New manned Dragon capsule forces NASA to shuffle ISS crew launch and return schedules
In order to give SpaceX more time to complete work on a new manned Dragon capsule, raising its fleet of capsules to five, NASA has shuffled its springtime ISS crew launch and return schedules.
The change gives NASA and SpaceX teams time to complete processing on a new Dragon spacecraft for the mission. The new spacecraft is set to arrive to the company’s processing facility in Florida in early January. “Fabrication, assembly, testing, and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail,” said Steve Stich, manager, NASA’s Commercial Crew Program.
…NASA and SpaceX assessed various options for managing the next crewed handover, including using another Dragon spacecraft and manifest adjustments. After careful consideration, the team determined that launching Crew-10 in late March, following completion of the new Dragon spacecraft, was the best option for meeting NASA’s requirements and achieving space station objectives for 2025.
This decision however impacts the return of the Dragon crew presently on board ISS, including the two astronauts launched in June on Boeing’s Starliner capsule and whose stay was extended from its initial length of one-to-eight weeks to more than six months when NASA made the decision to bring Starliner home unmanned. Instead of returning in February 2024, that crew will now have to return after the next crew arrives in late March.
Most of the press has focused on this two month extension to the Starliner crew, but to me the real news is that SpaceX is building a fifth manned capsule, as yet unnamed. Having five reusable capsules will give the company greater flexibility. I suspect SpaceX decided to build this additional capsule because, in addition to its ISS missions for NASA, it is going to be flying in 2025 both an Axiom mission to ISS as well as a 30-day mission to Vast’s Haven-1 space station. That latter mission will tie up one manned capsule for many months both before and after that long flight.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
In order to give SpaceX more time to complete work on a new manned Dragon capsule, raising its fleet of capsules to five, NASA has shuffled its springtime ISS crew launch and return schedules.
The change gives NASA and SpaceX teams time to complete processing on a new Dragon spacecraft for the mission. The new spacecraft is set to arrive to the company’s processing facility in Florida in early January. “Fabrication, assembly, testing, and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail,” said Steve Stich, manager, NASA’s Commercial Crew Program.
…NASA and SpaceX assessed various options for managing the next crewed handover, including using another Dragon spacecraft and manifest adjustments. After careful consideration, the team determined that launching Crew-10 in late March, following completion of the new Dragon spacecraft, was the best option for meeting NASA’s requirements and achieving space station objectives for 2025.
This decision however impacts the return of the Dragon crew presently on board ISS, including the two astronauts launched in June on Boeing’s Starliner capsule and whose stay was extended from its initial length of one-to-eight weeks to more than six months when NASA made the decision to bring Starliner home unmanned. Instead of returning in February 2024, that crew will now have to return after the next crew arrives in late March.
Most of the press has focused on this two month extension to the Starliner crew, but to me the real news is that SpaceX is building a fifth manned capsule, as yet unnamed. Having five reusable capsules will give the company greater flexibility. I suspect SpaceX decided to build this additional capsule because, in addition to its ISS missions for NASA, it is going to be flying in 2025 both an Axiom mission to ISS as well as a 30-day mission to Vast’s Haven-1 space station. That latter mission will tie up one manned capsule for many months both before and after that long flight.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I believe that SpaceX will also need additional crew capacity to serve as a taxi between Earth and LEO for Starship crews, both departing and returning from the Moon and elsewhere. For one thing this might sidestep the problematic issue of crewed Starships launching and landing with no crew escape capability.
Considering the number of potential manned flights to support upcoming station and orbital activity combined with the current flight rate of unmanned payloads will to two pads be sufficient?
It might be worth having ten–lots of back-ups.
As Robert notes, “This decision however impacts the return of the Dragon crew presently on board ISS, including the two astronauts launched in June on Boeing’s Starliner capsule and whose stay was extended from its initial length of one-to-eight weeks to more than six months when NASA made the decision to bring Starliner home unmanned. Instead of returning in February 2024, that crew will now have to return after the next crew arrives in late March.”
