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| Started by | "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> |
|---|---|
| First post | 2015-12-05 08:41 -0500 |
| Last post | 2016-04-16 23:59 -0700 |
| Articles | 20 on this page of 60 — 9 participants |
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Re: Successful flight by Blue Origin "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2015-12-05 08:41 -0500
Re: Successful flight by Blue Origin Jeff Findley <jfindley@cinci.nospam.rr.com> - 2015-12-05 10:14 -0500
Re: Successful flight by Blue Origin "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2016-04-05 21:49 -0400
Re: Successful flight by Blue Origin Thomas Koenig <tkoenig@netcologne.de> - 2016-04-06 21:30 +0000
Re: Successful flight by Blue Origin Jeff Findley <jfindley@cinci.nospam.rr.com> - 2016-04-07 06:07 -0400
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-07 12:45 -0700
Re: Successful flight by Blue Origin Thomas Womack <twomack@chiark.greenend.org.uk> - 2016-04-08 16:41 +0100
Re: Successful flight by Blue Origin Jeff Findley <jfindley@cinci.nospam.rr.com> - 2016-04-08 18:27 -0400
Re: Successful flight by Blue Origin Rick Jones <rick.jones2@hpe.com> - 2016-04-07 17:43 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-08 12:56 -0700
Re: Successful flight by Blue Origin Jeff Findley <jfindley@cinci.nospam.rr.com> - 2016-04-08 18:26 -0400
Re: Successful flight by Blue Origin "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> - 2016-04-10 08:40 -0400
Re: Successful flight by Blue Origin Jeff Findley <jfindley@cinci.nospam.rr.com> - 2016-04-11 06:11 -0400
Re: Successful flight by Blue Origin "Greg \(Strider\) Moore" <mooregr@deletethisgreenms.com> - 2016-04-11 06:37 -0400
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-08 23:13 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-08 22:01 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-09 06:27 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-09 08:08 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-09 19:03 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-09 13:20 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-09 21:17 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-09 20:22 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-10 06:11 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-10 06:43 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-10 17:09 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-10 17:39 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-11 19:13 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-11 19:59 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-12 06:10 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-12 07:12 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-12 18:25 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-12 15:36 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-12 23:19 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-12 22:23 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-13 18:18 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-13 13:06 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-13 20:44 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-13 19:24 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-14 04:29 +0000
Re: Successful flight by Blue Origin Greg Goss <gossg@gossg.org> - 2016-04-14 01:06 -0600
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-14 18:22 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-14 00:56 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-14 18:28 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-14 14:42 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-14 22:35 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-14 17:22 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-15 00:47 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-14 19:30 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-15 21:45 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-15 16:09 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-16 00:02 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-16 02:59 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-16 17:03 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-16 11:28 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-16 19:17 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-16 12:52 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-16 20:50 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-16 19:40 -0700
Re: Successful flight by Blue Origin jimp@specsol.spam.sux.com - 2016-04-17 05:24 +0000
Re: Successful flight by Blue Origin Fred J. McCall <fjmccall@gmail.com> - 2016-04-16 23:59 -0700
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| From | "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> |
|---|---|
| Date | 2015-12-05 08:41 -0500 |
| Subject | Re: Successful flight by Blue Origin |
| Message-ID | <n3upd4$hgo$2@dont-email.me> |
Kudos to Blue Origin. This is a MAJOR milestone towards reusable rockets. The key capability that allowed the New Shepard to land successfully while SpaceX failed is hovering ability. SpaceX would already have succeeded if they had given the F9 the ability to hover: Hovering capability for the reusable Falcon 9, page 2: Merlin engines in a pressure-fed mode? http://exoscientist.blogspot.com/2015/07/hovering-capability-for-reusable-falcon.html Bob Clark ----------------------------------------------------------------------------------------------------------------------------- A mission to Europa could result in the most important scientific advance in human history, dwarfing even the Apollo missions, to discover life on another world. By commercial space, launch and spacecraft costs can be slashed by a factor of 10 or more. This would be a cost that could be financed privately. And at costs this low it can even be done at a profit: Low cost Europa lander missions. http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html ----------------------------------------------------------------------------------------------------------------------------- "Jeff Findley" wrote in message news:MPG.30beb884bcf464f8989913@news.eternal-september.org... I saw this on Twitter this morning. Blue Origin - Historic Rocket Landing - Published on Nov 24, 2015 https://www.youtube.com/watch?v=9pillaOxGCo Yes, I know it's only suborbital, but a successful launch, separation, descent, and landing from 100 km is nothing to sneeze at. Jeff --
