QuoteNASA Program officials anticipate SpaceX will encounter additional delays on the path to certification. For example, in January 2015, the tunnel that provides a passageway for astronauts and cargo between the Dragon and the ISS was reported to have cracked during the heat treatment phase of the manufacturing process. As a result, SpaceX delayed qualification testing by approximately one year to better align the tests as SpaceX moves toward certification. SpaceX has also experienced ongoing issues with stress fractures in turbopumps that must be resolved prior to flight.
NASA Program officials anticipate SpaceX will encounter additional delays on the path to certification. For example, in January 2015, the tunnel that provides a passageway for astronauts and cargo between the Dragon and the ISS was reported to have cracked during the heat treatment phase of the manufacturing process. As a result, SpaceX delayed qualification testing by approximately one year to better align the tests as SpaceX moves toward certification. SpaceX has also experienced ongoing issues with stress fractures in turbopumps that must be resolved prior to flight.
NASA’s Commercial Crew Program Target Flight DatesPosted on December 12, 2016 at 5:11 pm by Stephanie MartinThe next generation of American spacecraft and rockets that will launch astronauts to the International Space Station are nearing the final stages of development and evaluation. NASA’s Commercial Crew Program will return human spaceflight launches to U.S. soil, providing reliable and cost-effective access to low-Earth orbit on systems that meet our safety and mission requirements. To meet NASA’s requirements, the commercial providers must demonstrate that their systems are ready to begin regular flights to the space station. Two of those demonstrations are uncrewed flight tests, known as Orbital Flight Test for Boeing, and Demonstration Mission 1 for SpaceX. After the uncrewed flight tests, both companies will execute a flight test with crew prior to being certified by NASA for crew rotation mission. The schedule below reflects a fourth quarter update from SpaceX and the dates Boeing released in October 2016.Targeted Flight Dates:Boeing Orbital Flight Test: June 2018Boeing Crew Flight Test: August 2018SpaceX Demonstration Mission 1: November 2017SpaceX Demonstration Mission 2: May 2018https://blogs.nasa.gov/commercialcrew/2016/12/12/nasas-commercial-crew-program-target-flight-dates
Eric Berger @SciGuySpace 6m6 minutes agoExcited to see the [Boeing] suit, but a good source tells me more delays likely for both Starliner and Dragon in coming months.
QuoteEric Berger @SciGuySpace 6m6 minutes agoExcited to see the [Boeing] suit, but a good source tells me more delays likely for both Starliner and Dragon in coming months.https://twitter.com/SciGuySpace/status/824285655643648004
Quote from: FutureSpaceTourist on 01/25/2017 03:07 pmQuoteEric Berger @SciGuySpace 6m6 minutes agoExcited to see the [Boeing] suit, but a good source tells me more delays likely for both Starliner and Dragon in coming months.https://twitter.com/SciGuySpace/status/824285655643648004Not surprising. NASA issued some additional requirements last year and extended several existing requirements. As long as NASA keeps doing that (and the CCtCAP agreements very much allows NASA to do so) the first flights of the CCP vehicles will keep shifting to the right.
@SafeNotAnOption @thehighfrontier more technical problems.
Eric has subsequently tweeted, when asked why the further delays:Quote@SafeNotAnOption @thehighfrontier more technical problems.https://twitter.com/sciguyspace/status/824313975047389185
Quote from: FutureSpaceTourist on 01/25/2017 06:44 pmEric has subsequently tweeted, when asked why the further delays:Quote@SafeNotAnOption @thehighfrontier more technical problems.https://twitter.com/sciguyspace/status/824313975047389185Yes. And some of the technical problems that bedeviled Dragon 2 in late 2015 were a direct result of NASA adding additional requirements. The most prominent one being the requirement to have early missions of Dragon 2 land in the ocean under parachutes, in stead of propulsive landing on land. Other technical problems are associated with the fact that both companies are now deep into the "bending metal" phase.
If mechanical development is like software development I found out the hard way that the quickest way to incorporate requirements changes was to complete the current stage and then modify the working product. The modifications can then be done in a top down fashion starting with requirements documents and managerial controls like budgets and PERTs.
Unlike software development, however, there are some decisions that can't be unmade without enormous cost.
Yes. And some of the technical problems that bedeviled Dragon 2 in late 2015 were a direct result of NASA adding additional requirements. The most prominent one being the requirement to have early missions of Dragon 2 land in the ocean under parachutes, in stead of propulsive landing on land. Other technical problems are associated with the fact that both companies are now deep into the "bending metal" phase.
There was a bootlegged computer generated video showing a Dragon parachute landing in the desert, assisted by Superdracos (like Soyuz but gentler).
I know it's true in software as well. I should have phrased it differently: hardware development is perhaps more susceptible to cases in which seemingly minor, innocuous tweaks in design parameters (as opposed to wholesale architectural changes) require complete scrap and rebuild of enormously expensive products.
Quote from: woods170 on 01/26/2017 08:29 amYes. And some of the technical problems that bedeviled Dragon 2 in late 2015 were a direct result of NASA adding additional requirements. The most prominent one being the requirement to have early missions of Dragon 2 land in the ocean under parachutes, in stead of propulsive landing on land. Other technical problems are associated with the fact that both companies are now deep into the "bending metal" phase.When did that change get made? I remember at the intro events in 2014 that NASA talked about where it was generally agreed that it would start with water landings and then move to land landings if it was proven, and I had assumed that was the plan from the outset, but I could easily have been mistaken. I thought that the public Commercial Crew documents showed that they had proposed the water landings at first, perhaps thinking that NASA wouldn't go for land landings at the outset (or maybe that it would've affected their bid for the contract?).
