Orbital's Antares rocket makes test flight | Hacker News Reader

Orbital's Antares rocket makes test flight

bbc.co.uk

54 pointsnkhumphreys28 comments

The phonesats got deployed! I'm happy because I worked on them.

This would be a routine flight if it wasn't for the fact that everything was done with a very low budget.

It's also (I think) the first flight to orbit for an NK-33 engine since they were built 40 years ago!

Yup. Soviet moon rocket engines! 120 of those suckers have been lit and running on rockets but none of the engines have ever put anything in orbit, until now!

Nope. N-1 which have flown 4 times with 30 engines on each first stage didn't use NK-33. It used NK-15, a very different engine with similar thrust. N-1 never flown with NK-33, having been scrapped before NK-33 were ready to fly.

The NK-33 is enormously similar to the NK-15. It's basically the same engine with modifications for higher chamber pressure which slightly increase thrust and Isp. Also, technically the Antares uses the Aerojet AJ26-58, if you want to get persnickity.

Here's a photo comparison of the NK-15 and the NK-33 or AJ26-58: http://i.imgur.com/vwYIwFd.jpg

Yes and no. NK-33 was developed from NK-15 but had a lot of difference. Mainly, NK-15 could not be restarted (i don't mean in flight, but at all: it could be lighted only once, then it went to the scrapyard). So, it couldn't be TESTED. That's why N-1 had 100% failure rate (another reason was a buggy engine-out management system, which was designed to enable rocket to fly with some engines out, but in fact did the reverse, twice causing it to fail when then failed engines could be simply ignored).

NK-33, on the other hand, could be restarted many times, and some copies counted a lot of time on the test stand.

Among other things NK-33 has completely redesigned turbopump comparing to NK-15. The pump believed to be the major cause of problems with NK-15.

can you tell use more about that ? I heard this rocket has put cubesats for radio amateurs communication I think, but I'm not sure about that.

Can 'I', if I were a HAM operator, connect to these cubesats ?

Phonesat only has a down link. Anyone can receive that data and decode it. It's pretty simple to do with a simple hand held antenna, a tracking program, and a $10 rtl-sdr device.

The only time you need an amateur license is to send on an uplink frequency that's in an amateur band. With a couple weeks of studying you can easily get your tech license which will give you enough privileges to send on the sat frequencies. If you're close to a club that tests under the Laurel VEC [0], then the test will be free. Even the most expensive tests are only $15.

[0] http://larcmdorg.doore.net/vec/index.php?pg=Exams13

Maybe. If you have digital packet radio equipment then you can indeed receive packets from these phonesats.

http://www.phonesat.org/packets.php

There's not even a high cost to the equipment. A $10 rtl-sdr with a $30 home built antenna will be enough to capture the audio data.

Why does Orbital Sciences get $1.9 billion for 8 missions but SpaceX $1.6 billion for 12 missions?

They both had previous experience building rockets (Orbital had Taurus/Minotaur families with launches over two decades while SpaceX had little experience with only the Falcon 1) so it seems strange for there to be such a large discrepancy. That's $133 million per mission including Dragon/Falcon 9 development vs $237.5 million per mission including Cygnus/Antares development, more than $100 million extra PER MISSION!!

At the time of contract being awarded, it was rational. Orbital had a lot of experience building and launching stuff (not just rockets, and you also forgot Pegasus air-launched rocket), and was in business for almost 25 years, while SpaceX has just started with their business and had almost no track record - 4 launches of light Falcon 1 with only 1 of them successful. So a more experienced contractor got a better price, which is natural. Now it seems to be the reversed, but it wasn't back then. It only demonstrates how much progress SpaceX made in these 3.5 years.