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2015-12-05 10:14 -0500 |
| Message-ID | <MPG.30ccc9764c8baf7989922@news.eternal-september.org> |
| In reply to | #57513 |
In article <n3upd4$hgo$2@dont-email.me>, rgregoryclark@gmSPAMBLOACKail.com says... > > Kudos to Blue Origin. This is a MAJOR milestone towards reusable rockets. > The key capability that allowed the New Shepard to land successfully while > SpaceX failed is hovering ability. Again, the suborbital stage used by Blue Origin does not have the same dry mass ratio requirement that the Falcon 9 first stage has. So, the problem is easier for Blue Origin to solve even discounting the differences in engine technology. > SpaceX would already have succeeded if > they had given the F9 the ability to hover: > > Hovering capability for the reusable Falcon 9, page 2: Merlin engines in a > pressure-fed mode? > http://exoscientist.blogspot.com/2015/07/hovering-capability-for-reusable-falcon.html Might work, but increases complexity because now the center Merlin engine has to work in both a turbo-pump mode and a pressure fed mode. How would this be possible without extensive hardware changes? SpaceX would *not* want to make such hardware changes because it would increase the likelihood of failure during launch. This would be unacceptable to them. Any recovery hardware on the first stage must not increase the risk of failure of the launch itself. An alternative would be SuperDraco engines, but that would require separate tanks, separate plumbing, separate engines, and etc. So the increase in dry mass would be *far* higher than the current "hover slam" approach. Jeff -- "the perennial claim that hypersonic airbreathing propulsion would magically make space launch cheaper is nonsense -- LOX is much cheaper than advanced airbreathing engines, and so are the tanks to put it in and the extra thrust to carry it." - Henry Spencer
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| From | "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> |
|---|---|
| Date | 2016-04-05 21:49 -0400 |
| Message-ID | <ne1poe$5pr$2@dont-email.me> |
| In reply to | #57513 |
Blue Origin once again relaunched the same copy of New Shepard: Why Blue Origin’s latest launch is a huge deal for cheap space access. Blue already proved it could land. Now it's showing it can rinse and repeat. by Eric Berger - Apr 2, 2016 3:36pm EDT [quote]After the January flight, Blue Origin's founder Jeff Bezos told Ars that refurbishing the propulsion module after that first flight cost “in the small tens of thousands of dollars.” His technicians never even removed the engine from the vehicle. “We inspected it and said, 'Let's go.' It was designed to be reusable from the start.”[/quote] http://arstechnica.com/science/2016/04/why-blue-origins-latest-launch-is-a-huge-deal-for-cheap-space-access/ Blue Origin has proven relanding is not particularly hard IF you have hovering ability. On the other hand, "suicide-burn" is the appropriate description for SpaceX's Falcon 9 landing technique, not the "hover-slam" term SpaceX has been using. Since the F9 can not hover, it is inappropriate to include the word "hover" in the landing description. A more appropriate name, aside from suicide-burn, would be "land-or-slam", since without hovering ability you only get one chance at it. You stick the landing on the first try or you crash and burn. SpaceX needs to stop trying to reinvent the wheel, and investigate means of giving the F9 hovering capability. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/nanotech-from-air-to-space/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- "Robert Clark" wrote in message news:n3upd4$hgo$2@dont-email.me... Kudos to Blue Origin. This is a MAJOR milestone towards reusable rockets. The key capability that allowed the New Shepard to land successfully while SpaceX failed is hovering ability. SpaceX would already have succeeded if they had given the F9 the ability to hover: Hovering capability for the reusable Falcon 9, page 2: Merlin engines in a pressure-fed mode? http://exoscientist.blogspot.com/2015/07/hovering-capability-for-reusable-falcon.html Bob Clark ----------------------------------------------------------------------------------------------------------------------------- A mission to Europa could result in the most important scientific advance in human history, dwarfing even the Apollo missions, to discover life on another world. By commercial space, launch and spacecraft costs can be slashed by a factor of 10 or more. This would be a cost that could be financed privately. And at costs this low it can even be done at a profit: Low cost Europa lander missions. http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html ----------------------------------------------------------------------------------------------------------------------------- "Jeff Findley" wrote in message news:MPG.30beb884bcf464f8989913@news.eternal-september.org... I saw this on Twitter this morning. Blue Origin - Historic Rocket Landing - Published on Nov 24, 2015 https://www.youtube.com/watch?v=9pillaOxGCo Yes, I know it's only suborbital, but a successful launch, separation, descent, and landing from 100 km is nothing to sneeze at. Jeff --
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| From | Thomas Koenig <tkoenig@netcologne.de> |
|---|---|
| Date | 2016-04-06 21:30 +0000 |
| Message-ID | <ne3v51$216$1@newsreader4.netcologne.de> |
| In reply to | #57967 |
Robert Clark <rgregoryclark@gmSPAMBLOACKail.com> schrieb: > SpaceX needs to stop trying to reinvent the wheel, and investigate means of > giving the F9 hovering capability. One second of hovering costs 9.81 m/s of delta v. If your aim is to achieve orbit with a reusable rocket and a reasonable payload, you need to save as much delta v as possible. If you aim is to ferry up tourists for a few minutes of zero g, you don't need to economize as much. Both choices are reasonable for what the respective companies want to do.
