Sierra Space Dream Chaser DISCUSSION Thread (was SNC)

[DanClemmensen]

Worriesome, at best. Was it a bookkeeping oversight, or deliberate non-payment due to a shortage of funds?
I'm still hopeful and optimistic, still have the Dream Chaser sticker on my toolbox. But I am making that face my dog makes when I'm down to the last bite of steak and still haven't given her any.

No shortage of NASA funds. Fixed-price contacts call for specific payments upon completion of well-defined milestones. NASA has already paid for milestones that have been completed. They will not pay for milestones that have not yet been completed.

[zubenelgenubi]

The Dream Chaser is a low G recovery-reentry spacecraft that is important for some cargo...

Haven't needed it for more than 10 years

How would anybody "need" it if it wasn't available? Nobody is going to make crystals or solutions or compounds in zero g that can't handle 3g landings if they can't get the ride.

⬆️ This.
Is there any back-log of proposed experiments' results that require Dream Chaser's gentle touchdown?

Also: I'm agreeing with Tywin and disagreeing with Jim. 🥴

Everybody playing along (legal, not on the wagon, and not the designated driver) drinks. 🍻

[jarmumd]

The Dream Chaser is a low G recovery-reentry spacecraft that is important for some cargo...

Haven't needed it for more than 10 years

How would anybody "need" it if it wasn't available? Nobody is going to make crystals or solutions or compounds in zero g that can't handle 3g landings if they can't get the ride.

⬆️ This.
Is there any back-log of proposed experiments' results that require Dream Chaser's gentle touchdown?

Also: I'm agreeing with Tywin and disagreeing with Jim. 🥴

Everybody playing along (legal, not on the wagon, and not the designated driver) drinks. 🍻

I'm agreeing with Jim.  Most things aren't that sensitive.  If they are, then they would need to be worth it.  What's been shown valuable enough to need a gentle ride?  I don't disagree in principal - if the cure for cancer was made in zero G and needed 1.5G max accel to survive the trip home, then someone would make the business case to pay for the development.  I think Jim's point is that there is no such product.  In researching this post, I found that in Feb, SS had a press release with Merck for just this kind of research - cancer.  But here's the thing... Merck will spend 1B opening up a facility in Kansas, and will walk away from a 1.4B UK lab.  I would think that if Merck saw a huge market in space, they would be willing to fund a similar amount.  I think the reality is that they don't.

This point is further made by other CLD providers also providing investment funding for research.  They are trying to find the product to make the business case.

[zubenelgenubi]

I'm agreeing with Jim.  Most things aren't that sensitive.  If they are, then they would need to be worth it.  What's been shown valuable enough to need a gentle ride?  I don't disagree in principal - if the cure for cancer was made in zero G and needed 1.5G max accel to survive the trip home, then someone would make the business case to pay for the development.  I think Jim's point is that there is no such product.  In researching this post, I found that in Feb, SS had a press release with Merck for just this kind of research - cancer.  But here's the thing... Merck will spend 1B opening up a facility in Kansas, and will walk away from a 1.4B UK lab.  I would think that if Merck saw a huge market in space, they would be willing to fund a similar amount.  I think the reality is that they don't.

This point is further made by other CLD providers also providing investment funding for research.  They are trying to find the product to make the business case.

Re: space research and manufacturing

I will grant that perhaps such a requirement did exist, but later disappeared, like the drug-making promise of continuous flow electrophoresis (CFES) pre-Challenger?

[vt_hokie]

I'm curious as to how complete the vehicle is. Is it possible that the vehicle is ready to go right now, i.e. could it successfully berth at ISS if launched in its present state?  It seems that Starliner's woes have really upped the bar for testing and verification, which is understandable but man, to get this close it would be a darn shame not to make it before ISS gets splashed.

[jarmumd]

I'm curious as to how complete the vehicle is. Is it possible that the vehicle is ready to go right now, i.e. could it successfully berth at ISS if launched in its present state?  It seems that Starliner's woes have really upped the bar for testing and verification, which is understandable but man, to get this close it would be a darn shame not to make it before ISS gets splashed.

My personal experience has been that verification for human space flight is probably 90% of the work.  I've been involved with just about every American docking system, and I can tell you that those systems are designed around failures.  What I mean is, maybe 10% of the design is actual docking performance, the other 90% is verifying that if something breaks, no one dies.

