January 3, 2025 Quick space links
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- SpaceX touts some of the changes in the latest Starship prototype
More information here. The 7th test flight will deploy 10 Starlink dummy satellites to test the deployment engineering. Superheavy will also re-use an engine that flew on the October test flight.
- On this day in 1999 the Mars Polar Lander was launched
The mission failed when the spacecraft crashed on landing.
- On this day in 2004 the probe Stardust made its close approach to Comet Wild-2 in order to capture samples
Those samples were successfully brought back to Earth two years later.
- On this day in 2004 the rover Spirit landed on Mars
Built to last 90 days, it continued to rove for six years, traveling almost five miles.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
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You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- SpaceX touts some of the changes in the latest Starship prototype
More information here. The 7th test flight will deploy 10 Starlink dummy satellites to test the deployment engineering. Superheavy will also re-use an engine that flew on the October test flight.
- On this day in 1999 the Mars Polar Lander was launched
The mission failed when the spacecraft crashed on landing.
- On this day in 2004 the probe Stardust made its close approach to Comet Wild-2 in order to capture samples
Those samples were successfully brought back to Earth two years later.
- On this day in 2004 the rover Spirit landed on Mars
Built to last 90 days, it continued to rove for six years, traveling almost five miles.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
regarding Starship improvements, is there much that could be improved on Falcon 9? Switching to raptor engines? Return the booster to the launch tower, which makes the landing legs unnecessary. But especially, can heat tile improvements be applied to the Falcon 9 2nd stage. Is it impossible to return the Falcon 9 2nd stage to the launch tower? Or does doing so require the reduction of too much payload capacity?
Hi Bob… I have found a couple of nice evening pauses for you… But I can’t remember the address to send them you, and apparently neither can my Gmail account…. Can you post / send me your address please.
Some exciting developments in this test flight.
Hoping they have well positioned streams on the Starlink simulator deployments that we’ll be able to see.
Richard M,
Ditto. I’d love to see a split-screen showing views from inside and outside as the dummy Starlinks are dispensed.
Steve Richter,
Other than a bit of incremental tweaking here and there, the Falcons will stay as-is for the rest of their run.
There won’t be any Raptors in the picture. Raptors burn methalox while the Falcons burn kerolox. The propellant tanks of the Falcons can’t be made larger to allow for the lower density of liquid methane vs. kerosene. To get the same total energy on-board, the tanks would have to get longer and/or wider and neither is possible without untenable changes to Falcon logistics practices and launch infrastructure. Falcon hulls are already at the maximum diameter that allows transport via road in the U.S. and they can’t be lengthened for aerodynamic reasons involving “fineness ratio” – the ratio of length to width. Changing these basics would also require extensive mods to the launch pads, putting them out of service for a minimum of months. That simply isn’t tenable given SpaceX’s Falcon launch requirements, especially for Starlink.
I don’t think more than three Raptors could be fitted to the extant 12-foot-diameter Falcon booster hulls. Even if the propellant tankage volume issue could somehow be hand-waved away, going from nine engines to three on a first stage would require all boostback, entry and landing burns to be done asymmetrically. Asymmetric burns have been standard operating procedure on Starships, so SpaceX definitely knows how to do them. But there is no percentage in introducing this additional complexity into Falcon operations. And, if one was to “Raptor-ize” the Falcon 2nd stage as well as the first, there might be a problem fitting the Rvac’s huge engine bell into the Falcon interstage. It’s probably both too wide and too long to fit without lengthening the interstage and that would get us into fineness ratio and infrastructure mod problem territory again.
Re-doing Falcon 2nd stages to enable re-entry and recovery would add far too much mass to be practical. Anyway, on a significant number of Falcon missions, the 2nd stage is unrecoverable for reasons of orbital mechanics vs. propellant load. Every mission to GTO and any deep space mission would fall into this category.
The Falcons will continue to fly, at a cadence that still has room for considerable increase, until at least the de-orbiting of the ISS and may well continue in service beyond that. And they will do so in essentially the same form as they now have.
Steve Richter,
These are good questions.
I don’t know what SpaceX was thinking when they decided that the upper stage was not worth redesigning for return and reuse, but in 2012 they intended to do just that. Later, they decided that it was not worth doing. Was it too expensive to do the redesign? Maybe, but they had done a lot of modification to the booster in order to make it reusable. Perhaps they thought it was time to move on to the next rocket, even beyond the Falcon Heavy, to the Mars Ship, the Fantastically Big Rocket (BFR). Clearly, they designed Starship to incorporate lessons learned from Falcon.
SpaceX has not been that concerned about the reduced payload capacity but has been adamant about lowering the cost to orbit, and they decided that keeping some propellant in order to reuse the booster was worth the reduced capacity. They were correct. Reduced capacity let them drastically reduce the cost to orbit, which was the goal. Could it be that reusing the upper stage would reduce the capacity too much and make Falcon cost more, not less, per kilogram taken to orbit?
Comparing Starship to the Falcon upper stage, it is clear to me that for reentry it is better to retain the fairings to protect the forward bulkhead (The Space Shuttle also reentered with its nose intact). The concept drawing that I saw in 2012 showed a bizarre heat shield for the front end of the upper stage. The fins on Starship were chosen for attitude control during reentry down to landing, although Falcon could have used wings and a runway landing, similar to Dream Chaser and the Shuttle. Adding a heat shield would also have increased the weight, and for the upper stage every kilogram of fairing, fin, wing, and heat shield is a kilogram of reduced payload. It is much easier to design from scratch than to retrofit. Retrofitting all these to an existing design may have left too little payload left over for the price per kilogram to orbit to remain low.
Could Falcon 9 be improved? Almost certainly. Is it worth improving? Maybe not. Starship may be far less expensive to operate. Except for flying the Dragons, Falcon 9 and Falcon Heavy may become relatively obsolete. The Dragons are likely to be better for docking with the new space stations than the massive, high moment-of-inertia Starship.
What would it take to make improvements? Switching to Raptor engines would require changing the fuel, which may require a change in the size of the fuel tank. Returning to the launch pad may work, but it still needs to come off the pad for preparations for the next flight. For the same reasons, the upper stage would also need to be removed from the pad, if that is where it would land. Integration of the rocket is done horizontally, not vertically, so Falcon cannot operate on the pad the way Starship does. Falcon is not designed for the same rapidity of reuse that Starship is. Return to the launch pad may just tie up the pad for a day while the stage is removed, reducing the time that they have to prepare the pad for the next launch. It may reduce Falcon’s launch cadence.
Modifying Falcon to be more like Starship could be like modifying a pickup truck to be more like a semi truck.