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2016-04-07 06:07 -0400 |
| Message-ID | <MPG.316ffb6f5d1870c49899a6@news.eternal-september.org> |
| In reply to | #57987 |
In article <ne3v51$216$1@newsreader4.netcologne.de>, tkoenig@netcologne.de says... > > Robert Clark <rgregoryclark@gmSPAMBLOACKail.com> schrieb: > > > SpaceX needs to stop trying to reinvent the wheel, and investigate means of > > giving the F9 hovering capability. > > One second of hovering costs 9.81 m/s of delta v. Yes, but hovering an almost empty first stage with no payload on top requires far less fuel and oxidizer than launch. Note that only one (the center engine) out of nine of the first stage engines are used for landing. On top of that, the engine is throttled down as much as it can be. So, fuel consumption upon landing is far, far less than during launch. > If your aim is to achieve orbit with a reusable rocket and a reasonable > payload, you need to save as much delta v as possible. Or make everything, but the payload, bigger. > If you aim is to ferry up tourists for a few minutes of zero g, you > don't need to economize as much. This is because a sub-orbital hop requires far less delta-V than attaining orbital velocity. > Both choices are reasonable for what the respective companies want to > do. They're reasonable if they work. SpaceX is trying to avoid adding other engines to the Falcon 9 first stage. The stage could hover and land, for example, if it added Super Draco engines to the first stage. But, they require different fuel and oxidizer than the first stage carries. This would mean adding completely different tanks, plumbing, and etc. for those engines. Also, if Super Dracos were used, it would be advantageous to deplete the kerosene and then vent any remaining LOX in the tanks before landing. So, any "leftover" fuel and oxidizer would be "wasted". In my book, this would not be a good trade to make. All of that added complexity and added mass would cost money compared to using "leftover" fuel and oxidizer and an engine that is already there for launch. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2016-04-07 12:45 -0700 |
| Message-ID | <brddgb96l4aj50rcpdnbfum6e7fubraf0k@4ax.com> |
| In reply to | #57999 |
Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
>In article <ne3v51$216$1@newsreader4.netcologne.de>,
>tkoenig@netcologne.de says...
>>
>> Robert Clark <rgregoryclark@gmSPAMBLOACKail.com> schrieb:
>>
>> > SpaceX needs to stop trying to reinvent the wheel, and investigate means of
>> > giving the F9 hovering capability.
>>
>> One second of hovering costs 9.81 m/s of delta v.
>
>Yes, but hovering an almost empty first stage with no payload on top
>requires far less fuel and oxidizer than launch. Note that only one
>(the center engine) out of nine of the first stage engines are used for
>landing. On top of that, the engine is throttled down as much as it can
>be. So, fuel consumption upon landing is far, far less than during
>launch.
>
SpaceX plans to reserve about 10% of the fuel load to get the first
stage back down. If someone needs more payload than that calculation
allows, they will have to buy off the booster because it will be
expended. That's going to be MUCH more expensive, so people are going
to size their loads to not require it.
Nothing says you have to use the full capacity of the booster for
payload. Fuel is cheap. Hardware is expensive.
