted onto a Super Heavy booster

The answer to the question in the title depends on the availability of SpaceX’s new Starship spacecraft and Super Heavy booster rocket, collectively referred to as Starship. Elon Musk says he is highly confident about getting Starship to orbit this year. He also says, “At Space X we specialize in converting things from impossible to late.” 
Starship is critical to Starlink because the version 2 satellites are seven meters long and weigh about 1.25 tons and the current Falcon 9 rockets have neither the cargo volume nor the mass-to-orbit capability to economically launch them. As Musk put it, they "need Starship to launch and fly frequently or Starlink version 2 will be stuck on the ground." 
Version 2 satellites will be ejected
using a "Pez dispenser" mechanism
modeled after industrial pallet
Musk has said the performance of the version 2 satellites will be nearly an order of magnitude better than that of the current satellites and they will include inter-satellite laser links. He did not elaborate on his order of magnitude estimate and it will be interesting to see how they handle a mixed-satellite constellation, but all the analysts predicting the profitability and capacity of Starlink will have to go back to work. The projected improvement also reminds us of the advantage of short satellite life.
Today's terminals will work with the version 2 satellites, but performance will be better with a new terminal that is being developed. Perhaps Starlink will allow current terminal owners to trade them in on Version 2 terminals.
But can SpaceX launch the remaining 9,500 approved satellites or the 30,000 that are awaiting approval in a timely manner? They can if they achieve rapid reuse of Starships. The total world mass-to-orbit to date is 16,000 tons. Musk estimates that a single Starship launching three times a day could put 109,000 tons in orbit in a year.
Today they are doing about one launch per week and the current average turnaround time for boosters is 21 days -- can they reuse a Starship three times a day? Boosters fly for about six minutes before returning to Earth and SpaceX plans to have them land back on the launch pad ready for refueling, installation of a spaceship, and re-launch. (They will need more spaceships than boosters). 
During an interview/tour of the Starbase manufacturing and launch site in Boca Chica, Texas, Musk spent time at a launch pad discussing the 10-second booster landing and capture sequence and the design decisions it entailed with Andrew Krebs, Director, Starship Launch Engineering. It was apparent that various tradeoffs are still being evaluated and change is constant. Musk said there is a good chance they will fail to capture the booster on the upcoming orbital flight. (Recall the "unscheduled disassembles" tape of attempts to safely land Falcon boosters). 
They spent some time on the tour at an assembly bay talking about Starship design and manufacturing. Since they need Starship to launch and fly frequently, they expect to eventually have ten or twelve manufacturing bays and Musk expects to manufacture a new spaceship and booster every month. (He estimates that they will eventually have 1,000 Starships for building a city on Mars).
Raptor 1 vs Raptor 2 (source SpaceX)
The greater mass of the Starship and satellites requires more powerful rocket engines than SpaceX is currently flying so Starship will use thirty-nine Raptor 2 engines -- 33 for the booster and six for the spaceship. The Raptor 2 is more powerful than its predecessor, has a much simpler design, and costs about half as much. They had trouble manufacturing them at first but now expect to make seven or more per week.
If all goes well, Musk estimated the variable cost per orbital flight as being a few million, "maybe" as low as one million, dollars. 
In addition to engineering and manufacturing, there are regulatory hurdles. The Federal Aviation Administration (FAA) requires an environmental review before they can do the first orbital test launch and they are currently being required to make over seventy-five environmental adjustments to do an orbital launch in Texas. I have no idea how long these adjustments will take, and Musk has considered moving the first orbital flight to Florida. You can see the latest FAA report here.
There are a lot of unknowns and precisely landing and catching a 68-meter long, 9-meter diameter rocket might turn out to be impossible, but SpaceX specializes in converting things from impossible to late.
This post is based on a Starship update talk Musk gave at Starbase in Boca, his recent all-hands company presentation, and videos of interviews with Tim Dodd, the "Everyday astronaut," conducted while touring Starbase. Those videos are here, here, and here. I've only selected some Starlink-related material from these sources. Check them out to learn a lot more about Elon Musk and rockets.

(Click here for a Starlink update).

Update 6/17/2022

The FAA has concluded that continued launches "would not significantly affect the quality of the human environment" and Elon Musk, who has said there would be no more "hops," expects to attempt a Starship orbital launch in July. Musk thinks they will be able to satisfy the FAA quickly and get on with the orbital launch test. He tweeted “There will probably be several launch countdowns before we pass all the abort triggers, but hopefully the first countdown is this month.”

Update 8/4/2022

Alternative plan -- booster returns to launch pad
The answer to the question in the title is "no," but they are pushing hard and next year is a possibility. Version 2 satellites are already at Starbase, and the next Starship launch will try to reach orbit. It would be surprising if the first attempt reached orbit, but Elon Musk is confident that they can do it within twelve months. Whenever they do it, if all goes well, they will try to land the booster on the launch pad rather than allowing it to fall into the ocean. 
Musk previously predicted that the first orbital test would be as early as last January, so he is nearly a year behind schedule, but that prediction did not include an attempt at landing on the launch pad. 

No comments:

Post a Comment