Question Radio Procedures for future SSTOs?

[TMac3000]

I was watching an interesting Bill Whittle video a few days ago, in which he was talking about airline operations, and some of the myriads of little things that go into launching and landing an airliner, including the radio procedure.

And I got wondering, how would future SSTO operations change airport ops and radio procedures? I mean, at some point, Wideawake Tower would have to hand you off to mission control, right? Or would mission control have control the entire time?

I could see a typical launch going something like this:

Pilot: "Wideawake Ground, Chronus ready to taxi."

WAI-G: "Chronus, taxi three-zero left via Bravo-six and Charlie, and contact tower on 127.5 for departure."

Pilot: "Tower, Chronus holding short three-zero left."

WAI-T: "Chronus cleared for takeoff. Contact WAMC on 120.3"

And once the craft leaves the runway, she's in mission control's hands. Does that sound feasible?

 

[Urwumpe]

And once the craft leaves the runway, she's in mission control's hands. Does that sound feasible?

Normal controlled airspace ends at 69000 feet ... that is a lot of air to cross before mission control would have full authority. There can be a earlier hand-over to mission control, but once you leave the planned flight path away from ATC (aborts), you would need to return under ATC control again.

The Shuttle avoided most of this by simply flying above 69000 ft until shortly before landing.

 

[TMac3000]

Hmmm...by the time I get to 69000 (~21 km), I'm usually under full SCRAM and just passing Mach 4. So ATC would tell me when to open up the SCRAMs?

 

[Urwumpe]

Hmmm...by the time I get to 69000 (~21 km), I'm usually under full SCRAM and just passing Mach 4. So ATC would tell me when to open up the SCRAMs?

No, that is part of your knowledge. But they would have to clear the corridor that you use for leaving the ATC controlled airspace according to your trajectory. Also, if you have one SSTO landing in your corridor, who would decide what? Would you have to delay your ascend and fly a racetrack? or would the landing vehicle have to fly to a different approach, if the energy of the landing vehicle permits?

 

[TMac3000]

I guess the tower would have to make that decision based on whether or not I have enough fuel, since if the returning craft is also an SSTO, it would likely be making an unpowered landing. If it were my decision (as the guy in the tower) I would have Chronus make a slight course change. Like you said, if the craft is below 69,000 feet, that order would come from ATC. Otherwise it would come from WAMC.

WAI Departure: "Chronus, one inbound in your area. Come left to two-four-zero before you SCRAM."

Pilot: "Left to two-four-zero. Chronus."

 

[Evil_Onyx]

I don't think any change would be required for Ground or Tower procedures.
Departure ATC and Arrival ATC would need some changes, mostly integrating Supersonic control procedures and when and where you would be handed over to Area or mission control. But on the whole Radio procedures would not change all the much.

I guess the tower would have to make that decision based on whether or not I have enough fuel,

Nope... Controllers don't need to know your fuel state unless you are running low, and even then all they would be concerned about would be if you have to go to an alternate or how long you can hold (in a landing pattern) for.

I think you may be confusing what ATC is for and is required to do, and what a mission control (for space flight) is for. ATC is to control Air traffic, to keep aircraft away from each other, to assist in the safe use of airspace. Not to baby sit one aircraft but to look after all of them in his or her area.

 

[Cras]

Look up how the Concorde was dealt with by ATC and you can get a sense of what it might look like.

It is not nearly as strict in terms of altitude as the crew had quite a bit of leeway on what altitude it was to fly so it could maintain its Mach 2 cruise speed.

I would imagine it would be you get a supersonic clearance that would entail a heading window as well as an altitude ceiling, along with a time that you must hit certain points or else your clearance is void and you need to get in touch with who ever is controlling you at that point for further instruction.

Someone said ATC goes up to 69,000 feet MSL, nothing flies that high anyway so it is more than reasonable to assume that anything that is going to fly itself to orbit could get clearance to do so from say....50,000 feet on. And things that are flying high up there are gonna be military, and when it comes to civilian planes, the general rule is military has to give way to civilian.