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
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| From | Thomas Womack <twomack@chiark.greenend.org.uk> |
|---|---|
| Date | 2016-04-08 16:41 +0100 |
| Message-ID | <2jr*hrFWv@news.chiark.greenend.org.uk> |
| In reply to | #58014 |
In article <brddgb96l4aj50rcpdnbfum6e7fubraf0k@4ax.com>, Fred J. McCall <fmccall@gmail.com> wrote: >Nothing says you have to use the full capacity of the booster for >payload. Fuel is cheap. Hardware is expensive. I think there's quite an interesting question as to what you can do with, say, launches which cost a million dollars and which put precisely one ton in a 1m x 1m x 2m volume into LEO. It's certainly not straightforward and I'd be unsure whether it's possible to put into one ton enough of a spacecraft to be able to rendezvous with something else and attach the remaining payload to it. Obviously the first priority would be to get something assembled which is large enough to stay on orbit indefinitely, do all the difficult bits of the rendezvous, and let you make the small spacecraft as stupid as possible. Almost every imaginable space concept was designed by bored graduate students in the sixties, I'd be quite intrigued to see how little you have to bolt around a quantity of liquid xenon to make it reasonable for some other spacecraft to collect and transfer to its own internal tankage the liquid xenon. Tom
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2016-04-08 18:27 -0400 |
| Message-ID | <MPG.3171fa549a9f14699899ac@news.eternal-september.org> |
| In reply to | #58014 |
In article <brddgb96l4aj50rcpdnbfum6e7fubraf0k@4ax.com>, fjmccall@gmail.com says... > > Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: > > >In article <ne3v51$216$1@newsreader4.netcologne.de>, > >tkoenig@netcologne.de says... > >> > >> Robert Clark <rgregoryclark@gmSPAMBLOACKail.com> schrieb: > >> > >> > SpaceX needs to stop trying to reinvent the wheel, and investigate means of > >> > giving the F9 hovering capability. > >> > >> One second of hovering costs 9.81 m/s of delta v. > > > >Yes, but hovering an almost empty first stage with no payload on top > >requires far less fuel and oxidizer than launch. Note that only one > >(the center engine) out of nine of the first stage engines are used for > >landing. On top of that, the engine is throttled down as much as it can > >be. So, fuel consumption upon landing is far, far less than during > >launch. > > > > SpaceX plans to reserve about 10% of the fuel load to get the first > stage back down. If someone needs more payload than that calculation > allows, they will have to buy off the booster because it will be > expended. That's going to be MUCH more expensive, so people are going > to size their loads to not require it. > > Nothing says you have to use the full capacity of the booster for > payload. Fuel is cheap. Hardware is expensive. Agreed. And if Falcon 9 is too small, buy a Falcon Heavy launch, assuming that its development progresses this year. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | Rick Jones <rick.jones2@hpe.com> |
|---|---|
| Date | 2016-04-07 17:43 +0000 |
| Message-ID | <ne6675$moj$1@news.hpeswlab.net> |
| In reply to | #57999 |
In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: > They're reasonable if they work. SpaceX is trying to avoid adding > other engines to the Falcon 9 first stage. The stage could hover > and land, for example, if it added Super Draco engines to the first > stage. But, they require different fuel and oxidizer than the first > stage carries. This would mean adding completely different tanks, > plumbing, and etc. for those engines. Also, if Super Dracos were > used, it would be advantageous to deplete the kerosene and then vent > any remaining LOX in the tanks before landing. So, any "leftover" > fuel and oxidizer would be "wasted". In my book, this would not be > a good trade to make. If one wanted to give the Falcon 9 first stage the ability to hover, wouldn't the most straightforward way to do that be create a deeply-throttled Merlin? rick jones -- a wide gulf separates "what if" from "if only" these opinions are mine, all mine; HPE might not want them anyway... :) feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...
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| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2016-04-08 12:56 -0700 |
| Message-ID | <d53ggbdkh7rh268kiug7h5kpsoofgqd4e8@4ax.com> |
| In reply to | #58034 |
Rick Jones <rick.jones2@hpe.com> wrote:
>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
>> They're reasonable if they work. SpaceX is trying to avoid adding
>> other engines to the Falcon 9 first stage. The stage could hover
>> and land, for example, if it added Super Draco engines to the first
>> stage. But, they require different fuel and oxidizer than the first
>> stage carries. This would mean adding completely different tanks,
>> plumbing, and etc. for those engines. Also, if Super Dracos were
>> used, it would be advantageous to deplete the kerosene and then vent
>> any remaining LOX in the tanks before landing. So, any "leftover"
>> fuel and oxidizer would be "wasted". In my book, this would not be
>> a good trade to make.
