Dan posts the latest update from SpaceX, featuring several views of the cargo and crewed variants of their Dragon capsule.
Hopefully there’s more detail to their actual design than what’s shown in those images. Granted, I’m working from a limited set of data, but to my eye there seem to be several major flaws in the design, not to mention a number of items missing or unrealistically sized/designed.
And no, before anyone asks, I’m not going to go into detail as to what those shortcomings are, since it’s not my job to give SpaceX free advice. Feel free to use the comments to this post if you’d like to speculate, however — I’m curious to see if anyone else spots the items I’ve noticed.
>I’m not going to go into detail as to what those shortcomings are, since it’s not my job to give SpaceX free advice.
That seems like a weird attitude to me from someone as interested in space as you are. You’ll spend time on your blog writing about politics and commenting on space-related ‘fluff’ like Branson’s SS2 marketing and Ansari’s ISS jaunt. However, you won’t provide your opinions on SpaceX’s design specifically because what you say might be valuable and they haven’t paid you. Mind you, I’d see the issue if your input was proprietary LM information, or if there was patentable designs involved. However, from your note, it appears that you’re primarily talking about problems in proportions and ‘missing’ items.
Unless you’ve seen more detailed graphics than I’ve so far located — missing items is a given. The graphics simply don’t provide much detail. Items not shown include the ECLSS, batteries, controls & displays, avionics, communications & other electronics, parachutes, and probably the OMS since I doubt the RCS shown is large enough for the required dv. Strangely enough, what *is* shown is a baseline RCS — which seems to be essentially a red herring because SpaceX has already stated that the Dragon sitting on their warehouse floor currently doesn’t have an RCS. Ergo — it seems to me that any flaws that you can see in the supplied graphics have to be taken with a very large grain of salt.
As to proportions — the only reasonable hard measurement I can see is the maximum diameter of the base — which should be the same as the Falcon 9 diameter. From that I’ve made estimates on various other outer dimensions of the craft. However — so far that’s consisted of holding a ruler up to my monitor… not the most accurate of methods. Other than exterior dimensions, the only items that I can see which are sizeable are the solar arrays, the crewmembers, and the RCS. None of these seem *obviously* off to me (in engineering terms, anyway — I question the utility of the solar arrays for the Dragon mission profile)… but then I’ve never claimed to be an aeronautics engineer.
All that aside — for my own part, I’d *love* to be able to offer SpaceX feedback on their design which they would find valuable. The thought that ten minutes of my time might actually make a real difference in a spacecraft is valuable to me. I have a job that pays the bills. SpaceX — or any company trying to advance space technology is welcome to some of the ‘idle CPU cycles’ of my brain.
I write about what I choose to write about, and don’t write what I don’t choose to write about.
I don’t think there’s anything weird about my attitude towards SpaceX. I too have a job which pays the bills, and it happens to be with another company in the same line of business. It’s simple loyalty — there’s no reason for me to offer free advice to one of my employer’s (wannabe) competitors, and every reason in the world not to. Just ask Kenneth Branch.
As for having access to other information, no, I have no other information on their configuration than what SpaceX has made public. As I noted in the post, my impressions were drawn from a limited set of data. But while the images may not show a complete or optimized configuration, they do show a few items which appear blatantly wrong to my eye. Not merely flaws at the detail level, but fundamental problems.
No question but that it’s your BLOG and you’ll write if you want to. Noting that you have LM as an employer is certainly a more understandable position than what you stated in the first post. Initially, you said Spacex isn’t paying you — therefore you’re not providing input. Your second post is more along the lines of: SpaceX’s competitor is paying you — therefore you’re not providing input.
The first is a personal choice — one which I considered strange for a space enthusiast. The second is a professional choice, which is only a personal choice if you have no concerns about remaining professionally employed. 🙂