Although both rockets have roughly equivalent upmass, their respective delivery vehicles are completely different beasts: Dragon is a compact spacecraft, designed to safely fly humans in a shirtsleeve environment and return them to Earth, whereas Cygnus is more like a large pressurised can with some thrusters attached. Cygnus has no downmass capability at all, but has a LOT more pressurised volume -- and in some cases (including, possibly, the recent SpaceX launches to the station), volume rather than weight can be the limiting factor for payloads. It's not implausible that NASA used some kind of formula which prioritised volume over weight, and arrived at the respective payments for each type of mission.

Of course neither is it implausible that Orbital Sciences simply has better lobbyists than SpaceX.

Both contracts are for 20 tons to orbit, so the difference is not as large. Also, there was no competition - both 1st place and 2nd place were assured contracts. So the competition would have been only for the second place, to not miss out. But since there were only two entrants...

Now Congress want to down-select commercial crew to force NASA to depend on a single contractor that can then start jacking up the price like Boeing and Lockheed Martin regularly do, to kill the commercial benefits of commercial space and protect the government monopoly way of doing business.

Correction: There was a third entrant which lost. So there was a competition, at the proposal phase. Apparently, they asked for even more money.

http://en.wikipedia.org/wiki/PlanetSpace

Welcome to the world of government contracting. There was a requirement for two vendors, they got 5 proposals, they chose what they believed to be the best two, at the price the vendors specified. They weren't allowed to haggle.

Orbital has been around the block many, many more times than SpaceX.

My big question about this, what does Orbital do once its supply of pre-built and never used Russian rockets runs out?

Aerojet, the company that reworks the old engines before sending them to Orbital, purchased 36 engines. That's enough for 18 Antares rockets. That will cover the current CRS contract and maybe a follow-up or some commercial satellite launches. Beyond that Aerojet has a license to manufacture US-made copies of the engines. That isn't as easy as following a recipe, but it is something they are working on.

Orbital has the US rights to build new copies of the original NK-33. Presumably they'd set up some kind of production line once they have enough customers to exhaust their russian-sourced supply.

Launch video (terrible camera work at launch. Also intermittent video feed in final minutes): http://www.youtube.com/watch?v=V3L7crGudVU

We watched on NASA TV (I think that's where this footage comes from) and whoever directed made the baffling choice to show the liftoff as the top half of the rocket. No flame, no smoke, no apparent movement. Pretty lame for my 3.5 year old son...

Why is it using a solid second stage? What are the advantages beyond weight? It isn´t more risky if you have to compensate for some kind of 1st stage under or over burn?

It's a solid upper stage because of time-to-market considerations, not because it's a good idea. For the first stage, thrust is more important than fuel efficiency, so a solid first stage (or boosters) make sense (at least for unmanned flights where there is no escape system), but for upper stages the fuel efficiency is more important than thrust so the upper stages should be liquid and if possible LH2/LOX, though that is the most expensive to develop (up front cost) and handle (recurring cost).

Castor 30 has vacuum isp of 300sec, while Merlin 1Dvac is around 340sec. There are rumors of SpaceX working on a closed cycle methane engine, which should have even better fuel efficiency.

http://www.spacelaunchreport.com/taurus2.html

http://www.spacelaunchreport.com/falcon9.html

It's not a rumor, SpaceX has stated publicly that they're working on LOX/Methane engines. There are two big reasons for this. On the one hand, it's just a good idea, liquid methane is a pretty decent compromise between LH2 and kerosene in terms of Isp vs. density (both of which affect overall stage performance) and since LCH4 exists at a similar temperature to LOX it doesn't add any exceptional problems into vehicle design or operations the way LH2 does. But perhaps more profoundly, methane is actually shockingly easy to manufacture on Mars with a very small amount of industrial equipment (we're talking about mere kilograms, provided there's sufficient power available). So the development of methane fueled rockets is also very much a way to build the systems and technology necessary for facilitating exploration and colonization of Mars.

Orbital has scads of experience with solid rocket motors. Simplicity is the major advantage (and disadvantage).

My god, look at the execution here. The CEO, David Thompson, is a visionary. Is there nothing he cannot do? Truly, I worship the ground he walks on.

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