Boeing's Starliner (CST-100) - Discussion Thread 4

[clongton]

NASA pays 30 million US$ for each successful pad abort or in-flight abort test. Due to the high cost of an Atlas V launch, of course it was financially unattractive to do a Starliner in-flight abort. For SpaceX on the other hand, with a three-times-flown booster, a dummy 2nd stage and reusing the Dragon for later cargo flights, this test is free.

Demonstrating beyond question the value of the SpaceX business case of reusability.

In the beginning the Commercial Crew RFP, NASA asked that the bidders provide an entire transportation system, including the launch vehicle. SpaceX chose to develop their own, fully reusable LV and "reusable" spacecraft. Boeing decided to provide a "reusable" spacecraft but to purchase a single-use existing launch vehicle. There is nothing wrong with either approach but boots on the ground has demonstrated which approach is fiscally superior.

Note "reusable" spacecraft. That ideal is still a long way off in reality but has been fully demonstrated in the reusability of the LVs.

[Alexphysics]

NASA pays 30 million US$ for each successful pad abort or in-flight abort test. Due to the high cost of an Atlas V launch, of course it was financially unattractive to do a Starliner in-flight abort. For SpaceX on the other hand, with a three-times-flown booster, a dummy 2nd stage and reusing the Dragon for later cargo flights, this test is free.

https://spacenews.com/nasa-and-spacex-delay-dragon-in-flight-abort-test/

https://www.nasa.gov/press-release/nasa-commercial-crew-partner-spacex-achieves-pad-abort-milestone-approval

For the nth time: they wouldn't need an Atlas V to perform an in flight abort test. And the second stage for SpaceX's IFA won't be a dummy second stage unless by "dummy second stage" you mean "it won't be used". The second stage will be a normal flight ready second stage without the engine.

[ZachS09]

We shouldn't be bringing SpaceX into a Boeing thread. Please talk about the Crew Dragon IFA in the proper thread in the SpaceX Section.

[Alexphysics]

We shouldn't be bringing SpaceX into a Boeing thread. Please talk about the Crew Dragon IFA in the proper thread in the SpaceX Section.

In general any comment on test requirements and all of that shouldn't go on either sections but rather on the commercial crew section. The SpaceX IFA thread is also full of that discussion and it is tiring to see it everywhere. There should be one thread for that so we can redirect people there to read all that discussion and contribute if they want. But I guess it is now too late to say this...

[sanman]

If you don't mind, how does the CST-100's abort thruster configuration compare to Dragon's? I was just watching videos of both the Dragon and CST-100 abort tests, and was wondering. While the SuperDracos on Dragon seem more slanted, those on CST-100 seem less so. Also, CST-100 thrusters seem to be on the back of the service module, while those on Dragon are naturally ahead of the trunk / service module, which makes for a quasi-tractor effect. Is it safer to have those thrusters on the service module rather than integrated into the capsule? Wouldn't it be useful for the thrusters to be closer to the top of CST-100's service module to give tractor-like effect, rather than being at the very bottom?

[Vettedrmr]

Wouldn't it be useful for the thrusters to be closer to the top of CST-100's service module to give tractor-like effect, rather than being at the very bottom?

IMO, not really.  Dragon's thrusters being integrated into the capsule is most likely due to the original plan to do powered landings, which precludes placing them in the trunk.  If they'd planned on parachute landings from the beginning, they may/may not have placed them in the trunk.

From a stability/control system POV having the thrusters higher up is easier to control than down on the trunk.  BUT, now you have to worry about exhaust plume, proximity to the exhaust residue, etc.  BUT, you also have a system that opens up the possibility of reuse.

Just some thoughts.

Have a good one,
Mike

[TripleSeven]

Note "reusable" spacecraft. That ideal is still a long way off in reality but has been fully demonstrated in the reusability of the LVs.

a reusable spacecraft is not that far off.  in fact we more or less have them.  the ISS modules have lasted an astonishingly long time without significant internal maintenance.   

the most reusable vehicle today is the X 37  in both its propulsion and "spacecraft" form it is long lived, has an impressive turnaround time" and seems to be doing multiple cycles. 

I would argue it is the first truly reuable vehicle with the rest so far being refurbishable

[Lars-J]

From a stability/control system POV having the thrusters higher up is easier to control than down on the trunk.

That’s not true. See the “pendulum fallacy”:

https://en.wikipedia.org/wiki/Pendulum_rocket_fallacy

[su27k]

Wouldn't it be useful for the thrusters to be closer to the top of CST-100's service module to give tractor-like effect, rather than being at the very bottom?

IMO, not really.  Dragon's thrusters being integrated into the capsule is most likely due to the original plan to do powered landings, which precludes placing them in the trunk.  If they'd planned on parachute landings from the beginning, they may/may not have placed them in the trunk.

I think for Dragon the thrusters are integrated to capsule because they wanted to recovery and reuse them. Note on Dragon 1 the thrusters and tanks are integrated to the capsule too, even though Dragon 1 was never designed to do propulsive landing.

[Vettedrmr]

I think for Dragon the thrusters are integrated to capsule because they wanted to recovery and reuse them. Note on Dragon 1 the thrusters and tanks are integrated to the capsule too, even though Dragon 1 was never designed to do propulsive landing.

