"Ride also presented two options that add more flights to the shuttle program, including one plan that would continue operating the system through 2014. That scenario, which has no credible cost estimate, would be a dramatic departure from NASA's current plans. Experts said a lengthy extension of shuttle operations should only be on the table if NASA scraps its Ares rocket and goes to a next-generation booster derived from the shuttle"(Spaceflightnow-July 30,2009) http://www.spaceflightnow.com/news/n0907/30augustine/ This SpaceFlightNow quote means that the Augustine Committee statement that they don't have enough funding for a full manned lunar Mars program refers to the Ares Program not Direct 3."\
Quote from: YoungMethuselah on 07/31/2009 01:56 pmHello Caps,Just seen this on New Scientist:http://www.newscientist.com/article/mg20327194.300-orbiting-gas-station-could-refuel-lunar-missions.htmlto be noted, that Depots and PT is not in the baseline of Direct, but is on the wish list for Future Vision, but does feed into Direct's capabilities and strong points... also, the last comments from the panel: Jeffery responding to Bo's comment; Bo - is it time now to start thinking about commercial fuel stations in space; Jeffery - it is time to be thinking about them, but not planning; (paraphrased, not word for word quote)there was a huge amount of comment on Fuel Depots yesterday, and I got the impression, that this was going to go toward either a Flexible Path option, or as a "IF CONGRESS WILL PROPERLY FUND HSF/EXPLORATION" option that will be one of the two options to be presented to the WH... the other option being put forwrd to the WH/CONGRESS "THIS IS WHAT WE CAN AFFORD ON THE MISERLY, PENNY PINCHING BUDGET YOU'VE GIVEN NASA"
Hello Caps,Just seen this on New Scientist:http://www.newscientist.com/article/mg20327194.300-orbiting-gas-station-could-refuel-lunar-missions.html
I talked with Jeff after the meeting with an observation that I really liked the PD discussion. He noted that his sub committee felt that this option must be more closely examined. I was really impressed with the amount of press the PD concept got. The feeling was that it could be a real game changer WRT beyond LEO operations and encouraging commercial space investment. I remember that statement that sending up fuel or oxygen was "cheap" compared to developing and launching satellites. It was interesting to hear that from somebody from the commercial space arena. There were moments of excitement in the room during yesterday's hearings, and the PD idea was one of them.
Quote from: agman25 on 07/28/2009 02:07 amHaving a time pressure on the launch crew is just not a good idea IMO. Again Please correct me if I am wrong.agman25, I wouldn't call it "time pressure". Both launchers would be fully checked-out and readied on the Pads, ready to launch. The EDS flight would go and 90 minutes later the crew/cargo flight would get its first opportunity to attempt a launch. If that doesn't work for any reason, DIRECT could actually support one launch attempt every day for the next 4 days and there is even an opportunity to try for the 5th day too in some circumstances.There are then three back-to-back opportunities, 90 minutes apart, to send the 'stack' thru TLI on that 5th day.That is the only real 'time pressure' -- but that's because those windows for the TLI only occur every ~14 days or so.But 5, perhaps 6, opportunities is not all much 'pressure', especially as you would only 'waste' an EDS even if you couldn't make it. In the current 1.5 launch arrangement you also 'waste' an Altair if the crew can't launch for any reason.And actually, the real specifications which we have for EDS boiloff would actually allow the EDS to have a workable LEO loiter time well above 14 days -- so theoretically, a single mission could actually get TWO TLI opportunities.[quote[I agree. LOR-LOR is safer despite the performance advantage in other methods.
Having a time pressure on the launch crew is just not a good idea IMO. Again Please correct me if I am wrong.
I'd happily accept nsc with lor-lor. I'd happily take nsc as it is following DIRECT principles even though, again, it is lower performance. I wold assume that the Basic version is the best we will get though - perhaps with 5 seg booster upgrade.Direct is fantastic - NSC is fantastic for the same reasons.
Direct is better for future growth but future growth needs to be paid for.
2017 was the estimated date before Aerospace Corp pointed out that DIRECT hadn't included the MSFC's ability to make mountains out of molehills. The IOC has been moved to 2018 to absorb the civil service inefficiency coefficient.
Danny, I understand the Orion diameter is 5.0 m. This gives a radius of 8.2 ft, not 7.5 ft as used in your simulations. This would increase drag on the capsule by 20%.
Converting to metric is going to kill somebody someday
snipWe discussed this at dinner following the Hearing and that is what Ross was saying too. I think there was a consensus among all of us there that a sustainer is needed. Fortunately, Direct is one of the options that has the margin to accomodate this, but it would add development time to Orion's schedule. The estimate discussed was at least 12 months.
Not quite.We went into Aerospace Corp with the attached manifest. As you will see, there are a total of five test flights in the Jupiter manifest, which take you through 2017 (J-130-X, J-130-Y, J-241-X, J-241-Y and J-241-Z). The first IOC Jupiter-241 flight would then be early in the following year (2018). That was what WE proposed.It appears their analysis says the J-241 can actually do better than that -- by two years!But Jupiter-24x is not the element which will determine the Lunar Landing -- Altair is the critical piece who's schedule will drive the date of the first mission. Anyone who think Altair will take less than 8 years to develop from now, is smoking something pretty strong and I guarantee that even that schedule will slip if NASA budget continues to be squeezed by the White House and Congress any further.So, IMHO, even if we got the green light TODAY, it would be extremely difficult to make a 2017 Lunar mission return date and I would suggest 2018 is more realistic at this point.But if the green light isn't given for another 6 months, that schedule will slip by the same amount -- guaranteed. And while I'd love government to be fast and efficient in making such decisions, I don't think anyone believes this is going to magically happen the day the Augustine Committee reports (end of August).I currently think 2018 is still quite possible. But if it takes until October/November to actually announce the new direction, its probably 50:50 it would slip to 2019.But 2020 was the 'target' set out in the original VSE, so this still achieves that target with room to spare, so that's all good. And compared to what the Committee said yesterday, 2024 for Ares, we're in much, much better shape. Ross.