Very likely DC could actually successfully berth to the space station.  But the question is... what if it can't?  What if the passive CBM is out of spec, what if the thrusters don't shut off when the arm latches, what if there is outgassing in the cargo module, what if it loses power during prox-ops?  Every single thing has to be checked off and get NASA concurrence.  The obvious consequence being a situation like starliner.

I hate to say it, but I wonder if things like the multi-mode thrusters are hurting them.  Look, springs and dampers are hard to verify on a good day.  Simple in space is still hard to verify.  Complex is a whole other world of pain.  Think of it this way...  can you show prox ops success in all three thruster settings, with one thruster failed (that's two faults)?  That's a lot of analysis.

[Jim]

The Dream Chaser is a low G recovery-reentry spacecraft that is important for some cargo...

Haven't needed it for more than 10 years

How would anybody "need" it if it wasn't available? Nobody is going to make crystals or solutions or compounds in zero g that can't handle 3G landings if they can't get the ride.

Nothing has changed in experiments from before the shuttle retired.  There wasn't a whole class of experiments that had to stop flying when the shuttle went away.

[thespacecow]

https://twitter.com/AlexanderJ91756/status/1971508045760098567

I spent years tiling this ship. Drilling composites and making every detail perfect. Management was a disaster and even tried to convince us they were on par with SpaceX. Now that I work on starship comments like that sound even more childish than before. Rip chaser. Never to be.

Also according to him and rumors on reddit, Sierra Space just had another round of layoff.

[woods170]

Maybe Sierra Space could market or sell Dream Chaser to the ESA or JAXA?

to do what?

European access to commercial space stations, of which several are in the works.

meh.  Are any cutting metal?

Also, such access to commercial space stations would be cargo only (current Dream Chaser is uncrewed). No need for Dream Chaser now that Europe has its own cargo vehicle in development.

[woods170]

The Dream Chaser is a low G recovery-reentry spacecraft that is important for some cargo...

Haven't needed it for more than 10 years

How would anybody "need" it if it wasn't available? Nobody is going to make crystals or solutions or compounds in zero g that can't handle 3g landings if they can't get the ride.

⬆️ This.
Is there any back-log of proposed experiments' results that require Dream Chaser's gentle touchdown?

No such back-log exists.

[woods170]

Ars Technica: Sierra’s Dream Chaser is starting to resemble a nightmare [Sep 25]

Although the NASA news release does not detail the space agency's concerns about allowing Dream Chaser to approach the station, sources have told Ars the space agency has yet to certify the spacecraft's propulsion system. The spacecraft is powered by more than two dozen small rocket engines, each capable of operating at three discrete levels of thrust for fine control or more significant orbit adjustments. Certification is a necessary precursor for allowing a vehicle to approach the orbiting laboratory.

Emphasis mine.

Given that the vast majority of Starliner's troubles involved its propulsion system, it would not surprise me that NASA is going over Dream Chaser's propulsion system with multiple very fine tooth combs. That could be one reason why Dream Chaser is now delayed by a year.

[DanClemmensen]

Ars Technica: Sierra’s Dream Chaser is starting to resemble a nightmare [Sep 25]

Although the NASA news release does not detail the space agency's concerns about allowing Dream Chaser to approach the station, sources have told Ars the space agency has yet to certify the spacecraft's propulsion system. The spacecraft is powered by more than two dozen small rocket engines, each capable of operating at three discrete levels of thrust for fine control or more significant orbit adjustments. Certification is a necessary precursor for allowing a vehicle to approach the orbiting laboratory.

Emphasis mine.

Given that the vast majority of Starliner's troubles involved its propulsion system, it would not surprise me that NASA is going over Dream Chaser's propulsion system with multiple very fine tooth combs. That could be one reason why Dream Chaser is now delayed by a year.

In general, it bothers me when NASA has to pay extra for what is supposed to be a fixed-price contract, or when they decide to relax the requirements for a milestone. This is what appears to have happened for Starliner.

However, in the case of Dream Chaser NASA seems to be imposing a new requirement on Sierra: an in-flight demo of the propulsion system prior to permitting ISS proximity operations. If this is really what happened, then it's appropriate to add a contract modification  that adds this milestone and adds a payment for its completion. It's not Sierra's fault that Starliner has made NASA more cautious.

The other "penalty" was the cancellation of the guarantee for the actual cargo missions. IMO this was mostly self-inflicted by Sierra's very severe schedule slips and is fully justified. The same thing seems to have happened to Starliner.

