Air Force Extends Plug-and-Play Spacecraft

coondoggie writes "Looking to build strategic satellites in days if need be, rather than months, the Air Force is pushing forward with what it calls plug-and-play spacecraft. This week it awarded a $500,000 order to Northrop Grumman to begin designing the plug-and-play spacecraft 'bus' which will offer standard interfaces for a variety of payload components, much like a laptop computer that immediately recognizes new hardware when it's plugged in, Northrop stated. The order was awarded under a contract that has a ceiling of $200 million."

USB analogy is a big bogus

[MichaelSmith]

They discuss having a standard power bus, and a tcp/ip LAN with something like a COTS router. So in fact its not plug and play like USB on a laptop it is plug and play like attaching your laptop to your LAN. It is exactly that.

I expect it will have a hard coded configuration with static IP addresses though. DHCP is a single point of failure and I don't think the complexity is justified here.

Re:USB analogy is a big bogus

[blueg3]

In the existing space PnP spec, the devices are autonomously numbered. In fact, the existing space PnP spec is designed to run over either USB or the SpaceWire bus.

If you read the article, you'll note that the comparison with USB is that the devices provide other devices on the network with a description of the functions they support. So, the bus has multinode network communication over a single common protocol, power, autonomous numbering, and devices indicating their capabilities. That's USB, not IP.

Re:$500,000 or $200,000,000 ?! Which is it ?

[NigelBeamenIII]

It's a question of how government contracts are awarded. They typically will have at least two things for each contract: the amount of money on the contract and the contract ceiling. The amount on the contract is the amount the company actually has in their accounts to spend. the ceiling is more like a "credit limit" which says the maximum amount of money the AF *can* ever put on the contract. Hope that explanation helps some.

Re:Finally

[Nutria]

they need to do it with weapons systems across the board.

They do a lot of this already. That's what the Joint in JSTARS, JSF, JDAM, etc, etc means. Then there's the commonality of small arms, payroll systems, M1 tanks run on jet fuel, and so forth.

However, there are lots of reasons why much of their material can not be common: sea-borne, air and ground equipment all have different "sturdiness" requirements, there are different RADAR frequencies for different tasks and that means different antennae, etc.

A good example of why this sometimes can, but usually can't work was that when Robert McNamara was SECDEF. He made all the branches use the same kind of gun and buy the same kind of boots, and that was great. But he also made them build a "Joint Strike Fighter" (the TFX, later named the F-111), which turned out to be way too heavy for carrier operations.

Standard communication bus

[Cochonou]

If you want to know where you are coming from, a bus interface commonly used right now on satellites in U.S. and Europe is MIL-STD-1553B [obspm.fr]. This is basically a dual-redundant differential 1 Mb/s bus over a wire pair. There's a single bus controller which initiates all the transactions, and up to 31 remote terminals which respond to the bus controller.
What is a bit surprising is that for military aircraft, current designs have been moving from 1553 to Firewire (which is plug and play). So that may suggest that Firewire would be unsuitable for satellites.

Re:$500,000 or $200,000,000 ?! Which is it ?

[damburger]

AC scores a hit whilst everyone else is flailing around with tropes about how government contracts are always absurd. The USAF have been given 500k to "begin" the project - probably to determine its feasibility - stipulating that if it looks promising they will be awarded the rest over the next few years

Existing space PnP spec

[teridon]

You mentioned the existing PnP spec, but didn't provide any details! The effort is called Space Plug and Play Avionics (SPA) [google.com].

Also I'm sure you already know this, but for the rest of the /. crowd: SpaceWire [esa.int] is an existing standard bus (like a router), but it doesn't currently have any PnP features.

Re:here's a crazy question

[Ironsides]

Wishbone is a communications interface for CPUs. The AF is looking for a standard interface for discovery, cooperation, power, communication and a host of other things and it has to be capable of sufficient redundancy in a space environment. An "Analysis of Alternatives" (seeing if there is anything already out there), is a requirement prior to any program like this going forward. In other words, they already checked.