>
>If one wanted to give the Falcon 9 first stage the ability to hover,
>wouldn't the most straightforward way to do that be create a
>deeply-throttled Merlin?
>
Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2016-04-08 18:26 -0400 |
| Message-ID | <MPG.3171fa19623b53449899ab@news.eternal-september.org> |
| In reply to | #58044 |
In article <d53ggbdkh7rh268kiug7h5kpsoofgqd4e8@4ax.com>, fjmccall@gmail.com says... > > Rick Jones <rick.jones2@hpe.com> wrote: > > >In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: > >> They're reasonable if they work. SpaceX is trying to avoid adding > >> other engines to the Falcon 9 first stage. The stage could hover > >> and land, for example, if it added Super Draco engines to the first > >> stage. But, they require different fuel and oxidizer than the first > >> stage carries. This would mean adding completely different tanks, > >> plumbing, and etc. for those engines. Also, if Super Dracos were > >> used, it would be advantageous to deplete the kerosene and then vent > >> any remaining LOX in the tanks before landing. So, any "leftover" > >> fuel and oxidizer would be "wasted". In my book, this would not be > >> a good trade to make. > > > >If one wanted to give the Falcon 9 first stage the ability to hover, > >wouldn't the most straightforward way to do that be create a > >deeply-throttled Merlin? > > > > Straightforward, perhaps, but it's a very big design change so you > start with having to requalify as if it's a whole new engine. And today's successful barge landing proves they don't *need* to hover! http://www.theverge.com/2016/4/8/11392138/spacex-landing-success-falcon- 9-rocket-barge-at-sea I watched it live and it looked like a very nice landing. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | "Robert Clark" <rgregoryclark@gmSPAMBLOACKail.com> |
|---|---|
| Date | 2016-04-10 08:40 -0400 |
| Message-ID | <nedhe6$rve$2@dont-email.me> |
| In reply to | #58054 |
If they can do this 4 or 5 times in a row even if they have 1 failure after that, then might be adequate for an unmanned booster. More likely though they'll have couple of successes then a failure. Suicide-burn is inherently less reliable than a hovering approach. Bob Clark ---------------------------------------------------------------------------------------------------------------------------------- Finally, nanotechnology can now fulfill its potential to revolutionize 21st-century technology, from the space elevator, to private, orbital launchers, to 'flying cars'. This crowdfunding campaign is to prove it: Nanotech: from air to space. https://www.indiegogo.com/projects/nanotech-from-air-to-space/x/13319568/ ---------------------------------------------------------------------------------------------------------------------------------- "Jeff Findley" wrote in message news:MPG.3171fa19623b53449899ab@news.eternal-september.org... In article <d53ggbdkh7rh268kiug7h5kpsoofgqd4e8@4ax.com>, fjmccall@gmail.com says... > > Rick Jones <rick.jones2@hpe.com> wrote: > > >In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: > >> They're reasonable if they work. SpaceX is trying to avoid adding > >> other engines to the Falcon 9 first stage. The stage could hover > >> and land, for example, if it added Super Draco engines to the first > >> stage. But, they require different fuel and oxidizer than the first > >> stage carries. This would mean adding completely different tanks, > >> plumbing, and etc. for those engines. Also, if Super Dracos were > >> used, it would be advantageous to deplete the kerosene and then vent > >> any remaining LOX in the tanks before landing. So, any "leftover" > >> fuel and oxidizer would be "wasted". In my book, this would not be > >> a good trade to make. > > > >If one wanted to give the Falcon 9 first stage the ability to hover, > >wouldn't the most straightforward way to do that be create a > >deeply-throttled Merlin? > > > > Straightforward, perhaps, but it's a very big design change so you > start with having to requalify as if it's a whole new engine. And today's successful barge landing proves they don't *need* to hover! http://www.theverge.com/2016/4/8/11392138/spacex-landing-success-falcon- 9-rocket-barge-at-sea I watched it live and it looked like a very nice landing. Jeff --
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2016-04-11 06:11 -0400 |
| Message-ID | <MPG.317542546b3a01499899ba@news.eternal-september.org> |
| In reply to | #58141 |
