A little bit off thread, but here it comes:Taurus, Minotaur and Antares all use a Hardware AND SOFTWARE architecture Orbital calls MACH (Modular Avionics something or other, pardon me, I have little patience for that stuff...) made up of about a dozen types of "slices" (computer, I/O, power supply, ordnance drives, etc. etc.) that can be stacked up in an enclosureless-type way (i.e. each slice has its own peripheral enclosure and the ends are closed up by plates) I've seen MACH stacks as small as 5 slices and as large as 11, IIRC. Intra-slice connections are built into the "sides" of each slice, and external connectors are on one of the sides of each slice. The result looks a lot like a loaf of sliced brad.Each of the above-mentioned launch vehicles has a number of differently-configured MACH "stacks" acting as the central avionics, stage remote I/O, engine controller, etc. Slices (and stacks) communicate via Ethernet. Indeed, a MACH stack is used in the Antares launch pad both to communicate with the rocket AND control the pad (e.g. TEL retraction after ignition.)Pegasus used an older design but is slowly converting to the MACH architecture (the last two Pegasi flew a MAC stack as its flight computer - the resulting change in software made NASA pause and take a deep breath, but it was the right thing to do and it worked.)More important, other Orbital products (e.g. targets) also use this architecture; the result is a) lots and lots of experience (dozens of MACH stacks and socres of MACH slices are flown every year) and b) non-trivial cost reductions. Similar benefit with software: the amount of NEW software needed for Antares was focused on the liquid propellant elements while, for instance, the basic GN&C has long heritage (yes, even the variable-azimuth feature!...)The MACH architecture is uniquely designed for Launch Vehicles and is not intended to be used on spacecraft, BTW.
Can anyone in the industry discuss the benefits of doing MACH as (apparently) a literal stack of hardware components rather than a modular software stack loaded into a single machine? Are the data ports required for each rocket different enough that the modular design is actually more about them than the software?
I would be curious if some of those boards contained gyro's and accellerometers or if they just interfaced to ones placed elsewhere in the rocket.
Originally (N-1 days) to increase the volumetric efficiency of the Oxydizer system (LOX itself and tanks). However, the NK33 LOX pump bearings take advantage of the properties of the apparently superior lubricating properties of sub cooled LOX so we're stuck. Pre-chill is a common requirement for any cryo system, sub-cooled or boiling-point.
I wonder if the Antares could handle 6- 7 Merlins.
Quote from: TrevorMonty on 01/16/2014 01:17 amI wonder if the Antares could handle 6- 7 Merlins.The core is wider than the Falcon 9, so physically yes. But it doesn't have enough isp, the piping, control and avionics would have to be redone. So it doesn't really makes much economic sense. Dual RD-191 or even an AJ-1E6 would give a much better performance with little engineering effort.
Not having a down mass capability is part of why it has the better up mass.
Nice review of soon to appear planned upgrades to Antares and Cygnus today over at that other site.http://www.spaceflightnow.com/news/n1401/14orbital/#.Utc2Gvt0lpECygnus, already carrying more up cargo than Dragon, will soon carry substantially more - and Orbital wants to start planning for post-2016 ISS missions soon. Also some hints about an increasingly dim future for NK-33/AJ-26. - Ed Kyle
Quote from: edkyle99 on 01/16/2014 12:32 amNice review of soon to appear planned upgrades to Antares and Cygnus today over at that other site.http://www.spaceflightnow.com/news/n1401/14orbital/#.Utc2Gvt0lpECygnus, already carrying more up cargo than Dragon, will soon carry substantially more - and Orbital wants to start planning for post-2016 ISS missions soon. Also some hints about an increasingly dim future for NK-33/AJ-26. - Ed Kylethx for the linkFound this interesting: " Antares rocket's more powerful Castor 30XL upper stage motor provided by ATK. The Castor 30XL is a lengthened version of the Antares rocket's flight-proven Castor 30 motor, boosting the launcher's maximum load to the space station by more than 1,000 pounds."Something to be said for the simple design.