After this further delay, I can’t help but think of the crew’s plight in the context of this old Kingston Trio song.
https://www.youtube.com/watch?v=XM2JpZ8Hu3E
“But did [they] ever return, no [they] never returned
And [their] fate is still unlearned (shame and scandal)
[They] may ride forever [above] the [town] of Boston
[They’re] the [crew] who never returned”
And the complete lyrics:
https://www.google.com/search?client=firefox-b-1-e&q=kingston+trio+man+who+never+returned#wptab=si:ACC90nxRWvuwqTR4TiacZ7sCfkHhcGgWdDOv2v2HxpHAAuIhwd0hqVQcoOD2_2OWmYVP1pjcWoOE8f0PhImT0y1td6GdkGw1Y8iDZzGfjKbCYppB5LLQOUirP8SPti16NgU_7mYUvxw9cAJ_jKlOZofbCUpVp6xC-lDShXHeFxA5RYi5BOiw3sk%3D
Falcon-Dragon will play no role in manned lunar missions. Giving them such a role would introduce a serious crew size and expense bottleneck to lunar expeditions for no gain in safety.
Right now, the baseline NASA Artemis plan for getting crews – very small crews – to the Moon is to launch them on SLS-Orion. Orion has “escape capability” only for the first three minutes or so of ascent. That isn’t nothing – it covers the entire interval during which the SLS SRBs are firing. That is by far the most likely interval during which to anticipate the occurrence of any boost-phase anomalies requiring crew escape.
But the Orion escape apparatus is to be jettisoned long before the SLS core stage ceases burning and the SLS upper stage lights up. From any serious anomalies occurring after escape system jettison there is no escape.
Starship, in contrast, is its own “escape capability” from a notional rogue Super Heavy. Hot-staging of Starship has already been demonstrated. Simply chilling in the Starship Raptors shortly before launch would provide escape capability for Starship from Super Heavy ignition to MECO.
Not that that’s likely to be an issue. Super Heavy and Starship will fly, unmanned, two or three orders of magnitude more often than SLS-Orion ever will over any given interval. That will quickly render the Starship stack vastly more reliable than SLS-Orion can ever get to be.
Any sustainable human presence on the Moon will require quite a bit of infrastructure build-out there and Optimus robots will not be able to do it all. Non-trivial numbers of humans will also need to travel to and from the Moon. Earth-to-lunar-orbit Starships and Starship lunar landers will quickly be fitted out to carry 20, 50, even 100, passengers at a time on such missions. Falcon-Dragon have no place in such scenarios.
Dick Eagleson wrote: “From any serious anomalies occurring after escape system jettison there is no escape.”
This is not really the case. The escape mode merely changes, just as it did with the Apollo launches.
You may have heard abort callouts during the manned Crew-Dragon launches (there have been plenty of them, now) in which they announce changing from one abort mode to the next. The same happened with Apollo, but I do not recall hearing the abort mode callouts.
The launch escape tower (LET) was used at low altitude and low speed (or from the pad, zero altitude and zero speed) to carry the Apollo capsule away from any flaming debris that could burn holes in the parachutes, to carry it to an altitude where the parachutes can open safely, and carry it to to a distance out to sea where the winds will not carry it back to land before the capsule can splash down into the ocean. For Apollo, this was abort mode one-alpha, up to about three kilometers (~10,000 feet), first ¾ minute.
The LET was used at higher altitudes and faster speeds to ensure the capsule was pointed heat shield-first, so it could jettison properly and the parachutes could open without tangling on the capsule. For Apollo, this was abort mode one-bravo, up to about thirty kilometers altitude (~100,000 feet). After this, the Apollo Command Module could use its own reaction control thrusters for orientation, abort mode one-charlie.
Some amount of time after the second stage was lit, the LET was no longer needed, so it was jettisoned, and Apollo flew in abort mode two. Aerodynamic forces were no longer considered enough to break up the launch stack, and the service module engine could take the capsule away from a disintegrating rocket stack. Even before the second stage expended all its propellants, the third stage had enough to take Apollo to orbit from a failing second stage, and this was abort mode three.
The same occurs with Orion. At some point, the escape tower is no longer needed for crew safety. Orion and its service module can escape from a failing rocket stack without it.
Rockets do not explode like firecrackers but burst. To carry a manned spacecraft, the burst must be designed to happen to the side,* radially, not upward toward the spacecraft, axially. Even without the escape tower, the maned spacecraft at altitude is made to be able to move away from a failing launch vehicle. This is assisted by the loss of thrust on the launch vehicle.
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* Even in my first design class in engineering school, we were taught to control where a failure would occur so that something less critical or less expensive broke before a major failure destroyed the whole thing. Think of a fuse in a stereo. The fuse blows, the stereo survives, and you replace the fuse. Recurring fuse failures suggests a persistent problem with the system, and that needs to be investigated, but it is only cheap, easily replaced fuses informing you of this problem, not a series of destroyed stereos.