In article <nedhe6$rve$2@dont-email.me>, rgregoryclark@gmSPAMBLOACKail.com says... > > If they can do this 4 or 5 times in a row even if they have 1 failure after > that, then might be adequate for an unmanned booster. More likely though > they'll have couple of successes then a failure. Suicide-burn is inherently > less reliable than a hovering approach. Agreed. But that said, space shuttle glide landings were inherently less reliable than powered landings, yet it was "safe enough" that we did not see a landing failure during that program. SpaceX is gaining experience with this mode of recovery even if a thrust to weight greater than one is not ideal. On their next reusable launch vehicle design, they should have the opportunity to make improvements. Exactly what improvements may very well depend on how the rest of the Falcon 9/Falcon Heavy program pans out. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | "Greg \(Strider\) Moore" <mooregr@deletethisgreenms.com> |
|---|---|
| Date | 2016-04-11 06:37 -0400 |
| Message-ID | <t8idncUkuc7g45bKnZ2dnUU7-dHNnZ2d@earthlink.com> |
| In reply to | #58189 |
"Jeff Findley" wrote in message news:MPG.317542546b3a01499899ba@news.eternal-september.org... > >In article <nedhe6$rve$2@dont-email.me>, >rgregoryclark@gmSPAMBLOACKail.com says... >> >> If they can do this 4 or 5 times in a row even if they have 1 failure >> after >> that, then might be adequate for an unmanned booster. More likely though >> they'll have couple of successes then a failure. Suicide-burn is >> inherently >> less reliable than a hovering approach. > >Agreed. But that said, space shuttle glide landings were inherently >less reliable than powered landings, yet it was "safe enough" that we >did not see a landing failure during that program. To fair we'd had over 8 decades of experience of gliding/horizontal landings and we had the Mark I eyeball in the cockpit to respond to unknowns. > >SpaceX is gaining experience with this mode of recovery even if a thrust >to weight greater than one is not ideal. On their next reusable launch >vehicle design, they should have the opportunity to make improvements. >Exactly what improvements may very well depend on how the rest of the >Falcon 9/Falcon Heavy program pans out. > Ayup. >Jeff -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-04-08 23:13 +0000 |
| Message-ID | <miqltc-fb8.ln1@mail.specsol.com> |
| In reply to | #58044 |
In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: > Rick Jones <rick.jones2@hpe.com> wrote: > >>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: >>> They're reasonable if they work. SpaceX is trying to avoid adding >>> other engines to the Falcon 9 first stage. The stage could hover >>> and land, for example, if it added Super Draco engines to the first >>> stage. But, they require different fuel and oxidizer than the first >>> stage carries. This would mean adding completely different tanks, >>> plumbing, and etc. for those engines. Also, if Super Dracos were >>> used, it would be advantageous to deplete the kerosene and then vent >>> any remaining LOX in the tanks before landing. So, any "leftover" >>> fuel and oxidizer would be "wasted". In my book, this would not be >>> a good trade to make. >> >>If one wanted to give the Falcon 9 first stage the ability to hover, >>wouldn't the most straightforward way to do that be create a >>deeply-throttled Merlin? >> > > Straightforward, perhaps, but it's a very big design change so you > start with having to requalify as if it's a whole new engine. Yet you were just saying in another thread space stuff doesn't have bureaucrat bullshit. -- Jim Pennino
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| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2016-04-08 22:01 -0700 |
| Message-ID | <853hgbhb1upineo2a2c743uvuvrapri720@4ax.com> |
| In reply to | #58063 |
jimp@specsol.spam.sux.com wrote:
>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote:
>> Rick Jones <rick.jones2@hpe.com> wrote:
>>
>>>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
>>>> They're reasonable if they work. SpaceX is trying to avoid adding
>>>> other engines to the Falcon 9 first stage. The stage could hover
>>>> and land, for example, if it added Super Draco engines to the first
>>>> stage. But, they require different fuel and oxidizer than the first
>>>> stage carries. This would mean adding completely different tanks,
>>>> plumbing, and etc. for those engines. Also, if Super Dracos were
>>>> used, it would be advantageous to deplete the kerosene and then vent
>>>> any remaining LOX in the tanks before landing. So, any "leftover"
>>>> fuel and oxidizer would be "wasted". In my book, this would not be
>>>> a good trade to make.
>>>
>>>If one wanted to give the Falcon 9 first stage the ability to hover,
>>>wouldn't the most straightforward way to do that be create a
>>>deeply-throttled Merlin?