The tricky part I would think is when you have multiple SSTOs going to the same place. SSTO, you are dealing with speed and margins that separation is not really going to be achieved with simple speed and vectors from ATC. They are gonna be achieved on the ground, and odds are when such technology is achieved, when you file a flight plane that says you are going to orbit, you will be flying on predetermined tracks and ATC will be busy telling other aircraft to stay out of your way, not telling you to watch out for the Cessna that might be in your path as you fire past Mach 1

 

[TMac3000]

Some interesting thoughts indeed. Thanks guys Maybe RTI can incorporate some of your advice into our chat sessions:thumbup:

 

[ADSWNJ]

I reckon by the time this multi-SSTO scenario plays out, air traffic will no longer be subject to the fallibilities of humans talking on VHF frequencies, but rather replaced with computers talking to computers in a full mesh including satellites and ground sites and plane to plane.

In the world, getting permission to fly in a particular corridor will start to look a bit strange, as this is negotiated in real time by the computers.

Granted, for relatively fixed trajectories (e.g. a shuttle insertion profile), you have relative little margin, but those tracks should be prioritized appropriately so that the flexible gives way to the inflexible.

 

[kamaz]

If the SSTO traffic is low then a very simple solution exists.

Start: SSTO notifies ATC in advance. ATC closes airspace East of Wideawake (all sector(s) the SSTO will fly through during ascent). ATC tells all inbound traffic to enter holding pattern west of Wideawake. SSTO takes off. Once it clears the runway, ATC begins issuing landing clearances to holding aircraft. Once SSTO goes above the controlled airspace, the ATC reopens the eastern sectors.

Landing: same pattern, just flipped east/west.

With more traffic:

Use E-W direction and runways exclusively for SSTO traffic and N-S direction and runways for regular traffic. Define sector boundaries so atmospheric and SSTO traffic never share the same volume of space.

 

[TMac3000]

So how and where does mission control fit into all of this?

 

[Evil_Onyx]

I don't know about anyone else but when im coming in to land from orbit i usually fly ether a hold (to bleed off the extra energy i aim to have when arriving) or fly strait into a HAC. In both cases i fly over the target runway at least once. So closing airspace North, East, South or West would not really work. Getting other traffic to hold would also not really work ether, unless you have lots of holding patters published and with that all the infrastructure (NDB, DME and VOR transmitters). A quick look at AIA says to me a minimum of six, all of them over water, in comparison EGLL (London Heathrow) has 12 and it is a busy international airport.


As for Mission control, they would be mostly hands off during stages around the runway. But I'm shore they would be involved with all the back room stuff (Flight plans, Clearances and all the rest)

 

[n122vu]

What if in the future SSTO world, a traditional Mission Control as we have come to know it becomes obsolete? I'm suggesting these services would be combined into one. Similar to an [ame="http://en.wikipedia.org/wiki/ARTCC"]ARTCC[/ame], you'd have an Aerial/Orbital Traffic Control Center, for example, that would be a combined center for both atmospheric flight in the area as well as mission-specific flight services for craft on their flight to orbit. And possibly, rather than follow the entire flight, as you flew out of their coverage area, your mission would be handed over to the next AOTCC in the appropriate part of the globe.

Thoughts?

 

[Hielor]

From a procedural standpoint (notsomuch the small details of what actually happens on the radio)...

It largely depends on what the delta-v budget of these hypothetical SSTOs is. Is it so low that they have little margin for changes in their launch profile, like modern ascent vehicles? Or has technology advanced to the point where carrying excess fuel is a matter of course and you have plenty of "room to maneuver" in your budget?

In the former case, I would imagine that times would be scheduled as needed (or possibly a regular daily timeslot) where the ascent vehicle would have full use of the airspace, and anything else would need to get out of its way. Same for landing.

In the latter case, I could see a system similar to what the modern airspace system uses. Since the vessels would be expected to have some leeway in what they could do, they could operate "within the system" that also handles normal air traffic.