Danny DegerHas Ross learned to say y'all yet?
Well, then let's convert to metric once and for all. The rest of the world has already done so...
Quote from: Danny Dot on 07/31/2009 03:49 pmConverting to metric is going to kill somebody someday Well, then let's convert to metric once and for all. The rest of the world has already done so...
Quote from: Steven Pietrobon on 07/31/2009 08:00 amDanny, I understand the Orion diameter is 5.0 m. This gives a radius of 8.2 ft, not 7.5 ft as used in your simulations. This would increase drag on the capsule by 20%.Converting to metric is going to kill somebody someday I forgot it was times 3 and "add a little". For some reason I had 15 feet diameter stuck in my head. This is going to hurt. Maybe quite a bit. Drag on Orion post LAS burn is a big, big problem. Thanks for catching my gross incompetence as an engineer. Next time can you PM me Seriously, post it here so all using the model can make an update.Danny Deger
Quote from: simon-th on 07/31/2009 03:51 pmQuote from: Danny Dot on 07/31/2009 03:49 pmConverting to metric is going to kill somebody someday Well, then let's convert to metric once and for all. The rest of the world has already done so... we're traditional English/Imperial here. get over it.
snip1) Danny's simulation has the debris expanding more along the path of flight than in other direction, presumably because different debris particles have different sizes and hence drag to mass ratios. Neither being above nor below the debris field sound like fun, so it seems to me that the proper direction to escape the debris field is to go out of plane, in the third dimension (that Danny's spreadsheet doesn't simulate). Might thrusting the LAS 15 degrees out of plane help?2) The Orion has more than enough velocity to get away; the only problem is it's going in the same direction as the debris cloud so its velocity is not useful. The troublesome aborts occur inside the atmosphere, so why not deploy a pair of small wings to gradually convert Orion's forward velocity into out-of-plane velocity? Hopefully these wings could be made somewhat lighter than the sustainer would be.3) How hard would it be to make a drogue that can handle high temperatures? For example make the entire drogue out of the titanium shape memory alloy used in high-end eyeglasses. Might a tougher drogue be lighter than a sustainer rocket?Update: according to http://www.mdc.umn.edu/nitinol_facts.pdf nitinol is only superelastic over a roughly 50 degree C range and is heat treated using temperatures around 400 degrees C. So the drogue would deploy superelastically but then lose its superelastic properties as it heats up. That might be OK as long as it would retain sufficient tensile strength. According to http://www.shape-memory-alloys.com/data_nitinol.htm its melting point is around 1300 degrees C. Does anyone know how much tensile strength nitinol retains at high temperature?
2) The Orion has more than enough velocity to get away; the only problem is it's going in the same direction as the debris cloud so its velocity is not useful. The troublesome aborts occur inside the atmosphere, so why not deploy a pair of small wings to gradually convert Orion's forward velocity into out-of-plane velocity? Hopefully these wings could be made somewhat lighter than the sustainer would be.
snipIs there anyone else left in the commercial/international space industry working in Imperial Units?
On 1 and 2. Excellent ideas. It would take me a day or two to add the third dimension to the sim. My first guess is left and right will not be a lot better than the up Ross invented.
The following is an e-mail I ‘m sending to the Augustine Committee and my Senators. Any comments?“In the early 1960’s NASA told us that the only way to go to the moon was by Direct Ascent or Earth Orbit Rendezvous. Then Dr. John Houbolt of Langley wrote a letter to Robert Seamans, Associate Administrator for NASA, saying that Lunar Orbit Rendezvous was a better way. Houbolt was chastised for going outside the chain of command but he was right. Today, NASA tells us that Ares I/V is the way to leave Earth’s orbit. However, in the spirit of John Houbolt, a group of NASA engineers, scientist and ordinary people have come up with a better way and it is falling on deaf ears within NASA.Jupiter Direct uses the same 4 segment SRB’s, the same diameter ET and the same shuttle main engines to produce a more powerful, versatile, expandable and safer vehicle than the two stage Ares I. It can support many of the safety features removed by Ares I, like landing on the ground, due to Ares weight restrictions plus it has addition margin to bringing payloads to the ISS. It can also be built sooner and save cost.If and when commercial companies prove they can safely and consistently launch a man-rated vehicle into LEO then the Jupiter Direct can move on to a heavy-lift vehicle by adding the second stage that the Ares I needed just to launch the Orion crew capsule. The cost savings from building one vehicle that is expandable over two vehicles (Ares I/V) are obvious.Direct is a vehicle we can afford now and expand later by adding a second stage, more powerful liquid engines and possibly fifth segment SRB’s. It can shorten or eliminate the gap at the end of the shuttle program. Why is NASA ignoring the Jupiter Direct vehicle even after Aerospace corp. has independently confirmed that the Direct team’s numbers are correct?It’s time to put the “not invented here” attitude and ego’s aside and embrace a vehicle that is less expensive, more versatile and faster to build.”