>>>
>>
>> Straightforward, perhaps, but it's a very big design change so you
>> start with having to requalify as if it's a whole new engine.
>
>Yet you were just saying in another thread space stuff doesn't have
>bureaucrat bullshit.
>
Cite?
--
"You take the lies out of him, and he'll shrink to the size of
your hat; you take the malice out of him, and he'll disappear."
-- Mark Twain
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-04-09 06:27 +0000 |
| Message-ID | <5vjmtc-mua.ln1@mail.specsol.com> |
| In reply to | #58069 |
In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: > jimp@specsol.spam.sux.com wrote: > >>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >>> Rick Jones <rick.jones2@hpe.com> wrote: >>> >>>>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: >>>>> They're reasonable if they work. SpaceX is trying to avoid adding >>>>> other engines to the Falcon 9 first stage. The stage could hover >>>>> and land, for example, if it added Super Draco engines to the first >>>>> stage. But, they require different fuel and oxidizer than the first >>>>> stage carries. This would mean adding completely different tanks, >>>>> plumbing, and etc. for those engines. Also, if Super Dracos were >>>>> used, it would be advantageous to deplete the kerosene and then vent >>>>> any remaining LOX in the tanks before landing. So, any "leftover" >>>>> fuel and oxidizer would be "wasted". In my book, this would not be >>>>> a good trade to make. >>>> >>>>If one wanted to give the Falcon 9 first stage the ability to hover, >>>>wouldn't the most straightforward way to do that be create a >>>>deeply-throttled Merlin? >>>> >>> >>> Straightforward, perhaps, but it's a very big design change so you >>> start with having to requalify as if it's a whole new engine. >> >>Yet you were just saying in another thread space stuff doesn't have >>bureaucrat bullshit. >> > > Cite? Sure, it was by someone called Fred J. McCall talking about nuclear reactors on Mars being cheap for lack of bureaucrat bullshit. -- Jim Pennino
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| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2016-04-09 08:08 -0700 |
| Message-ID | <6i6igbhie0a1jvhj9s56rcdv907svf5v20@4ax.com> |
| In reply to | #58078 |
jimp@specsol.spam.sux.com wrote:
>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote:
>> jimp@specsol.spam.sux.com wrote:
>>
>>>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote:
>>>> Rick Jones <rick.jones2@hpe.com> wrote:
>>>>
>>>>>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
>>>>>> They're reasonable if they work. SpaceX is trying to avoid adding
>>>>>> other engines to the Falcon 9 first stage. The stage could hover
>>>>>> and land, for example, if it added Super Draco engines to the first
>>>>>> stage. But, they require different fuel and oxidizer than the first
>>>>>> stage carries. This would mean adding completely different tanks,
>>>>>> plumbing, and etc. for those engines. Also, if Super Dracos were
>>>>>> used, it would be advantageous to deplete the kerosene and then vent
>>>>>> any remaining LOX in the tanks before landing. So, any "leftover"
>>>>>> fuel and oxidizer would be "wasted". In my book, this would not be
>>>>>> a good trade to make.
>>>>>
>>>>>If one wanted to give the Falcon 9 first stage the ability to hover,
>>>>>wouldn't the most straightforward way to do that be create a
>>>>>deeply-throttled Merlin?
>>>>>
>>>>
>>>> Straightforward, perhaps, but it's a very big design change so you
>>>> start with having to requalify as if it's a whole new engine.
>>>
>>>Yet you were just saying in another thread space stuff doesn't have
>>>bureaucrat bullshit.
>>>
>>
>> Cite?
>>
>
>Sure, it was by someone called Fred J. McCall talking about nuclear
>reactors on Mars being cheap for lack of bureaucrat bullshit.
>
Wow, you REALLY don't comprehend English, do you? Either that or
you're just so intellectually dishonest everything sounds different to
you. Note that even if you interpret that one instance the way you do
(which is twisted) it doesn't say what you claim I've said.
Stop making up lies, Chimp.
--
"You take the lies out of him, and he'll shrink to the size of
your hat; you take the malice out of him, and he'll disappear."
