This first DreamChaser is essentially a prototype. They are both building and learning as they go, while assembling Tenacity. After is has flown once or twice, I am sure there will be tweaks and improvements. But they will have the advantage of having built one already. Knowledge Gained.

I would rather they take their time and get it right, so that that: A) future iterations can be produced quicker; B) construction and assembly lessons are studies and retained; and C) they avoid the same lesson of Starliner.

The only other thing I would add is that the design was derived from HL-20, however, under the skin, I imagine that the differences in tech evolution are mind boggling. Even since SNC took over, some of the leaps in tech and shifts in the commercial space market have been fast paced. Making sure the final product takes advantage of the best tech while still being a viable and competitive product is a challenge in and of itself.

Ps. As I think I said before, as a former glider instructor I used to enjoy reminding power pilots doing their first “dead stick” landing that there was no go-around option! Not cruel in my opinion because most of them were way overconfident in their actual stick-and-rudder skills!

In Waterfall one example of skullduggery is everyone pads the amount of time it will take to get work done and then usually puts the work off until the very last minute. Been there, done that. No one ever noticed. That said every software company I’ve worked at has used Waterfall except one that tried to implement Agile and it wasn’t done well and the results weren’t that great. Agile is tricky which is why I doubted Elon Musk’s success. But it is favored by creative people for its flexibility.

I think Amazon also uses Agile which is one reason they implement change so quickly and successfully.

There are thousands of successful landings every day that didn’t require a second approach. If your avionics and controls can get you into the glide slope window then you are pretty much landing in one piece. If they can’t then you have big problems and having an “engine” with limited range isn’t going to help you much.

Aborted landings are usually due to weather or other air traffic.

You have plenty of time to find an alternative if you prime landing strip is socked in. Or you just wait a day or so for things to clear up.

There are other phases of the flight that have higher risks.

So in the realm of getting back you either glide or dive. Musk thinks there is another way but we shall see how that works out soon.

Capsules are even better known—so Agile works fine there.

Unless the craft has a engine to give it a second chance at landing. The shuttle did not have a second chance. One try or death.

As an emergency ship how long will it orbit until a landing field opens up?

There’s something elegant and practical about gliding back and landing on a runway on good old dry land. Good luck to them.

I can’t help but be a fan. Maybe it’s not *entirely* rational. The obvious advantages: lower g-forces on reentry (which would be very valuable for emergency medical evacuations), greater cross range, and more rapid access to the vehicle for time-sensitive cargo or medically compromised crew. Maybe that’s not enough to make it as valuable as Crew Dragon (let alone Starship!), but maybe there’s a niche case for it….

I’m unclear just exactly how Sierra is doing Dream Chaser development in this regard. Everything I’ve seen suggests, admittedly, that they are not as agile or driven as SpaceX, though I think at least *part* of the problem is that they simply are not as well capitalized as SpaceX has been for the last decade. They did a Series A funding round last fall for $1.4 billion to ramp up development of a crew version…which is money Elon Musk could probably find in his couch cushions. Allowance must be made, too, for the fact that a fair bit of SpaceX’s Crew Dragon development could lean on work done on the Dragon 1 cargo vehicle (though on the other hand, NASA kibitzing surely delayed Crew Dragon deployment in other ways), an advantage Sierra does not have. In short, I have some reservations about how Sierra’s DC work is going, but I am hesitant to push that very far without more information.

It’s also true, by the way, that Sierra does indeed plan to build just the one DC vehicle (Tenacity) for fulfillment of its CRS-2 contract (and NASA’s OIG has expressed concern about that), but according to the AIAA they apparently plan to build as many as 10-15 DC’s by the 2030’s to meet government and commercial demand. That seems awfully optimistic to me, but it does seem likely that they’re working to build at least a couple more, though they surely won’t be ready until the CRS-2 contract has run its course. If I have hope for Dream Chaser’s propects, it’s that at least Sierra seems to be seriously pursuing a business case with commercial customers, and that is something we have seen zero evidence of in regards to Boeing and Starliner.

I’d go for “Kick Ass” instead.

Get’r done!

James Street: As an outsider my first impression of these two approaches is clearcut:

Waterfall: Designed to stifle creativity, innovation, and improvisation. Also designed to guarantee costs will go up.

Agile: Designed to encourage the former, with the consequence that the latter will likely be kept under tight control.

When Elon Musk first started SpaceX I read an article that he was going to use the Agile project management methodology used in computer programming where tasks and construction are done in 2-week “sprints” allowing great flexibility and creative problem solving and testing within and at the end of each 2-week sprint. The author of the article was really negative on Musk’s chances of success. I’ll admit I was doubtful he could do it.