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Tuesday, March 7, 2023

Falcon 9 Achieves What The Space Shuttle Dreamed Of Achieving

 

Falcon 9
A Falcon 9 lifts of on its most recent launch March 3. SpaceX has already performed 15 launches this year as it seeks to fly up to 100 times in 2023. (credit: SpaceX)

The Falcon 9 achieves the shuttle’s dreams


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One fascinating way of looking at Falcon 9 is to compare it to the late Space Shuttle. While completely different from a technical standpoint, they nonetheless have three basic objectives in common:

  • partially reusable: check
  • places up to 23 tons into orbit: check
  • launches once a week: check.

The last point is worth closer examination.

Fly a lot and prosper

In 2022, the Falcon family (Falcon 9 and Falcon Heavy) flew 61 times; all but one were of the Falcon 9. This is a remarkable number for many reasons, if only because of a forgotten number related to the Space Shuttle: the 1969–1972 dreamed vehicle, not the controversial one we got in 1981 to 2011.

baseline mission model developed by The Aerospace Corporation projected 736 launches from 1978 through 1990, or about 57 launches per year. While nobody noticed, last year the Falcon 9 has exceeded the long-forgotten shuttle projected flight rate.

The shuttle, of course, never achieved a flight rate of 57 launches per year. Instead, the progression of launches looked like this:

  • 57 flights per year: a 6.4-day turnaround.
  • 52 flights per year: a 7-day turnaround (once a week)
  • 36 flights per year: a 10-day turnaround: often quoted in NASA 1970s documents.
  • 24 flights a year: that was the (1988) objective, fixed somewhere in the late 1970s.
  • 11 flights in a year: the real world record of 1985–1986, and we all know how it ended (shudders).
  • 8 flights in a year: that’s 1996 for you. The post-Challenger record.
It is fascinating to realize that, in 2022, Falcon 9 achieved the shuttle’s early objectives at last.

With perfect hindsight 1996 seems to be the closest we ever got from a reasonable, realistic Space Shuttle annual flight rate. Remember: the fleet was back to four orbiters since 1992: Columbia, Discovery, Atlantis, and Endeavour. For the record, 1996 was also the beginning of a new and dangerous era that drove the shuttle into the wall for the second time: STS-107. The CAIB clearly identified severe budget cuts of the late Goldin era as a major driving force there. Faster-better-cheaper may have been useful early on, but they pushed it way too far. The 1999 Great Mars Fiasco was an early warning through the robotic exploration program. STS-107 was its counterpart in the human spaceflight area, unfortunately.

Now, how do Falcon 9 flight rates compare to the above? Falcon 9 started flying in June 2010 and has now flown more than 200 times. What can be said about it, though, compared to Space Shuttle own flight rates?

Falcon 9 launch chart

Falcon 9 flight rates reached a first plateau in the 2010s that put them in line with the shuttle’s highest flight rates. It took Falcon 9 until 2020, though, to get itself out of that plateau. In 2020 and 2021 the flight rate jumped significantly. The reason is all too obvious: Starlink.

Conclusion

And so, by 2022 there it is: the Falcon 9 flight rate exceeded NASA’s early 1970s projections of one shuttle launch every 6.4 days. And it will not stop there. SpaceX’s next objective is 100 flights a year. (As of early March SpaceX had conducted 14 Falcon 9 launches and one Falcon Heavy.)

As noted in the introduction, it is pretty interesting to try and compare Falcon 9/Dragon and Space Shuttle. They are both partially reusable with a crewed capability and/or 23 tons to orbit payload, not to mention the goal of flying once a week to support a space station.

But beyond that, they are utterly and absolutely different. Still, as a space nerd who grew up in the 1990s it is fascinating to realize that, in 2022, Falcon 9 achieved the shuttle’s early objectives at last!


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