-- Mark Twain
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| From | jimp@specsol.spam.sux.com |
|---|---|
| Date | 2016-04-09 19:03 +0000 |
| Message-ID | <l90otc-2gf.ln1@mail.specsol.com> |
| In reply to | #58088 |
In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: > jimp@specsol.spam.sux.com wrote: > >>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >>> jimp@specsol.spam.sux.com wrote: >>> >>>>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >>>>> Rick Jones <rick.jones2@hpe.com> wrote: >>>>> >>>>>>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: >>>>>>> They're reasonable if they work. SpaceX is trying to avoid adding >>>>>>> other engines to the Falcon 9 first stage. The stage could hover >>>>>>> and land, for example, if it added Super Draco engines to the first >>>>>>> stage. But, they require different fuel and oxidizer than the first >>>>>>> stage carries. This would mean adding completely different tanks, >>>>>>> plumbing, and etc. for those engines. Also, if Super Dracos were >>>>>>> used, it would be advantageous to deplete the kerosene and then vent >>>>>>> any remaining LOX in the tanks before landing. So, any "leftover" >>>>>>> fuel and oxidizer would be "wasted". In my book, this would not be >>>>>>> a good trade to make. >>>>>> >>>>>>If one wanted to give the Falcon 9 first stage the ability to hover, >>>>>>wouldn't the most straightforward way to do that be create a >>>>>>deeply-throttled Merlin? >>>>>> >>>>> >>>>> Straightforward, perhaps, but it's a very big design change so you >>>>> start with having to requalify as if it's a whole new engine. >>>> >>>>Yet you were just saying in another thread space stuff doesn't have >>>>bureaucrat bullshit. >>>> >>> >>> Cite? >>> >> >>Sure, it was by someone called Fred J. McCall talking about nuclear >>reactors on Mars being cheap for lack of bureaucrat bullshit. >> > > Wow, you REALLY don't comprehend English, do you? Either that or > you're just so intellectually dishonest everything sounds different to > you. Note that even if you interpret that one instance the way you do > (which is twisted) it doesn't say what you claim I've said. > > Stop making up lies, Chimp. Stop taking mind altering drugs, space cadet. -- Jim Pennino
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| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2016-04-09 13:20 -0700 |
| Message-ID | <h0pigb5c8g4mm67hc421idi3dqeugq8nk2@4ax.com> |
| In reply to | #58105 |
jimp@specsol.spam.sux.com wrote: >In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >> jimp@specsol.spam.sux.com wrote: >> >>>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >>>> jimp@specsol.spam.sux.com wrote: >>>> >>>>>In sci.physics Fred J. McCall <fjmccall@gmail.com> wrote: >>>>>> Rick Jones <rick.jones2@hpe.com> wrote: >>>>>> >>>>>>>In sci.space.policy Jeff Findley <jfindley@cinci.nospam.rr.com> wrote: >>>>>>>> They're reasonable if they work. SpaceX is trying to avoid adding >>>>>>>> other engines to the Falcon 9 first stage. The stage could hover >>>>>>>> and land, for example, if it added Super Draco engines to the first >>>>>>>> stage. But, they require different fuel and oxidizer than the first >>>>>>>> stage carries. This would mean adding completely different tanks, >>>>>>>> plumbing, and etc. for those engines. Also, if Super Dracos were >>>>>>>> used, it would be advantageous to deplete the kerosene and then vent >>>>>>>> any remaining LOX in the tanks before landing. So, any "leftover" >>>>>>>> fuel and oxidizer would be "wasted". In my book, this would not be >>>>>>>> a good trade to make. >>>>>>> >>>>>>>If one wanted to give the Falcon 9 first stage the ability to hover, >>>>>>>wouldn't the most straightforward way to do that be create a >>>>>>>deeply-throttled Merlin? >>>>>>> >>>>>> >>>>>> Straightforward, perhaps, but it's a very big design change so you >>>>>> start with having to requalify as if it's a whole new engine. >>>>> >>>>>Yet you were just saying in another thread space stuff doesn't have >>>>>bureaucrat bullshit. >>>>> >>>> >>>> Cite? >>>> >>> >>>Sure, it was by someone called Fred J. McCall talking about nuclear >>>reactors on Mars being cheap for lack of bureaucrat bullshit. >>> >> >> Wow, you REALLY don't comprehend English, do you? Either that or >> you're just so intellectually dishonest everything sounds different to >> you. Note that even if you interpret that one instance the way you do >> (which is twisted) it doesn't say what you claim I've said. >> >> Stop making up lies, Chimp. > >Stop taking mind altering drugs, space cadet. > Stop begging to suck my dick, Chimp. -- You are What you do When it counts.
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