Good point.

[Thunderscreech]

It looks like the stacked Atlas-Starliner doesn't have nosecones on the SRMs yet in a photo in this AmericaSpace photo by Jeff Seibert: (source) https://twitter.com/AmericaSpace/status/1202552861319520256

Will they be installed later, or does the N22 configuration have a different, stubbier nosecone than usual or something?

[Welsh Dragon]

I know it's been simulated to hell and back and it will almost certainly fly just fine, but damn that's one ugly looking stack.

[Vettedrmr]

So it doesn't have all the aerodynamic fairings installed yet, right? I'm still curious about that abrupt transition to the skirt of the SM (or whatever it's called today.

Have a good one,
Mike

[punder]

So it doesn't have all the aerodynamic fairings installed yet, right? I'm still curious about that abrupt transition to the skirt of the SM (or whatever it's called today.

Have a good one,
Mike

Nope that's it. Hammerhead! (You are right about the SRMs, they need nosecones.)

The skirt is the aerodynamic fairing, it had to be added after wind tunnel tests showed a problem.

[ZachS09]

crew photo

jsc2019e066953
From left to right, NASA astronaut Mike Fincke, Boeing astronaut Chris Ferguson, and NASA astronaut Nicole Mann pose for the official crew portrait for Boeing's Crew Flight Test to the International Space Station, part of NASA's Commercial Crew Program.

Photo credit: NASA/Johnson Space Center

Have they ever announced who the commander will be for the Crew Flight Test?

There was one photo in which Ferguson, Fincke, and Mann were seated in a mockup capsule.

Ferguson was in the left-hand seat with Fincke in the right-hand seat and Mann in the middle.

Using the Apollo capsule seating as an example, I would say that Ferguson will be Commander of Boe-CFT.

[Hog]

crew photo

jsc2019e066953
From left to right, NASA astronaut Mike Fincke, Boeing astronaut Chris Ferguson, and NASA astronaut Nicole Mann pose for the official crew portrait for Boeing's Crew Flight Test to the International Space Station, part of NASA's Commercial Crew Program.

Photo credit: NASA/Johnson Space Center

Have they ever announced who the commander will be for the Crew Flight Test?

There was one photo in which Ferguson, Fincke, and Mann were seated in a mockup capsule.

Ferguson was in the left-hand seat with Fincke in the right-hand seat and Mann in the middle.

Using the Apollo capsule seating as an example, I would say that Ferguson will be Commander of Boe-CFT.

I'm pretty sure this would be the first non-NASA astronaut to launch as commander of a space vehicle.

[edkyle99]

So it doesn't have all the aerodynamic fairings installed yet, right? I'm still curious about that abrupt transition to the skirt of the SM (or whatever it's called today.

Have a good one,
Mike

Nope that's it. Hammerhead! (You are right about the SRMs, they need nosecones.)

The skirt is the aerodynamic fairing, it had to be added after wind tunnel tests showed a problem.

Right.  It's called an "aeroskirt", designed to minimize aerodynamic loading on the Centaur stage itself, I believe.  It will separate in two pieces after Centaur ignites.

 - Ed Kyle

[DigitalMan]

I was hoping for a later launch of OFT (it's 6:36am) since I am not exactly a morning person.  At least traffic before and after should be reasonable.

[NGCHunter]

Does anyone have a link to a timeline of the rendezvous and docking operations for OFT? There's going to be an ISS pass here in Florida 1.5 hours before the scheduled docking time and I'd like to know how far apart the spacecraft will be from the space station. I do a lot of satellite tracking and ISS videography with my telescope using satellite tracking software that I've written. I should be able to fit them both in the camera if I set the magnification correctly but I need to have some idea of how far apart they will be.

[Hog]

Does anyone have a link to a timeline of the rendezvous and docking operations for OFT? There's going to be an ISS pass here in Florida 1.5 hours before the scheduled docking time and I'd like to know how far apart the spacecraft will be from the space station. I do a lot of satellite tracking and ISS videography with my telescope using satellite tracking software that I've written. I should be able to fit them both in the camera if I set the magnification correctly but I need to have some idea of how far apart they will be.

In my past experience 1.5 hours the Starliner will be in the immediate vicinity of the ISS.  As the pass begins you will probably see a single dot, that separates into 2 distinct dots as the pass progresses.  There was a morning STS-134 pass just prior to docking that I thought that had already docked, until the 2 came right overhead and the 2 dots separated.

December 20, Friday
5:30 a.m. – Launch coverage of the Boeing CST-100 Starliner Commercial Crew Vehicle Orbital Flight Test; launch is scheduled at 6:36 a.m. EST (All Channels)
9 a.m. – NASA Administrator Boeing Starliner CST-100 post-launch briefings (time subject to change) (All Channels)
9:30 a.m. – Boeing Orbital Flight Test Launch Team post-launch news conference (All Channels)

December 21, Saturday
5 a.m. - Coverage of the Rendezvous and Docking of the Boeing CST-100 Starliner Commercial Crew Vehicle to the International Space Station (Docking is scheduled at 8:27 a.m. EST; coverage will continue through hatch opening at appx. 11 a.m. EST) - Johnson Space Center (All Channels)