[jarmumd]

However, in the case of Dream Chaser NASA seems to be imposing a new requirement on Sierra: an in-flight demo of the propulsion system prior to permitting ISS proximity operations. If this is really what happened, then it's appropriate to add a contract modification  that adds this milestone and adds a payment for its completion. It's not Sierra's fault that Starliner has made NASA more cautious.

I'm not sure that's what's happened?  I look at it this way... There are so many unknown unknowns, so many things that simply cannot be tested and proven until you just fly the ship.  Certifying all those things for ISS is a ton of work.  Doing a flight test buys down risk and gets you flight experience.  Why wait until after a ton of certification work just to find something you missed (re: Starliner)?  In some ways this is what we like from SpaceX, fly-break-redesign.

So is it that NASA imposed a new requirement?  Or did NASA agree that they could "take credit" for a flight test?  I don't know, just tossing out an idea.

[DanClemmensen]

However, in the case of Dream Chaser NASA seems to be imposing a new requirement on Sierra: an in-flight demo of the propulsion system prior to permitting ISS proximity operations. If this is really what happened, then it's appropriate to add a contract modification  that adds this milestone and adds a payment for its completion. It's not Sierra's fault that Starliner has made NASA more cautious.

I'm not sure that's what's happened?  I look at it this way... There are so many unknown unknowns, so many things that simply cannot be tested and proven until you just fly the ship.  Certifying all those things for ISS is a ton of work.  Doing a flight test buys down risk and gets you flight experience.  Why wait until after a ton of certification work just to find something you missed (re: Starliner)?  In some ways this is what we like from SpaceX, fly-break-redesign.

So is it that NASA imposed a new requirement?  Or did NASA agree that they could "take credit" for a flight test?  I don't know, just tossing out an idea.

I'm just speculating based solely on my interpretations of what I read here on NASASpaceflight. Your analysis may be better than mine. We won't know until we see what happens and who pays for it, for both Starliner and Dream Chaser. Even then we may still end up speculating on the motivations behind the decisions.

I do see several differences between the two cases. This apparent new requirement laid on Dream Chaser is preemptive. There is no particular reason to believe the system will not work. It's unclear why they cannot be allowed to demonstrate proximity operations on the same flight where they then do a docking. This is what all other new spacecraft did. You may be correct and NASA may be making the right choice, but it's not Sierra's fault.

For Starliner, the system demonstrated several serious failures during RPOD and NASA apparently does not feel that the system should fly with crew even after the exhaustive analysis and the corrective modifications. NASA had a reasonable expectation that Starliner would function properly after OFT-1 and the two attempts at OFT-2. NASA should not relax milestone requirements to pay Boeing for this mess, which was all on Boeing.

[Jim]

I'm just speculating based solely on my interpretations of what I read here on NASASpaceflight. Your analysis may be better than mine. We won't know until we see what happens and who pays for it, for both Starliner and Dream Chaser. Even then we may still end up speculating on the motivations behind the decisions.

I do see several differences between the two cases. This apparent new requirement laid on Dream Chaser is preemptive. There is no particular reason to believe the system will not work.

Huh?   It is a system with components that have never flown in space or anything similar has ever flown.  this is more likely about qualification.  The "new" flight may be a derived requirement and not one directly mandated by NASA.

[DanClemmensen]

I'm just speculating based solely on my interpretations of what I read here on NASASpaceflight. Your analysis may be better than mine. We won't know until we see what happens and who pays for it, for both Starliner and Dream Chaser. Even then we may still end up speculating on the motivations behind the decisions.

I do see several differences between the two cases. This apparent new requirement laid on Dream Chaser is preemptive. There is no particular reason to believe the system will not work.

Huh?   It is a system with components that have never flown in space or anything similar has ever flown.  this is more likely about qualification.  The "new" flight may be a derived requirement and not one directly mandated by NASA.

That may well be. I don't think we know that yet and we may never know. Boeing did not self-impose this requirement on Starliner and SpaceX did not self-impose it on Dragon. If I recall correctly, in each of those cases they planned to perform initial tests of the system well away from ISS, and then attempt docking to ISS on the same flight.

Boeing did end up doing a free-flier test, but not on purpose.

[Jim]

That may well be. I don't think we know that yet and we may never know. Boeing did not self-impose this requirement on Starliner and SpaceX did not self-impose it on Dragon. If I recall correctly, in each of those cases they planned to perform initial tests of the system well away from ISS, and then attempt docking to ISS on the same flight.

Boeing did end up doing a free-flier test, but not on purpose.

Dragon and Starliner used systems with flight heritage, unlike Sierra. The only way to provide/create the data to allow for certification may have to be a flight.

[mn]

I'm just speculating based solely on my interpretations of what I read here on NASASpaceflight. Your analysis may be better than mine. We won't know until we see what happens and who pays for it, for both Starliner and Dream Chaser. Even then we may still end up speculating on the motivations behind the decisions.

I do see several differences between the two cases. This apparent new requirement laid on Dream Chaser is preemptive. There is no particular reason to believe the system will not work.

Huh?   It is a system with components that have never flown in space or anything similar has ever flown.  this is more likely about qualification.  The "new" flight may be a derived requirement and not one directly mandated by NASA.

That may well be. I don't think we know that yet and we may never know. Boeing did not self-impose this requirement on Starliner and SpaceX did not self-impose it on Dragon. If I recall correctly, in each of those cases they planned to perform initial tests of the system well away from ISS, and then attempt docking to ISS on the same flight.

Boeing did end up doing a free-flier test, but not on purpose.

SpaceX did do the cots 1 demo flight.

[DanClemmensen]

I'm just speculating based solely on my interpretations of what I read here on NASASpaceflight. Your analysis may be better than mine. We won't know until we see what happens and who pays for it, for both Starliner and Dream Chaser. Even then we may still end up speculating on the motivations behind the decisions.

I do see several differences between the two cases. This apparent new requirement laid on Dream Chaser is preemptive. There is no particular reason to believe the system will not work.

Huh?   It is a system with components that have never flown in space or anything similar has ever flown.  this is more likely about qualification.  The "new" flight may be a derived requirement and not one directly mandated by NASA.

That may well be. I don't think we know that yet and we may never know. Boeing did not self-impose this requirement on Starliner and SpaceX did not self-impose it on Dragon. If I recall correctly, in each of those cases they planned to perform initial tests of the system well away from ISS, and then attempt docking to ISS on the same flight.

Boeing did end up doing a free-flier test, but not on purpose.

SpaceX did do the cots 1 demo flight.

Yep. In 2010, on atop only the second flight of a Falcon 9, by a fairly young company with a "hardware-rich" testing philosophy. Their original proposal to NASA included this flight plus two others (COTS-2 and COTS-3), where COTS-2 was supposed to be a free-flier that demonstrated proximity ops and COTS-3 was supposed to be the first actual berthing to ISS. COTS-1 went so well that SpaceX proposed that COTS-2 and COTS-3 be combined, and NASA agreed. They basically did the COTS-2 mission to near the ISS, and then backed off and did the actual approach and berthing from the COTS-3 mission.
    https://en.wikipedia.org/wiki/SpaceX_COTS_Demo_Flight_1
    https://en.wikipedia.org/wiki/SpaceX_COTS_Demo_Flight_2
A few years later Sierra proposed Dream Chaser for CRS phase 2, with a plan that included berthing on the first flight. NASA approved this plan. Maybe NASA should not have approved the plan, but they did. Now, a decade later, the plan got changed. That's OK. I think a free-flying test is a good idea, although it's not clear that berthing to ISS on that same flight after the initial tests succeed is much of a risk. I'm just wondering who is going to pay for this.

[woods170]

That may well be. I don't think we know that yet and we may never know. Boeing did not self-impose this requirement on Starliner and SpaceX did not self-impose it on Dragon. If I recall correctly, in each of those cases they planned to perform initial tests of the system well away from ISS, and then attempt docking to ISS on the same flight.

Boeing did end up doing a free-flier test, but not on purpose.

Dragon and Starliner used systems with flight heritage, unlike Sierra. The only way to provide/create the data to allow for certification may have to be a flight.

Emphasis mine.

Although some of the RCS systems and propulsion systems flown on Starliner have flight heritage, the "clustered-inside-a-doghouse" configuration had no flight heritage. Combined with insufficient modeling of the thermal "climate" inside and around the "doghouse", this resulted in Starliner suffering from (RCS) thrusters going offline (due to thermal limits) on all three flown Starliner missions.

Merely having stuff with flight heritage doesn't guarantee that it will work-as-advertised when applied in a new configuration. Starliner is ample evidence of this fact. Courtesy of the three Starliner missions, NASA is now very aware of this fact. Which gives them all the more reason to go over the Dream Chaser propulsion and RCS systems with a very fine tooth comb. NASA would very much not be interested in another commercial vehicle demonstrating unwanted RCS and propulsion "surprises".